WO2020189776A1 - Conductive particle, conductive material, and connection structure - Google Patents

Conductive particle, conductive material, and connection structure Download PDF

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Publication number
WO2020189776A1
WO2020189776A1 PCT/JP2020/012462 JP2020012462W WO2020189776A1 WO 2020189776 A1 WO2020189776 A1 WO 2020189776A1 JP 2020012462 W JP2020012462 W JP 2020012462W WO 2020189776 A1 WO2020189776 A1 WO 2020189776A1
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Prior art keywords
conductive
conductive portion
particles
weight
boron
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PCT/JP2020/012462
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French (fr)
Japanese (ja)
Inventor
裕輔 後藤
昌男 笹平
Original Assignee
積水化学工業株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Application filed by 積水化学工業株式会社 filed Critical 積水化学工業株式会社
Priority to KR1020217029563A priority Critical patent/KR20210135522A/en
Priority to CN202080021850.3A priority patent/CN113614852A/en
Priority to JP2020538861A priority patent/JPWO2020189776A1/ja
Publication of WO2020189776A1 publication Critical patent/WO2020189776A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
    • H01B1/20—Conductive material dispersed in non-conductive organic material
    • H01B1/22—Conductive material dispersed in non-conductive organic material the conductive material comprising metals or alloys
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B5/00—Non-insulated conductors or conductive bodies characterised by their form
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B5/00—Non-insulated conductors or conductive bodies characterised by their form
    • H01B5/16—Non-insulated conductors or conductive bodies characterised by their form comprising conductive material in insulating or poorly conductive material, e.g. conductive rubber
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
    • H01R11/00—Individual connecting elements providing two or more spaced connecting locations for conductive members which are, or may be, thereby interconnected, e.g. end pieces for wires or cables supported by the wire or cable and having means for facilitating electrical connection to some other wire, terminal, or conductive member, blocks of binding posts
    • H01R11/01—Individual connecting elements providing two or more spaced connecting locations for conductive members which are, or may be, thereby interconnected, e.g. end pieces for wires or cables supported by the wire or cable and having means for facilitating electrical connection to some other wire, terminal, or conductive member, blocks of binding posts characterised by the form or arrangement of the conductive interconnection between the connecting locations

Definitions

  • the present invention relates to conductive particles in which a conductive portion is arranged on the surface of the base particle.
  • the present invention also relates to a conductive material and a connecting structure using the above conductive particles.
  • Anisotropic conductive materials such as anisotropic conductive paste and anisotropic conductive film are widely known.
  • anisotropic conductive material conductive particles are dispersed in the binder resin.
  • the anisotropic conductive material is used to obtain various connection structures.
  • Examples of the connection using the anisotropic conductive material include a connection between a flexible printed circuit board and a glass substrate (FOG (Film on Glass)), a connection between a semiconductor chip and a flexible printed circuit board (COF (Chip on Film)), and the like. Examples thereof include a connection between a semiconductor chip and a glass substrate (COG (Chip on Glass)) and a connection between a flexible printed circuit board and a glass epoxy substrate (FOB (Film on Board)).
  • the anisotropic conductive material for example, when electrically connecting the electrode of the semiconductor chip and the electrode of the glass substrate, the anisotropic conductive material containing the conductive particles is arranged on the glass substrate. Next, the semiconductor chips are laminated and heated and pressurized. As a result, the anisotropic conductive material is cured, and the electrodes are electrically connected via the conductive particles to obtain a connection structure.
  • Patent Document 1 discloses conductive particles having a core particle, a Ni plating layer, a precious metal plating layer, and a rust preventive film.
  • the Ni plating layer covers the core particles and contains Ni.
  • the noble metal plating layer covers at least a part of the Ni plating layer and contains at least one of Au and Pd.
  • the rust preventive film covers at least one of the plating layer and the noble metal plating layer and contains an organic compound.
  • connection at a lower pressure than before so-called low-pressure mounting
  • a semiconductor chip is directly mounted on a flexible printed circuit board, it is necessary to mount the semiconductor chip at a low pressure in order to suppress deformation of the flexible printed circuit board.
  • a noble metal having a low resistance value is used on the outermost surface of the conductive portion, and the noble metal portion may be formed.
  • the conductive part containing nickel is corroded and sufficient conduction reliability is obtained. It may not be obtained. Therefore, a noble metal is used on the outermost surface of the conductive portion to prevent corrosion, and the noble metal portion may be formed.
  • the noble metal part When the noble metal part is formed on the outermost surface of the conductive part, metal diffusion occurs between the noble metal part and the base metal part (generally a nickel-phosphorus alloy), and the metal is not between the noble metal part and the base metal part. A crystalline part (lin-rich part) may be formed. If an amorphous part (phosphorrich layer) is formed between the noble metal part and the base metal part, the conductive part may be cracked at the time of mounting. As a result, it may be difficult to sufficiently improve the conduction reliability between the electrodes.
  • the base metal part generally a nickel-phosphorus alloy
  • the nickel-phosphorus alloy used as the base metal may have a higher resistance value than the nickel-boron alloy, pure nickel, etc. As a result, it may be difficult to sufficiently reduce the connection resistance between the electrodes.
  • the first conductive portion contains nickel and boron and does not contain phosphorus, and 100% by weight of a region having a thickness of 1/5 from the inner surface to the outside of the first conductive portion.
  • the absolute value of the difference between the average content of boron in the inside and the average content of boron in 100% by weight of the region having a thickness of 1/5 from the outer surface to the inside of the first conductive portion is 0 weight. % Or more and 10% by weight or less, and the standard electrode potential of the main metal in the first conductive portion is smaller than the standard electrode potential of the main metal in the second conductive portion, providing conductive particles.
  • the absolute value of the difference between the standard electrode potential of the main metal in the first conductive portion and the standard electrode potential of the main metal in the second conductive portion is It is 0.05V or more and 3V or less.
  • the average content of boron in 100% by weight of the region having a thickness of 1/5 from the inner surface to the outside of the first conductive portion is 0% by weight.
  • the average content of boron in 100% by weight of the region having a thickness of 1/5 from the outer surface of the first conductive portion toward the inside is 0% by weight or more and 10% by weight or less. is there.
  • the average content of nickel in 100% by weight of the first conductive portion is 50% by weight or more and 99.9% by weight or less.
  • the average content of boron in 100% by weight of the first conductive portion is 0.001% by weight or more and 10% by weight or less.
  • the main metal in the second conductive portion is tin, copper, palladium, ruthenium, platinum, silver, rhodium, iridium or gold.
  • the outer surface of the second conductive portion is rust-proofed.
  • the outer surface of the second conductive portion is rust-proofed with a compound having an alkyl group having 6 to 22 carbon atoms.
  • the particle size of the base particles is 0.1 ⁇ m or more and 100 ⁇ m or less.
  • the conductive particles according to the present invention there are a plurality of protrusions on the outer surface of the first conductive portion or the second conductive portion.
  • the first conductive portion or the first conductive portion or the like so as to form a plurality of the protrusions inside or inside the first conductive portion or the second conductive portion.
  • a plurality of core materials that raise the surface of the second conductive portion are provided.
  • the first conductive portion or the first conductive portion or the like so as to form a plurality of the protrusions inside or inside the first conductive portion or the second conductive portion. It does not include a plurality of core materials that raise the surface of the second conductive portion.
  • an insulating substance arranged on the outer surface of the second conductive portion is provided.
  • the conductive particles are used for conductive connection of an electrode with a protective layer including an electrode and a protective layer arranged on the surface of the electrode.
  • the conductive particles are used for conductive connection of electrodes of flexible members.
  • a conductive material containing the above-mentioned conductive particles and a binder resin is provided.
  • a first connection target member having a first electrode on the surface
  • a second connection target member having a second electrode on the surface
  • the first connection target member It is provided with a connecting portion connecting the second connection target member, and the connecting portion is formed of the above-mentioned conductive particles or a conductive material containing the conductive particles and a binder resin.
  • a connection structure in which the first electrode and the second electrode are electrically connected by the conductive particles.
  • the standard electrode potential of the main metal in the first conductive portion is the standard electrode potential of the main metal on the outer surface of the first electrode or the second electrode. Smaller than
  • the conductive particles according to the present invention include base particles, a first conductive portion arranged on the surface of the base particles, and a second conductive portion arranged on the surface of the first conductive portion. And.
  • the first conductive portion contains nickel and boron and does not contain phosphorus.
  • the average content of boron in 100% by weight of the region having a thickness of 1/5 from the inner surface to the outside of the first conductive portion and the outside of the first conductive portion The absolute value of the difference from the average content of boron in 100% by weight of the region having a thickness of 1/5 from the surface to the inside is 0% by weight or more and 10% by weight or less.
  • the standard electrode potential of the main metal in the first conductive portion is smaller than the standard electrode potential of the main metal in the second conductive portion. Since the conductive particles according to the present invention have the above configuration, it is possible to effectively suppress the occurrence of cracks in the conductive portion at the time of mounting, and it is possible to effectively reduce the connection resistance between the electrodes. it can.
  • FIG. 1 is a cross-sectional view showing conductive particles according to the first embodiment of the present invention.
  • FIG. 2 is a cross-sectional view showing conductive particles according to a second embodiment of the present invention.
  • FIG. 3 is a cross-sectional view showing the conductive particles according to the third embodiment of the present invention.
  • FIG. 4 is a cross-sectional view showing the conductive particles according to the fourth embodiment of the present invention.
  • FIG. 5 is a schematic diagram for explaining each region for obtaining the average content of boron in the first conductive portion of the conductive particles according to the first embodiment of the present invention.
  • FIG. 6 is a schematic diagram for explaining each region for obtaining the average content of boron in the first conductive portion of the conductive particles according to the second embodiment of the present invention.
  • FIG. 7 is a front sectional view schematically showing a connection structure using conductive particles according to the first embodiment of the present invention.
  • the conductive particles according to the present invention include base particles, a first conductive portion arranged on the surface of the base particles, and a second conductive portion arranged on the surface of the first conductive portion. And.
  • the first conductive portion contains nickel and boron and does not contain phosphorus.
  • the average content of boron in 100% by weight of the region having a thickness of 1/5 from the inner surface to the outside of the first conductive portion and the outside of the first conductive portion The absolute value of the difference from the average content of boron in 100% by weight of the region having a thickness of 1/5 from the surface to the inside is 0% by weight or more and 10% by weight or less.
  • the standard electrode potential of the main metal in the first conductive portion is smaller than the standard electrode potential of the main metal in the second conductive portion.
  • the conductive particles according to the present invention have the above-mentioned configuration, it is possible to effectively suppress the occurrence of cracks in the conductive portion at the time of mounting, and it is possible to effectively reduce the connection resistance between the electrodes. it can.
  • the content of boron in the plating bath changes as the plating progresses. Therefore, the average content of boron in 100% by weight of the region having a thickness of 1/5 from the inner surface of the first conductive portion to the outside and the outer surface of the first conductive portion toward the inside. There is a difference from the absolute value of the difference from the average content of boron in 100% by weight of the 1/5 thickness region.
  • the content of boron in the nickel plating film is made uniform with high accuracy when the nickel plating film is formed by appropriately controlling the temperature during the reaction, the nickel ion concentration, the dropping rate of the reducing agent, the stirring conditions, and the like. By adopting a method of keeping, etc., the above absolute value can be reduced.
  • a noble metal may be used on the outermost surface of the conductive part to form a noble metal part in order to ensure sufficient conduction reliability and to prevent corrosion of the conductive part.
  • the noble metal part When the noble metal part is formed on the outermost surface of the conductive part, metal diffusion occurs between the noble metal part and the base metal part (generally a nickel-phosphorus alloy), and the metal is not between the noble metal part and the base metal part.
  • a crystalline part (lin-rich part) may be formed. If an amorphous part (lin-rich part) is formed between the noble metal part and the base metal part, the conductive part may be cracked at the time of mounting. As a result, it may be difficult to sufficiently increase the conduction reliability between the electrodes with the conventional conductive particles.
  • the nickel-phosphorus alloy used as the base metal may have a higher resistance value than the nickel-boron alloy, pure nickel, etc. As a result, it may be difficult to sufficiently reduce the connection resistance between the electrodes.
  • the conductive particles according to the present invention adopt the above configuration, even if a noble metal is used for the conductive portion, metal diffusion does not occur between the noble metal portion and the base metal portion, and the noble metal portion and the noble metal portion An amorphous part (lin-rich part) is not formed between the metal part and the base metal part. Therefore, it is possible to effectively suppress the occurrence of cracks in the conductive portion during mounting, and it is possible to effectively reduce the connection resistance between the electrodes.
  • the standard electrode potential of the main metal in the first conductive portion is smaller than the standard electrode potential of the main metal in the second conductive portion.
  • the standard electrode potential of the main metal in the first conductive portion and the standard electrode potential of the main metal is preferably 0.05 V or more, more preferably 0.1 V or more, still more preferably 0.5 V or more.
  • the standard electrode potential of the main metal in the first conductive portion and the standard electrode potential of the main metal is preferably 3 V or less, more preferably 2.1 V or less, and further preferably 1.3 V or less.
  • the main metal in the conductive portion means the metal species having the highest content among the metal species contained in the conductive portion.
  • FIG. 1 is a cross-sectional view showing conductive particles according to the first embodiment of the present invention.
  • the conductive particle 1 shown in FIG. 1 includes a base particle 2, a first conductive portion 3, and a second conductive portion 4.
  • the first conductive portion 3 is arranged on the surface of the base particle 2.
  • the second conductive portion 4 is arranged on the surface of the first conductive portion 3.
  • the conductive particles 1 are coated particles in which the surface of the base particle 2 is coated with the first conductive portion 3, and the surface of the first conductive portion 3 is coated with the second conductive portion 4. It is a coated particle.
  • the entire surface of the base material particles may be entirely covered with the first conductive portion, and a part of the surface of the base material particles is covered with the first conductive portion. May be good.
  • the entire surface of the first conductive portion may be covered with the second conductive portion, and a part of the surface of the first conductive portion may be covered with the second conductive portion. It may be covered.
  • the first conductive portion 3 contains nickel and boron and does not contain phosphorus.
  • the absolute value of the difference from the average content of boron in 100% by weight of the region (R2) having a thickness of 1/5 is 0% by weight or more and 10% by weight or less. When the absolute value is 0% by weight, the average content of boron in the two regions (R1) and (R2) is the same.
  • the region (R1) is a region between the inner surface of the first conductive portion 3 (the outer surface of the base particle 2) and the broken line L1 in FIG.
  • the region (R2) is a region between the outer surface of the first conductive portion 3 (the inner surface of the second conductive portion 4) and the broken line L2 in FIG.
  • the conductive particles 1 do not have a core substance.
  • the conductive particles 1 do not have protrusions, unlike the conductive particles 21 and 31 described later.
  • the conductive particles 1 are spherical.
  • the first conductive portion 3 and the second conductive portion 4 do not have protrusions on the outer surface.
  • the conductive particles according to the present invention may not have protrusions on the conductive surface and may be spherical.
  • the conductive particles 1 do not have an insulating substance, unlike the conductive particles 21 and 31 described later.
  • the conductive particles 1 may have an insulating substance arranged on the outer surface of the second conductive portion 4.
  • the base particles 2 and the first conductive portion 3 are in contact with each other.
  • the first conductive portion 3 and the second conductive portion 4 are in contact with each other.
  • FIG. 2 is a cross-sectional view showing the conductive particles according to the second embodiment of the present invention.
  • the conductive particle 11 shown in FIG. 2 includes a base particle 2, a first conductive portion 13, and a second conductive portion 4.
  • the first conductive portion 3 and the first conductive portion 13 are different.
  • the first conductive portion 13 as a whole has a conductive portion 13A arranged on the base particle 2 side and a conductive portion 13B arranged on the side opposite to the base particle 2 side.
  • the first conductive portion 3 having a one-layer structure is formed, whereas in the conductive particle 11, the first conductive portion having a two-layer structure having the conductive portion 13A and the conductive portion 13B is formed.
  • the portion 13 is formed.
  • the conductive portion 13A and the conductive portion 13B may be formed as different conductive portions, or may be formed as the same conductive layer.
  • the first conductive portion may have a one-layer structure or a multi-layer structure having two or more layers.
  • the conductive portion 13A is arranged on the surface of the base particle 2.
  • the conductive portion 13A is arranged between the base particle 2 and the conductive portion 13B.
  • the conductive portion 13A is in contact with the base particle 2.
  • the conductive portion 13B is in contact with the conductive portion 13A.
  • the conductive portion 13A is arranged on the surface of the base particle 2, and the conductive portion 13B is arranged on the outer surface of the conductive portion 13A.
  • the first conductive portion 13 contains nickel and boron and does not contain phosphorus.
  • the conductive portion 13A may be a nickel-boron plating layer
  • the conductive portion 13B may be a pure nickel layer or a nickel-tin alloy layer.
  • the absolute value of the difference from the average content of boron in 100% by weight of the region (R2) having a thickness of 1/5 is 0% by weight or more and 10% by weight or less.
  • the region (R1) is a region between the inner surface of the first conductive portion 13 (the inner surface of the conductive portion 13A and the outer surface of the base particle 2) and the broken line L1 in FIG.
  • the region (R2) is a region between the outer surface of the first conductive portion 13 (the outer surface of the conductive portion 13B and the inner surface of the second conductive portion 4) and the broken line L2 in FIG.
  • the region (R1) and the region (R2) are preferably calculated from the thickness of the entire first conductive portion.
  • FIG. 3 is a cross-sectional view showing the conductive particles according to the third embodiment of the present invention.
  • the conductive particle 21 shown in FIG. 3 includes a base particle 2, a first conductive portion 23, a second conductive portion 24, a plurality of core substances 25, and a plurality of insulating substances 26.
  • the first conductive portion 23 is arranged on the surface of the base particle 2.
  • the second conductive portion 24 is arranged on the surface of the first conductive portion 23.
  • the first conductive portion 23 is arranged on the surface of the base particle 2, and the second conductive portion 24 is arranged on the surface of the first conductive portion 23.
  • the first conductive portion 23 contains nickel and boron and does not contain phosphorus.
  • the absolute value of the difference from the average content of boron in 100% by weight of the region (R2) having a thickness of 1/5 is 0% by weight or more and 10% by weight or less.
  • the conductive particles 21 have a plurality of protrusions 21A on the conductive surface.
  • the first conductive portion 23 has a plurality of protrusions 23A on the outer surface.
  • the second conductive portion 24 has a plurality of protrusions 24A on the outer surface.
  • a plurality of core substances 25 are arranged on the surface of the base particle 2.
  • the plurality of core substances 25 are embedded in the first conductive portion 23.
  • the plurality of core substances 25 are embedded inside the second conductive portion 24.
  • the core material 25 is arranged inside the protrusions 21A, 23A, and 24A.
  • the first conductive portion 23 covers a plurality of core substances 25.
  • the outer surfaces of the first conductive portion 23 and the second conductive portion 24 are raised by the plurality of core materials 25, and protrusions 21A, 23A, and 24A are formed.
  • the conductive particles 21 have an insulating substance 26 arranged on the outer surface of the second conductive portion 24. At least a part of the outer surface of the second conductive portion 24 is covered with the insulating substance 26.
  • the insulating substance 26 is formed of a material having an insulating property. In this embodiment, the insulating substance 26 is an insulating particle.
  • the conductive particles according to the present invention may have the insulating substance arranged on the outer surface of the second conductive portion. However, the conductive particles according to the present invention do not necessarily have the above-mentioned insulating substance.
  • FIG. 4 is a cross-sectional view showing the conductive particles according to the fourth embodiment of the present invention.
  • the conductive particle 31 shown in FIG. 4 includes a base particle 2, a first conductive portion 33, a second conductive portion 34, and a plurality of insulating substances 26.
  • the first conductive portion 33 is arranged on the surface of the base particle 2.
  • the second conductive portion 34 is arranged on the surface of the first conductive portion 33.
  • the first conductive portion 33 is arranged on the surface of the base particle 2, and the second conductive portion 34 is arranged on the surface of the first conductive portion 33.
  • the first conductive portion 33 contains nickel and boron and does not contain phosphorus.
  • the absolute value of the difference from the average content of boron in 100% by weight of the region (R2) having a thickness of 1/5 is 0% by weight or more and 10% by weight or less.
  • the conductive particles 31 do not have a core substance.
  • the conductive particles 31 do not have a core material, but have a plurality of protrusions 31A on the conductive surface.
  • the first conductive portion 33 has a plurality of protrusions 33A on the outer surface.
  • the second conductive portion 34 has a plurality of protrusions 34A on the outer surface.
  • the first conductive portion 33 has a first portion and a second portion that is thicker than the first portion.
  • the portion excluding the plurality of protrusions is the first portion of the first conductive portion 33.
  • the plurality of protrusions are the second portion in which the thickness of the first conductive portion 33 is thick.
  • the conductive particles 31 have an insulating substance 26 arranged on the outer surface of the second conductive portion 34. At least a part of the outer surface of the second conductive portion 34 is covered with the insulating substance 26.
  • the insulating substance 26 is formed of a material having an insulating property. In this embodiment, the insulating substance 26 is an insulating particle.
  • the conductive particles according to the present invention may have the insulating substance arranged on the outer surface of the second conductive portion. However, the conductive particles according to the present invention do not necessarily have the above-mentioned insulating substance.
  • base material particles examples include resin particles, inorganic particles other than metal particles, organic-inorganic hybrid particles, and metal particles.
  • the base material particles are preferably base particles excluding metal particles, and more preferably resin particles, inorganic particles excluding metal particles, or organic-inorganic hybrid particles.
  • the base material particles may have a core and a shell arranged on the surface of the core, or may be core-shell particles.
  • the core may be an organic core, and the shell may be an inorganic shell.
  • the base material particles are more preferably resin particles or organic-inorganic hybrid particles, and may be resin particles or organic-inorganic hybrid particles.
  • the conductive particles are placed between the electrodes and then crimped to compress the conductive particles.
  • the base material particles are resin particles or organic-inorganic hybrid particles, the conductive particles are easily deformed during the pressure bonding, and the contact area between the conductive particles and the electrode becomes large. Therefore, the conduction reliability between the electrodes can be further improved.
  • the resin for forming the resin particles include polyolefin resins such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyisobutylene, and polybutadiene; acrylic resins such as polymethylmethacrylate and polymethylacrylate; polycarbonate.
  • Polyamide Polyamide, phenol formaldehyde resin, melamine formaldehyde resin, benzoguanamine formaldehyde resin, urea formaldehyde resin, phenol resin, melamine resin, benzoguanamine resin, urea resin, epoxy resin, unsaturated polyester resin, saturated polyester resin, polyethylene terephthalate, polysulfone, polyphenylene oxide , Polyacetal, polyimide, polyamideimide, polyether ether ketone, polyether sulfone, divinylbenzene polymer, divinylbenzene-based copolymer and the like.
  • the divinylbenzene-based copolymer and the like examples include a divinylbenzene-styrene copolymer and a divinylbenzene- (meth) acrylic acid ester copolymer. Since the hardness of the resin particles can be easily controlled within a suitable range, the resin for forming the resin particles is a weight obtained by polymerizing one or more polymerizable monomers having an ethylenically unsaturated group. It is preferably coalesced.
  • the polymerizable monomer having an ethylenically unsaturated group is crosslinkable with a non-crosslinkable monomer.
  • non-crosslinkable monomer examples include styrene-based monomers such as styrene and ⁇ -methylstyrene; carboxyl group-containing monomers such as (meth) acrylic acid, maleic acid, and maleic anhydride; and methyl ( Meta) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) Alkyl (meth) acrylate compounds such as meta) acrylate and isobornyl (meth) acrylate; oxygen atoms such as 2-hydroxyethyl (meth) acrylate, glycerol (meth) acrylate, polyoxyethylene (meth) acrylate and glycid
  • (meth) acrylate compound nitrile-containing monomer such as (meth) acrylonitrile
  • vinyl ether compound such as methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether
  • acid vinyl ester such as vinyl acetate, vinyl butyrate, vinyl laurate, vinyl stearate, etc.
  • unsaturated hydrocarbons such as ethylene, propylene, isoprene, and butadiene
  • halogen-containing monomers such as trifluoromethyl (meth) acrylate, pentafluoroethyl (meth) acrylate, vinyl chloride, vinyl fluoride, and chlorostyrene.
  • crosslinkable monomer examples include tetramethylol methanetetra (meth) acrylate, tetramethylol methanetri (meth) acrylate, tetramethylol methanedi (meth) acrylate, trimethyl propanetri (meth) acrylate, and dipenta.
  • the resin particles can be obtained by polymerizing the polymerizable monomer having an ethylenically unsaturated group by a known method. Examples of this method include a method of suspension polymerization in the presence of a radical polymerization initiator, and a method of swelling and polymerizing a monomer together with a radical polymerization initiator using non-crosslinked seed particles.
  • the particle size of the resin particles is preferably 0.1 ⁇ m or more, more preferably 1 ⁇ m or more, still more preferably 1.5 ⁇ m or more, particularly preferably 2 ⁇ m or more, and most preferably 3 ⁇ m or more.
  • the particle size of the resin particles is preferably 500 ⁇ m or less, more preferably 100 ⁇ m or less, still more preferably 50 ⁇ m or less, particularly preferably 20 ⁇ m or less, and most preferably 10 ⁇ m or less.
  • the conductive portion is formed on the surface of the resin particles by electroless plating, it is possible to make it difficult for the aggregated conductive particles to be formed.
  • the particle size of the resin particles is not more than the above upper limit, the conductive particles are easily sufficiently compressed, the connection resistance between the electrodes can be further lowered, and the distance between the electrodes can be further reduced. it can.
  • the base material particles are inorganic particles other than metal or organic-inorganic hybrid particles
  • examples of the inorganic material for forming the base material particles include silica, alumina, barium titanate, zirconia, and carbon black. It is preferable that the inorganic substance is not a metal.
  • the particles formed of the silica are not particularly limited, but for example, after hydrolyzing a silicon compound having two or more hydrolyzable alkoxysilyl groups to form crosslinked polymer particles, firing is performed if necessary. Examples include particles obtained by doing so.
  • examples of the organic-inorganic hybrid particles include organic-inorganic hybrid particles formed of a crosslinked alkoxysilyl polymer and an acrylic resin.
  • the organic-inorganic hybrid particles are preferably core-shell type organic-inorganic hybrid particles having a core and a shell arranged on the surface of the core. It is preferable that the core is an organic core. It is preferable that the shell is an inorganic shell. From the viewpoint of effectively reducing the connection resistance between the electrodes, the base material particles are preferably organic-inorganic hybrid particles having an organic core and an inorganic shell arranged on the surface of the organic core.
  • Examples of the material for forming the organic core include the resin for forming the resin particles described above.
  • Examples of the material for forming the above-mentioned inorganic shell include the above-mentioned inorganic substances for forming the base particle.
  • the material for forming the inorganic shell is preferably silica.
  • the inorganic shell is preferably formed by forming a metal alkoxide into a shell-like material by a sol-gel method on the surface of the core and then sintering the shell-like material.
  • the metal alkoxide is preferably a silane alkoxide.
  • the inorganic shell is preferably formed of silane alkoxide.
  • the particle size of the core is preferably 0.1 ⁇ m or more, more preferably 1 ⁇ m or more, further preferably 1.5 ⁇ m or more, particularly preferably 2 ⁇ m or more, most preferably 3 ⁇ m or more, preferably 500 ⁇ m or less, more preferably. It is 100 ⁇ m or less, more preferably 50 ⁇ m or less, particularly preferably 20 ⁇ m or less, and most preferably 10 ⁇ m or less.
  • the particle size of the core is not less than the above lower limit and not more than the above upper limit, more suitable conductive particles can be obtained by electrical connection between the electrodes, and the base particles can be suitably used for the use of the conductive particles. become.
  • the contact area between the conductive particles and the electrodes becomes sufficiently large when the electrodes are connected using the conductive particles.
  • the distance between the electrodes connected via the conductive particles does not become too large, and the conductive portion can be made difficult to peel off from the surface of the substrate particles.
  • the particle diameter of the core means the diameter when the core is a true sphere, and means the equivalent circle diameter when the core has a shape other than the true sphere. Further, the particle size of the core means the average particle size of the core measured by an arbitrary particle size measuring device.
  • the average particle size is preferably a number average particle size.
  • a particle size distribution measuring device using principles such as laser light scattering, change in electrical resistance value, and image analysis after imaging can be used.
  • the thickness of the shell is preferably 0.1 ⁇ m or more, more preferably 0.2 ⁇ m or more, preferably 5 ⁇ m or less, and more preferably 3 ⁇ m or less.
  • the thickness of the shell is not less than the above lower limit and not more than the above upper limit, more suitable conductive particles can be obtained by electrical connection between the electrodes, and the base particles can be suitably used for the use of the conductive particles.
  • the thickness of the shell is the average thickness per base particle.
  • the thickness of the shell can be controlled by controlling the sol-gel method.
  • the particle size of the inorganic particles excluding the metal particles and the organic-inorganic hybrid particles is preferably 0.1 ⁇ m or more, more preferably 1 ⁇ m or more, still more preferably 1.5 ⁇ m or more, particularly preferably 2 ⁇ m or more, and most preferably 3 ⁇ m or more. Is.
  • the particle size of the inorganic particles excluding the metal particles and the organic-inorganic hybrid particles is preferably 500 ⁇ m or less, more preferably 100 ⁇ m or less, still more preferably 50 ⁇ m or less, particularly preferably 20 ⁇ m or less, and most preferably 10 ⁇ m or less.
  • the contact area between the conductive particles and the electrodes becomes large, so that the conduction reliability between the electrodes is improved. It can be further increased, and the connection resistance between the electrodes connected via the conductive particles can be further reduced. Further, when a conductive portion is formed on the surface of inorganic particles other than metal particles or organic-inorganic hybrid particles by electroless plating, it is possible to make it difficult for aggregated conductive particles to be formed.
  • the particle size of the organic-inorganic hybrid particles is not more than the above upper limit, the conductive particles are easily sufficiently compressed, the connection resistance between the electrodes can be further lowered, and the distance between the electrodes is further reduced. be able to.
  • the base material particles are metal particles
  • examples of the metal that is the material of the metal particles include silver, copper, nickel, silicon, gold, and titanium.
  • the particle size of the metal particles is preferably 0.1 ⁇ m or more, more preferably 1 ⁇ m or more, still more preferably 1.5 ⁇ m or more, particularly preferably 2 ⁇ m or more, and most preferably 3 ⁇ m or more.
  • the particle size of the metal particles is preferably 500 ⁇ m or less, more preferably 100 ⁇ m or less, still more preferably 50 ⁇ m or less, particularly preferably 20 ⁇ m or less, and most preferably 10 ⁇ m or less.
  • the particle size of the base particles is preferably 0.1 ⁇ m or more, more preferably 1 ⁇ m or more, still more preferably 1.5 ⁇ m or more, particularly preferably 2 ⁇ m or more, and most preferably 3 ⁇ m or more.
  • the particle size of the base particles is preferably 500 ⁇ m or less, more preferably 100 ⁇ m or less, still more preferably 50 ⁇ m or less, particularly preferably 20 ⁇ m or less, and most preferably 10 ⁇ m or less.
  • connection resistance between the connected electrodes can be further reduced. Further, when the conductive portion is formed on the surface of the base material particles by electroless plating, it is possible to make it difficult for the agglomerated conductive particles to be formed. When the particle size of the base material particles is not more than the above upper limit, the conductive particles are easily sufficiently compressed, the connection resistance between the electrodes can be further reduced, and the distance between the electrodes can be further reduced. Can be done.
  • the particle size of the base material particles indicates the diameter when the base material particles are spherical, and indicates the equivalent circle diameter when the base material particles are not spherical. Further, the particle size of the base material particles means the average particle size of the base material particles measured by an arbitrary particle size measuring device.
  • the average particle size is preferably a number average particle size.
  • a particle size distribution measuring device using principles such as laser light scattering, change in electrical resistance value, and image analysis after imaging can be used.
  • the particle size of the base particle is 2 ⁇ m or more and 20 ⁇ m or less.
  • the particle diameter of the base material particles is within the range of 2 ⁇ m or more and 20 ⁇ m or less, the distance between the electrodes can be made smaller, and even if the thickness of the conductive portion is increased, small conductive particles can be obtained. it can.
  • the first conductive portion contains nickel and boron and does not contain phosphorus.
  • the absolute value of the difference from the average content of boron in 100% by weight of the region (R2) having a thickness of 1/5 from the outer surface to the inside of the portion is 0% by weight or more and 10% by weight or less.
  • the region (R1) is represented by the inner surface of the first conductive portion 3 (the outer surface of the base particle 2) and the broken line L1 in FIG. The area between.
  • the region (R2) is a broken line with the outer surface of the first conductive portion 3 (inner surface of the second conductive portion 4) in FIG. It is an area between L2 and L2.
  • the region (R1) is the inner surface of the first conductive portion 13 (inner surface of the conductive portion 13A, outer surface of the base particle 2) in FIG. The area between the surface) and the broken line L1.
  • the region (R2) is the outer surface of the first conductive portion 13 (the outer surface of the conductive portion 13B, the second conductive portion 4) in FIG. The region between (inner surface of) and the broken line L2.
  • the region (R1) and the region (R2) are preferably calculated from the thickness of the entire first conductive portion.
  • the absolute value of the difference from the average content of boron in 100% by weight of the region (R2) having a thickness of 1/5 may exceed 0% by weight, or may be 0.5% by weight or more.
  • the absolute value of the difference between the average content of boron in 100% by weight of the region (R1) and the average content of boron in 100% by weight of the region (R2) is 1.0% by weight or more. Is preferable.
  • the absolute value of the difference between the average content of boron in 100% by weight of the region (R1) and the average content of boron in 100% by weight of the region (R2) is equal to or greater than the above lower limit, at the time of mounting. It is possible to more effectively suppress the occurrence of cracks in the conductive portion.
  • the absolute value of the difference from the average content of boron in 100% by weight of the region (R2) having a thickness of 1/5 is preferably 5% by weight or less.
  • the average content of boron in 100% by weight of the region (R1) having a thickness of 1/5 from the inner surface to the outside of the first conductive portion is preferably 0% by weight or more, more preferably 0.001% by weight. % Or more, more preferably 0.01% by weight or more, and particularly preferably 0.1% by weight or more.
  • the average content of boron in 100% by weight of the region (R1) having a thickness of 1/5 from the inner surface to the outside of the first conductive portion is preferably 10% by weight or less, more preferably 5% by weight or less. More preferably, it is 4% by weight or less, and particularly preferably 3% by weight or less.
  • the average content of boron in 100% by weight of the region (R1) is not less than the above lower limit and not more than the above upper limit, the occurrence of cracks in the conductive portion can be more effectively suppressed during mounting, and the electrode The connection resistance between them can be lowered even more effectively.
  • the region where the average content of boron is 0% by weight does not contain boron.
  • the average content of boron in 100% by weight of the region (R2) having a thickness of 1/5 from the outer surface to the inside of the first conductive portion is preferably 0% by weight or more, more preferably 0.001% by weight. % Or more, more preferably 0.01% by weight or more, and particularly preferably 0.1% by weight or more.
  • the average content of boron in 100% by weight of the region (R2) having a thickness of 1/5 from the outer surface to the inside of the first conductive portion is preferably 10% by weight or less, more preferably 5% by weight or less. More preferably, it is 4% by weight or less, and particularly preferably 3% by weight or less.
  • the average content of boron in 100% by weight of the region (R2) is not less than the above lower limit and not more than the above upper limit, the occurrence of cracks in the conductive portion can be more effectively suppressed during mounting, and the electrode The connection resistance between them can be lowered even more effectively.
  • Boron is uniformly distributed in the first conductive portion from the viewpoint of more effectively suppressing the occurrence of cracks in the conductive portion during mounting and further effectively reducing the connection resistance between the electrodes. It is preferable to have.
  • the average content of nickel in 100% by weight of the first conductive portion is preferably 50% by weight or more, more preferably 65% by weight or more, preferably 99.9% by weight or less, more preferably 95% by weight. It is less than% by weight.
  • the average content of nickel in 100% by weight of the first conductive portion is equal to or higher than the lower limit and lower than the upper limit, cracking of the conductive portion can be more effectively suppressed during mounting. , The connection resistance between the electrodes can be lowered even more effectively.
  • the average content of boron in 100% by weight of the first conductive portion is preferably 0.001% by weight or more, more preferably 0.01% by weight or more, still more preferably 0.1% by weight or more. It is preferably 10% by weight or less, more preferably 5% by weight or less, still more preferably 3% by weight or less.
  • the average content of boron in 100% by weight of the first conductive portion is equal to or higher than the lower limit and lower than the upper limit, cracking of the conductive portion can be more effectively suppressed during mounting. , The connection resistance between the electrodes can be lowered even more effectively.
  • the method for measuring the average contents of nickel and boron in the first conductive portion can use various known analytical methods and is not particularly limited. Examples of this measuring method include an absorption analysis method and a spectrum analysis method. In the above absorption analysis method, a frame absorptiometer, an electric heating furnace absorptiometer, or the like can be used. Examples of the spectrum analysis method include a plasma emission spectrometry method and a plasma ion source mass spectrometry method.
  • ICP emission spectrometer when measuring the average contents of nickel and boron in the first conductive portion.
  • ICP emission spectrometers examples include ICP emission spectrometers manufactured by HORIBA and "ICP-MS” manufactured by Hitachi High-Tech Science.
  • ICP emission spectrometers manufactured by HORIBA and "ICP-MS” manufactured by Hitachi High-Tech Science.
  • JEM-2010FEF electric field radiation transmission electron microscope
  • EDS energy dispersive X-ray analyzer
  • JEM-2010FEF electric field radiation transmission electron microscope
  • EDS energy dispersive X-ray analyzer
  • the thickness of the first conductive portion is preferably 0.005 ⁇ m or more, more preferably 0.01 ⁇ m or more, still more preferably 0.05 ⁇ m or more, preferably 1 ⁇ m or less, and more preferably 0.3 ⁇ m or less.
  • the thickness of the first conductive portion is not less than the above lower limit and not more than the above upper limit, sufficient conductivity can be obtained, the conductive particles do not become too hard, and conductivity is formed when the electrodes are connected. The particles can be sufficiently deformed.
  • the thickness of the first conductive portion is preferably the total thickness of all the layers.
  • the thickness of the first conductive portion is 0.05 ⁇ m or more and 0.3 ⁇ m or less. Further, it is particularly preferable that the particle size of the base material particles is 2 ⁇ m or more and 20 ⁇ m or less, and the thickness of the first conductive portion is 0.05 ⁇ m or more and 0.3 ⁇ m or less. In this case, the conductive particles can be more preferably used depending on the application in which a large current flows. Further, when the conductive particles are compressed and connected between the electrodes, damage to the electrodes can be further suppressed.
  • the thickness of the second conductive portion is preferably 0.005 ⁇ m or more, more preferably 0.01 ⁇ m or more, still more preferably 0.02 ⁇ m or more, preferably 1 ⁇ m or less, and more preferably 0.3 ⁇ m or less.
  • the thickness of the second conductive portion is not less than the above lower limit and not more than the above upper limit, sufficient conductivity can be obtained, the conductive particles do not become too hard, and conductivity is formed when the electrodes are connected. The particles can be sufficiently deformed.
  • the thickness of the second conductive portion is 0.02 ⁇ m or more and 0.3 ⁇ m or less. Further, it is particularly preferable that the particle size of the base material particles is 2 ⁇ m or more and 20 ⁇ m or less, and the thickness of the second conductive portion is 0.02 ⁇ m or more and 0.3 ⁇ m or less. In this case, the conductive particles can be more preferably used depending on the application in which a large current flows. Further, when the conductive particles are compressed and connected between the electrodes, damage to the electrodes can be further suppressed.
  • the thickness of the first conductive portion and the thickness of the second conductive portion can be measured by observing the cross section of the conductive particles using, for example, a transmission electron microscope (“JEM-2100” manufactured by JEOL Ltd.) or the like. it can.
  • JEM-2100 manufactured by JEOL Ltd.
  • the first conductive portion contains nickel as a main metal.
  • the first conductive portion may contain a metal other than nickel.
  • the metal other than nickel in the first conductive portion include gold, silver, copper, platinum, zinc, iron, tin, lead, aluminum, cobalt, indium, palladium, chromium, seaborgium, titanium, antimony, bismuth, and tarium.
  • examples thereof include tungsten, germanium, cadmium, silicon, molybdenum, tin-doped indium oxide (ITO) and solder. Only one of these metals may be used, or two or more of these metals may be used in combination. When a plurality of metals are contained in the first conductive portion, the plurality of metals may be alloyed.
  • the metal for forming the second conductive portion is not particularly limited.
  • the metal include gold, silver, copper, platinum, zinc, iron, tin, lead, aluminum, cobalt, indium, palladium, chromium, ruthenium, rhodium, iridium, bismuth, thallium, tungsten, germanium, cadmium, and silicon. And molybdenum and the like. From the viewpoint of further effectively lowering the connection resistance between the electrodes, it is preferable that the metal has a higher potential than nickel, which is the main metal of the first conductive portion.
  • the metal is preferably tin, copper, palladium, ruthenium, platinum, silver, rhodium, iridium or gold, and more preferably gold, silver, copper or palladium.
  • the main metal in the second conductive portion is preferably tin, copper, palladium, ruthenium, platinum, silver, rhodium, iridium or gold. , Gold or palladium is more preferred.
  • the main metal in the second conductive portion is preferably palladium or ruthenium, and more preferably palladium.
  • the main metal in the first conductive portion and the main metal in the second conductive portion are the metals having the highest content among the metals contained in the first conductive portion and the second conductive portion. Means.
  • the content of the main metal in 100% by weight of all the metals contained in the first conductive portion and the second conductive portion is preferably 50% by weight or more, more preferably 80% by weight or more, still more preferably. It is 90% by weight or more.
  • the first conductive portion and the second conductive portion may contain only one kind of metal, or may contain two or more kinds of metals.
  • the method of forming the first conductive portion and the second conductive portion is not particularly limited.
  • the method for forming the first conductive portion and the second conductive portion includes, for example, a method by electroless plating, a method by electroplating, a method by physical vapor deposition, and a metal powder or a metal powder and a binder. Examples thereof include a method of coating the surface of the base material particles or other conductive parts with the paste. Since the formation of the conductive portion is simple, the method by electroless plating is preferable.
  • Examples of the method by physical vapor deposition include methods such as vacuum vapor deposition, ion plating, and ion sputtering.
  • the particle size of the conductive particles is preferably 0.1 ⁇ m or more, more preferably 1 ⁇ m or more, still more preferably 1.5 ⁇ m or more, particularly preferably 2 ⁇ m or more, and most preferably 3 ⁇ m or more.
  • the particle size of the conductive particles is preferably 500 ⁇ m or less, more preferably 100 ⁇ m or less, still more preferably 50 ⁇ m or less, particularly preferably 20 ⁇ m or less, and most preferably 10 ⁇ m or less.
  • the contact area between the conductive particles and the electrodes can be sufficiently increased when the electrodes are connected using the conductive particles.
  • the agglomerated conductive particles it is possible to make it difficult for the agglomerated conductive particles to be formed when the conductive portion is formed.
  • the distance between the electrodes connected via the conductive particles does not become too large, and the conductive portion can be made difficult to peel off from the surface of the substrate particles.
  • the particle diameter of the conductive particles indicates the diameter when the conductive particles are spherical, and indicates the equivalent circle diameter when the conductive particles are not spherical.
  • the particle size of the conductive particles is preferably an average particle size, and more preferably a number average particle size.
  • the particle size of the conductive particles can be determined by, for example, observing 50 arbitrary conductive particles with an electron microscope or an optical microscope, calculating the average value of the particle size of each conductive particle, or laser diffraction type particle size distribution. Obtained by making measurements. In observation with an electron microscope or an optical microscope, the particle size of each conductive particle is determined as the particle size in the equivalent circle diameter.
  • the average particle diameter of any 50 conductive particles in the equivalent circle diameter is substantially equal to the average particle diameter in the equivalent diameter of the sphere.
  • the particle size of each conductive particle is determined as the particle size in the equivalent sphere diameter.
  • the particle size of the conductive particles is preferably calculated by laser diffraction type particle size distribution measurement.
  • a nickel plating solution is used as a method of controlling each content and each average content of nickel and boron in each region of the first conductive portion.
  • a nickel plating solution is used as a method of controlling the pH of the nickel plating solution, a method of adjusting the boron concentration in the nickel plating solution, and a method of adjusting the nickel concentration in the nickel plating solution.
  • a catalysis step and an electroless plating step are generally performed.
  • an example of a method of forming a first conductive portion containing nickel and boron on the surface of the base material particles by electroless plating will be described.
  • a catalyst serving as a starting point for forming a plating layer by electroless plating is formed on the surface of the substrate particles.
  • Examples of the method for forming the catalyst on the surface of the substrate particles include the following methods.
  • a boron-containing reducing agent is used as the reducing agent. Further, by using a boron-containing reducing agent as the reducing agent, a first conductive portion containing boron can be formed.
  • a nickel plating bath containing a nickel-containing compound, a boron-containing reducing agent, and if necessary, a complexing agent and a stabilizer is preferably used.
  • nickel By immersing the base material particles in the nickel plating bath, nickel can be precipitated on the surface of the base material particles on which the catalyst is formed on the surface, and a first conductive portion containing nickel and boron can be formed. ..
  • nickel-containing compound examples include nickel sulfate and nickel chloride.
  • the nickel-containing compound is preferably a nickel salt.
  • Examples of the boron-containing reducing agent include dimethylamine borane, sodium borohydride, potassium borohydride and the like.
  • the complexing agent examples include monocarboxylic acid complexing agents such as sodium acetate and sodium propionate; dicarboxylic acid complexing agents such as disodium malonate; tricarboxylic acid complexing agents such as disodium succinate; lactic acid. , DL-malic acid, Rochelle salt, hydroxy acid complex agents such as sodium citrate and sodium gluconate; amino acid complex agents such as glycine and EDTA; amine complex agents such as ethylenediamine; organics such as maleic acid Acid-based complexing agents; and salts thereof. Only one kind of the complexing agent may be used, or two or more kinds thereof may be used in combination.
  • a lead compound, a bismuth compound or a thallium compound may be added.
  • these compounds include sulfates, carbonates, acetates, nitrates, and hydrochlorides of metals (lead, bismuth, thallium) constituting the compounds.
  • metals lead, bismuth, thallium
  • it is preferably a bismuth compound or a thallium compound.
  • Preferred examples of the method of increasing the boron content in the first conductive portion include a method of lowering the pH of the plating solution to slow down the reaction rate of the nickel plating solution, a method of lowering the temperature of the nickel plating solution, and nickel.
  • Examples thereof include a method of increasing the concentration of the boron-containing reducing agent in the plating solution, a method of increasing the concentration of the complexing agent in the nickel plating solution, and the like. These methods may be used alone or in combination of two or more.
  • the average content of boron in 100% by weight of the region (R1) and the average content of boron in 100% by weight of the region (R2) can be adjusted.
  • the absolute value of the difference between the average content of boron in 100% by weight of the region (R1) and the average content of boron in 100% by weight of the region (R2) is 0% by weight or more. It becomes easy to make it less than% by weight.
  • the conductive particles preferably have protrusions on the conductive surface. It is preferable that the first conductive portion or the second conductive portion has protrusions on the outer surface. It is preferable that the first conductive portion and the second conductive portion have protrusions on the outer surface. It is preferable that the number of the protrusions is plurality.
  • An oxide film is often formed on the surface of the electrode connected by the conductive particles. Further, an oxide film is often formed on the surface of the conductive portion of the conductive particles.
  • the electrodes and the conductive particles can be brought into contact with each other more reliably, and the connection resistance between the electrodes can be lowered.
  • the conductive particles have an insulating substance on the surface, or when the conductive particles are dispersed in the binder resin and used as a conductive material, the protrusions of the conductive particles cause the conductive particles to be connected to the electrode.
  • the insulating substance or binder resin between them can be effectively eliminated. Therefore, the conduction reliability between the electrodes can be improved.
  • the conductive particles have protrusions on the outer surface of the first conductive portion or the second conductive portion, the area where the conductive particles come into contact with each other can be reduced. Therefore, the aggregation of the plurality of conductive particles can be suppressed. Therefore, it is possible to prevent electrical connection between electrodes that should not be connected, and it is possible to further improve insulation reliability.
  • the first conductive portion or the second conductive portion has a plurality of protrusions on the outer surface. Is easy. From the viewpoint of easily forming the plurality of protrusions, the first conductive portion or the first conductive portion is formed so as to form the plurality of protrusions inside or inside the first conductive portion or the second conductive portion. It is preferable to include a plurality of core substances that raise the surface of the conductive portion of 2. However, in order to form protrusions on the outer surfaces of the conductive particles, the first conductive portion, and the second conductive portion, it is not always necessary to use the core material, and it is preferable not to use the core material.
  • the conductive particles do not have a core substance for raising the outer surfaces of the first conductive portion and the second conductive portion.
  • the surface of the first conductive portion or the second conductive portion is formed so as to form a plurality of the protrusions inside or inside the first conductive portion or the second conductive portion. It is preferable not to have a plurality of core materials that raise the surface.
  • the core material it is preferable that the core material is arranged inside or inside the first conductive portion.
  • the core material may be arranged inside or inside the second conductive portion.
  • Examples of the method for forming the protrusions include the following methods.
  • Examples of the method for arranging the core substance on the surface of the base material particles include the following methods. A method in which a core substance is added to a dispersion of base particles, and the core substance is accumulated and adhered to the surface of the base particles by van der Waals force or the like. A method in which a core substance is added to a container containing base particles, and the core substance is attached to the surface of the base particles by a mechanical action such as rotation of the container. Since it is easy to control the amount of the core substance to be attached, the method of arranging the core substance on the surface of the base material particles is a method of accumulating and adhering the core substance on the surface of the base material particles in the dispersion liquid. Is preferable.
  • Examples of the material of the core substance include a conductive substance and a non-conductive substance.
  • Examples of the conductive substance include metals, metal oxides, conductive non-metals such as graphite, and conductive polymers.
  • Examples of the conductive polymer include polyacetylene and the like.
  • Examples of the non-conductive substance include silica, alumina, barium titanate and zirconia.
  • the core material is preferably hard. Metals are preferred because they can increase conductivity and effectively reduce connection resistance.
  • the core material is preferably metal particles. As the metal that is the material of the core substance, the metals listed as the materials of the first conductive portion and the second conductive portion can be appropriately used.
  • the material of the core material examples include barium titanate (Mohs hardness 4.5), nickel (Mohs hardness 5), silica (silicon dioxide, Mohs hardness 6-7), titanium oxide (Mohs hardness 7), and zirconia (Mohs hardness 7). Examples thereof include Mohs hardness 8 to 9), alumina (Mohs hardness 9), tungsten carbide (Mohs hardness 9), and diamond (Mohs hardness 10). From the viewpoint of further increasing the conductivity more effectively and further effectively lowering the connection resistance, the core material may be nickel, silica, titanium oxide, zirconia, alumina, tungsten carbide or diamond.
  • the core material is more preferably titanium oxide, zirconia, alumina, tungsten carbide or diamond, and zirconia.
  • Alumina, Tungsten Carbide or Diamond is particularly preferred.
  • the Mohs hardness of the material of the core material is preferably 5 or more, more preferably 6 or more, still more preferably. It is 7 or more, particularly preferably 7.5 or more.
  • the shape of the core substance is not particularly limited.
  • the shape of the core material is preferably lumpy.
  • Examples of the core material include particulate lumps, agglomerates in which a plurality of fine particles are aggregated, and amorphous lumps.
  • the particle size of the core substance is preferably 0.001 ⁇ m or more, more preferably 0.05 ⁇ m or more, preferably 1 ⁇ m or less, and more preferably 0.5 ⁇ m or less.
  • the particle size of the core substance is at least the above lower limit and at least the above upper limit, the connection resistance between the electrodes can be effectively reduced.
  • the particle diameter of the core material indicates the diameter when the core material is spherical, and indicates the equivalent circle diameter when the core material is not spherical.
  • the particle size of the core material is preferably an average particle size, and more preferably a number average particle size.
  • the average value of the particle size of each core material is calculated, and the laser diffraction type particle size distribution measurement is performed. It is required by. In observation with an electron microscope or an optical microscope, the particle size of each core substance is determined as the particle size in the equivalent circle diameter.
  • the average particle diameter of any 50 core materials in the circle equivalent diameter is substantially equal to the average particle diameter in the sphere equivalent diameter.
  • the particle size of the core material per piece is obtained as the particle size in the equivalent sphere diameter.
  • the particle size of the core material is preferably calculated by laser diffraction type particle size distribution measurement.
  • the number of the protrusions per conductive particle is preferably 3 or more, and more preferably 5 or more.
  • the upper limit of the number of the protrusions is not particularly limited.
  • the upper limit of the number of protrusions can be appropriately selected in consideration of the particle size of the conductive particles and the like. When the average height of the protrusions is at least the above lower limit, the connection resistance between the electrodes can be further effectively reduced.
  • the average height of the plurality of protrusions is preferably 0.001 ⁇ m or more, more preferably 0.05 ⁇ m or more, preferably 1 ⁇ m or less, and more preferably 0.5 ⁇ m or less.
  • the connection resistance between the electrodes can be further effectively reduced.
  • the conductive particles include an insulating substance arranged on the outer surface of the second conductive portion.
  • an insulating substance exists between the plurality of electrodes, so that it is possible to prevent a short circuit between the electrodes adjacent to each other in the lateral direction rather than between the upper and lower electrodes.
  • the insulating substance is preferably insulating particles because the insulating substance can be more easily removed during crimping between the electrodes.
  • the insulating substance may be an insulating layer.
  • Examples of the material of the insulating substance include the above-mentioned resin particle material and the above-mentioned inorganic substance as the base particle material.
  • the material of the insulating substance is preferably the material of the resin particles described above.
  • the insulating substance is preferably the above-mentioned resin particles or the above-mentioned organic-inorganic hybrid particles, and may be resin particles or organic-inorganic hybrid particles.
  • insulating substance examples include polyolefin compounds, (meth) acrylate polymers, (meth) acrylate copolymers, block polymers, thermoplastic resins, crosslinked products of thermoplastic resins, thermosetting resins and water-soluble materials. Examples include resin.
  • As the material of the insulating substance only one kind may be used, or two or more kinds may be used in combination.
  • Examples of the polyolefin compound include polyethylene, ethylene-vinyl acetate copolymer, ethylene-acrylic acid ester copolymer and the like.
  • Examples of the (meth) acrylate polymer include polymethyl (meth) acrylate, polydodecyl (meth) acrylate, and polystearyl (meth) acrylate.
  • Examples of the block polymer include polystyrene, styrene-acrylic acid ester copolymer, SB type styrene-butadiene block copolymer, SBS type styrene-butadiene block copolymer, and hydrogenated products thereof.
  • Examples of the thermoplastic resin include vinyl polymers and vinyl copolymers.
  • thermosetting resin examples include epoxy resin, phenol resin, melamine resin and the like.
  • crosslinked product of the thermoplastic resin examples include the introduction of polyethylene glycol methacrylate, alkoxylated trimethylolpropane methacrylate, alkoxylated pentaerythritol methacrylate and the like.
  • water-soluble resin examples include polyvinyl alcohol, polyacrylic acid, polyacrylamide, polyvinylpyrrolidone, polyethylene oxide, methyl cellulose and the like.
  • a chain transfer agent may be used to adjust the degree of polymerization. Examples of the chain transfer agent include thiols and carbon tetrachloride.
  • Examples of the method of arranging the insulating substance on the outer surface of the second conductive portion include a chemical method and a physical or mechanical method.
  • Examples of the chemical method include an interfacial polymerization method, a suspension polymerization method in the presence of particles, and an emulsion polymerization method.
  • Examples of the physical or mechanical method include spray drying, hybridization, electrostatic adhesion method, spraying method, dipping and vacuum deposition method. Since the insulating substance is difficult to be detached, a method of arranging the insulating substance on the surface of the second conductive portion via a chemical bond is preferable.
  • polar groups such as hydroxyl groups are present on the surface of the insulating substance.
  • the continuous film described later can coat the surface of the insulating substance more uniformly.
  • the outer surface of the second conductive portion and the surface of the insulating particles may each be coated with a compound having a reactive functional group.
  • the outer surface of the second conductive portion and the surface of the insulating particles may not be directly chemically bonded, or may be indirectly chemically bonded by a compound having a reactive functional group.
  • the carboxyl group may be chemically bonded to a functional group on the surface of the insulating particles via a polymer electrolyte such as polyethyleneimine.
  • the particle size of the insulating particle can be appropriately selected depending on the particle size of the conductive particle, the application, and the like.
  • the particle size of the insulating particles is preferably 10 nm or more, more preferably 100 nm or more, preferably 4000 nm or less, and more preferably 2000 nm or less.
  • the particle size of the insulating particles is at least the above lower limit, it becomes difficult for the conductive portions of the plurality of conductive particles to come into contact with each other when the conductive particles are dispersed in the binder resin.
  • the particle size of the insulating particles is not more than the above upper limit, it is not necessary to increase the pressure too high in order to eliminate the insulating particles between the electrodes and the conductive particles when connecting the electrodes. There is no need to heat to high temperature.
  • the particle diameter of the insulating particles indicates the diameter when the insulating particles are spherical, and indicates the equivalent circle diameter when the insulating particles are not spherical.
  • the particle size of the insulating particles is preferably an average particle size, and more preferably a number average particle size.
  • 50 arbitrary insulating particles can be observed with an electron microscope or an optical microscope to calculate the average value of the particle size of each insulating particle, or a laser diffraction type particle size distribution. Obtained by making measurements. In observation with an electron microscope or an optical microscope, the particle size of each insulating particle is determined as the particle size in the equivalent circle diameter.
  • the average particle diameter of any 50 insulating particles in the equivalent circle diameter is substantially equal to the average particle diameter in the equivalent diameter of the sphere.
  • the particle size of each insulating particle is determined as the particle size in the equivalent sphere diameter.
  • the particle size of the insulating particles is preferably calculated by laser diffraction type particle size distribution measurement. Further, in the case of measuring the particle size of the insulating particles in the conductive particles, for example, the measurement can be performed as follows.
  • Conductive particles are added to "Technobit 4000” manufactured by Kulzer so as to have a content of 30% by weight and dispersed to prepare an embedded resin body for conducting conductive particle inspection.
  • a cross section of the conductive particles is cut out using an ion milling device (“IM4000” manufactured by Hitachi High-Technologies Corporation) so as to pass near the center of the dispersed conductive particles in the embedded resin body for inspection.
  • IM4000 manufactured by Hitachi High-Technologies Corporation
  • FE-SEM field emission scanning electron microscope
  • the ratio of the particle size of the conductive particle to the particle size of the insulating particle is preferably 3. As mentioned above, it is more preferably 5 or more, even more preferably 8 or more, still more preferably 10 or more, and particularly preferably 12 or more.
  • the ratio of the particle size of the conductive particle to the particle size of the insulating particle is preferably 1000. Below, it is more preferably 100 or less, even more preferably 75 or less, still more preferably 50 or less, and particularly preferably 30 or less.
  • the insulating particles are arranged more uniformly on the outer surface of the second conductive portion. It is possible to further effectively enhance the insulation reliability between the electrodes.
  • the conductive particles When the conductive particles include the insulating substance, the conductive particles preferably include a continuous film containing an inorganic material.
  • the continuous film preferably has a portion that covers the surface of the second conductive portion and a portion that covers the surface of the insulating substance.
  • the surface of the second conductive portion and the surface of the insulating substance are covered with the continuous film, and the continuous surface of the second conductive portion is covered. It is preferable that the film and the continuous film covering the insulating substance are connected. In this case, it is possible to more effectively prevent the insulating substance from being unintentionally desorbed from the surface of the conductive particles before the conductive connection such as dispersing the conductive particles in the binder resin. As a result, the insulation reliability between adjacent electrodes can be further effectively enhanced.
  • the continuous film is preferably an inorganic oxide film.
  • the continuous film is preferably formed of an inorganic material.
  • the insulating substance can be more easily desorbed from the surface of the conductive particles. As a result, the conduction reliability between the electrodes can be further effectively enhanced.
  • Examples of the inorganic material and the material of the inorganic oxide film include oxides such as silicon, titanium, zirconium, and aluminum, and composites of these oxides.
  • the thickness of the continuous film is preferably 1 nm or more, more preferably 10 nm or more. It is preferably 500 nm or less, more preferably 100 nm or less.
  • the thickness of the continuous film is preferably the total thickness of all the layers.
  • the thickness of the continuous film is preferably determined by observing 50 arbitrary conductive particles with an electron microscope and calculating an average value.
  • it can be measured as follows.
  • Conductive particles are added to "Technobit 4000” manufactured by Kulzer so as to have a content of 30% by weight and dispersed to prepare an embedded resin body for conducting conductive particle inspection.
  • a cross section of the conductive particles is cut out using an ion milling device (“IM4000” manufactured by Hitachi High-Technologies Corporation) so as to pass near the center of the dispersed conductive particles in the embedded resin body for inspection.
  • IM4000 manufactured by Hitachi High-Technologies Corporation
  • FE-SEM field emission scanning electron microscope
  • the image magnification is set to 50,000 times, 50 conductive particles are randomly selected, and a continuous film in each conductive particle is observed. ..
  • the thickness of the continuous film in each conductive particle is measured, and they are arithmetically averaged to obtain the thickness of the continuous film.
  • the ratio of the thickness of the continuous film to the particle size of the insulating particle is preferably 0.01 or more. It is more preferably 0.05 or more, preferably 1 or less, and more preferably 0.1 or less.
  • the above ratio thickness of continuous film / particle size of insulating particles
  • the insulation reliability between the electrodes can be further effectively enhanced, and the conduction reliability between the electrodes can be further improved.
  • the sex can be enhanced even more effectively.
  • the surface of the second conductive portion and the surface of the insulating substance are used by using an alkoxide hydrolysis reaction.
  • examples thereof include a method of coating an insulating composition (composition containing a metal alkoxide).
  • the outer surface of the second conductive portion is rust-proofed with a compound having an alkyl group having 6 to 22 carbon atoms.
  • the outer surface of the second conductive portion may be rust-proofed with a phosphorus-free compound, or may be rust-proofed with a phosphorus-free compound having an alkyl group having 6 to 22 carbon atoms. May be good.
  • the outer surface of the second conductive portion is rust-proofed with an alkylphosphoric acid compound or an alkylthiol.
  • the rust preventive film is preferably formed of a compound having an alkyl group having 6 to 22 carbon atoms (hereinafter, also referred to as compound A).
  • the outer surface of the second conductive portion is preferably surface-treated with the compound A.
  • the number of carbon atoms of the alkyl group is 6 or more, rust is less likely to occur in the entire second conductive portion.
  • the conductivity of the conductive particles becomes high. From the viewpoint of further increasing the conductivity of the conductive particles, the number of carbon atoms of the alkyl group in the compound A is preferably 16 or less.
  • the alkyl group may have a linear structure or a branched structure.
  • the alkyl group preferably has a linear structure.
  • the compound A is not particularly limited as long as it has an alkyl group having 6 to 22 carbon atoms.
  • the compound A contains a phosphoric acid ester having an alkyl group having 6 to 22 carbon atoms or a salt thereof, a phosphite ester having an alkyl group having 6 to 22 carbon atoms or a salt thereof, or an alkyl group having 6 to 22 carbon atoms. It is preferably an alkoxysilane having.
  • the compound A is preferably an alkyl thiol having an alkyl group having 6 to 22 carbon atoms or a dialkyl disulfide having an alkyl group having 6 to 22 carbon atoms.
  • the compound A having an alkyl group having 6 to 22 carbon atoms is preferably a phosphoric acid ester or a salt thereof, a phosphite ester or a salt thereof, an alkoxysilane, an alkylthiol or a dialkyldisulfide.
  • the compound A is preferably a phosphoric acid ester or a salt thereof, a phosphite ester or a salt thereof, or an alkylthiol, and the phosphoric acid ester or a salt thereof.
  • it is more preferably a phosphite ester or a salt thereof.
  • the compound A only one kind may be used, or two or more kinds may be used in combination.
  • the compound A preferably has a reactive functional group capable of reacting with the outer surface of the second conductive portion.
  • the compound A preferably has a reactive functional group capable of reacting with the insulating substance.
  • the rust preventive film is preferably chemically bonded to the second conductive portion.
  • the rust preventive film is preferably chemically bonded to the insulating substance. It is more preferable that the rust preventive film is chemically bonded to both the second conductive portion and the insulating substance. Due to the presence of the reactive functional group and the chemical bond, the rust preventive film is less likely to be peeled off, and as a result, rust is less likely to occur on the second conductive portion, and from the surface of the conductive particles.
  • the insulating material becomes more difficult to detach unintentionally.
  • Examples of the phosphoric acid ester having an alkyl group having 6 to 22 carbon atoms or a salt thereof include phosphoric acid hexyl ester, phosphoric acid heptyl ester, phosphoric acid monooctyl ester, phosphoric acid monononyl ester, and phosphoric acid monodecyl ester.
  • Organophosphate monoundecyl ester Organophosphate monoundecyl ester, phosphate monododecyl ester, phosphate monotridecyl ester, phosphate monotetradecyl ester, phosphate monopentadecyl ester, phosphate monohexyl ester monosodium salt, phosphate monoheptyl ester monosodium Salt, monooctyl phosphate monosodium salt, mononoyl phosphate monosodium salt, monodecyl phosphate monosodium salt, monoundecyl phosphate monosodium salt, monododecyl phosphate monosodium salt, phosphate Examples thereof include a monotridecyl ester monosodium salt, a monotetradecyl phosphate monosodium salt, and a monopentadecyl phosphate monosodium salt.
  • Examples of the phosphite ester having an alkyl group having 6 to 22 carbon atoms or a salt thereof include hexyl phosphite ester, heptyl phosphite ester, monooctyl phosphite ester, monononyl phosphite ester, and sub-phosphate.
  • alkoxysilane having an alkyl group having 6 to 22 carbon atoms examples include hexyltrimethoxysilane, hexyltriethoxysilane, heptyltrimethoxysilane, heptyltriethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, and nonyltri.
  • alkyl thiol having an alkyl group having 6 to 22 carbon atoms examples include hexyl thiol, heptyl thiol, octyl thiol, nonyl thiol, decyl thiol, undecyl thiol, dodecyl thiol, tridecyl thiol, tetradecyl thiol and pentadecyl. Examples thereof include thiols and hexadecylthiols.
  • the alkyl thiol preferably has a thiol group at the end of the alkyl chain.
  • dialkyl disulfide having an alkyl group having 6 to 22 carbon atoms examples include dihexyl disulfide, diheptyl disulfide, dioctyl disulfide, dinonyl disulfide, didecyl disulfide, diundecyl disulfide, didodecyl disulfide, ditridecyl disulfide, and ditetra. Examples thereof include decyl disulfide, dipenta decyl disulfide and dihexadecyl disulfide.
  • the conductive particles can be suitably used for conductive connection of an electrode with a protective layer including an electrode and a protective layer arranged on the surface of the electrode.
  • the conductive particles can be suitably used for conductive connection of wiring with a protective layer including the wiring and a protective layer arranged on the surface of the wiring.
  • Examples of the material of the electrode and the wiring include a precious metal such as gold, silver or copper.
  • the protective layer comprises a triazole compound having a mercapto group, a tetrazole compound having a mercapto group, a thiazazole compound having a mercapto group, a triazole compound having an amino group, or an amino group.
  • the tetrazole compound having is preferable to contain the tetrazole compound having.
  • the connection resistance between the electrodes can be lowered more effectively, and the conduction reliability can be further improved. Can be effectively enhanced.
  • the conductive particles can be suitably used for conductive connection of electrodes of flexible members.
  • Examples of the connection structure using the flexible member include a flexible panel and the like.
  • the flexible panel can be used as a curved panel.
  • the conductive particles are preferably used for forming the connecting portion of the flexible panel, and preferably used for forming the connecting portion of the curved panel.
  • the conductive material according to the present invention includes the above-mentioned conductive particles and a binder resin.
  • the conductive particles are preferably dispersed in the binder resin and used as a conductive material.
  • the conductive material is preferably an anisotropic conductive material. It is preferable that the conductive particles and the conductive material are used for electrical connection between the electrodes, respectively.
  • the conductive material is preferably a circuit connection material.
  • the binder resin is not particularly limited.
  • As the binder resin a known insulating resin is used.
  • binder resin examples include vinyl resins, thermoplastic resins, curable resins, thermoplastic block copolymers, and elastomers. Only one kind of the binder resin may be used, or two or more kinds may be used in combination.
  • Examples of the vinyl resin include vinyl acetate resin, acrylic resin, styrene resin and the like.
  • the thermoplastic resin include polyolefin resins, ethylene-vinyl acetate copolymers, and polyamide resins.
  • Examples of the curable resin include epoxy resin, urethane resin, polyimide resin, unsaturated polyester resin and the like.
  • the curable resin may be a room temperature curable resin, a thermosetting resin, a photocurable resin, or a moisture curable resin.
  • the curable resin may be used in combination with a curing agent.
  • thermoplastic block copolymer examples include a styrene-butadiene-styrene block copolymer, a styrene-isoprene-styrene block copolymer, a hydrogenated additive of a styrene-butadiene-styrene block copolymer, and a styrene-isoprene.
  • -Hydrogen additives for styrene block copolymers and the like can be mentioned.
  • the elastomer examples include styrene-butadiene copolymer rubber and acrylonitrile-styrene block copolymer rubber.
  • the conductive material and the binder resin preferably contain a thermoplastic component or a thermosetting component.
  • the conductive material and the binder resin may contain a thermoplastic component or may contain a thermosetting component.
  • the conductive material and the binder resin preferably contain a thermosetting component.
  • the thermosetting component preferably contains a curable compound that can be cured by heating and a thermosetting agent.
  • the thermosetting agent is preferably a thermal cation curing initiator. The curable compound curable by heating and the thermosetting agent are used in an appropriate compounding ratio so that the binder resin is cured.
  • the conductive material includes, for example, a filler, a bulking agent, a softening agent, a plasticizer, a polymerization catalyst, a curing catalyst, a colorant, an antioxidant, a heat stabilizer, and a photostabilizer. It may contain various additives such as an agent, an ultraviolet absorber, a lubricant, an antistatic agent and a flame retardant.
  • the method for dispersing the conductive particles in the binder can be a conventionally known dispersion method and is not particularly limited.
  • Examples of the method of dispersing the conductive particles in the binder include a method of adding the conductive particles to the binder and then kneading and dispersing the conductive particles with a planetary mixer or the like, and a method of dispersing the conductive particles in water or an organic solvent. After uniformly dispersing the particles with a homogenizer or the like, the particles are added to the binder and kneaded with a planetary mixer or the like to disperse the particles.
  • a method for dispersing the conductive particles in the binder a method in which the binder is diluted with water or an organic solvent, the conductive particles are added, and the particles are kneaded and dispersed with a planetary mixer or the like. Can be mentioned.
  • the conductive material can be used as a conductive paste, a conductive film, or the like.
  • the conductive material is a conductive film
  • a film containing no conductive particles may be laminated on the conductive film containing the conductive particles.
  • the conductive paste is preferably an anisotropic conductive paste.
  • the conductive film is preferably an anisotropic conductive film.
  • the content of the binder resin in 100% by weight of the conductive material is preferably 10% by weight or more, more preferably 30% by weight or more, still more preferably 50% by weight or more, particularly preferably 70% by weight or more, and preferably 70% by weight or more. It is 99.99% by weight or less, more preferably 99.9% by weight or less.
  • the content of the binder resin is not less than the above lower limit and not more than the above upper limit, the conductive particles are efficiently arranged between the electrodes, and the connection reliability of the connection target member connected by the conductive material is further improved. be able to.
  • the content of the conductive particles in 100% by weight of the conductive material is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, preferably 80% by weight or less, and more preferably 60% by weight. Below, it is more preferably 40% by weight or less, particularly preferably 20% by weight or less, and most preferably 10% by weight or less.
  • the content of the conductive particles is not less than the above lower limit and not more than the above upper limit, the conduction reliability between the electrodes can be further increased.
  • connection structure can be obtained by connecting the members to be connected with the conductive particles or with the conductive material containing the conductive particles and the binder resin.
  • connection structure includes a first connection target member, a second connection target member, and a connection portion connecting the first and second connection target members.
  • the material of the connection portion is the above-mentioned conductive particles or a conductive material containing the above-mentioned conductive particles and a binder resin.
  • the connecting portion is formed of the above-mentioned conductive particles or a conductive material containing the above-mentioned conductive particles and a binder resin.
  • the first electrode and the second electrode are electrically connected by the conductive particles.
  • the connecting portion itself is the conductive particles. That is, the first and second connection target members are connected by the conductive particles.
  • the standard electrode potential of the main metal in the first conductive portion is the same as that of the first electrode or the second electrode. It is preferably smaller than the standard electrode potential of the main metal on the outer surface.
  • FIG. 7 schematically shows a connection structure using conductive particles according to the first embodiment of the present invention in a front sectional view.
  • connection structure 51 shown in FIG. 7 connects a first connection target member 52, a second connection target member 53, and a connection portion 54 connecting the first and second connection target members 52 and 53. Be prepared.
  • the connecting portion 54 is formed by curing a conductive material containing the conductive particles 1.
  • the conductive particles 1 are shown schematically for convenience of illustration. Conductive particles 11, 21, 31 and the like may be used instead of the conductive particles 1.
  • the first connection target member 52 has a plurality of first electrodes 52a on the surface (upper surface).
  • the second connection target member 53 has a plurality of second electrodes 53a on the surface (lower surface).
  • the first electrode 52a and the second electrode 53a are electrically connected by one or more conductive particles 1. Therefore, the first and second connection target members 52 and 53 are electrically connected by the conductive particles 1.
  • the method for manufacturing the connection structure is not particularly limited.
  • the conductive material is arranged between the first connection target member and the second connection target member, and after obtaining a laminate, the laminate is heated. And a method of pressurizing and the like.
  • the pressurizing pressure is about 9.8 ⁇ 10 4 Pa to 4.9 ⁇ 10 6 Pa.
  • the heating temperature is about 50 ° C. to 220 ° C.
  • the pressure of the pressurization for connecting the electrodes of the flexible printed circuit board, the electrodes arranged on the resin film, and the electrodes of the touch panel is about 9.8 ⁇ 10 4 Pa to 1.0 ⁇ 10 6 Pa.
  • connection target member examples include electronic components such as semiconductor chips, capacitors and diodes, and circuit boards such as printed circuit boards, flexible printed circuit boards, glass epoxy boards and glass boards.
  • the connection target member is preferably an electronic component.
  • the conductive particles are preferably used for electrical connection of electrodes in electronic components.
  • the electrodes provided on the connection target member include metal electrodes such as gold electrodes, nickel electrodes, tin electrodes, aluminum electrodes, copper electrodes, silver electrodes, SUS electrodes, molybdenum electrodes and tungsten electrodes.
  • the electrode is preferably a gold electrode, a nickel electrode, a tin electrode, or a copper electrode.
  • the electrode is preferably an aluminum electrode, a copper electrode, a molybdenum electrode, or a tungsten electrode.
  • the electrode is an aluminum electrode, it may be an electrode formed only of aluminum, or an electrode in which an aluminum layer is laminated on the surface of a metal oxide layer.
  • the material of the metal oxide layer include indium oxide doped with a trivalent metal element and zinc oxide doped with a trivalent metal element. Examples of the trivalent metal element include Al and Ga.
  • the standard electrode potential of the metal is as follows.
  • Example 1 Preparation of conductive particles (formation of first conductive portion) Divinylbenzene copolymer resin particles (base particle A, "Micropearl SP-203" manufactured by Sekisui Chemical Industry Co., Ltd., particle diameter 3 ⁇ m) were prepared. After dispersing 10 parts by weight of the base particle A in 100 parts by weight of an alkaline solution containing 5% by weight of a palladium catalyst solution using an ultrasonic disperser, the base particle A was taken out by filtering the solution. .. Next, the base particle A was added to 100 parts by weight of a 1 wt% dimethylamine borane solution to activate the surface of the substrate particle A. The surface-activated substrate particles A were thoroughly washed with water, and then added to 500 parts by weight of distilled water and dispersed to obtain a suspension.
  • base particle A "Micropearl SP-203" manufactured by Sekisui Chemical Industry Co., Ltd., particle diameter 3 ⁇ m
  • a nickel plating solution (pH 8.5) containing nickel sulfate 0.14 mol / L, dimethylamine borane 0.46 mol / L and sodium citrate 0.2 mol / L was prepared.
  • the nickel plating solution was added dropwise to the suspension at a dropping rate of 30 mL / min for 10 minutes. Then, the mixture was added dropwise at a dropping rate of 10 mL / min for 40 minutes, and then dropped at a dropping rate of 4 mL / min for 80 minutes to control the content of boron incorporated in the plating film without electrolessing. Nickel-boron alloy plating was performed.
  • the particles are taken out by filtering the suspension, washed with water, and dried to form a first conductive portion (conductive layer containing nickel, thickness 0.1 ⁇ m) on the surface of the base particle A. Placed particles were obtained.
  • Electroless palladium plating was completed when the thickness of the second conductive portion reached 20 nm.
  • Conductive particles particle diameter 3.24 ⁇ m
  • a second conductive portion palladium layer, thickness 0.02 ⁇ m
  • a compound containing 30 parts by weight of "Novacure HXA3922" manufactured by the same company was obtained.
  • 1 part by weight of a silane coupling agent (“KBM-403” manufactured by Shin-Etsu Chemical Co., Ltd.) was added to the obtained formulation, and the obtained conductive particles were further contained in 100% by weight of the obtained conductive film. It was added so that the amount was 10% by weight.
  • methyl ethyl ketone was added so that the solid content was 50%, and the mixture was stirred at 2000 rpm for 5 minutes using a planetary stirrer to obtain a mixture.
  • the obtained mixture was applied onto the stripped polyethylene terephthalate, and the solvent was dried to obtain an anisotropic conductive film having a thickness of 20 ⁇ m.
  • connection target member a plastic substrate having a copper electrode pattern (first electrode) having an L / S of 10 ⁇ m / 10 ⁇ m on the upper surface was prepared. Further, as a second connection target member, a flexible substrate having a copper electrode pattern (second electrode) having an L / S of 10 ⁇ m / 10 ⁇ m on the lower surface was prepared.
  • a conductive film (anisotropic conductive film) immediately after production was placed on the upper surface of the plastic substrate to form a conductive film layer (anisotropic conductive film layer).
  • the flexible substrate was laminated on the upper surface of the conductive film layer (anisotropic conductive film layer) so that the electrodes face each other.
  • the pressure heating head is placed on the upper surface of the flexible substrate, and the pressure is 60 MPa with respect to the electrode area.
  • the conductive film was cured at 100 ° C. to obtain a connecting structure.
  • Example 2 When forming the first conductive portion, 1 g of nickel particle slurry (average particle diameter 150 nm) was added to the suspension of the base particle A. Conductive particles, a conductive film, and a connecting structure were obtained in the same manner as in Example 1 except that particles having a core substance adhered to the surface of the base particles A were used instead of the base particles A. ..
  • Example 3 Conductivity in the same manner as in Example 2 except that an alumina particle slurry (average particle diameter 150 nm) was used instead of the nickel particle slurry (average particle diameter 150 nm) when forming the first conductive portion. Particles, conductive film and connecting structure were obtained.
  • Example 4 Conductivity in the same manner as in Example 2 except that a titania particle slurry (average particle diameter 150 nm) was used instead of the nickel particle slurry (average particle diameter 150 nm) when forming the first conductive portion. Particles, conductive film and connecting structure were obtained.
  • Example 5 The conductive particles, the conductive film, and the connecting structure were formed in the same manner as in Example 3 except that the particle size of the base particle A was changed from 3 ⁇ m to 1.5 ⁇ m when the first conductive portion was formed. Obtained.
  • Example 6 Conductive particles, a conductive film, and a connecting structure were obtained in the same manner as in Example 3 except that the particle size of the base particle A was changed from 3 ⁇ m to 20 ⁇ m when the first conductive portion was formed. ..
  • Example 7 Conductivity in the same manner as in Example 3 except that the outer surface of the conductive particles was rust-proofed by dispersing the obtained conductive particles using a compound having an alkyl group having 6 carbon atoms. Particles, conductive film and connecting structure were obtained.
  • Example 8 The following monomer composition is placed in a 1000 mL separable flask equipped with a 4-port separable cover, stirring blade, three-way cock, cooling tube and temperature probe, and the solid content of the monomer composition becomes 5% by weight. After weighing the ion-exchanged water as described above, the mixture was stirred at 200 rpm and polymerized at 70 ° C. for 24 hours under a nitrogen atmosphere.
  • the above-mentioned monomer composition comprises 100 mmol of methyl methacrylate, 1 mmol of N, N, N-trimethyl-N-2-methacryloyloxyethylammonium chloride, and 1 mmol of 2,2'-azobis (2-amidinopropane) dihydrochloride. Including. After completion of the reaction, the reaction was freeze-dried to obtain insulating particles having an ammonium group on the surface, having an average particle diameter of 220 nm and a CV value of 10%.
  • Insulating particles were dispersed in ion-exchanged water under ultrasonic irradiation to obtain a 10% by weight aqueous dispersion of insulating particles.
  • Example 3 10 g of the conductive particles obtained in Example 3 were dispersed in 500 mL of ion-exchanged water, 4 g of an aqueous dispersion of insulating particles was added, and the mixture was stirred at room temperature for 6 hours. After filtering with a 3 ⁇ m mesh filter, the mixture was further washed with methanol and dried to obtain conductive particles to which insulating particles were attached (conductive particles with insulating particles).
  • the covering area of the insulating particles that is, the projected area of the particle diameter of the insulating particles
  • the covering ratio was 40%.
  • the conductive film and the connecting structure are the same as in Example 3 except that the conductive particles with insulating particles are used instead of the conductive particles when the conductive film (anisometric conductive film) is produced.
  • Example 9 Conductive particles, a conductive film, and a connecting structure were obtained in the same manner as in Example 3 except that electroless gold plating was applied instead of electroless palladium plating when forming the second conductive portion. It was.
  • Example 10 Conductive particles, a conductive film, and a connecting structure were obtained in the same manner as in Example 3 except that electroless ruthenium plating was applied instead of electroless palladium plating when forming the second conductive portion. It was.
  • Example 11 As the second connection target member, a flexible substrate having an electrode pattern (second electrode) in which the main metal of the outer surface of the electrode in the second connection target member is gold is prepared on the lower surface.
  • Example 3 except that a prepared flexible substrate was used instead of the flexible substrate having a copper electrode pattern (second electrode) having an L / S of 10 ⁇ m / 10 ⁇ m on the lower surface when producing the connection structure.
  • the connection structure was obtained in the same manner as above.
  • Example 12 As the second connection target member, a flexible substrate having an electrode pattern (second electrode) on the lower surface in which the main metal of the outer surface of the electrode in the second connection target member is silver was prepared.
  • Example 3 except that the prepared flexible substrate was used instead of the flexible substrate having a copper electrode pattern (second electrode) having an L / S of 10 ⁇ m / 10 ⁇ m on the lower surface when producing the connection structure.
  • the connection structure was obtained in the same manner as above.
  • Example 13 As the first connection target member, a plastic substrate having an electrode pattern (first electrode) on which the main metal of the outer surface of the electrode in the first connection target member is gold was prepared. Further, as the second connection target member, a flexible substrate having an electrode pattern (second electrode) in which the main metal of the outer surface of the electrode in the second connection target member is gold is prepared on the lower surface.
  • connection structure When producing the connection structure, a plastic substrate having a copper electrode pattern (first electrode) having an L / S of 10 ⁇ m / 10 ⁇ m on the upper surface and a copper electrode pattern having an L / S of 10 ⁇ m / 10 ⁇ m (second electrode) A connection structure was obtained in the same manner as in Example 3 except that the prepared substrate was used instead of the flexible substrate having the above.
  • Example 14 300 g of a 0.13 wt% ammonia aqueous solution was placed in a 500 mL reaction vessel equipped with a stirrer and a thermometer. Next, in the aqueous ammonia solution in the reaction vessel, 1.9 g of methyltrimethoxysilane, 12.7 g of vinyltrimethoxysilane, and 0.4 g of silicone alkoxy oligomer A (“KR-517” manufactured by Shinetsu Chemical Industry Co., Ltd.) were added. The mixture of was added slowly.
  • KR-517 silicone alkoxy oligomer A
  • Organic-inorganic hybrid particles were obtained by firing at 380 ° C. (baking temperature) for 2 hours (baking time). The particle size of the obtained organic-inorganic hybrid particles (base particle B) was 3 ⁇ m.
  • Conductive particles, a conductive film, and a connecting structure were obtained in the same manner as in Example 3 except that the base particles B were used instead of the base particles A when producing the conductive particles.
  • Example 15 As the nickel plating solution (1), a nickel plating solution (pH 8.5) containing nickel sulfate 0.14 mol / L, dimethylamine borane 0.46 mol / L and sodium citrate 0.2 mol / L was prepared. Further, as the nickel plating solution (2), a nickel plating solution (pH 8.0) containing nickel sulfate 0.14 mol / L and titanium chloride (III) 0.60 mol / L was prepared.
  • the nickel plating solution (1) was added dropwise to the suspension at a dropping rate of 6 mL / min for 10 minutes while stirring the obtained suspension at 60 ° C. did. Then, the particles were added dropwise at a dropping rate of 2 mL / min for 40 minutes, and then dropped at a dropping rate of 0.8 mL / min for 80 minutes to control the content of boron incorporated in the plating film. Electroless nickel-boron alloy plating was performed on the surface of the base particle A (thickness 0.02 ⁇ m). Subsequently, the liquid temperature was set to 70 ° C., the nickel plating liquid (2) was gradually added dropwise, electroless nickel plating was performed, and a suspension (2) was obtained.
  • Example 16 A plastic substrate and a flexible substrate having a protective layer containing 3-mercapto-triazole formed on the outer surface of the electrode in the first connection target member and the outer surface of the electrode in the second connection target member were prepared.
  • a connection structure was obtained in the same manner as in Example 3 except that the prepared substrate was used instead of the flexible substrate having the above.
  • Example 17 As the nickel plating solution, a nickel plating solution (pH 8.5) containing nickel sulfate 0.14 mol / L, dimethylamine borane 0.46 mol / L and sodium citrate 0.2 mol / L was prepared.
  • the nickel plating solution When forming the first conductive portion, the nickel plating solution was added dropwise to the suspension at a dropping rate of 30 mL / min for 10 minutes while stirring the obtained suspension at 60 ° C., and then. , The dropping speed was 10 mL / min for 40 minutes. After that, the pH of the nickel plating solution was adjusted to 6.8 with sulfuric acid to reduce the reaction temperature to 30 ° C. or lower, and then the nickel plating solution was added dropwise to the plating film at a dropping rate of 4 mL / min for 80 minutes. Electroless nickel-boron alloy plating was performed while controlling the content of boron to be incorporated to obtain a suspension (2).
  • the particles are taken out, washed with water, and dried to form a first conductive portion (thickness 0.1 ⁇ m) containing nickel as the main metal on the surface of the base particle A. Obtained the formed particles.
  • the average content of boron in 100% by weight of the region (R1) having a thickness of 1/5 from the inner surface to the outside of the first conductive portion is 1.0 weight by weight.
  • the average content of boron in 100% by weight of the region (R2) having a thickness of 1/5 from the outer surface to the inside of the first conductive portion was 6.0% by weight.
  • Conductive particles, a conductive film, and a connecting structure were obtained in the same manner as in Example 3 except that the obtained particles were used.
  • a nickel plating solution (pH 8.0) containing nickel sulfate 0.14 mol / L, dimethylamine borane 0.46 mol / L and sodium citrate 0.4 mol / L was prepared.
  • a nickel plating solution (pH 6.0) containing nickel sulfate 0.05 mol / L, dimethylamine borane 0.95 mol / L and sodium citrate 0.8 mol / L was prepared.
  • the nickel plating solution (1) was added dropwise to the suspension at a dropping rate of 5 mL / min for 40 minutes while stirring the obtained suspension at 60 ° C. did. Then, the liquid temperature was set to 20 ° C., and the nickel plating liquid (2) (pH 6.0) was gradually added dropwise to perform electroless nickel-boron alloy plating to obtain a suspension (2).
  • the suspension (2) is filtered to take out the particles, washed with water, and dried to obtain a first conductive portion (conductive layer containing nickel, thickness 0.1 ⁇ m) on the surface of the base particle A. ) Was placed.
  • the average content of boron in 100% by weight of the region having a thickness of 1/5 from the inner surface to the outside of the first conductive portion is 0.05% by weight.
  • the average content of boron in 100% by weight of the region having a thickness of 1/5 from the outer surface to the inside of the first conductive portion was 15.0% by weight.
  • Conductive particles, a conductive film, and a connecting structure were obtained in the same manner as in Example 3 except that the obtained particles were used.
  • a nickel plating solution (pH 9.0) containing nickel sulfate 0.25 mol / L, sodium hypophosphite 0.25 mol / L, and sodium citrate 0.15 mol / L was prepared.
  • the nickel plating solution was gradually added dropwise to the suspension while stirring the obtained suspension at 60 ° C. to perform electroless nickel-phosphorus alloy plating. Then, the suspension was filtered to take out the particles, washed with water, and dried to obtain particles in which a nickel-phosphorus layer (thickness 0.1 ⁇ m) was arranged on the surface of the base particle A.
  • the nickel content in 100% by weight of the conductive layer was 97.0% by weight, and the phosphorus content was 3.0% by weight.
  • Conductive particles, a conductive material, and a connecting structure were obtained in the same manner as in Example 3 except that the obtained particles were used.
  • a nickel plating solution (pH 10.0) containing nickel sulfate 0.40 mol / L, sodium hypophosphite 0.15 mol / L, and sodium citrate 0.15 mol / L was prepared.
  • the nickel plating solution was gradually added dropwise to the suspension while stirring the obtained suspension at 80 ° C. to perform electroless nickel-phosphorus alloy plating. Then, the suspension was filtered to take out the particles, washed with water, and dried to obtain particles in which a nickel-phosphorus layer (thickness 0.1 ⁇ m) was arranged on the surface of the base particle A.
  • the content of nickel in 100% by weight of the conductive layer was 99.5% by weight, and the content of phosphorus was 0.5% by weight.
  • Conductive particles, a conductive material, and a connecting structure were obtained in the same manner as in Example 3 except that the obtained particles were used.
  • first connection target member a plastic substrate having an electrode pattern (first electrode) on which the main metal of the outer surface of the electrode in the first connection target member is gold was prepared. Further, as the second connection target member, a flexible substrate having an electrode pattern (second electrode) in which the main metal of the outer surface of the electrode in the second connection target member is gold is prepared on the lower surface.
  • connection structure When producing the connection structure, a plastic substrate having a copper electrode pattern (first electrode) having an L / S of 10 ⁇ m / 10 ⁇ m on the upper surface and a copper electrode pattern having an L / S of 10 ⁇ m / 10 ⁇ m (second electrode) A connection structure was obtained in the same manner as in Comparative Example 3 except that the prepared substrate was used instead of the flexible substrate having the above.
  • the particle size of the conductive particles was measured using a laser diffraction type particle size distribution measuring device (“LA-920” manufactured by HORIBA, Ltd.).
  • a thin film section of the obtained conductive particles was prepared using a focused ion beam.
  • JEM-2010FEF field emission transmission electron microscope
  • EDS energy dispersive X-ray analyzer
  • the average contents of nickel (Ni) and boron (B) in 100% by weight of the above region (R2) (region having a thickness of 20% on the outer surface side) up to 1/5 of the thickness toward the inside were determined. From the obtained results, the absolute value of the difference between the average content of boron in 100% by weight of the region (R1) and the average content of boron in 100% by weight of the region (R2) (average of boron). The absolute value of the difference in content) was calculated.
  • connection resistance A is 2.0 ⁇ or less ⁇ : Connection resistance A is more than 2.0 ⁇ and 3.0 ⁇ or less ⁇ : Connection resistance A is more than 3.0 ⁇ and 5.0 ⁇ or less ⁇ : Connection resistance A is 5 More than 0.0 ⁇ and less than 10 ⁇ ⁇ : Connection resistance A exceeds 10 ⁇
  • connection resistor B (after reliability test) The connection structure obtained in the above (1) initial evaluation of connection resistance was left to stand under the conditions of 85 ° C. and 85% relative humidity. After 1000 hours from the start of leaving, the connection resistance B between the electrodes was measured by the 4-terminal method in the same manner as in the evaluation of the connection resistance A in (3) above. Further, the connection resistance B was determined according to the following criteria.
  • connection resistance B is less than 1.25 times the connection resistance A ⁇ ⁇ : Connection resistance B is 1.25 times or more and less than 1.5 times the connection resistance A ⁇ : Connection resistance B is the connection resistance A 1.5 times or more and less than 2 times ⁇ : Connection resistance B is 2 times or more and less than 3 times of connection resistance A ⁇ : Connection resistance B is 3 times or more of connection resistance A

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Abstract

Provided is a conductive particle which makes it possible to effectively suppress cracking of a conductive portion during mounting and effectively reduce connection resistance between electrodes.　The conductive particle according to the present invention includes a base particle, a first conductive portion arranged on the surface of the base particle, and a second conductive portion arranged on the surface of the first conductive portion, the first conductive portion includes nickel and boron and does not contain phosphorus, an absolute value of the difference between an average amount of boron in 100% by weight in a region having a thickness of 1/5 from the inner surface of the first conductive portion toward the outer side and an average amount of boron in 100% by weight in a region having a thickness of 1/5 from the outer surface of the first conductive portion toward the inner side is 0-10% by weight, and a standard electrode potential of a main metal in the first conductive portion is smaller than a standard electrode potential of a main metal in the second conductive portion.

Description

導電性粒子、導電材料及び接続構造体Conductive particles, conductive materials and connecting structures
　本発明は、基材粒子の表面上に導電部が配置されている導電性粒子に関する。また、本発明は、上記導電性粒子を用いた導電材料及び接続構造体に関する。 The present invention relates to conductive particles in which a conductive portion is arranged on the surface of the base particle. The present invention also relates to a conductive material and a connecting structure using the above conductive particles.
　異方性導電ペースト及び異方性導電フィルム等の異方性導電材料が広く知られている。該異方性導電材料では、バインダー樹脂中に導電性粒子が分散されている。 Anisotropic conductive materials such as anisotropic conductive paste and anisotropic conductive film are widely known. In the anisotropic conductive material, conductive particles are dispersed in the binder resin.
　上記異方性導電材料は、各種の接続構造体を得るために用いられている。上記異方性導電材料を用いる接続としては、例えば、フレキシブルプリント基板とガラス基板との接続（ＦＯＧ（Ｆｉｌｍ　ｏｎ　Ｇｌａｓｓ））、半導体チップとフレキシブルプリント基板との接続（ＣＯＦ（Ｃｈｉｐ　ｏｎ　Ｆｉｌｍ））、半導体チップとガラス基板との接続（ＣＯＧ（Ｃｈｉｐ　ｏｎ　Ｇｌａｓｓ））、並びにフレキシブルプリント基板とガラスエポキシ基板との接続（ＦＯＢ（Ｆｉｌｍ　ｏｎ　Ｂｏａｒｄ））等が挙げられる。 The anisotropic conductive material is used to obtain various connection structures. Examples of the connection using the anisotropic conductive material include a connection between a flexible printed circuit board and a glass substrate (FOG (Film on Glass)), a connection between a semiconductor chip and a flexible printed circuit board (COF (Chip on Film)), and the like. Examples thereof include a connection between a semiconductor chip and a glass substrate (COG (Chip on Glass)) and a connection between a flexible printed circuit board and a glass epoxy substrate (FOB (Film on Board)).
　上記異方性導電材料により、例えば、半導体チップの電極とガラス基板の電極とを電気的に接続する際には、ガラス基板上に、導電性粒子を含む異方性導電材料を配置する。次に、半導体チップを積層して、加熱及び加圧する。これにより、異方性導電材料を硬化させて、導電性粒子を介して電極間を電気的に接続して接続構造体を得る。 With the anisotropic conductive material, for example, when electrically connecting the electrode of the semiconductor chip and the electrode of the glass substrate, the anisotropic conductive material containing the conductive particles is arranged on the glass substrate. Next, the semiconductor chips are laminated and heated and pressurized. As a result, the anisotropic conductive material is cured, and the electrodes are electrically connected via the conductive particles to obtain a connection structure.
　上記導電性粒子の一例として、下記の特許文献１には、コア粒子と、Ｎｉめっき層と、貴金属めっき層と、防錆膜とを備える導電粒子が開示されている。上記Ｎｉめっき層は、上記コア粒子を被覆し、Ｎｉを含む。上記貴金属めっき層は、上記Ｎｉめっき層の少なくとも一部を被覆し、Ａｕ及びＰｄのうち少なくともいずれかを含む。上記防錆膜は、上記めっき層及び上記貴金属めっき層のうち少なくともいずれかを被覆し、有機化合物を含む。 As an example of the above conductive particles, Patent Document 1 below discloses conductive particles having a core particle, a Ni plating layer, a precious metal plating layer, and a rust preventive film. The Ni plating layer covers the core particles and contains Ni. The noble metal plating layer covers at least a part of the Ni plating layer and contains at least one of Au and Pd. The rust preventive film covers at least one of the plating layer and the noble metal plating layer and contains an organic compound.
特開２０１３－２０７２１号公報Japanese Unexamined Patent Publication No. 2013-20721
　近年、異方性導電材料を用いて接続構造体を得る際に、電極の接続工程において、従来よりも低圧力での接続、いわゆる低圧実装が行われている。例えば、柔軟なフレキシブルプリント基板上に、半導体チップを直接実装する場合には、フレキシブルプリント基板の変形を抑えるために、低圧での実装を行う必要がある。 In recent years, when obtaining a connection structure using an anisotropic conductive material, connection at a lower pressure than before, so-called low-pressure mounting, has been performed in the electrode connection process. For example, when a semiconductor chip is directly mounted on a flexible printed circuit board, it is necessary to mount the semiconductor chip at a low pressure in order to suppress deformation of the flexible printed circuit board.
　しかしながら、低圧での実装では、異方性導電材料中の導電性粒子に付与される圧力が低く、十分な導通信頼性が得られないことがある。このため、導電部の最表面には、抵抗値の低い貴金属が用いられ、貴金属部が形成されることがある。 However, when mounted at a low pressure, the pressure applied to the conductive particles in the anisotropic conductive material is low, and sufficient conduction reliability may not be obtained. Therefore, a noble metal having a low resistance value is used on the outermost surface of the conductive portion, and the noble metal portion may be formed.
　また、導電部と電極との間に電位差が存在したり、電極の表面を保護するために保護層が存在したりする場合には、ニッケルを含む導電部が腐食され、十分な導通信頼性が得られないことがある。このため、導電部の最表面には、腐食防止のために貴金属が用いられ、貴金属部が形成されることがある。 Further, if there is a potential difference between the conductive part and the electrode, or if a protective layer is present to protect the surface of the electrode, the conductive part containing nickel is corroded and sufficient conduction reliability is obtained. It may not be obtained. Therefore, a noble metal is used on the outermost surface of the conductive portion to prevent corrosion, and the noble metal portion may be formed.
　導電部の最表面に貴金属部が形成されると、貴金属部と下地金属部（一般的にはニッケル－リン合金）との間で金属拡散が起こり、貴金属部と下地金属部との間に非晶質部（リンリッチ部）が形成される場合がある。貴金属部と下地金属部との間に非晶質部（リンリッチ層）が形成されると、実装時に導電部の割れが発生することがある。結果として、電極間の導通信頼性を十分に高めることが困難な場合がある。 When the noble metal part is formed on the outermost surface of the conductive part, metal diffusion occurs between the noble metal part and the base metal part (generally a nickel-phosphorus alloy), and the metal is not between the noble metal part and the base metal part. A crystalline part (lin-rich part) may be formed. If an amorphous part (phosphorrich layer) is formed between the noble metal part and the base metal part, the conductive part may be cracked at the time of mounting. As a result, it may be difficult to sufficiently improve the conduction reliability between the electrodes.
　また、下地金属に用いられるニッケル－リン合金は、ニッケル－ボロン合金や純ニッケル等と比較して、抵抗値が高くなることがある。結果として、電極間の接続抵抗を十分に低くすることが困難な場合がある。 In addition, the nickel-phosphorus alloy used as the base metal may have a higher resistance value than the nickel-boron alloy, pure nickel, etc. As a result, it may be difficult to sufficiently reduce the connection resistance between the electrodes.
　本発明の目的は、実装時に導電部の割れの発生を効果的に抑制することができ、電極間の接続抵抗を効果的に低くすることができる導電性粒子を提供することである。また、本発明の目的は、上記導電性粒子を用いた導電材料及び接続構造体を提供することである。 An object of the present invention is to provide conductive particles capable of effectively suppressing the occurrence of cracks in the conductive portion during mounting and effectively reducing the connection resistance between the electrodes. Another object of the present invention is to provide a conductive material and a connecting structure using the above conductive particles.
　本発明の広い局面によれば、基材粒子と、前記基材粒子の表面上に配置された第１の導電部と、前記第１の導電部の表面上に配置された第２の導電部とを備え、前記第１の導電部が、ニッケルとホウ素とを含み、かつ、リンを含まず、前記第１の導電部の内表面から外側に向かって厚み１／５の領域の１００重量％中におけるホウ素の平均含有量と、前記第１の導電部の外表面から内側に向かって厚み１／５の領域の１００重量％中におけるホウ素の平均含有量との差の絶対値が、０重量％以上１０重量％以下であり、前記第１の導電部における主金属の標準電極電位が、前記第２の導電部における主金属の標準電極電位よりも小さい、導電性粒子が提供される。 According to a broad aspect of the present invention, the substrate particles, the first conductive portion arranged on the surface of the substrate particles, and the second conductive portion arranged on the surface of the first conductive portion. The first conductive portion contains nickel and boron and does not contain phosphorus, and 100% by weight of a region having a thickness of 1/5 from the inner surface to the outside of the first conductive portion. The absolute value of the difference between the average content of boron in the inside and the average content of boron in 100% by weight of the region having a thickness of 1/5 from the outer surface to the inside of the first conductive portion is 0 weight. % Or more and 10% by weight or less, and the standard electrode potential of the main metal in the first conductive portion is smaller than the standard electrode potential of the main metal in the second conductive portion, providing conductive particles.
　本発明に係る導電性粒子のある特定の局面では、前記第１の導電部における主金属の標準電極電位と、前記第２の導電部における主金属の標準電極電位との差の絶対値が、０．０５Ｖ以上３Ｖ以下である。 In a specific aspect of the conductive particles according to the present invention, the absolute value of the difference between the standard electrode potential of the main metal in the first conductive portion and the standard electrode potential of the main metal in the second conductive portion is It is 0.05V or more and 3V or less.
　本発明に係る導電性粒子のある特定の局面では、前記第１の導電部の内表面から外側に向かって厚み１／５の領域の１００重量％中におけるホウ素の平均含有量が、０重量％以上１０重量％以下であり、前記第１の導電部の外表面から内側に向かって厚み１／５の領域の１００重量％中におけるホウ素の平均含有量が、０重量％以上１０重量％以下である。 In a specific aspect of the conductive particles according to the present invention, the average content of boron in 100% by weight of the region having a thickness of 1/5 from the inner surface to the outside of the first conductive portion is 0% by weight. The average content of boron in 100% by weight of the region having a thickness of 1/5 from the outer surface of the first conductive portion toward the inside is 0% by weight or more and 10% by weight or less. is there.
　本発明に係る導電性粒子のある特定の局面では、前記第１の導電部の全体１００重量％中におけるニッケルの平均含有量が、５０重量％以上９９．９重量％以下である。 In a specific aspect of the conductive particles according to the present invention, the average content of nickel in 100% by weight of the first conductive portion is 50% by weight or more and 99.9% by weight or less.
　本発明に係る導電性粒子のある特定の局面では、前記第１の導電部の全体１００重量％中におけるホウ素の平均含有量が、０．００１重量％以上１０重量％以下である。 In a specific aspect of the conductive particles according to the present invention, the average content of boron in 100% by weight of the first conductive portion is 0.001% by weight or more and 10% by weight or less.
　本発明に係る導電性粒子のある特定の局面では、前記第２の導電部における主金属が、錫、銅、パラジウム、ルテニウム、白金、銀、ロジウム、イリジウム又は金である。 In a specific aspect of the conductive particles according to the present invention, the main metal in the second conductive portion is tin, copper, palladium, ruthenium, platinum, silver, rhodium, iridium or gold.
　本発明に係る導電性粒子のある特定の局面では、前記第２の導電部の外表面が防錆処理されている。 In a specific aspect of the conductive particles according to the present invention, the outer surface of the second conductive portion is rust-proofed.
　本発明に係る導電性粒子のある特定の局面では、前記第２の導電部の外表面が、炭素数６～２２のアルキル基を有する化合物により防錆処理されている。 In a specific aspect of the conductive particles according to the present invention, the outer surface of the second conductive portion is rust-proofed with a compound having an alkyl group having 6 to 22 carbon atoms.
　本発明に係る導電性粒子のある特定の局面では、前記基材粒子の粒子径が、０．１μｍ以上１００μｍ以下である。 In a specific aspect of the conductive particles according to the present invention, the particle size of the base particles is 0.1 μm or more and 100 μm or less.
　本発明に係る導電性粒子のある特定の局面では、前記第１の導電部又は前記第２の導電部の外表面に複数の突起を有する。 In a specific aspect of the conductive particles according to the present invention, there are a plurality of protrusions on the outer surface of the first conductive portion or the second conductive portion.
　本発明に係る導電性粒子のある特定の局面では、前記第１の導電部又は前記第２の導電部の内部又は内側において、複数の前記突起を形成するように、前記第１の導電部又は前記第２の導電部の表面を隆起させている複数の芯物質を備える。 In a specific aspect of the conductive particles according to the present invention, the first conductive portion or the first conductive portion or the like so as to form a plurality of the protrusions inside or inside the first conductive portion or the second conductive portion. A plurality of core materials that raise the surface of the second conductive portion are provided.
　本発明に係る導電性粒子のある特定の局面では、前記第１の導電部又は前記第２の導電部の内部又は内側において、複数の前記突起を形成するように、前記第１の導電部又は前記第２の導電部の表面を隆起させている複数の芯物質を備えていない。 In a specific aspect of the conductive particles according to the present invention, the first conductive portion or the first conductive portion or the like so as to form a plurality of the protrusions inside or inside the first conductive portion or the second conductive portion. It does not include a plurality of core materials that raise the surface of the second conductive portion.
　本発明に係る導電性粒子のある特定の局面では、前記第２の導電部の外表面上に配置された絶縁性物質を備える。 In a specific aspect of the conductive particles according to the present invention, an insulating substance arranged on the outer surface of the second conductive portion is provided.
　本発明に係る導電性粒子のある特定の局面では、前記導電性粒子が、電極と、上記電極の表面上に配置された保護層とを備える保護層付き電極の導電接続用途に用いられる。 In a specific aspect of the conductive particles according to the present invention, the conductive particles are used for conductive connection of an electrode with a protective layer including an electrode and a protective layer arranged on the surface of the electrode.
　本発明に係る導電性粒子のある特定の局面では、前記導電性粒子が、フレキシブル部材の電極の導電接続用途に用いられる。 In a specific aspect of the conductive particles according to the present invention, the conductive particles are used for conductive connection of electrodes of flexible members.
　本発明の広い局面によれば、上述した導電性粒子と、バインダー樹脂とを含む、導電材料が提供される。 According to a broad aspect of the present invention, a conductive material containing the above-mentioned conductive particles and a binder resin is provided.
　本発明の広い局面によれば、第１の電極を表面に有する第１の接続対象部材と、第２の電極を表面に有する第２の接続対象部材と、前記第１の接続対象部材と、前記第２の接続対象部材とを接続している接続部とを備え、前記接続部が、上述した導電性粒子により形成されているか、又は前記導電性粒子とバインダー樹脂とを含む導電材料により形成されており、前記第１の電極と前記第２の電極とが、前記導電性粒子により電気的に接続されている、接続構造体が提供される。 According to a broad aspect of the present invention, a first connection target member having a first electrode on the surface, a second connection target member having a second electrode on the surface, and the first connection target member. It is provided with a connecting portion connecting the second connection target member, and the connecting portion is formed of the above-mentioned conductive particles or a conductive material containing the conductive particles and a binder resin. Provided is a connection structure in which the first electrode and the second electrode are electrically connected by the conductive particles.
　本発明に係る接続構造体のある特定の局面では、前記第１の導電部における主金属の標準電極電位が、前記第１の電極又は前記第２の電極の外表面の主金属の標準電極電位よりも小さい。 In a specific aspect of the connection structure according to the present invention, the standard electrode potential of the main metal in the first conductive portion is the standard electrode potential of the main metal on the outer surface of the first electrode or the second electrode. Smaller than
　本発明に係る導電性粒子は、基材粒子と、上記基材粒子の表面上に配置された第１の導電部と、上記第１の導電部の表面上に配置された第２の導電部とを備える。本発明に係る導電性粒子では、上記第１の導電部が、ニッケルとホウ素とを含み、かつ、リンを含まない。本発明に係る導電性粒子では、上記第１の導電部の内表面から外側に向かって厚み１／５の領域の１００重量％中におけるホウ素の平均含有量と、上記第１の導電部の外表面から内側に向かって厚み１／５の領域の１００重量％中におけるホウ素の平均含有量との差の絶対値が、０重量％以上１０重量％以下である。本発明に係る導電性粒子では、上記第１の導電部における主金属の標準電極電位が、上記第２の導電部における主金属の標準電極電位よりも小さい。本発明に係る導電性粒子では、上記の構成が備えられているので、実装時に導電部の割れの発生を効果的に抑制することができ、電極間の接続抵抗を効果的に低くすることができる。 The conductive particles according to the present invention include base particles, a first conductive portion arranged on the surface of the base particles, and a second conductive portion arranged on the surface of the first conductive portion. And. In the conductive particles according to the present invention, the first conductive portion contains nickel and boron and does not contain phosphorus. In the conductive particles according to the present invention, the average content of boron in 100% by weight of the region having a thickness of 1/5 from the inner surface to the outside of the first conductive portion and the outside of the first conductive portion The absolute value of the difference from the average content of boron in 100% by weight of the region having a thickness of 1/5 from the surface to the inside is 0% by weight or more and 10% by weight or less. In the conductive particles according to the present invention, the standard electrode potential of the main metal in the first conductive portion is smaller than the standard electrode potential of the main metal in the second conductive portion. Since the conductive particles according to the present invention have the above configuration, it is possible to effectively suppress the occurrence of cracks in the conductive portion at the time of mounting, and it is possible to effectively reduce the connection resistance between the electrodes. it can.
図１は、本発明の第１の実施形態に係る導電性粒子を示す断面図である。FIG. 1 is a cross-sectional view showing conductive particles according to the first embodiment of the present invention. 図２は、本発明の第２の実施形態に係る導電性粒子を示す断面図である。FIG. 2 is a cross-sectional view showing conductive particles according to a second embodiment of the present invention. 図３は、本発明の第３の実施形態に係る導電性粒子を示す断面図である。FIG. 3 is a cross-sectional view showing the conductive particles according to the third embodiment of the present invention. 図４は、本発明の第４の実施形態に係る導電性粒子を示す断面図である。FIG. 4 is a cross-sectional view showing the conductive particles according to the fourth embodiment of the present invention. 図５は、本発明の第１の実施形態に係る導電性粒子における第１の導電部において、ホウ素の平均含有量を求める各領域を説明するための模式図である。FIG. 5 is a schematic diagram for explaining each region for obtaining the average content of boron in the first conductive portion of the conductive particles according to the first embodiment of the present invention. 図６は、本発明の第２の実施形態に係る導電性粒子における第１の導電部において、ホウ素の平均含有量を求める各領域を説明するための模式図である。FIG. 6 is a schematic diagram for explaining each region for obtaining the average content of boron in the first conductive portion of the conductive particles according to the second embodiment of the present invention. 図７は、本発明の第１の実施形態に係る導電性粒子を用いた接続構造体を模式的に示す正面断面図である。FIG. 7 is a front sectional view schematically showing a connection structure using conductive particles according to the first embodiment of the present invention.
　以下、本発明の詳細を説明する。 The details of the present invention will be described below.
　（導電性粒子）
　本発明に係る導電性粒子は、基材粒子と、上記基材粒子の表面上に配置された第１の導電部と、上記第１の導電部の表面上に配置された第２の導電部とを備える。本発明に係る導電性粒子では、上記第１の導電部が、ニッケルとホウ素とを含み、かつ、リンを含まない。本発明に係る導電性粒子では、上記第１の導電部の内表面から外側に向かって厚み１／５の領域の１００重量％中におけるホウ素の平均含有量と、上記第１の導電部の外表面から内側に向かって厚み１／５の領域の１００重量％中におけるホウ素の平均含有量との差の絶対値が、０重量％以上１０重量％以下である。本発明に係る導電性粒子では、上記第１の導電部における主金属の標準電極電位が、上記第２の導電部における主金属の標準電極電位よりも小さい。 (Conductive particles)
The conductive particles according to the present invention include base particles, a first conductive portion arranged on the surface of the base particles, and a second conductive portion arranged on the surface of the first conductive portion. And. In the conductive particles according to the present invention, the first conductive portion contains nickel and boron and does not contain phosphorus. In the conductive particles according to the present invention, the average content of boron in 100% by weight of the region having a thickness of 1/5 from the inner surface to the outside of the first conductive portion and the outside of the first conductive portion The absolute value of the difference from the average content of boron in 100% by weight of the region having a thickness of 1/5 from the surface to the inside is 0% by weight or more and 10% by weight or less. In the conductive particles according to the present invention, the standard electrode potential of the main metal in the first conductive portion is smaller than the standard electrode potential of the main metal in the second conductive portion.
　本発明に係る導電性粒子では、上記の構成が備えられているので、実装時に導電部の割れの発生を効果的に抑制することができ、電極間の接続抵抗を効果的に低くすることができる。 Since the conductive particles according to the present invention have the above-mentioned configuration, it is possible to effectively suppress the occurrence of cracks in the conductive portion at the time of mounting, and it is possible to effectively reduce the connection resistance between the electrodes. it can.
　一般的に、無電解めっきによりニッケルとホウ素とを含む導電層を形成する場合に、めっきの進行とともにめっき浴中のホウ素の含有量が変わる。このため、上記第１の導電部の内表面から外側に向かって厚み１／５の領域の１００重量％中におけるホウ素の平均含有量と、上記第１の導電部の外表面から内側に向かって厚み１／５の領域の１００重量％中におけるホウ素の平均含有量との差の絶対値とに差異が生じる。本発明では、反応中の温度、ニッケルイオン濃度、還元剤滴下速度、及び撹拌条件等を適切に管理することで、ニッケルめっき膜形成時にニッケルめっき膜中のホウ素の含有量を高精度に均一に保つ方法等を採用することで、上記の絶対値を小さくすることを実現している。 Generally, when a conductive layer containing nickel and boron is formed by electroless plating, the content of boron in the plating bath changes as the plating progresses. Therefore, the average content of boron in 100% by weight of the region having a thickness of 1/5 from the inner surface of the first conductive portion to the outside and the outer surface of the first conductive portion toward the inside. There is a difference from the absolute value of the difference from the average content of boron in 100% by weight of the 1/5 thickness region. In the present invention, the content of boron in the nickel plating film is made uniform with high accuracy when the nickel plating film is formed by appropriately controlling the temperature during the reaction, the nickel ion concentration, the dropping rate of the reducing agent, the stirring conditions, and the like. By adopting a method of keeping, etc., the above absolute value can be reduced.
　低圧実装において、十分な導通信頼性を確保するために、また、導電部の腐食を防止するために、導電部の最表面に貴金属が用いられ、貴金属部が形成されることがある。 In low-pressure mounting, a noble metal may be used on the outermost surface of the conductive part to form a noble metal part in order to ensure sufficient conduction reliability and to prevent corrosion of the conductive part.
　導電部の最表面に貴金属部が形成されると、貴金属部と下地金属部（一般的にはニッケル－リン合金）との間で金属拡散が起こり、貴金属部と下地金属部との間に非晶質部（リンリッチ部）が形成される場合がある。貴金属部と下地金属部との間に非晶質部（リンリッチ部）が形成されると、実装時に導電部の割れが発生することがある。結果として、従来の導電性粒子では、電極間の導通信頼性を十分に高めることが困難な場合がある。 When the noble metal part is formed on the outermost surface of the conductive part, metal diffusion occurs between the noble metal part and the base metal part (generally a nickel-phosphorus alloy), and the metal is not between the noble metal part and the base metal part. A crystalline part (lin-rich part) may be formed. If an amorphous part (lin-rich part) is formed between the noble metal part and the base metal part, the conductive part may be cracked at the time of mounting. As a result, it may be difficult to sufficiently increase the conduction reliability between the electrodes with the conventional conductive particles.
　また、下地金属に用いられるニッケル－リン合金は、ニッケル－ボロン合金や純ニッケル等と比較して、抵抗値が高くなることがある。結果として、電極間の接続抵抗を十分に低くすることが困難な場合がある。 In addition, the nickel-phosphorus alloy used as the base metal may have a higher resistance value than the nickel-boron alloy, pure nickel, etc. As a result, it may be difficult to sufficiently reduce the connection resistance between the electrodes.
　本発明に係る導電性粒子では、上記の構成が採用されているので、導電部に貴金属が用いられても、貴金属部と下地金属部との間で金属拡散が起こることがなく、貴金属部と下地金属部との間に非晶質部（リンリッチ部）が形成されることもない。従って、実装時に導電部の割れの発生を効果的に抑制することができ、電極間の接続抵抗を効果的に低くすることができる。 Since the conductive particles according to the present invention adopt the above configuration, even if a noble metal is used for the conductive portion, metal diffusion does not occur between the noble metal portion and the base metal portion, and the noble metal portion and the noble metal portion An amorphous part (lin-rich part) is not formed between the metal part and the base metal part. Therefore, it is possible to effectively suppress the occurrence of cracks in the conductive portion during mounting, and it is possible to effectively reduce the connection resistance between the electrodes.
　本発明に係る導電性粒子では、上記第１の導電部における主金属の標準電極電位が、上記第２の導電部における主金属の標準電極電位よりも小さい。実装時に導電部の割れの発生をより一層効果的に抑制する観点、電極間の接続抵抗をより一層効果的に低くする観点からは、上記第１の導電部における主金属の標準電極電位と、上記第２の導電部における主金属の標準電極電位との差の絶対値は、好ましくは０．０５Ｖ以上、より好ましくは０．１Ｖ以上、さらに好ましくは０．５Ｖ以上である。実装時に導電部の割れの発生をより一層効果的に抑制する観点、電極間の接続抵抗をより一層効果的に低くする観点からは、上記第１の導電部における主金属の標準電極電位と、上記第２の導電部における主金属の標準電極電位との差の絶対値は、好ましくは３Ｖ以下、より好ましくは２．１Ｖ以下、さらに好ましくは１．３Ｖ以下である。導電部における主金属とは、導電部に含まれる金属種のうち、最も含有量の多い金属種を意味する。 In the conductive particles according to the present invention, the standard electrode potential of the main metal in the first conductive portion is smaller than the standard electrode potential of the main metal in the second conductive portion. From the viewpoint of more effectively suppressing the occurrence of cracks in the conductive portion at the time of mounting and from the viewpoint of further effectively lowering the connection resistance between the electrodes, the standard electrode potential of the main metal in the first conductive portion and the standard electrode potential of the main metal The absolute value of the difference between the main metal and the standard electrode potential in the second conductive portion is preferably 0.05 V or more, more preferably 0.1 V or more, still more preferably 0.5 V or more. From the viewpoint of more effectively suppressing the occurrence of cracks in the conductive portion during mounting and further effectively reducing the connection resistance between the electrodes, the standard electrode potential of the main metal in the first conductive portion and the standard electrode potential of the main metal The absolute value of the difference between the main metal and the standard electrode potential in the second conductive portion is preferably 3 V or less, more preferably 2.1 V or less, and further preferably 1.3 V or less. The main metal in the conductive portion means the metal species having the highest content among the metal species contained in the conductive portion.
　以下、図面を参照しつつ、本発明を具体的に説明する。 Hereinafter, the present invention will be specifically described with reference to the drawings.
　図１は、本発明の第１の実施形態に係る導電性粒子を示す断面図である。 FIG. 1 is a cross-sectional view showing conductive particles according to the first embodiment of the present invention.
　図１に示す導電性粒子１は、基材粒子２と、第１の導電部３と、第２の導電部４とを備える。第１の導電部３は、基材粒子２の表面上に配置されている。第２の導電部４は、第１の導電部３の表面上に配置されている。導電性粒子１は、基材粒子２の表面上に第１の導電部３が配置されており、第１の導電部３の表面上に第２の導電部４が配置されている。本実施形態では、導電性粒子１は、基材粒子２の表面が第１の導電部３により被覆された被覆粒子であり、第１の導電部３の表面が第２の導電部４により被覆された被覆粒子である。上記導電性粒子は、上記基材粒子の表面の全てが上記第１の導電部により覆われていてもよく、上記基材粒子の表面の一部が上記第１の導電部により覆われていてもよい。上記導電性粒子は、上記第１の導電部の表面の全てが上記第２の導電部により覆われていてもよく、上記第１の導電部の表面の一部が上記第２の導電部により覆われていてもよい。 The conductive particle 1 shown in FIG. 1 includes a base particle 2, a first conductive portion 3, and a second conductive portion 4. The first conductive portion 3 is arranged on the surface of the base particle 2. The second conductive portion 4 is arranged on the surface of the first conductive portion 3. In the conductive particles 1, the first conductive portion 3 is arranged on the surface of the base particle 2, and the second conductive portion 4 is arranged on the surface of the first conductive portion 3. In the present embodiment, the conductive particles 1 are coated particles in which the surface of the base particle 2 is coated with the first conductive portion 3, and the surface of the first conductive portion 3 is coated with the second conductive portion 4. It is a coated particle. In the conductive particles, the entire surface of the base material particles may be entirely covered with the first conductive portion, and a part of the surface of the base material particles is covered with the first conductive portion. May be good. In the conductive particles, the entire surface of the first conductive portion may be covered with the second conductive portion, and a part of the surface of the first conductive portion may be covered with the second conductive portion. It may be covered.
　導電性粒子１では、第１の導電部３が、ニッケルとホウ素とを含み、かつ、リンを含まない。第１の導電部３の内表面から外側に向かって厚み１／５の領域（Ｒ１）の１００重量％中におけるホウ素の平均含有量と、第１の導電部３の外表面から内側に向かって厚み１／５の領域（Ｒ２）の１００重量％中におけるホウ素の平均含有量との差の絶対値は、０重量％以上１０重量％以下である。該絶対値が０重量％であるときに、２つの領域（Ｒ１），（Ｒ２）におけるホウ素の平均含有量は同じである。上記領域（Ｒ１）は、図５において、第１の導電部３の内表面（基材粒子２の外表面）と、破線Ｌ１との間の領域である。上記領域（Ｒ２）は、図５において、第１の導電部３の外表面（第２の導電部４の内表面）と、破線Ｌ２との間の領域である。 In the conductive particles 1, the first conductive portion 3 contains nickel and boron and does not contain phosphorus. The average content of boron in 100% by weight of the region (R1) having a thickness of 1/5 from the inner surface of the first conductive portion 3 to the outside, and from the outer surface of the first conductive portion 3 toward the inside. The absolute value of the difference from the average content of boron in 100% by weight of the region (R2) having a thickness of 1/5 is 0% by weight or more and 10% by weight or less. When the absolute value is 0% by weight, the average content of boron in the two regions (R1) and (R2) is the same. The region (R1) is a region between the inner surface of the first conductive portion 3 (the outer surface of the base particle 2) and the broken line L1 in FIG. The region (R2) is a region between the outer surface of the first conductive portion 3 (the inner surface of the second conductive portion 4) and the broken line L2 in FIG.
　導電性粒子１は、後述する導電性粒子２１とは異なり、芯物質を有しない。導電性粒子１は後述する導電性粒子２１，３１とは異なり、突起を有しない。導電性粒子１は球状である。第１の導電部３及び第２の導電部４は外表面に突起を有しない。このように、本発明に係る導電性粒子は導電性の表面に突起を有していなくてもよく、球状であってもよい。また、導電性粒子１は、後述する導電性粒子２１，３１とは異なり、絶縁性物質を有しない。但し、導電性粒子１は、第２の導電部４の外表面上に配置された絶縁性物質を有していてもよい。 Unlike the conductive particles 21 described later, the conductive particles 1 do not have a core substance. The conductive particles 1 do not have protrusions, unlike the conductive particles 21 and 31 described later. The conductive particles 1 are spherical. The first conductive portion 3 and the second conductive portion 4 do not have protrusions on the outer surface. As described above, the conductive particles according to the present invention may not have protrusions on the conductive surface and may be spherical. Further, the conductive particles 1 do not have an insulating substance, unlike the conductive particles 21 and 31 described later. However, the conductive particles 1 may have an insulating substance arranged on the outer surface of the second conductive portion 4.
　導電性粒子１では、基材粒子２と第１の導電部３とが接している。導電性粒子１では、第１の導電部３と第２の導電部４とが接している。 In the conductive particles 1, the base particles 2 and the first conductive portion 3 are in contact with each other. In the conductive particles 1, the first conductive portion 3 and the second conductive portion 4 are in contact with each other.
　図２は、本発明の第２の実施形態に係る導電性粒子を示す断面図である。 FIG. 2 is a cross-sectional view showing the conductive particles according to the second embodiment of the present invention.
　図２に示す導電性粒子１１は、基材粒子２と、第１の導電部１３と、第２の導電部４とを備える。 The conductive particle 11 shown in FIG. 2 includes a base particle 2, a first conductive portion 13, and a second conductive portion 4.
　導電性粒子１と導電性粒子１１とでは、第１の導電部３と第１の導電部１３とが異なる。第１の導電部１３は全体で、基材粒子２側に配置された導電部１３Ａと、基材粒子２側とは反対側に配置された導電部１３Ｂとを有する。導電性粒子１では、１層構造の第１の導電部３が形成されているのに対して、導電性粒子１１では、導電部１３Ａと導電部１３Ｂとを有する２層構造の第１の導電部１３が形成されている。導電部１３Ａと導電部１３Ｂとは、異なる導電部として形成されていてもよく、同一の導電層として形成されていてもよい。上記第１の導電部は、１層構造であってもよく、２層以上の複層構造であってもよい。 In the conductive particles 1 and the conductive particles 11, the first conductive portion 3 and the first conductive portion 13 are different. The first conductive portion 13 as a whole has a conductive portion 13A arranged on the base particle 2 side and a conductive portion 13B arranged on the side opposite to the base particle 2 side. In the conductive particle 1, the first conductive portion 3 having a one-layer structure is formed, whereas in the conductive particle 11, the first conductive portion having a two-layer structure having the conductive portion 13A and the conductive portion 13B is formed. The portion 13 is formed. The conductive portion 13A and the conductive portion 13B may be formed as different conductive portions, or may be formed as the same conductive layer. The first conductive portion may have a one-layer structure or a multi-layer structure having two or more layers.
　導電部１３Ａは、基材粒子２の表面上に配置されている。基材粒子２と導電部１３Ｂとの間に、導電部１３Ａが配置されている。導電部１３Ａは、基材粒子２に接している。導電部１３Ｂは、導電部１３Ａに接している。基材粒子２の表面上に導電部１３Ａが配置されており、導電部１３Ａの外表面上に導電部１３Ｂが配置されている。 The conductive portion 13A is arranged on the surface of the base particle 2. The conductive portion 13A is arranged between the base particle 2 and the conductive portion 13B. The conductive portion 13A is in contact with the base particle 2. The conductive portion 13B is in contact with the conductive portion 13A. The conductive portion 13A is arranged on the surface of the base particle 2, and the conductive portion 13B is arranged on the outer surface of the conductive portion 13A.
　導電性粒子１１では、第１の導電部１３が、ニッケルとホウ素とを含み、かつ、リンを含まない。例えば、導電部１３Ａがニッケル－ボロンめっき層であり、導電部１３Ｂが純ニッケル層又はニッケル－錫合金層であってもよい。第１の導電部１３の内表面から外側に向かって厚み１／５の領域（Ｒ１）の１００重量％中におけるホウ素の平均含有量と、第１の導電部１３の外表面から内側に向かって厚み１／５の領域（Ｒ２）の１００重量％中におけるホウ素の平均含有量との差の絶対値は、０重量％以上１０重量％以下である。上記領域（Ｒ１）は、図６において、第１の導電部１３の内表面（導電部１３Ａの内表面、基材粒子２の外表面）と、破線Ｌ１との間の領域である。上記領域（Ｒ２）は、図６において、第１の導電部１３の外表面（導電部１３Ｂの外表面、第２の導電部４の内表面）と、破線Ｌ２との間の領域である。上記第１の導電部が２層以上の複層構造である場合には、上記領域（Ｒ１）及び上記領域（Ｒ２）は、上記第１の導電部全体の厚みから算出されることが好ましい。 In the conductive particles 11, the first conductive portion 13 contains nickel and boron and does not contain phosphorus. For example, the conductive portion 13A may be a nickel-boron plating layer, and the conductive portion 13B may be a pure nickel layer or a nickel-tin alloy layer. The average content of boron in 100% by weight of the region (R1) having a thickness of 1/5 from the inner surface of the first conductive portion 13 toward the outside and the outer surface of the first conductive portion 13 toward the inside. The absolute value of the difference from the average content of boron in 100% by weight of the region (R2) having a thickness of 1/5 is 0% by weight or more and 10% by weight or less. The region (R1) is a region between the inner surface of the first conductive portion 13 (the inner surface of the conductive portion 13A and the outer surface of the base particle 2) and the broken line L1 in FIG. The region (R2) is a region between the outer surface of the first conductive portion 13 (the outer surface of the conductive portion 13B and the inner surface of the second conductive portion 4) and the broken line L2 in FIG. When the first conductive portion has a multi-layer structure of two or more layers, the region (R1) and the region (R2) are preferably calculated from the thickness of the entire first conductive portion.
　図３は、本発明の第３の実施形態に係る導電性粒子を示す断面図である。 FIG. 3 is a cross-sectional view showing the conductive particles according to the third embodiment of the present invention.
　図３に示す導電性粒子２１は、基材粒子２と、第１の導電部２３と、第２の導電部２４と、複数の芯物質２５と、複数の絶縁性物質２６とを備える。第１の導電部２３は、基材粒子２の表面上に配置されている。第２の導電部２４は、第１の導電部２３の表面上に配置されている。導電性粒子２１は、基材粒子２の表面上に第１の導電部２３が配置されており、第１の導電部２３の表面上に第２の導電部２４が配置されている。 The conductive particle 21 shown in FIG. 3 includes a base particle 2, a first conductive portion 23, a second conductive portion 24, a plurality of core substances 25, and a plurality of insulating substances 26. The first conductive portion 23 is arranged on the surface of the base particle 2. The second conductive portion 24 is arranged on the surface of the first conductive portion 23. In the conductive particles 21, the first conductive portion 23 is arranged on the surface of the base particle 2, and the second conductive portion 24 is arranged on the surface of the first conductive portion 23.
　導電性粒子２１では、第１の導電部２３が、ニッケルとホウ素とを含み、かつ、リンを含まない。第１の導電部２３の内表面から外側に向かって厚み１／５の領域（Ｒ１）の１００重量％中におけるホウ素の平均含有量と、第１の導電部３Ａの外表面から内側に向かって厚み１／５の領域（Ｒ２）の１００重量％中におけるホウ素の平均含有量との差の絶対値は、０重量％以上１０重量％以下である。 In the conductive particles 21, the first conductive portion 23 contains nickel and boron and does not contain phosphorus. The average content of boron in 100% by weight of the region (R1) having a thickness of 1/5 from the inner surface of the first conductive portion 23 toward the outside and the outer surface of the first conductive portion 3A toward the inside. The absolute value of the difference from the average content of boron in 100% by weight of the region (R2) having a thickness of 1/5 is 0% by weight or more and 10% by weight or less.
　導電性粒子２１は、導電性の表面に複数の突起２１Ａを有する。第１の導電部２３は、外表面に複数の突起２３Ａを有する。第２の導電部２４は、外表面に複数の突起２４Ａを有する。複数の芯物質２５が、基材粒子２の表面上に配置されている。複数の芯物質２５は第１の導電部２３内に埋め込まれている。複数の芯物質２５は第２の導電部２４の内側に埋め込まれている。芯物質２５は、突起２１Ａ，２３Ａ，２４Ａの内側に配置されている。第１の導電部２３は、複数の芯物質２５を被覆している。複数の芯物質２５により第１の導電部２３及び第２の導電部２４の外表面が隆起されており、突起２１Ａ，２３Ａ，２４Ａが形成されている。 The conductive particles 21 have a plurality of protrusions 21A on the conductive surface. The first conductive portion 23 has a plurality of protrusions 23A on the outer surface. The second conductive portion 24 has a plurality of protrusions 24A on the outer surface. A plurality of core substances 25 are arranged on the surface of the base particle 2. The plurality of core substances 25 are embedded in the first conductive portion 23. The plurality of core substances 25 are embedded inside the second conductive portion 24. The core material 25 is arranged inside the protrusions 21A, 23A, and 24A. The first conductive portion 23 covers a plurality of core substances 25. The outer surfaces of the first conductive portion 23 and the second conductive portion 24 are raised by the plurality of core materials 25, and protrusions 21A, 23A, and 24A are formed.
　導電性粒子２１は、第２の導電部２４の外表面上に配置された絶縁性物質２６を有する。第２の導電部２４の外表面の少なくとも一部の領域が、絶縁性物質２６により被覆されている。絶縁性物質２６は絶縁性を有する材料により形成されている。本実施形態では、絶縁性物質２６は、絶縁性粒子である。このように、本発明に係る導電性粒子は、上記第２の導電部の外表面上に配置された上記絶縁性物質を有していてもよい。但し、本発明に係る導電性粒子は、上記絶縁性物質を必ずしも有していなくてもよい。 The conductive particles 21 have an insulating substance 26 arranged on the outer surface of the second conductive portion 24. At least a part of the outer surface of the second conductive portion 24 is covered with the insulating substance 26. The insulating substance 26 is formed of a material having an insulating property. In this embodiment, the insulating substance 26 is an insulating particle. As described above, the conductive particles according to the present invention may have the insulating substance arranged on the outer surface of the second conductive portion. However, the conductive particles according to the present invention do not necessarily have the above-mentioned insulating substance.
　図４は、本発明の第４の実施形態に係る導電性粒子を示す断面図である。 FIG. 4 is a cross-sectional view showing the conductive particles according to the fourth embodiment of the present invention.
　図４に示す導電性粒子３１は、基材粒子２と、第１の導電部３３と、第２の導電部３４と、複数の絶縁性物質２６とを備える。第１の導電部３３は、基材粒子２の表面上に配置されている。第２の導電部３４は、第１の導電部３３の表面上に配置されている。導電性粒子３１は、基材粒子２の表面上に第１の導電部３３が配置されており、第１の導電部３３の表面上に第２の導電部３４が配置されている。 The conductive particle 31 shown in FIG. 4 includes a base particle 2, a first conductive portion 33, a second conductive portion 34, and a plurality of insulating substances 26. The first conductive portion 33 is arranged on the surface of the base particle 2. The second conductive portion 34 is arranged on the surface of the first conductive portion 33. In the conductive particles 31, the first conductive portion 33 is arranged on the surface of the base particle 2, and the second conductive portion 34 is arranged on the surface of the first conductive portion 33.
　導電性粒子３１では、第１の導電部３３が、ニッケルとホウ素とを含み、かつ、リンを含まない。第１の導電部３３の内表面から外側に向かって厚み１／５の領域（Ｒ１）の１００重量％中におけるホウ素の平均含有量と、第１の導電部３Ｂの外表面から内側に向かって厚み１／５の領域（Ｒ２）の１００重量％中におけるホウ素の平均含有量との差の絶対値は、０重量％以上１０重量％以下である。 In the conductive particles 31, the first conductive portion 33 contains nickel and boron and does not contain phosphorus. The average content of boron in 100% by weight of the region (R1) having a thickness of 1/5 from the inner surface of the first conductive portion 33 to the outside and the outer surface of the first conductive portion 3B toward the inside. The absolute value of the difference from the average content of boron in 100% by weight of the region (R2) having a thickness of 1/5 is 0% by weight or more and 10% by weight or less.
　導電性粒子３１は、導電性粒子２１とは異なり、芯物質を備えていない。導電性粒子３１は芯物質を備えていないが、導電性の表面に複数の突起３１Ａを有する。第１の導電部３３は、外表面に複数の突起３３Ａを有する。第２の導電部３４は、外表面に複数の突起３４Ａを有する。 Unlike the conductive particles 21, the conductive particles 31 do not have a core substance. The conductive particles 31 do not have a core material, but have a plurality of protrusions 31A on the conductive surface. The first conductive portion 33 has a plurality of protrusions 33A on the outer surface. The second conductive portion 34 has a plurality of protrusions 34A on the outer surface.
　第１の導電部３３は、第１の部分と、該第１の部分よりも厚みが厚い第２の部分とを有する。複数の突起を除く部分が、第１の導電部３３の上記第１の部分である。複数の突起は、第１の導電部３３の厚みが厚い上記第２の部分である。 The first conductive portion 33 has a first portion and a second portion that is thicker than the first portion. The portion excluding the plurality of protrusions is the first portion of the first conductive portion 33. The plurality of protrusions are the second portion in which the thickness of the first conductive portion 33 is thick.
　導電性粒子３１は、第２の導電部３４の外表面上に配置された絶縁性物質２６を有する。第２の導電部３４の外表面の少なくとも一部の領域が、絶縁性物質２６により被覆されている。絶縁性物質２６は絶縁性を有する材料により形成されている。本実施形態では、絶縁性物質２６は、絶縁性粒子である。このように、本発明に係る導電性粒子は、上記第２の導電部の外表面上に配置された上記絶縁性物質を有していてもよい。但し、本発明に係る導電性粒子は、上記絶縁性物質を必ずしも有していなくてもよい。 The conductive particles 31 have an insulating substance 26 arranged on the outer surface of the second conductive portion 34. At least a part of the outer surface of the second conductive portion 34 is covered with the insulating substance 26. The insulating substance 26 is formed of a material having an insulating property. In this embodiment, the insulating substance 26 is an insulating particle. As described above, the conductive particles according to the present invention may have the insulating substance arranged on the outer surface of the second conductive portion. However, the conductive particles according to the present invention do not necessarily have the above-mentioned insulating substance.
　以下、導電性粒子の他の詳細について説明する。 The other details of the conductive particles will be described below.
　（基材粒子）
　上記基材粒子としては、樹脂粒子、金属粒子を除く無機粒子、有機無機ハイブリッド粒子及び金属粒子等が挙げられる。上記基材粒子は、金属粒子を除く基材粒子であることが好ましく、樹脂粒子、金属粒子を除く無機粒子又は有機無機ハイブリッド粒子であることがより好ましい。上記基材粒子は、コアと、該コアの表面上に配置されたシェルとを有していてもよく、コアシェル粒子であってもよい。上記コアが有機コアであってもよく、上記シェルが無機シェルであってもよい。 (Base particles)
Examples of the base material particles include resin particles, inorganic particles other than metal particles, organic-inorganic hybrid particles, and metal particles. The base material particles are preferably base particles excluding metal particles, and more preferably resin particles, inorganic particles excluding metal particles, or organic-inorganic hybrid particles. The base material particles may have a core and a shell arranged on the surface of the core, or may be core-shell particles. The core may be an organic core, and the shell may be an inorganic shell.
　上記基材粒子は、樹脂粒子又は有機無機ハイブリッド粒子であることがさらに好ましく、樹脂粒子であってもよく、有機無機ハイブリッド粒子であってもよい。上記導電性粒子を用いて電極間を接続する際には、上記導電性粒子を電極間に配置した後、圧着することにより上記導電性粒子を圧縮させる。上記基材粒子が樹脂粒子又は有機無機ハイブリッド粒子であると、上記圧着の際に上記導電性粒子が変形しやすく、導電性粒子と電極との接触面積が大きくなる。このため、電極間の導通信頼性をより一層高めることができる。 The base material particles are more preferably resin particles or organic-inorganic hybrid particles, and may be resin particles or organic-inorganic hybrid particles. When connecting the electrodes using the conductive particles, the conductive particles are placed between the electrodes and then crimped to compress the conductive particles. When the base material particles are resin particles or organic-inorganic hybrid particles, the conductive particles are easily deformed during the pressure bonding, and the contact area between the conductive particles and the electrode becomes large. Therefore, the conduction reliability between the electrodes can be further improved.
　上記樹脂粒子を形成するための樹脂として、種々の有機物が好適に用いられる。上記樹脂粒子を形成するための樹脂としては、例えば、ポリエチレン、ポリプロピレン、ポリスチレン、ポリ塩化ビニル、ポリ塩化ビニリデン、ポリイソブチレン、ポリブタジエン等のポリオレフィン樹脂；ポリメチルメタクリレート及びポリメチルアクリレート等のアクリル樹脂；ポリカーボネート、ポリアミド、フェノールホルムアルデヒド樹脂、メラミンホルムアルデヒド樹脂、ベンゾグアナミンホルムアルデヒド樹脂、尿素ホルムアルデヒド樹脂、フェノール樹脂、メラミン樹脂、ベンゾグアナミン樹脂、尿素樹脂、エポキシ樹脂、不飽和ポリエステル樹脂、飽和ポリエステル樹脂、ポリエチレンテレフタレート、ポリスルホン、ポリフェニレンオキサイド、ポリアセタール、ポリイミド、ポリアミドイミド、ポリエーテルエーテルケトン、ポリエーテルスルホン、ジビニルベンゼン重合体、並びにジビニルベンゼン系共重合体等が挙げられる。上記ジビニルベンゼン系共重合体等としては、ジビニルベンゼン－スチレン共重合体及びジビニルベンゼン－（メタ）アクリル酸エステル共重合体等が挙げられる。上記樹脂粒子の硬度を好適な範囲に容易に制御できるので、上記樹脂粒子を形成するための樹脂は、エチレン性不飽和基を有する重合性単量体を１種又は２種以上重合させた重合体であることが好ましい。 Various organic substances are preferably used as the resin for forming the resin particles. Examples of the resin for forming the resin particles include polyolefin resins such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyisobutylene, and polybutadiene; acrylic resins such as polymethylmethacrylate and polymethylacrylate; polycarbonate. , Polyamide, phenol formaldehyde resin, melamine formaldehyde resin, benzoguanamine formaldehyde resin, urea formaldehyde resin, phenol resin, melamine resin, benzoguanamine resin, urea resin, epoxy resin, unsaturated polyester resin, saturated polyester resin, polyethylene terephthalate, polysulfone, polyphenylene oxide , Polyacetal, polyimide, polyamideimide, polyether ether ketone, polyether sulfone, divinylbenzene polymer, divinylbenzene-based copolymer and the like. Examples of the divinylbenzene-based copolymer and the like include a divinylbenzene-styrene copolymer and a divinylbenzene- (meth) acrylic acid ester copolymer. Since the hardness of the resin particles can be easily controlled within a suitable range, the resin for forming the resin particles is a weight obtained by polymerizing one or more polymerizable monomers having an ethylenically unsaturated group. It is preferably coalesced.
　上記樹脂粒子を、エチレン性不飽和基を有する重合性単量体を重合させて得る場合、上記エチレン性不飽和基を有する重合性単量体としては、非架橋性の単量体と架橋性の単量体とが挙げられる。 When the resin particles are obtained by polymerizing a polymerizable monomer having an ethylenically unsaturated group, the polymerizable monomer having an ethylenically unsaturated group is crosslinkable with a non-crosslinkable monomer. The monomer of.
　上記非架橋性の単量体としては、例えば、スチレン、α－メチルスチレン等のスチレン系単量体；（メタ）アクリル酸、マレイン酸、無水マレイン酸等のカルボキシル基含有単量体；メチル（メタ）アクリレート、エチル（メタ）アクリレート、プロピル（メタ）アクリレート、ブチル（メタ）アクリレート、２－エチルヘキシル（メタ）アクリレート、ラウリル（メタ）アクリレート、セチル（メタ）アクリレート、ステアリル（メタ）アクリレート、シクロヘキシル（メタ）アクリレート、イソボルニル（メタ）アクリレート等のアルキル（メタ）アクリレート化合物；２－ヒドロキシエチル（メタ）アクリレート、グリセロール（メタ）アクリレート、ポリオキシエチレン（メタ）アクリレート、グリシジル（メタ）アクリレート等の酸素原子含有（メタ）アクリレート化合物；（メタ）アクリロニトリル等のニトリル含有単量体；メチルビニルエーテル、エチルビニルエーテル、プロピルビニルエーテル等のビニルエーテル化合物；酢酸ビニル、酪酸ビニル、ラウリン酸ビニル、ステアリン酸ビニル等の酸ビニルエステル化合物；エチレン、プロピレン、イソプレン、ブタジエン等の不飽和炭化水素；トリフルオロメチル（メタ）アクリレート、ペンタフルオロエチル（メタ）アクリレート、塩化ビニル、フッ化ビニル、クロルスチレン等のハロゲン含有単量体等が挙げられる。 Examples of the non-crosslinkable monomer include styrene-based monomers such as styrene and α-methylstyrene; carboxyl group-containing monomers such as (meth) acrylic acid, maleic acid, and maleic anhydride; and methyl ( Meta) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) Alkyl (meth) acrylate compounds such as meta) acrylate and isobornyl (meth) acrylate; oxygen atoms such as 2-hydroxyethyl (meth) acrylate, glycerol (meth) acrylate, polyoxyethylene (meth) acrylate and glycidyl (meth) acrylate. Contains (meth) acrylate compound; nitrile-containing monomer such as (meth) acrylonitrile; vinyl ether compound such as methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether; acid vinyl ester such as vinyl acetate, vinyl butyrate, vinyl laurate, vinyl stearate, etc. Compounds; unsaturated hydrocarbons such as ethylene, propylene, isoprene, and butadiene; halogen-containing monomers such as trifluoromethyl (meth) acrylate, pentafluoroethyl (meth) acrylate, vinyl chloride, vinyl fluoride, and chlorostyrene. Can be mentioned.
　上記架橋性の単量体としては、例えば、テトラメチロールメタンテトラ（メタ）アクリレート、テトラメチロールメタントリ（メタ）アクリレート、テトラメチロールメタンジ（メタ）アクリレート、トリメチロールプロパントリ（メタ）アクリレート、ジペンタエリスリトールヘキサ（メタ）アクリレート、ジペンタエリスリトールペンタ（メタ）アクリレート、グリセロールトリ（メタ）アクリレート、グリセロールジ（メタ）アクリレート、（ポリ）エチレングリコールジ（メタ）アクリレート、（ポリ）プロピレングリコールジ（メタ）アクリレート、（ポリ）テトラメチレングリコールジ（メタ）アクリレート、１，４－ブタンジオールジ（メタ）アクリレート等の多官能（メタ）アクリレート化合物；トリアリル（イソ）シアヌレート、トリアリルトリメリテート、ジビニルベンゼン、ジアリルフタレート、ジアリルアクリルアミド、ジアリルエーテル、γ－（メタ）アクリロキシプロピルトリメトキシシラン、トリメトキシシリルスチレン、ビニルトリメトキシシラン等のシラン含有単量体等が挙げられる。 Examples of the crosslinkable monomer include tetramethylol methanetetra (meth) acrylate, tetramethylol methanetri (meth) acrylate, tetramethylol methanedi (meth) acrylate, trimethyl propanetri (meth) acrylate, and dipenta. Elythritol hexa (meth) acrylate, dipenta erythritol penta (meth) acrylate, glycerol tri (meth) acrylate, glycerol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) Polyfunctional (meth) acrylate compounds such as acrylates, (poly) tetramethylene glycol di (meth) acrylates, 1,4-butanediol di (meth) acrylates; triallyl (iso) cyanurate, triallyl trimellitate, divinylbenzene, Examples thereof include silane-containing monomers such as diallyl phthalate, diallyl acrylamide, diallyl ether, γ- (meth) acryloxipropyltrimethoxysilane, trimethoxysilylstyrene, and vinyltrimethoxysilane.
　上記エチレン性不飽和基を有する重合性単量体を、公知の方法により重合させることで、上記樹脂粒子を得ることができる。この方法としては、例えば、ラジカル重合開始剤の存在下で懸濁重合する方法、並びに非架橋の種粒子を用いてラジカル重合開始剤とともに単量体を膨潤させて重合する方法等が挙げられる。 The resin particles can be obtained by polymerizing the polymerizable monomer having an ethylenically unsaturated group by a known method. Examples of this method include a method of suspension polymerization in the presence of a radical polymerization initiator, and a method of swelling and polymerizing a monomer together with a radical polymerization initiator using non-crosslinked seed particles.
　上記樹脂粒子の粒子径は、好ましくは０．１μｍ以上、より好ましくは１μｍ以上、さらに好ましくは１．５μｍ以上、特に好ましくは２μｍ以上、最も好ましくは３μｍ以上である。上記樹脂粒子の粒子径は、好ましくは５００μｍ以下、より好ましくは１００μｍ以下、さらに好ましくは５０μｍ以下、特に好ましくは２０μｍ以下、最も好ましくは１０μｍ以下である。上記樹脂粒子の粒子径が、上記下限以上であると、導電性粒子と電極との接触面積が大きくなるため、電極間の導通信頼性をより一層高めることができ、導電性粒子を介して接続された電極間の接続抵抗をより一層低くすることができる。さらに樹脂粒子の表面に導電部を無電解めっきにより形成する際に、凝集した導電性粒子を形成され難くすることができる。上記樹脂粒子の粒子径が、上記上限以下であると、導電性粒子が充分に圧縮されやすく、電極間の接続抵抗をより一層低くすることができ、さらに電極間の間隔をより小さくすることができる。 The particle size of the resin particles is preferably 0.1 μm or more, more preferably 1 μm or more, still more preferably 1.5 μm or more, particularly preferably 2 μm or more, and most preferably 3 μm or more. The particle size of the resin particles is preferably 500 μm or less, more preferably 100 μm or less, still more preferably 50 μm or less, particularly preferably 20 μm or less, and most preferably 10 μm or less. When the particle size of the resin particles is equal to or larger than the above lower limit, the contact area between the conductive particles and the electrodes becomes large, so that the conduction reliability between the electrodes can be further improved, and the resin particles are connected via the conductive particles. The connection resistance between the electrodes can be further reduced. Further, when the conductive portion is formed on the surface of the resin particles by electroless plating, it is possible to make it difficult for the aggregated conductive particles to be formed. When the particle size of the resin particles is not more than the above upper limit, the conductive particles are easily sufficiently compressed, the connection resistance between the electrodes can be further lowered, and the distance between the electrodes can be further reduced. it can.
　上記基材粒子が金属を除く無機粒子又は有機無機ハイブリッド粒子である場合には、基材粒子を形成するための無機物としては、シリカ、アルミナ、チタン酸バリウム、ジルコニア及びカーボンブラック等が挙げられる。上記無機物は金属ではないことが好ましい。上記シリカにより形成された粒子としては特に限定されないが、例えば、加水分解性のアルコキシシリル基を２つ以上有するケイ素化合物を加水分解して架橋重合体粒子を形成した後に、必要に応じて焼成を行うことにより得られる粒子が挙げられる。上記有機無機ハイブリッド粒子としては、例えば、架橋したアルコキシシリルポリマーとアクリル樹脂とにより形成された有機無機ハイブリッド粒子等が挙げられる。 When the base material particles are inorganic particles other than metal or organic-inorganic hybrid particles, examples of the inorganic material for forming the base material particles include silica, alumina, barium titanate, zirconia, and carbon black. It is preferable that the inorganic substance is not a metal. The particles formed of the silica are not particularly limited, but for example, after hydrolyzing a silicon compound having two or more hydrolyzable alkoxysilyl groups to form crosslinked polymer particles, firing is performed if necessary. Examples include particles obtained by doing so. Examples of the organic-inorganic hybrid particles include organic-inorganic hybrid particles formed of a crosslinked alkoxysilyl polymer and an acrylic resin.
　上記有機無機ハイブリッド粒子は、コアと、該コアの表面上に配置されたシェルとを有するコアシェル型の有機無機ハイブリッド粒子であることが好ましい。上記コアが有機コアであることが好ましい。上記シェルが無機シェルであることが好ましい。電極間の接続抵抗を効果的に低くする観点からは、上記基材粒子は、有機コアと上記有機コアの表面上に配置された無機シェルとを有する有機無機ハイブリッド粒子であることが好ましい。 The organic-inorganic hybrid particles are preferably core-shell type organic-inorganic hybrid particles having a core and a shell arranged on the surface of the core. It is preferable that the core is an organic core. It is preferable that the shell is an inorganic shell. From the viewpoint of effectively reducing the connection resistance between the electrodes, the base material particles are preferably organic-inorganic hybrid particles having an organic core and an inorganic shell arranged on the surface of the organic core.
　上記有機コアを形成するための材料としては、上述した樹脂粒子を形成するための樹脂等が挙げられる。 Examples of the material for forming the organic core include the resin for forming the resin particles described above.
　上記無機シェルを形成するための材料としては、上述した基材粒子を形成するための無機物が挙げられる。上記無機シェルを形成するための材料は、シリカであることが好ましい。上記無機シェルは、上記コアの表面上で、金属アルコキシドをゾルゲル法によりシェル状物とした後、該シェル状物を焼結させることにより形成されていることが好ましい。上記金属アルコキシドはシランアルコキシドであることが好ましい。上記無機シェルはシランアルコキシドにより形成されていることが好ましい。 Examples of the material for forming the above-mentioned inorganic shell include the above-mentioned inorganic substances for forming the base particle. The material for forming the inorganic shell is preferably silica. The inorganic shell is preferably formed by forming a metal alkoxide into a shell-like material by a sol-gel method on the surface of the core and then sintering the shell-like material. The metal alkoxide is preferably a silane alkoxide. The inorganic shell is preferably formed of silane alkoxide.
　上記コアの粒子径は、好ましくは０．１μｍ以上、より好ましくは１μｍ以上、さらに好ましくは１．５μｍ以上、特に好ましくは２μｍ以上、最も好ましくは３μｍ以上であり、好ましくは５００μｍ以下、より好ましくは１００μｍ以下、さらに好ましくは５０μｍ以下、特に好ましくは２０μｍ以下、最も好ましくは１０μｍ以下である。上記コアの粒子径が、上記下限以上及び上記上限以下であると、電極間の電気的な接続により一層適した導電性粒子が得られ、基材粒子を導電性粒子の用途に好適に使用可能になる。例えば、上記コアの粒子径が、上記下限以上及び上記上限以下であると、上記導電性粒子を用いて電極間を接続した場合に、導電性粒子と電極との接触面積が十分に大きくなり、かつ導電部を形成する際に凝集した導電性粒子を形成され難くすることができる。また、導電性粒子を介して接続された電極間の間隔が大きくなりすぎず、かつ導電部を基材粒子の表面から剥離し難くすることができる。 The particle size of the core is preferably 0.1 μm or more, more preferably 1 μm or more, further preferably 1.5 μm or more, particularly preferably 2 μm or more, most preferably 3 μm or more, preferably 500 μm or less, more preferably. It is 100 μm or less, more preferably 50 μm or less, particularly preferably 20 μm or less, and most preferably 10 μm or less. When the particle size of the core is not less than the above lower limit and not more than the above upper limit, more suitable conductive particles can be obtained by electrical connection between the electrodes, and the base particles can be suitably used for the use of the conductive particles. become. For example, when the particle size of the core is equal to or greater than the lower limit and equal to or lower than the upper limit, the contact area between the conductive particles and the electrodes becomes sufficiently large when the electrodes are connected using the conductive particles. Moreover, it is possible to make it difficult for the agglomerated conductive particles to be formed when the conductive portion is formed. In addition, the distance between the electrodes connected via the conductive particles does not become too large, and the conductive portion can be made difficult to peel off from the surface of the substrate particles.
　上記コアの粒子径は、上記コアが真球状である場合には直径を意味し、上記コアが真球状以外の形状である場合には、円相当径を意味する。また、コアの粒子径は、コアを任意の粒子径測定装置により測定した平均粒子径を意味する。上記平均粒子径は、数平均粒子径であることが好ましい。例えば、レーザー光散乱、電気抵抗値変化、撮像後の画像解析等の原理を用いた粒度分布測定装置が利用できる。 The particle diameter of the core means the diameter when the core is a true sphere, and means the equivalent circle diameter when the core has a shape other than the true sphere. Further, the particle size of the core means the average particle size of the core measured by an arbitrary particle size measuring device. The average particle size is preferably a number average particle size. For example, a particle size distribution measuring device using principles such as laser light scattering, change in electrical resistance value, and image analysis after imaging can be used.
　上記シェルの厚みは、好ましくは０．１μｍ以上、より好ましくは０．２μｍ以上であり、好ましくは５μｍ以下、より好ましくは３μｍ以下である。上記シェルの厚みが、上記下限以上及び上記上限以下であると、電極間の電気的な接続により一層適した導電性粒子が得られ、基材粒子を導電性粒子の用途に好適に使用可能になる。上記シェルの厚みは、基材粒子１個あたりの平均厚みである。ゾルゲル法の制御によって、上記シェルの厚みを制御可能である。 The thickness of the shell is preferably 0.1 μm or more, more preferably 0.2 μm or more, preferably 5 μm or less, and more preferably 3 μm or less. When the thickness of the shell is not less than the above lower limit and not more than the above upper limit, more suitable conductive particles can be obtained by electrical connection between the electrodes, and the base particles can be suitably used for the use of the conductive particles. Become. The thickness of the shell is the average thickness per base particle. The thickness of the shell can be controlled by controlling the sol-gel method.
　上記金属粒子を除く無機粒子及び上記有機無機ハイブリッド粒子の粒子径は、好ましくは０．１μｍ以上、より好ましくは１μｍ以上、さらに好ましくは１．５μｍ以上、特に好ましくは２μｍ以上、最も好ましくは３μｍ以上である。上記金属粒子を除く無機粒子及び上記有機無機ハイブリッド粒子の粒子径は、好ましくは５００μｍ以下、より好ましくは１００μｍ以下、さらに好ましくは５０μｍ以下、特に好ましくは２０μｍ以下、最も好ましくは１０μｍ以下である。上記金属粒子を除く無機粒子及び上記有機無機ハイブリッド粒子の粒子径が、上記下限以上及び上記上限以下であると、導電性粒子と電極との接触面積が大きくなるため、電極間の導通信頼性をより一層高めることができ、導電性粒子を介して接続された電極間の接続抵抗をより一層低くすることができる。さらに金属粒子を除く無機粒子又は有機無機ハイブリッド粒子の表面に導電部を無電解めっきにより形成する際に、凝集した導電性粒子を形成され難くすることができる。上記有機無機ハイブリッド粒子の粒子径が、上記上限以下であると、導電性粒子が充分に圧縮されやすく、電極間の接続抵抗をより一層低くすることができ、さらに電極間の間隔をより小さくすることができる。 The particle size of the inorganic particles excluding the metal particles and the organic-inorganic hybrid particles is preferably 0.1 μm or more, more preferably 1 μm or more, still more preferably 1.5 μm or more, particularly preferably 2 μm or more, and most preferably 3 μm or more. Is. The particle size of the inorganic particles excluding the metal particles and the organic-inorganic hybrid particles is preferably 500 μm or less, more preferably 100 μm or less, still more preferably 50 μm or less, particularly preferably 20 μm or less, and most preferably 10 μm or less. When the particle diameters of the inorganic particles other than the metal particles and the organic-inorganic hybrid particles are equal to or more than the above lower limit and not more than the above upper limit, the contact area between the conductive particles and the electrodes becomes large, so that the conduction reliability between the electrodes is improved. It can be further increased, and the connection resistance between the electrodes connected via the conductive particles can be further reduced. Further, when a conductive portion is formed on the surface of inorganic particles other than metal particles or organic-inorganic hybrid particles by electroless plating, it is possible to make it difficult for aggregated conductive particles to be formed. When the particle size of the organic-inorganic hybrid particles is not more than the above upper limit, the conductive particles are easily sufficiently compressed, the connection resistance between the electrodes can be further lowered, and the distance between the electrodes is further reduced. be able to.
　上記基材粒子が金属粒子である場合に、該金属粒子の材料である金属としては、銀、銅、ニッケル、ケイ素、金及びチタン等が挙げられる。 When the base material particles are metal particles, examples of the metal that is the material of the metal particles include silver, copper, nickel, silicon, gold, and titanium.
　上記金属粒子の粒子径は、好ましくは０．１μｍ以上、より好ましくは１μｍ以上、さらに好ましくは１．５μｍ以上、特に好ましくは２μｍ以上、最も好ましくは３μｍ以上である。上記金属粒子の粒子径は、好ましくは５００μｍ以下、より好ましくは１００μｍ以下、さらに好ましくは５０μｍ以下、特に好ましくは２０μｍ以下、最も好ましくは１０μｍ以下である。上記金属粒子の粒子径が、上記下限以上及び上記上限以下であると、導電性粒子と電極との接触面積が大きくなるため、電極間の導通信頼性をより一層高めることができ、導電性粒子を介して接続された電極間の接続抵抗をより一層低くすることができる。さらに樹脂粒子の表面に導電部を無電解めっきにより形成する際に、凝集した導電性粒子を形成され難くすることができる。 The particle size of the metal particles is preferably 0.1 μm or more, more preferably 1 μm or more, still more preferably 1.5 μm or more, particularly preferably 2 μm or more, and most preferably 3 μm or more. The particle size of the metal particles is preferably 500 μm or less, more preferably 100 μm or less, still more preferably 50 μm or less, particularly preferably 20 μm or less, and most preferably 10 μm or less. When the particle size of the metal particles is not less than the above lower limit and not more than the above upper limit, the contact area between the conductive particles and the electrodes becomes large, so that the conduction reliability between the electrodes can be further improved, and the conductive particles. The connection resistance between the electrodes connected via the above can be further reduced. Further, when the conductive portion is formed on the surface of the resin particles by electroless plating, it is possible to make it difficult for the aggregated conductive particles to be formed.
　上記基材粒子の粒子径は、好ましくは０．１μｍ以上、より好ましくは１μｍ以上、さらに好ましくは１．５μｍ以上、特に好ましくは２μｍ以上、最も好ましくは３μｍ以上である。上記基材粒子の粒子径は、好ましくは５００μｍ以下、より好ましくは１００μｍ以下、さらに好ましくは５０μｍ以下、特に好ましくは２０μｍ以下、最も好ましくは１０μｍ以下である。上記基材粒子の粒子径が、上記下限以上であると、導電性粒子と電極との接触面積が大きくなるため、電極間の導通信頼性をより一層高めることができ、導電性粒子を介して接続された電極間の接続抵抗をより一層低くすることができる。さらに基材粒子の表面に導電部を無電解めっきにより形成する際に、凝集した導電性粒子を形成され難くすることができる。上記基材粒子の粒子径が、上記上限以下であると、導電性粒子が充分に圧縮されやすく、電極間の接続抵抗をより一層低くすることができ、さらに電極間の間隔をより小さくすることができる。 The particle size of the base particles is preferably 0.1 μm or more, more preferably 1 μm or more, still more preferably 1.5 μm or more, particularly preferably 2 μm or more, and most preferably 3 μm or more. The particle size of the base particles is preferably 500 μm or less, more preferably 100 μm or less, still more preferably 50 μm or less, particularly preferably 20 μm or less, and most preferably 10 μm or less. When the particle size of the base material particles is not more than the above lower limit, the contact area between the conductive particles and the electrodes becomes large, so that the conduction reliability between the electrodes can be further improved, and the conduction reliability between the electrodes can be further improved. The connection resistance between the connected electrodes can be further reduced. Further, when the conductive portion is formed on the surface of the base material particles by electroless plating, it is possible to make it difficult for the agglomerated conductive particles to be formed. When the particle size of the base material particles is not more than the above upper limit, the conductive particles are easily sufficiently compressed, the connection resistance between the electrodes can be further reduced, and the distance between the electrodes can be further reduced. Can be done.
　上記基材粒子の粒子径は、基材粒子が真球状である場合には、直径を示し、基材粒子が真球状ではない場合には、円相当径を示す。また、上記基材粒子の粒子径は、基材粒子を任意の粒子径測定装置により測定した平均粒子径を意味する。上記平均粒子径は、数平均粒子径であることが好ましい。例えば、レーザー光散乱、電気抵抗値変化、撮像後の画像解析等の原理を用いた粒度分布測定装置が利用できる。 The particle size of the base material particles indicates the diameter when the base material particles are spherical, and indicates the equivalent circle diameter when the base material particles are not spherical. Further, the particle size of the base material particles means the average particle size of the base material particles measured by an arbitrary particle size measuring device. The average particle size is preferably a number average particle size. For example, a particle size distribution measuring device using principles such as laser light scattering, change in electrical resistance value, and image analysis after imaging can be used.
　上記基材粒子の粒子径は、２μｍ以上２０μｍ以下であることが特に好ましい。上記基材粒子の粒子径が２μｍ以上２０μｍ以下の範囲内であると、電極間の間隔をより小さくすることができ、かつ導電部の厚みを厚くしても、小さい導電性粒子を得ることができる。 It is particularly preferable that the particle size of the base particle is 2 μm or more and 20 μm or less. When the particle diameter of the base material particles is within the range of 2 μm or more and 20 μm or less, the distance between the electrodes can be made smaller, and even if the thickness of the conductive portion is increased, small conductive particles can be obtained. it can.
　（第１の導電部及び第２の導電部）
　本発明に係る導電性粒子では、上記第１の導電部が、ニッケルとホウ素とを含み、かつ、リンを含まない。本発明に係る導電性粒子では、上記第１の導電部の内表面から外側に向かって厚み１／５の領域（Ｒ１）の１００重量％中におけるホウ素の平均含有量と、上記第１の導電部の外表面から内側に向かって厚み１／５の領域（Ｒ２）の１００重量％中におけるホウ素の平均含有量との差の絶対値は、０重量％以上１０重量％以下である。上記第１の導電部が１層構造である場合には、上記領域（Ｒ１）は、図５において、第１の導電部３の内表面（基材粒子２の外表面）と、破線Ｌ１との間の領域である。上記第１の導電部が１層構造である場合には、上記領域（Ｒ２）は、図５において、第１の導電部３の外表面（第２の導電部４の内表面）と、破線Ｌ２との間の領域である。上記第１の導電部が２層構造である場合には、上記領域（Ｒ１）は、図６において、第１の導電部１３の内表面（導電部１３Ａの内表面、基材粒子２の外表面）と、破線Ｌ１との間の領域である。上記第１の導電部が２層構造である場合には、上記領域（Ｒ２）は、図６において、第１の導電部１３の外表面（導電部１３Ｂの外表面、第２の導電部４の内表面）と、破線Ｌ２との間の領域である。上記第１の導電部が２層以上の複層構造である場合には、上記領域（Ｒ１）及び上記領域（Ｒ２）は、上記第１の導電部全体の厚みから算出されることが好ましい。 (1st conductive part and 2nd conductive part)
In the conductive particles according to the present invention, the first conductive portion contains nickel and boron and does not contain phosphorus. In the conductive particles according to the present invention, the average content of boron in 100% by weight of the region (R1) having a thickness of 1/5 from the inner surface to the outside of the first conductive portion and the first conductivity. The absolute value of the difference from the average content of boron in 100% by weight of the region (R2) having a thickness of 1/5 from the outer surface to the inside of the portion is 0% by weight or more and 10% by weight or less. When the first conductive portion has a one-layer structure, the region (R1) is represented by the inner surface of the first conductive portion 3 (the outer surface of the base particle 2) and the broken line L1 in FIG. The area between. When the first conductive portion has a one-layer structure, the region (R2) is a broken line with the outer surface of the first conductive portion 3 (inner surface of the second conductive portion 4) in FIG. It is an area between L2 and L2. When the first conductive portion has a two-layer structure, the region (R1) is the inner surface of the first conductive portion 13 (inner surface of the conductive portion 13A, outer surface of the base particle 2) in FIG. The area between the surface) and the broken line L1. When the first conductive portion has a two-layer structure, the region (R2) is the outer surface of the first conductive portion 13 (the outer surface of the conductive portion 13B, the second conductive portion 4) in FIG. The region between (inner surface of) and the broken line L2. When the first conductive portion has a multi-layer structure of two or more layers, the region (R1) and the region (R2) are preferably calculated from the thickness of the entire first conductive portion.
　上記第１の導電部の内表面から外側に向かって厚み１／５の領域（Ｒ１）の１００重量％中におけるホウ素の平均含有量と、上記第１の導電部の外表面から内側に向かって厚み１／５の領域（Ｒ２）の１００重量％中におけるホウ素の平均含有量との差の絶対値は、０重量％を超えていてもよく、０．５重量％以上であってもよい。上記領域（Ｒ１）の１００重量％中におけるホウ素の平均含有量と、上記領域（Ｒ２）の１００重量％中におけるホウ素の平均含有量との差の絶対値は、１．０重量％以上であることが好ましい。上記領域（Ｒ１）の１００重量％中におけるホウ素の平均含有量と、上記領域（Ｒ２）の１００重量％中におけるホウ素の平均含有量との差の絶対値が上記下限以上であると、実装時に導電部の割れの発生をより一層効果的に抑制することができる。上記第１の導電部の内表面から外側に向かって厚み１／５の領域（Ｒ１）の１００重量％中におけるホウ素の平均含有量と、上記第１の導電部の外表面から内側に向かって厚み１／５の領域（Ｒ２）の１００重量％中におけるホウ素の平均含有量との差の絶対値は、好ましくは５重量％以下である。上記領域（Ｒ１）の１００重量％中におけるホウ素の平均含有量と、上記領域（Ｒ２）の１００重量％中におけるホウ素の平均含有量との差の絶対値が上記上限以下であると、実装時に導電部の割れの発生をより一層効果的に抑制することができ、電極間の接続抵抗をより一層効果的に低くすることができる。 The average content of boron in 100% by weight of the region (R1) having a thickness of 1/5 from the inner surface to the outside of the first conductive portion, and from the outer surface to the inside of the first conductive portion. The absolute value of the difference from the average content of boron in 100% by weight of the region (R2) having a thickness of 1/5 may exceed 0% by weight, or may be 0.5% by weight or more. The absolute value of the difference between the average content of boron in 100% by weight of the region (R1) and the average content of boron in 100% by weight of the region (R2) is 1.0% by weight or more. Is preferable. When the absolute value of the difference between the average content of boron in 100% by weight of the region (R1) and the average content of boron in 100% by weight of the region (R2) is equal to or greater than the above lower limit, at the time of mounting. It is possible to more effectively suppress the occurrence of cracks in the conductive portion. The average content of boron in 100% by weight of the region (R1) having a thickness of 1/5 from the inner surface to the outside of the first conductive portion, and from the outer surface of the first conductive portion to the inside. The absolute value of the difference from the average content of boron in 100% by weight of the region (R2) having a thickness of 1/5 is preferably 5% by weight or less. When the absolute value of the difference between the average content of boron in 100% by weight of the region (R1) and the average content of boron in 100% by weight of the region (R2) is equal to or less than the above upper limit, at the time of mounting. The occurrence of cracks in the conductive portion can be suppressed more effectively, and the connection resistance between the electrodes can be further effectively reduced.
　上記第１の導電部の内表面から外側に向かって厚み１／５の領域（Ｒ１）の１００重量％中におけるホウ素の平均含有量は、好ましくは０重量％以上、より好ましくは０．００１重量％以上、さらに好ましくは０．０１重量％以上、特に好ましくは０．１重量％以上である。上記第１の導電部の内表面から外側に向かって厚み１／５の領域（Ｒ１）の１００重量％中におけるホウ素の平均含有量は、好ましくは１０重量％以下、より好ましくは５重量％以下、さらに好ましくは４重量％以下、特に好ましくは３重量％以下である。上記領域（Ｒ１）の１００重量％中におけるホウ素の平均含有量が、上記下限以上及び上記上限以下であると、実装時に導電部の割れの発生をより一層効果的に抑制することができ、電極間の接続抵抗をより一層効果的に低くすることができる。ホウ素の平均含有量が０重量％である領域は、ホウ素を含まない。 The average content of boron in 100% by weight of the region (R1) having a thickness of 1/5 from the inner surface to the outside of the first conductive portion is preferably 0% by weight or more, more preferably 0.001% by weight. % Or more, more preferably 0.01% by weight or more, and particularly preferably 0.1% by weight or more. The average content of boron in 100% by weight of the region (R1) having a thickness of 1/5 from the inner surface to the outside of the first conductive portion is preferably 10% by weight or less, more preferably 5% by weight or less. More preferably, it is 4% by weight or less, and particularly preferably 3% by weight or less. When the average content of boron in 100% by weight of the region (R1) is not less than the above lower limit and not more than the above upper limit, the occurrence of cracks in the conductive portion can be more effectively suppressed during mounting, and the electrode The connection resistance between them can be lowered even more effectively. The region where the average content of boron is 0% by weight does not contain boron.
　上記第１の導電部の外表面から内側に向かって厚み１／５の領域（Ｒ２）の１００重量％中におけるホウ素の平均含有量は、好ましくは０重量％以上、より好ましくは０．００１重量％以上、さらに好ましくは０．０１重量％以上、特に好ましく０．１重量％以上である。上記第１の導電部の外表面から内側に向かって厚み１／５の領域（Ｒ２）の１００重量％中におけるホウ素の平均含有量は、好ましくは１０重量％以下、より好ましくは５重量％以下、さらに好ましくは４重量％以下、特に好ましくは３重量％以下である。上記領域（Ｒ２）の１００重量％中におけるホウ素の平均含有量が、上記下限以上及び上記上限以下であると、実装時に導電部の割れの発生をより一層効果的に抑制することができ、電極間の接続抵抗をより一層効果的に低くすることができる。 The average content of boron in 100% by weight of the region (R2) having a thickness of 1/5 from the outer surface to the inside of the first conductive portion is preferably 0% by weight or more, more preferably 0.001% by weight. % Or more, more preferably 0.01% by weight or more, and particularly preferably 0.1% by weight or more. The average content of boron in 100% by weight of the region (R2) having a thickness of 1/5 from the outer surface to the inside of the first conductive portion is preferably 10% by weight or less, more preferably 5% by weight or less. More preferably, it is 4% by weight or less, and particularly preferably 3% by weight or less. When the average content of boron in 100% by weight of the region (R2) is not less than the above lower limit and not more than the above upper limit, the occurrence of cracks in the conductive portion can be more effectively suppressed during mounting, and the electrode The connection resistance between them can be lowered even more effectively.
　実装時に導電部の割れの発生をより一層効果的に抑制する観点、電極間の接続抵抗をより一層効果的に低くする観点からは、上記第１の導電部において、ホウ素は均一に分布していることが好ましい。 Boron is uniformly distributed in the first conductive portion from the viewpoint of more effectively suppressing the occurrence of cracks in the conductive portion during mounting and further effectively reducing the connection resistance between the electrodes. It is preferable to have.
　上記第１の導電部の全体１００重量％中におけるニッケルの平均含有量は、好ましくは５０重量％以上、より好ましくは６５重量％以上であり、好ましくは９９．９重量％以下、より好ましくは９５重量％以下である。上記第１の導電部の全体１００重量％中におけるニッケルの平均含有量が、上記下限以上及び上記上限以下であると、実装時に導電部の割れの発生をより一層効果的に抑制することができ、電極間の接続抵抗をより一層効果的に低くすることができる。 The average content of nickel in 100% by weight of the first conductive portion is preferably 50% by weight or more, more preferably 65% by weight or more, preferably 99.9% by weight or less, more preferably 95% by weight. It is less than% by weight. When the average content of nickel in 100% by weight of the first conductive portion is equal to or higher than the lower limit and lower than the upper limit, cracking of the conductive portion can be more effectively suppressed during mounting. , The connection resistance between the electrodes can be lowered even more effectively.
　上記第１の導電部の全体１００重量％中におけるホウ素の平均含有量は、好ましくは０．００１重量％以上、より好ましくは０．０１重量％以上、さらに好ましくは０．１重量％以上であり、好ましくは１０重量％以下、より好ましくは５重量％以下、さらに好ましくは３重量％以下である。上記第１の導電部の全体１００重量％中におけるホウ素の平均含有量が、上記下限以上及び上記上限以下であると、実装時に導電部の割れの発生をより一層効果的に抑制することができ、電極間の接続抵抗をより一層効果的に低くすることができる。 The average content of boron in 100% by weight of the first conductive portion is preferably 0.001% by weight or more, more preferably 0.01% by weight or more, still more preferably 0.1% by weight or more. It is preferably 10% by weight or less, more preferably 5% by weight or less, still more preferably 3% by weight or less. When the average content of boron in 100% by weight of the first conductive portion is equal to or higher than the lower limit and lower than the upper limit, cracking of the conductive portion can be more effectively suppressed during mounting. , The connection resistance between the electrodes can be lowered even more effectively.
　上記第１の導電部におけるニッケル及びホウ素の各平均含有量の測定方法は、既知の種々の分析法を用いることができ、特に限定されない。この測定方法として、吸光分析法又はスペクトル分析法等が挙げられる。上記吸光分析法では、フレーム吸光光度計及び電気加熱炉吸光光度計等を用いることができる。上記スペクトル分析法としては、プラズマ発光分析法及びプラズマイオン源質量分析法等が挙げられる。 The method for measuring the average contents of nickel and boron in the first conductive portion can use various known analytical methods and is not particularly limited. Examples of this measuring method include an absorption analysis method and a spectrum analysis method. In the above absorption analysis method, a frame absorptiometer, an electric heating furnace absorptiometer, or the like can be used. Examples of the spectrum analysis method include a plasma emission spectrometry method and a plasma ion source mass spectrometry method.
　上記第１の導電部におけるニッケル及びホウ素の各平均含有量を測定する際には、ＩＣＰ発光分析装置を用いることが好ましい。ＩＣＰ発光分析装置の市販品としては、ＨＯＲＩＢＡ社製のＩＣＰ発光分析装置、日立ハイテクサイエンス社製「ＩＣＰ－ＭＳ」等が挙げられる。なお、上記第２の導電部を形成した後に上記第１の導電部におけるニッケル及びホウ素の平均含有量を測定する場合に、電界放射型透過電子顕微鏡（日本電子社製「ＪＥＭ－２０１０ＦＥＦ」）等を用いて、エネルギー分散型Ｘ線分析装置（ＥＤＳ）により測定することができる。 It is preferable to use an ICP emission spectrometer when measuring the average contents of nickel and boron in the first conductive portion. Examples of commercially available ICP emission spectrometers include ICP emission spectrometers manufactured by HORIBA and "ICP-MS" manufactured by Hitachi High-Tech Science. When measuring the average contents of nickel and boron in the first conductive portion after forming the second conductive portion, an electric field radiation transmission electron microscope (“JEM-2010FEF” manufactured by JEOL Ltd.) or the like is used. Can be measured by an energy dispersive X-ray analyzer (EDS).
　上記第１の導電部の厚み方向の各領域におけるニッケル及びホウ素の各含有量及び各平均含有量を測定する際には、電界放射型透過電子顕微鏡（日本電子社製「ＪＥＭ－２０１０ＦＥＦ」）等を用いて、エネルギー分散型Ｘ線分析装置（ＥＤＳ）により測定することができる。 When measuring the respective contents of nickel and boron and the respective average contents in each region in the thickness direction of the first conductive portion, an electric field radiation transmission electron microscope (“JEM-2010FEF” manufactured by JEOL Ltd.) or the like is used. Can be measured by an energy dispersive X-ray analyzer (EDS).
　上記第１の導電部の厚みは、好ましくは０．００５μｍ以上、より好ましくは０．０１μｍ以上、さらに好ましくは０．０５μｍ以上であり、好ましくは１μｍ以下、より好ましくは０．３μｍ以下である。上記第１の導電部の厚みが、上記下限以上及び上記上限以下であると、十分な導電性を得ることができ、かつ導電性粒子が硬くなりすぎず、電極間の接続の際に導電性粒子が十分に変形できる。上記第１の導電部が２層以上の複層構造である場合には、上記第１の導電部の厚みは、すべての層の合計の厚みであることが好ましい。 The thickness of the first conductive portion is preferably 0.005 μm or more, more preferably 0.01 μm or more, still more preferably 0.05 μm or more, preferably 1 μm or less, and more preferably 0.3 μm or less. When the thickness of the first conductive portion is not less than the above lower limit and not more than the above upper limit, sufficient conductivity can be obtained, the conductive particles do not become too hard, and conductivity is formed when the electrodes are connected. The particles can be sufficiently deformed. When the first conductive portion has a multi-layer structure of two or more layers, the thickness of the first conductive portion is preferably the total thickness of all the layers.
　上記第１の導電部の厚みは、０．０５μｍ以上０．３μｍ以下であることが特に好ましい。さらに、上記基材粒子の粒子径が２μｍ以上２０μｍ以下であり、かつ、上記第１の導電部の厚みが０．０５μｍ以上０．３μｍ以下であることが特に好ましい。この場合には、導電性粒子を大きな電流が流れる用途により好適に用いることができる。さらに、導電性粒子を圧縮して電極間を接続した場合に、電極が損傷するのをより一層抑制することができる。 It is particularly preferable that the thickness of the first conductive portion is 0.05 μm or more and 0.3 μm or less. Further, it is particularly preferable that the particle size of the base material particles is 2 μm or more and 20 μm or less, and the thickness of the first conductive portion is 0.05 μm or more and 0.3 μm or less. In this case, the conductive particles can be more preferably used depending on the application in which a large current flows. Further, when the conductive particles are compressed and connected between the electrodes, damage to the electrodes can be further suppressed.
　上記第２の導電部の厚みは、好ましくは０．００５μｍ以上、より好ましくは０．０１μｍ以上、さらに好ましくは０．０２μｍ以上であり、好ましくは１μｍ以下、より好ましくは０．３μｍ以下である。上記第２の導電部の厚みが、上記下限以上及び上記上限以下であると、十分な導電性を得ることができ、かつ導電性粒子が硬くなりすぎず、電極間の接続の際に導電性粒子が十分に変形できる。 The thickness of the second conductive portion is preferably 0.005 μm or more, more preferably 0.01 μm or more, still more preferably 0.02 μm or more, preferably 1 μm or less, and more preferably 0.3 μm or less. When the thickness of the second conductive portion is not less than the above lower limit and not more than the above upper limit, sufficient conductivity can be obtained, the conductive particles do not become too hard, and conductivity is formed when the electrodes are connected. The particles can be sufficiently deformed.
　上記第２の導電部の厚みは、０．０２μｍ以上０．３μｍ以下であることが特に好ましい。さらに、上記基材粒子の粒子径が２μｍ以上２０μｍ以下であり、かつ、上記第２の導電部の厚みが０．０２μｍ以上０．３μｍ以下であることが特に好ましい。この場合には、導電性粒子を大きな電流が流れる用途により好適に用いることができる。さらに、導電性粒子を圧縮して電極間を接続した場合に、電極が損傷するのをより一層抑制することができる。 It is particularly preferable that the thickness of the second conductive portion is 0.02 μm or more and 0.3 μm or less. Further, it is particularly preferable that the particle size of the base material particles is 2 μm or more and 20 μm or less, and the thickness of the second conductive portion is 0.02 μm or more and 0.3 μm or less. In this case, the conductive particles can be more preferably used depending on the application in which a large current flows. Further, when the conductive particles are compressed and connected between the electrodes, damage to the electrodes can be further suppressed.
　上記第１の導電部の厚み及び第２の導電部の厚みは、例えば透過型電子顕微鏡（日本電子社製「ＪＥＭ－２１００」）等を用いて、導電性粒子の断面観察により測定することができる。 The thickness of the first conductive portion and the thickness of the second conductive portion can be measured by observing the cross section of the conductive particles using, for example, a transmission electron microscope (“JEM-2100” manufactured by JEOL Ltd.) or the like. it can.
　上記第１の導電部は、ニッケルを主金属として含むことが好ましい。上記第１の導電部は、ニッケル以外の金属を含んでいてもよい。上記第１の導電部におけるニッケル以外の金属としては、金、銀、銅、白金、亜鉛、鉄、錫、鉛、アルミニウム、コバルト、インジウム、パラジウム、クロム、シーボーギウム、チタン、アンチモン、ビスマス、タリウム、タングステン、ゲルマニウム、カドミウム、ケイ素、モリブデン、錫ドープ酸化インジウム（ＩＴＯ）及びはんだ等が挙げられる。これらの金属は、１種のみが用いられてもよく、２種以上が併用されてもよい。上記第１の導電部において、複数の金属が含まれる場合に、複数の金属は合金化していてもよい。 It is preferable that the first conductive portion contains nickel as a main metal. The first conductive portion may contain a metal other than nickel. Examples of the metal other than nickel in the first conductive portion include gold, silver, copper, platinum, zinc, iron, tin, lead, aluminum, cobalt, indium, palladium, chromium, seaborgium, titanium, antimony, bismuth, and tarium. Examples thereof include tungsten, germanium, cadmium, silicon, molybdenum, tin-doped indium oxide (ITO) and solder. Only one of these metals may be used, or two or more of these metals may be used in combination. When a plurality of metals are contained in the first conductive portion, the plurality of metals may be alloyed.
　上記第２の導電部を形成するための金属は特に限定されない。上記金属としては、例えば、金、銀、銅、白金、亜鉛、鉄、錫、鉛、アルミニウム、コバルト、インジウム、パラジウム、クロム、ルテニウム、ロジウム、イリジウム、ビスマス、タリウム、タングステン、ゲルマニウム、カドミウム、ケイ素及びモリブデン等が挙げられる。電極間の接続抵抗をより一層効果的に低くする観点からは、上記金属は、上記第１の導電部の主金属であるニッケルよりも電位が大きいことが好ましい。上記金属は、錫、銅、パラジウム、ルテニウム、白金、銀、ロジウム、イリジウム又は金であることが好ましく、金、銀、銅又はパラジウムであることがより好ましい。電極間の接続抵抗をより一層効果的に低くする観点からは、上記第２の導電部における主金属は、錫、銅、パラジウム、ルテニウム、白金、銀、ロジウム、イリジウム又は金であることが好ましく、金又はパラジウムであることがより好ましい。また、実装時に導電部の割れの発生をより一層効果的に抑制する観点からは、上記第２の導電部における主金属は、パラジウム又はルテニウムであることが好ましく、パラジウムであることがより好ましい。 The metal for forming the second conductive portion is not particularly limited. Examples of the metal include gold, silver, copper, platinum, zinc, iron, tin, lead, aluminum, cobalt, indium, palladium, chromium, ruthenium, rhodium, iridium, bismuth, thallium, tungsten, germanium, cadmium, and silicon. And molybdenum and the like. From the viewpoint of further effectively lowering the connection resistance between the electrodes, it is preferable that the metal has a higher potential than nickel, which is the main metal of the first conductive portion. The metal is preferably tin, copper, palladium, ruthenium, platinum, silver, rhodium, iridium or gold, and more preferably gold, silver, copper or palladium. From the viewpoint of further effectively lowering the connection resistance between the electrodes, the main metal in the second conductive portion is preferably tin, copper, palladium, ruthenium, platinum, silver, rhodium, iridium or gold. , Gold or palladium is more preferred. Further, from the viewpoint of more effectively suppressing the occurrence of cracks in the conductive portion during mounting, the main metal in the second conductive portion is preferably palladium or ruthenium, and more preferably palladium.
　なお、上記第１の導電部における主金属及び上記第２の導電部における主金属とは、上記第１の導電部及び上記第２の導電部に含まれる金属のうち、最も含有量が多い金属を意味する。上記第１の導電部及び上記第２の導電部に含まれる全ての金属１００重量％中、上記主金属の含有量は、好ましくは５０重量％以上、より好ましくは８０重量％以上、さらに好ましくは９０重量％以上である。上記第１の導電部及び上記第２の導電部には、１種のみの金属が含まれていてもよく、２種以上の金属が含まれていてもよい。 The main metal in the first conductive portion and the main metal in the second conductive portion are the metals having the highest content among the metals contained in the first conductive portion and the second conductive portion. Means. The content of the main metal in 100% by weight of all the metals contained in the first conductive portion and the second conductive portion is preferably 50% by weight or more, more preferably 80% by weight or more, still more preferably. It is 90% by weight or more. The first conductive portion and the second conductive portion may contain only one kind of metal, or may contain two or more kinds of metals.
　上記第１の導電部及び上記第２の導電部を形成する方法は特に限定されない。上記第１の導電部及び上記第２の導電部を形成する方法としては、例えば、無電解めっきによる方法、電気めっきによる方法、物理的蒸着による方法、並びに金属粉末もしくは金属粉末とバインダーとを含むペーストを基材粒子又は他の導電部の表面にコーティングする方法等が挙げられる。導電部の形成が簡便であるので、無電解めっきによる方法が好ましい。上記物理的蒸着による方法としては、真空蒸着、イオンプレーティング及びイオンスパッタリング等の方法が挙げられる。 The method of forming the first conductive portion and the second conductive portion is not particularly limited. The method for forming the first conductive portion and the second conductive portion includes, for example, a method by electroless plating, a method by electroplating, a method by physical vapor deposition, and a metal powder or a metal powder and a binder. Examples thereof include a method of coating the surface of the base material particles or other conductive parts with the paste. Since the formation of the conductive portion is simple, the method by electroless plating is preferable. Examples of the method by physical vapor deposition include methods such as vacuum vapor deposition, ion plating, and ion sputtering.
　上記導電性粒子の粒子径は、好ましくは０．１μｍ以上、より好ましくは１μｍ以上、さらに好ましくは１．５μｍ以上、特に好ましくは２μｍ以上、最も好ましくは３μｍ以上である。上記導電性粒子の粒子径は、好ましくは５００μｍ以下、より好ましくは１００μｍ以下、さらに好ましくは５０μｍ以下、特に好ましくは２０μｍ以下、最も好ましくは１０μｍ以下である。導電性粒子の粒子径が、上記下限以上及び上限以下であると、上記導電性粒子を用いて電極間を接続した場合に、導電性粒子と電極との接触面積を十分に大きくすることができ、かつ導電部を形成する際に凝集した導電性粒子を形成され難くすることができる。また、導電性粒子を介して接続された電極間の間隔が大きくなりすぎず、かつ導電部を基材粒子の表面から剥離し難くすることができる。 The particle size of the conductive particles is preferably 0.1 μm or more, more preferably 1 μm or more, still more preferably 1.5 μm or more, particularly preferably 2 μm or more, and most preferably 3 μm or more. The particle size of the conductive particles is preferably 500 μm or less, more preferably 100 μm or less, still more preferably 50 μm or less, particularly preferably 20 μm or less, and most preferably 10 μm or less. When the particle size of the conductive particles is equal to or greater than the above lower limit and equal to or less than the upper limit, the contact area between the conductive particles and the electrodes can be sufficiently increased when the electrodes are connected using the conductive particles. Moreover, it is possible to make it difficult for the agglomerated conductive particles to be formed when the conductive portion is formed. In addition, the distance between the electrodes connected via the conductive particles does not become too large, and the conductive portion can be made difficult to peel off from the surface of the substrate particles.
　上記導電性粒子の粒子径は、導電性粒子が真球状である場合には、直径を示し、導電性粒子が真球状ではない場合には、円相当径を示す。上記導電性粒子の粒子径は、平均粒子径であることが好ましく、数平均粒子径であることがより好ましい。上記導電性粒子の粒子径は、例えば、任意の導電性粒子５０個を電子顕微鏡又は光学顕微鏡にて観察し、各導電性粒子の粒子径の平均値を算出することや、レーザー回折式粒度分布測定を行うことにより求められる。電子顕微鏡又は光学顕微鏡での観察では、１個当たりの導電性粒子の粒子径は、円相当径での粒子径として求められる。電子顕微鏡又は光学顕微鏡での観察において、任意の５０個の導電性粒子の円相当径での平均粒子径は、球相当径での平均粒子径とほぼ等しくなる。レーザー回折式粒度分布測定では、１個当たりの導電性粒子の粒子径は、球相当径での粒子径として求められる。上記導電性粒子の粒子径は、レーザー回折式粒度分布測定により算出することが好ましい。 The particle diameter of the conductive particles indicates the diameter when the conductive particles are spherical, and indicates the equivalent circle diameter when the conductive particles are not spherical. The particle size of the conductive particles is preferably an average particle size, and more preferably a number average particle size. The particle size of the conductive particles can be determined by, for example, observing 50 arbitrary conductive particles with an electron microscope or an optical microscope, calculating the average value of the particle size of each conductive particle, or laser diffraction type particle size distribution. Obtained by making measurements. In observation with an electron microscope or an optical microscope, the particle size of each conductive particle is determined as the particle size in the equivalent circle diameter. In observation with an electron microscope or an optical microscope, the average particle diameter of any 50 conductive particles in the equivalent circle diameter is substantially equal to the average particle diameter in the equivalent diameter of the sphere. In the laser diffraction type particle size distribution measurement, the particle size of each conductive particle is determined as the particle size in the equivalent sphere diameter. The particle size of the conductive particles is preferably calculated by laser diffraction type particle size distribution measurement.
　上記第１の導電部の各領域におけるニッケル及びホウ素の各含有量及び各平均含有量を制御する方法としては、例えば、無電解ニッケルめっきにより第１の導電部を形成する際に、ニッケルめっき液のｐＨを制御する方法、ニッケルめっき液中のホウ素濃度を調整する方法並びにニッケルめっき液中のニッケル濃度を調整する方法等が挙げられる。 As a method of controlling each content and each average content of nickel and boron in each region of the first conductive portion, for example, when forming the first conductive portion by electroless nickel plating, a nickel plating solution is used. Examples thereof include a method of controlling the pH of the nickel plating solution, a method of adjusting the boron concentration in the nickel plating solution, and a method of adjusting the nickel concentration in the nickel plating solution.
　無電解めっきにより形成する方法では、一般的に、触媒化工程と、無電解めっき工程とが行われる。以下、無電解めっきにより、基材粒子の表面に、ニッケルとホウ素とを含む第１の導電部を形成する方法の一例を説明する。 In the method of forming by electroless plating, a catalysis step and an electroless plating step are generally performed. Hereinafter, an example of a method of forming a first conductive portion containing nickel and boron on the surface of the base material particles by electroless plating will be described.
　上記触媒化工程では、無電解めっきによりめっき層を形成するための起点となる触媒を、基材粒子の表面に形成させる。 In the above-mentioned catalystization step, a catalyst serving as a starting point for forming a plating layer by electroless plating is formed on the surface of the substrate particles.
　上記触媒を基材粒子の表面に形成させる方法としては、例えば、以下の方法等が挙げられる。塩化パラジウムと塩化錫とを含む溶液に、基材粒子を添加した後、酸溶液又はアルカリ溶液により基材粒子の表面を活性化させて、基材粒子の表面にパラジウムを析出させる方法。硫酸パラジウムとアミノピリジンとを含有する溶液に、基材粒子を添加した後、還元剤を含む溶液により基材粒子の表面を活性化させて、基材粒子の表面にパラジウムを析出させる方法。上記還元剤として、ホウ素含有還元剤が用いられる。また、上記還元剤として、ホウ素含有還元剤を用いることで、ホウ素を含む第１の導電部を形成できる。 Examples of the method for forming the catalyst on the surface of the substrate particles include the following methods. A method in which base particles are added to a solution containing palladium chloride and tin chloride, and then the surface of the base particles is activated by an acid solution or an alkaline solution to precipitate palladium on the surface of the base particles. A method in which base particles are added to a solution containing palladium sulfate and aminopyridine, and then the surface of the base particles is activated by a solution containing a reducing agent to precipitate palladium on the surface of the base particles. A boron-containing reducing agent is used as the reducing agent. Further, by using a boron-containing reducing agent as the reducing agent, a first conductive portion containing boron can be formed.
　上記無電解めっき工程では、ニッケル含有化合物、ホウ素含有還元剤、必要に応じて、錯化剤、及び安定剤を含むニッケルめっき浴が好適に用いられる。 In the electroless plating step, a nickel plating bath containing a nickel-containing compound, a boron-containing reducing agent, and if necessary, a complexing agent and a stabilizer is preferably used.
　ニッケルめっき浴中に基材粒子を浸漬することにより、触媒が表面に形成された基材粒子の表面に、ニッケルを析出させることができ、ニッケルとホウ素とを含む第１の導電部を形成できる。 By immersing the base material particles in the nickel plating bath, nickel can be precipitated on the surface of the base material particles on which the catalyst is formed on the surface, and a first conductive portion containing nickel and boron can be formed. ..
　上記ニッケル含有化合物としては、硫酸ニッケル及び塩化ニッケル等が挙げられる。上記ニッケル含有化合物は、ニッケル塩であることが好ましい。 Examples of the nickel-containing compound include nickel sulfate and nickel chloride. The nickel-containing compound is preferably a nickel salt.
　上記ホウ素含有還元剤としては、ジメチルアミンボラン、水素化ホウ素ナトリウム及び水素化ホウ素カリウム等が挙げられる。 Examples of the boron-containing reducing agent include dimethylamine borane, sodium borohydride, potassium borohydride and the like.
　上記錯化剤としては、酢酸ナトリウム及びプロピオン酸ナトリウム等のモノカルボン酸系錯化剤；マロン酸ニナトリウム等のジカルボン酸系錯化剤；コハク酸ニナトリウム等のトリカルボン酸系錯化剤；乳酸、ＤＬ－リンゴ酸、ロシェル塩、クエン酸ナトリウム及びグルコン酸ナトリウム等のヒドロキシ酸系錯化剤；グリシン及びＥＤＴＡ等のアミノ酸系錯化剤；エチレンジアミン等のアミン系錯化剤；マレイン酸等の有機酸系錯化剤；並びに、これらの塩等が挙げられる。上記錯化剤は、１種のみが用いられてもよく、２種以上が併用されてもよい。 Examples of the complexing agent include monocarboxylic acid complexing agents such as sodium acetate and sodium propionate; dicarboxylic acid complexing agents such as disodium malonate; tricarboxylic acid complexing agents such as disodium succinate; lactic acid. , DL-malic acid, Rochelle salt, hydroxy acid complex agents such as sodium citrate and sodium gluconate; amino acid complex agents such as glycine and EDTA; amine complex agents such as ethylenediamine; organics such as maleic acid Acid-based complexing agents; and salts thereof. Only one kind of the complexing agent may be used, or two or more kinds thereof may be used in combination.
　上記安定剤として、鉛化合物、ビスマス化合物又はタリウム化合物を添加してもよい。これらの化合物の具体例としては、化合物を構成する金属（鉛、ビスマス、タリウム）の硫酸塩、炭酸塩、酢酸塩、硝酸塩、及び塩酸塩等が挙げられる。環境への影響を考慮すると、ビスマス化合物又はタリウム化合物であることが好ましい。 As the stabilizer, a lead compound, a bismuth compound or a thallium compound may be added. Specific examples of these compounds include sulfates, carbonates, acetates, nitrates, and hydrochlorides of metals (lead, bismuth, thallium) constituting the compounds. Considering the impact on the environment, it is preferably a bismuth compound or a thallium compound.
　上記第１の導電部中のホウ素含有量を増加させる方法の好ましい例としては、めっき液のｐＨを低くしニッケルめっき液の反応の速度を遅くする方法、ニッケルめっき液の温度を下げる方法、ニッケルめっき液中のホウ素含有還元剤の濃度を高くする方法、ニッケルめっき液中の錯化剤濃度を高くする方法等が挙げられる。これらの方法は、単独で用いてもよく、２種類以上を組み合わせて用いてもよい。上記の好ましい方法により、上記領域（Ｒ１）の１００重量％中におけるホウ素の平均含有量及び、上記領域（Ｒ２）の１００重量％中におけるホウ素の平均含有量を、調整することができる。結果として、上記領域（Ｒ１）の１００重量％中におけるホウ素の平均含有量と、上記領域（Ｒ２）の１００重量％中におけるホウ素の平均含有量との差の絶対値を、０重量％以上１０重量％以下とすることが容易となる。 Preferred examples of the method of increasing the boron content in the first conductive portion include a method of lowering the pH of the plating solution to slow down the reaction rate of the nickel plating solution, a method of lowering the temperature of the nickel plating solution, and nickel. Examples thereof include a method of increasing the concentration of the boron-containing reducing agent in the plating solution, a method of increasing the concentration of the complexing agent in the nickel plating solution, and the like. These methods may be used alone or in combination of two or more. By the above preferred method, the average content of boron in 100% by weight of the region (R1) and the average content of boron in 100% by weight of the region (R2) can be adjusted. As a result, the absolute value of the difference between the average content of boron in 100% by weight of the region (R1) and the average content of boron in 100% by weight of the region (R2) is 0% by weight or more. It becomes easy to make it less than% by weight.
　（芯物質）
　上記導電性粒子は導電性の表面に突起を有することが好ましい。上記第１の導電部又は上記第２の導電部は外表面に突起を有することが好ましい。上記第１の導電部及び上記第２の導電部は外表面に突起を有することが好ましい。上記突起は複数であることが好ましい。上記導電性粒子により接続される電極の表面には、酸化被膜が形成されていることが多い。さらに、上記導電性粒子の導電部の表面には、酸化被膜が形成されていることが多い。上記突起を有する導電性粒子の使用により、電極間に導電性粒子を配置した後、圧着させることにより、突起により酸化被膜が効果的に排除される。このため、電極と導電性粒子とをより一層確実に接触させることができ、電極間の接続抵抗を低くすることができる。さらに、上記導電性粒子が表面に絶縁性物質を有する場合、又は導電性粒子がバインダー樹脂中に分散されて導電材料として用いられる場合に、導電性粒子の突起によって、導電性粒子と電極との間の絶縁性物質又はバインダー樹脂を効果的に排除できる。このため、電極間の導通信頼性を高めることができる。 (Core substance)
The conductive particles preferably have protrusions on the conductive surface. It is preferable that the first conductive portion or the second conductive portion has protrusions on the outer surface. It is preferable that the first conductive portion and the second conductive portion have protrusions on the outer surface. It is preferable that the number of the protrusions is plurality. An oxide film is often formed on the surface of the electrode connected by the conductive particles. Further, an oxide film is often formed on the surface of the conductive portion of the conductive particles. By using the conductive particles having the protrusions, the conductive particles are arranged between the electrodes and then crimped, so that the oxide film is effectively removed by the protrusions. Therefore, the electrodes and the conductive particles can be brought into contact with each other more reliably, and the connection resistance between the electrodes can be lowered. Further, when the conductive particles have an insulating substance on the surface, or when the conductive particles are dispersed in the binder resin and used as a conductive material, the protrusions of the conductive particles cause the conductive particles to be connected to the electrode. The insulating substance or binder resin between them can be effectively eliminated. Therefore, the conduction reliability between the electrodes can be improved.
　また、上記導電性粒子が第１の導電部又は第２の導電部の外表面に突起を有していると、上記導電性粒子同士が接触する面積を小さくすることができる。そのため、複数の上記導電性粒子の凝集を抑制することができる。したがって、接続されてはならない電極間の電気的な接続を防ぐことができ、絶縁信頼性をより一層高めることができる。 Further, when the conductive particles have protrusions on the outer surface of the first conductive portion or the second conductive portion, the area where the conductive particles come into contact with each other can be reduced. Therefore, the aggregation of the plurality of conductive particles can be suppressed. Therefore, it is possible to prevent electrical connection between electrodes that should not be connected, and it is possible to further improve insulation reliability.
　上記芯物質が第１の導電部又は第２の導電部中に埋め込まれていることによって、上記第１の導電部又は上記第２の導電部が外表面に複数の突起を有するようにすることが容易である。複数の突起を容易に形成する観点からは、上記第１の導電部又は上記第２の導電部の内部又は内側において、複数の上記突起を形成するように、上記第１の導電部又は上記第２の導電部の表面を隆起させている複数の芯物質を備えることが好ましい。但し、上記導電性粒子、上記第１の導電部及び上記第２の導電部の外表面に突起を形成するために、芯物質を必ずしも用いなくてもよく、芯物質を用いないことが好ましい。上記導電性粒子は、上記第１の導電部及び上記第２の導電部の外表面を隆起させるための芯物質を有しないことが好ましい。上記導電性粒子では、上記第１の導電部又は上記第２の導電部の内部又は内側において、複数の上記突起を形成するように、上記第１の導電部又は上記第２の導電部の表面を隆起させている複数の芯物質を備えていないことが好ましい。上記芯物質が用いられる場合に、上記芯物質は、上記第１の導電部の内側又は内部に配置されることが好ましい。上記芯物質が用いられる場合に、上記芯物質は、上記第２の導電部の内側又は内部に配置されていてもよい。 By embedding the core material in the first conductive portion or the second conductive portion, the first conductive portion or the second conductive portion has a plurality of protrusions on the outer surface. Is easy. From the viewpoint of easily forming the plurality of protrusions, the first conductive portion or the first conductive portion is formed so as to form the plurality of protrusions inside or inside the first conductive portion or the second conductive portion. It is preferable to include a plurality of core substances that raise the surface of the conductive portion of 2. However, in order to form protrusions on the outer surfaces of the conductive particles, the first conductive portion, and the second conductive portion, it is not always necessary to use the core material, and it is preferable not to use the core material. It is preferable that the conductive particles do not have a core substance for raising the outer surfaces of the first conductive portion and the second conductive portion. In the conductive particles, the surface of the first conductive portion or the second conductive portion is formed so as to form a plurality of the protrusions inside or inside the first conductive portion or the second conductive portion. It is preferable not to have a plurality of core materials that raise the surface. When the core material is used, it is preferable that the core material is arranged inside or inside the first conductive portion. When the core material is used, the core material may be arranged inside or inside the second conductive portion.
　上記突起を形成する方法としては、以下の方法等が挙げられる。基材粒子の表面に芯物質を付着させた後、無電解めっきにより導電部を形成する方法。基材粒子の表面に無電解めっきにより導電部を形成した後、芯物質を付着させ、さらに無電解めっきにより導電部を形成する方法。基材粒子の表面に無電解めっきにより導電部を形成する途中段階で芯物質を添加する方法。 Examples of the method for forming the protrusions include the following methods. A method of forming a conductive part by electroless plating after adhering a core substance to the surface of base particle. A method in which a conductive portion is formed on the surface of a base particle by electroless plating, a core substance is attached, and the conductive portion is further formed by electroless plating. A method of adding a core substance in the middle of forming a conductive portion by electroless plating on the surface of base particle.
　上記基材粒子の表面上に芯物質を配置させる方法としては、以下の方法等が挙げられる。基材粒子の分散液中に、芯物質を添加し、基材粒子の表面に芯物質を、ファンデルワールス力等により集積させ、付着させる方法。基材粒子を入れた容器に、芯物質を添加し、容器の回転等による機械的な作用により基材粒子の表面に芯物質を付着させる方法。付着させる芯物質の量を制御しやすいため、上記基材粒子の表面上に芯物質を配置させる方法は、分散液中の基材粒子の表面に芯物質を集積させ、付着させる方法であることが好ましい。 Examples of the method for arranging the core substance on the surface of the base material particles include the following methods. A method in which a core substance is added to a dispersion of base particles, and the core substance is accumulated and adhered to the surface of the base particles by van der Waals force or the like. A method in which a core substance is added to a container containing base particles, and the core substance is attached to the surface of the base particles by a mechanical action such as rotation of the container. Since it is easy to control the amount of the core substance to be attached, the method of arranging the core substance on the surface of the base material particles is a method of accumulating and adhering the core substance on the surface of the base material particles in the dispersion liquid. Is preferable.
　上記芯物質の材料としては、導電性物質及び非導電性物質が挙げられる。上記導電性物質としては、例えば、金属、金属の酸化物、黒鉛等の導電性非金属及び導電性ポリマー等が挙げられる。上記導電性ポリマーとしては、ポリアセチレン等が挙げられる。上記非導電性物質としては、シリカ、アルミナ、チタン酸バリウム及びジルコニア等が挙げられる。酸化被膜を効果的に排除するために、芯物質は硬い方が好ましい。導電性を高めることができ、さらに接続抵抗を効果的に低くすることができるので、金属が好ましい。上記芯物質は金属粒子であることが好ましい。上記芯物質の材料である金属としては、上記第１の導電部及び上記第２の導電部の材料として挙げた金属を適宜使用可能である。 Examples of the material of the core substance include a conductive substance and a non-conductive substance. Examples of the conductive substance include metals, metal oxides, conductive non-metals such as graphite, and conductive polymers. Examples of the conductive polymer include polyacetylene and the like. Examples of the non-conductive substance include silica, alumina, barium titanate and zirconia. In order to effectively eliminate the oxide film, the core material is preferably hard. Metals are preferred because they can increase conductivity and effectively reduce connection resistance. The core material is preferably metal particles. As the metal that is the material of the core substance, the metals listed as the materials of the first conductive portion and the second conductive portion can be appropriately used.
　上記芯物質の材料としては、例えば、チタン酸バリウム（モース硬度４．５）、ニッケル（モース硬度５）、シリカ（二酸化珪素、モース硬度６～７）、酸化チタン（モース硬度７）、ジルコニア（モース硬度８～９）、アルミナ（モース硬度９）、炭化タングステン（モース硬度９）及びダイヤモンド（モース硬度１０）等が挙げられる。導電性をより一層効果的に高める観点、及び接続抵抗をより一層効果的に低くする観点からは、上記芯物質は、ニッケル、シリカ、酸化チタン、ジルコニア、アルミナ、炭化タングステン又はダイヤモンドであることが好ましく、シリカ、酸化チタン、ジルコニア、アルミナ、炭化タングステン又はダイヤモンドであることがより好ましい。導電性をより一層効果的に高める観点、及び接続抵抗をより一層効果的に低くする観点からは、上記芯物質は、酸化チタン、ジルコニア、アルミナ、炭化タングステン又はダイヤモンドであることがさらに好ましく、ジルコニア、アルミナ、炭化タングステン又はダイヤモンドであることが特に好ましい。導電性をより一層効果的に高める観点、及び接続抵抗をより一層効果的に低くする観点からは、上記芯物質の材料のモース硬度は、好ましくは５以上、より好ましくは６以上、さらに好ましくは７以上、特に好ましくは７．５以上である。 Examples of the material of the core material include barium titanate (Mohs hardness 4.5), nickel (Mohs hardness 5), silica (silicon dioxide, Mohs hardness 6-7), titanium oxide (Mohs hardness 7), and zirconia (Mohs hardness 7). Examples thereof include Mohs hardness 8 to 9), alumina (Mohs hardness 9), tungsten carbide (Mohs hardness 9), and diamond (Mohs hardness 10). From the viewpoint of further increasing the conductivity more effectively and further effectively lowering the connection resistance, the core material may be nickel, silica, titanium oxide, zirconia, alumina, tungsten carbide or diamond. More preferably, it is silica, titanium oxide, zirconia, alumina, tungsten carbide or diamond. From the viewpoint of further increasing the conductivity more effectively and further effectively lowering the connection resistance, the core material is more preferably titanium oxide, zirconia, alumina, tungsten carbide or diamond, and zirconia. , Alumina, Tungsten Carbide or Diamond is particularly preferred. From the viewpoint of further increasing the conductivity more effectively and further effectively lowering the connection resistance, the Mohs hardness of the material of the core material is preferably 5 or more, more preferably 6 or more, still more preferably. It is 7 or more, particularly preferably 7.5 or more.
　上記芯物質の形状は特に限定されない。上記芯物質の形状は塊状であることが好ましい。芯物質としては、例えば、粒子状の塊、複数の微小粒子が凝集した凝集塊及び不定形の塊等が挙げられる。 The shape of the core substance is not particularly limited. The shape of the core material is preferably lumpy. Examples of the core material include particulate lumps, agglomerates in which a plurality of fine particles are aggregated, and amorphous lumps.
　上記芯物質の粒子径は、好ましくは０．００１μｍ以上、より好ましくは０．０５μｍ以上であり、好ましくは１μｍ以下、より好ましくは０．５μｍ以下である。上記芯物質の粒子径が、上記下限以上及び上記上限以下であると、電極間の接続抵抗を効果的に低くすることができる。 The particle size of the core substance is preferably 0.001 μm or more, more preferably 0.05 μm or more, preferably 1 μm or less, and more preferably 0.5 μm or less. When the particle size of the core substance is at least the above lower limit and at least the above upper limit, the connection resistance between the electrodes can be effectively reduced.
　上記芯物質の粒子径は、芯物質が真球状である場合には、直径を示し、芯物質が真球状ではない場合には、円相当径を示す。上記芯物質の粒子径は、平均粒子径であることが好ましく、数平均粒子径であることがより好ましい。上記芯物質の粒子径は、例えば、任意の芯物質５０個を電子顕微鏡又は光学顕微鏡にて観察し、各芯物質の粒子径の平均値を算出することや、レーザー回折式粒度分布測定を行うことにより求められる。電子顕微鏡又は光学顕微鏡での観察では、１個当たりの芯物質の粒子径は、円相当径での粒子径として求められる。電子顕微鏡又は光学顕微鏡での観察において、任意の５０個の芯物質の円相当径での平均粒子径は、球相当径での平均粒子径とほぼ等しくなる。レーザー回折式粒度分布測定では、１個当たりの芯物質の粒子径は、球相当径での粒子径として求められる。上記芯物質の粒子径は、レーザー回折式粒度分布測定により算出することが好ましい。 The particle diameter of the core material indicates the diameter when the core material is spherical, and indicates the equivalent circle diameter when the core material is not spherical. The particle size of the core material is preferably an average particle size, and more preferably a number average particle size. For the particle size of the core material, for example, 50 arbitrary core materials are observed with an electron microscope or an optical microscope, the average value of the particle size of each core material is calculated, and the laser diffraction type particle size distribution measurement is performed. It is required by. In observation with an electron microscope or an optical microscope, the particle size of each core substance is determined as the particle size in the equivalent circle diameter. In observation with an electron microscope or an optical microscope, the average particle diameter of any 50 core materials in the circle equivalent diameter is substantially equal to the average particle diameter in the sphere equivalent diameter. In the laser diffraction type particle size distribution measurement, the particle size of the core material per piece is obtained as the particle size in the equivalent sphere diameter. The particle size of the core material is preferably calculated by laser diffraction type particle size distribution measurement.
　上記導電性粒子１個当たりの上記突起の数は、好ましくは３個以上、より好ましくは５個以上である。上記突起の数の上限は特に限定されない。上記突起の数の上限は導電性粒子の粒子径等を考慮して適宜選択できる。上記突起の平均高さが、上記下限以上であると、電極間の接続抵抗をより一層効果的に低くすることができる。 The number of the protrusions per conductive particle is preferably 3 or more, and more preferably 5 or more. The upper limit of the number of the protrusions is not particularly limited. The upper limit of the number of protrusions can be appropriately selected in consideration of the particle size of the conductive particles and the like. When the average height of the protrusions is at least the above lower limit, the connection resistance between the electrodes can be further effectively reduced.
　複数の上記突起の平均高さは、好ましくは０．００１μｍ以上、より好ましくは０．０５μｍ以上であり、好ましくは１μｍ以下、より好ましくは０．５μｍ以下である。上記突起の平均高さが、上記下限以上及び上記上限以下であると、電極間の接続抵抗をより一層効果的に低くすることができる。 The average height of the plurality of protrusions is preferably 0.001 μm or more, more preferably 0.05 μm or more, preferably 1 μm or less, and more preferably 0.5 μm or less. When the average height of the protrusions is not less than the lower limit and not more than the upper limit, the connection resistance between the electrodes can be further effectively reduced.
　（絶縁性物質）
　上記導電性粒子は、上記第２の導電部の外表面上に配置された絶縁性物質を備えることが好ましい。この場合には、上記導電性粒子を電極間の接続に用いると、隣接する電極間の短絡をより一層防止できる。具体的には、複数の導電性粒子が接触したときに、複数の電極間に絶縁性物質が存在するので、上下の電極間ではなく横方向に隣り合う電極間の短絡を防止できる。なお、電極間の接続の際に、２つの電極で導電性粒子を加圧することにより、上記第２の導電部と電極との間の絶縁性物質を容易に排除できる。上記導電性粒子が上記第２の導電部の外表面に複数の突起を有する場合には、上記第２の導電部と電極との間の絶縁性物質をより一層容易に排除できる。 (Insulating substance)
It is preferable that the conductive particles include an insulating substance arranged on the outer surface of the second conductive portion. In this case, if the conductive particles are used for the connection between the electrodes, a short circuit between adjacent electrodes can be further prevented. Specifically, when a plurality of conductive particles come into contact with each other, an insulating substance exists between the plurality of electrodes, so that it is possible to prevent a short circuit between the electrodes adjacent to each other in the lateral direction rather than between the upper and lower electrodes. By pressurizing the conductive particles with the two electrodes when connecting the electrodes, the insulating substance between the second conductive portion and the electrodes can be easily removed. When the conductive particles have a plurality of protrusions on the outer surface of the second conductive portion, the insulating substance between the second conductive portion and the electrode can be more easily removed.
　電極間の圧着時に上記絶縁性物質をより一層容易に排除できることから、上記絶縁性物質は、絶縁性粒子であることが好ましい。上記絶縁性物質は、絶縁層であってもよい。 The insulating substance is preferably insulating particles because the insulating substance can be more easily removed during crimping between the electrodes. The insulating substance may be an insulating layer.
　上記絶縁性物質の材料としては、上述した樹脂粒子の材料、及び上述した基材粒子の材料として挙げた無機物等が挙げられる。上記絶縁性物質の材料は、上述した樹脂粒子の材料であることが好ましい。上記絶縁性物質は、上述した樹脂粒子又は上述した有機無機ハイブリッド粒子であることが好ましく、樹脂粒子であってもよく、有機無機ハイブリッド粒子であってもよい。 Examples of the material of the insulating substance include the above-mentioned resin particle material and the above-mentioned inorganic substance as the base particle material. The material of the insulating substance is preferably the material of the resin particles described above. The insulating substance is preferably the above-mentioned resin particles or the above-mentioned organic-inorganic hybrid particles, and may be resin particles or organic-inorganic hybrid particles.
　上記絶縁性物質の他の材料としては、ポリオレフィン化合物、（メタ）アクリレート重合体、（メタ）アクリレート共重合体、ブロックポリマー、熱可塑性樹脂、熱可塑性樹脂の架橋物、熱硬化性樹脂及び水溶性樹脂等が挙げられる。上記絶縁性物質の材料は、１種のみが用いられてもよく、２種以上が併用されてもよい。 Other materials of the insulating substance include polyolefin compounds, (meth) acrylate polymers, (meth) acrylate copolymers, block polymers, thermoplastic resins, crosslinked products of thermoplastic resins, thermosetting resins and water-soluble materials. Examples include resin. As the material of the insulating substance, only one kind may be used, or two or more kinds may be used in combination.
　上記ポリオレフィン化合物としては、ポリエチレン、エチレン－酢酸ビニル共重合体及びエチレン－アクリル酸エステル共重合体等が挙げられる。上記（メタ）アクリレート重合体としては、ポリメチル（メタ）アクリレート、ポリドデシル（メタ）アクリレート及びポリステアリル（メタ）アクリレート等が挙げられる。上記ブロックポリマーとしては、ポリスチレン、スチレン－アクリル酸エステル共重合体、ＳＢ型スチレン－ブタジエンブロック共重合体、及びＳＢＳ型スチレン－ブタジエンブロック共重合体、並びにこれらの水素添加物等が挙げられる。上記熱可塑性樹脂としては、ビニル重合体及びビニル共重合体等が挙げられる。上記熱硬化性樹脂としては、エポキシ樹脂、フェノール樹脂及びメラミン樹脂等が挙げられる。上記熱可塑性樹脂の架橋物としては、ポリエチレングリコールメタクリレート、アルコキシ化トリメチロールプロパンメタクリレートやアルコキシ化ペンタエリスリトールメタクリレート等の導入が挙げられる。上記水溶性樹脂としては、ポリビニルアルコール、ポリアクリル酸、ポリアクリルアミド、ポリビニルピロリドン、ポリエチレンオキシド及びメチルセルロース等が挙げられる。また、重合度の調整に、連鎖移動剤を使用してもよい。連鎖移動剤としては、チオールや四塩化炭素等が挙げられる。 Examples of the polyolefin compound include polyethylene, ethylene-vinyl acetate copolymer, ethylene-acrylic acid ester copolymer and the like. Examples of the (meth) acrylate polymer include polymethyl (meth) acrylate, polydodecyl (meth) acrylate, and polystearyl (meth) acrylate. Examples of the block polymer include polystyrene, styrene-acrylic acid ester copolymer, SB type styrene-butadiene block copolymer, SBS type styrene-butadiene block copolymer, and hydrogenated products thereof. Examples of the thermoplastic resin include vinyl polymers and vinyl copolymers. Examples of the thermosetting resin include epoxy resin, phenol resin, melamine resin and the like. Examples of the crosslinked product of the thermoplastic resin include the introduction of polyethylene glycol methacrylate, alkoxylated trimethylolpropane methacrylate, alkoxylated pentaerythritol methacrylate and the like. Examples of the water-soluble resin include polyvinyl alcohol, polyacrylic acid, polyacrylamide, polyvinylpyrrolidone, polyethylene oxide, methyl cellulose and the like. Further, a chain transfer agent may be used to adjust the degree of polymerization. Examples of the chain transfer agent include thiols and carbon tetrachloride.
　上記第２の導電部の外表面上に絶縁性物質を配置する方法としては、化学的方法、及び物理的もしくは機械的方法等が挙げられる。上記化学的方法としては、例えば、界面重合法、粒子存在下での懸濁重合法及び乳化重合法等が挙げられる。上記物理的もしくは機械的方法としては、スプレードライ、ハイブリダイゼーション、静電付着法、噴霧法、ディッピング及び真空蒸着による方法等が挙げられる。絶縁性物質が脱離し難いことから、上記第２の導電部の表面に、化学結合を介して上記絶縁性物質を配置する方法が好ましい。 Examples of the method of arranging the insulating substance on the outer surface of the second conductive portion include a chemical method and a physical or mechanical method. Examples of the chemical method include an interfacial polymerization method, a suspension polymerization method in the presence of particles, and an emulsion polymerization method. Examples of the physical or mechanical method include spray drying, hybridization, electrostatic adhesion method, spraying method, dipping and vacuum deposition method. Since the insulating substance is difficult to be detached, a method of arranging the insulating substance on the surface of the second conductive portion via a chemical bond is preferable.
　上記絶縁性物質の表面には、水酸基等の極性基が存在することが好ましい。上記極性基が存在することで、後述する連続膜が、上記絶縁性物質の表面をより一層均一に被覆することができる。 It is preferable that polar groups such as hydroxyl groups are present on the surface of the insulating substance. In the presence of the polar group, the continuous film described later can coat the surface of the insulating substance more uniformly.
　上記第２の導電部の外表面及び上記絶縁性粒子の表面はそれぞれ、反応性官能基を有する化合物によって被覆されていてもよい。上記第２の導電部の外表面と上記絶縁性粒子の表面とは、直接化学結合していなくてもよく、反応性官能基を有する化合物によって間接的に化学結合していてもよい。上記第２の導電部の外表面にカルボキシル基を導入した後、該カルボキシル基がポリエチレンイミン等の高分子電解質を介して絶縁性粒子の表面の官能基と化学結合していても構わない。 The outer surface of the second conductive portion and the surface of the insulating particles may each be coated with a compound having a reactive functional group. The outer surface of the second conductive portion and the surface of the insulating particles may not be directly chemically bonded, or may be indirectly chemically bonded by a compound having a reactive functional group. After introducing a carboxyl group into the outer surface of the second conductive portion, the carboxyl group may be chemically bonded to a functional group on the surface of the insulating particles via a polymer electrolyte such as polyethyleneimine.
　上記絶縁性物質が絶縁性粒子である場合に、上記絶縁性粒子の粒子径は、上記導電性粒子の粒子径及び用途等によって適宜選択できる。上記絶縁性粒子の粒子径は、好ましくは１０ｎｍ以上、より好ましくは１００ｎｍ以上であり、好ましくは４０００ｎｍ以下、より好ましくは２０００ｎｍ以下である。上記絶縁性粒子の粒子径が、上記下限以上であると、導電性粒子がバインダー樹脂中に分散されたときに、複数の導電性粒子における導電部同士が接触し難くなる。上記絶縁性粒子の粒子径が、上記上限以下であると、電極間の接続の際に、電極と導電性粒子との間の絶縁性粒子を排除するために、圧力を高くしすぎる必要がなくなり、高温に加熱する必要もなくなる。 When the insulating substance is an insulating particle, the particle size of the insulating particle can be appropriately selected depending on the particle size of the conductive particle, the application, and the like. The particle size of the insulating particles is preferably 10 nm or more, more preferably 100 nm or more, preferably 4000 nm or less, and more preferably 2000 nm or less. When the particle size of the insulating particles is at least the above lower limit, it becomes difficult for the conductive portions of the plurality of conductive particles to come into contact with each other when the conductive particles are dispersed in the binder resin. When the particle size of the insulating particles is not more than the above upper limit, it is not necessary to increase the pressure too high in order to eliminate the insulating particles between the electrodes and the conductive particles when connecting the electrodes. There is no need to heat to high temperature.
　上記絶縁性粒子の粒子径は、絶縁性粒子が真球状である場合には、直径を示し、絶縁性粒子が真球状ではない場合には、円相当径を示す。上記絶縁性粒子の粒子径は、平均粒子径であることが好ましく、数平均粒子径であることがより好ましい。上記絶縁性粒子の粒子径は、例えば、任意の絶縁性粒子５０個を電子顕微鏡又は光学顕微鏡にて観察し、各絶縁性粒子の粒子径の平均値を算出することや、レーザー回折式粒度分布測定を行うことにより求められる。電子顕微鏡又は光学顕微鏡での観察では、１個当たりの絶縁性粒子の粒子径は、円相当径での粒子径として求められる。電子顕微鏡又は光学顕微鏡での観察において、任意の５０個の絶縁性粒子の円相当径での平均粒子径は、球相当径での平均粒子径とほぼ等しくなる。レーザー回折式粒度分布測定では、１個当たりの絶縁性粒子の粒子径は、球相当径での粒子径として求められる。上記絶縁性粒子の粒子径は、レーザー回折式粒度分布測定により算出することが好ましい。また、導電性粒子において、絶縁性粒子の粒子径を測定する場合には、例えば、以下のようにして測定できる。 The particle diameter of the insulating particles indicates the diameter when the insulating particles are spherical, and indicates the equivalent circle diameter when the insulating particles are not spherical. The particle size of the insulating particles is preferably an average particle size, and more preferably a number average particle size. For the particle size of the insulating particles, for example, 50 arbitrary insulating particles can be observed with an electron microscope or an optical microscope to calculate the average value of the particle size of each insulating particle, or a laser diffraction type particle size distribution. Obtained by making measurements. In observation with an electron microscope or an optical microscope, the particle size of each insulating particle is determined as the particle size in the equivalent circle diameter. When observed with an electron microscope or an optical microscope, the average particle diameter of any 50 insulating particles in the equivalent circle diameter is substantially equal to the average particle diameter in the equivalent diameter of the sphere. In the laser diffraction type particle size distribution measurement, the particle size of each insulating particle is determined as the particle size in the equivalent sphere diameter. The particle size of the insulating particles is preferably calculated by laser diffraction type particle size distribution measurement. Further, in the case of measuring the particle size of the insulating particles in the conductive particles, for example, the measurement can be performed as follows.
　導電性粒子を含有量が３０重量％となるように、Ｋｕｌｚｅｒ社製「テクノビット４０００」に添加し、分散させて、導電性粒子検査用埋め込み樹脂体を作製する。その検査用埋め込み樹脂体中の分散した導電性粒子の中心付近を通るようにイオンミリング装置（日立ハイテクノロジーズ社製「ＩＭ４０００」）を用いて、導電性粒子の断面を切り出す。そして、電界放射型走査型電子顕微鏡（ＦＥ－ＳＥＭ）を用いて、画像倍率５万倍に設定し、５０個の導電性粒子を無作為に選択し、各導電性粒子における絶縁性粒子を観察する。各導電性粒子における絶縁性粒子の粒子径を計測し、それらを算術平均して絶縁性粒子の粒子径とする。 Conductive particles are added to "Technobit 4000" manufactured by Kulzer so as to have a content of 30% by weight and dispersed to prepare an embedded resin body for conducting conductive particle inspection. A cross section of the conductive particles is cut out using an ion milling device (“IM4000” manufactured by Hitachi High-Technologies Corporation) so as to pass near the center of the dispersed conductive particles in the embedded resin body for inspection. Then, using a field emission scanning electron microscope (FE-SEM), the image magnification was set to 50,000 times, 50 conductive particles were randomly selected, and the insulating particles in each conductive particle were observed. To do. The particle size of the insulating particles in each conductive particle is measured, and they are arithmetically averaged to obtain the particle size of the insulating particles.
　上記絶縁性物質が絶縁性粒子である場合に、上記導電性粒子の粒子径の上記絶縁性粒子の粒子径に対する比（導電性粒子の粒子径／絶縁性粒子の粒子径）は、好ましくは３以上、より好ましくは５以上、より一層好ましくは８以上、さらに好ましくは１０以上、特に好ましくは１２以上である。上記絶縁性物質が絶縁性粒子である場合に、上記導電性粒子の粒子径の上記絶縁性粒子の粒子径に対する比（導電性粒子の粒子径／絶縁性粒子の粒子径）は、好ましくは１０００以下、より好ましくは１００以下、より一層好ましくは７５以下、さらに好ましくは５０以下、特に好ましくは３０以下である。上記比（導電性粒子の粒子径／絶縁性粒子の粒子径）が、上記下限以上及び上記上限以下であると、上記第２の導電部の外表面上に絶縁性粒子をより一層均一に配置することができ、電極間の絶縁信頼性をより一層効果的に高めることができる。 When the insulating substance is an insulating particle, the ratio of the particle size of the conductive particle to the particle size of the insulating particle (particle size of the conductive particle / particle size of the insulating particle) is preferably 3. As mentioned above, it is more preferably 5 or more, even more preferably 8 or more, still more preferably 10 or more, and particularly preferably 12 or more. When the insulating substance is an insulating particle, the ratio of the particle size of the conductive particle to the particle size of the insulating particle (particle size of the conductive particle / particle size of the insulating particle) is preferably 1000. Below, it is more preferably 100 or less, even more preferably 75 or less, still more preferably 50 or less, and particularly preferably 30 or less. When the ratio (particle size of conductive particles / particle size of insulating particles) is equal to or higher than the lower limit and lower than the upper limit, the insulating particles are arranged more uniformly on the outer surface of the second conductive portion. It is possible to further effectively enhance the insulation reliability between the electrodes.
　（連続膜）
　上記導電性粒子が上記絶縁性物質を備える場合に、上記導電性粒子は、無機材料を含む連続膜を備えることが好ましい。上記連続膜は、上記第２の導電部の表面を覆っている部分と、上記絶縁性物質の表面を覆っている部分とを有することが好ましい。上記導電性粒子では、上記第２の導電部の表面と上記絶縁性物質の表面とが上記連続膜により被覆されていることが好ましく、上記第２の導電部の表面を被覆している上記連続膜と上記絶縁性物質を被覆している上記連続膜とが連なっていることが好ましい。この場合には、導電性粒子をバインダー樹脂中に分散させる等の導電接続前に導電性粒子の表面から絶縁性物質が意図せずに脱離することをより一層効果的に防止できる。結果として、隣接する電極間の絶縁信頼性をより一層効果的に高めることができる。 (Continuous membrane)
When the conductive particles include the insulating substance, the conductive particles preferably include a continuous film containing an inorganic material. The continuous film preferably has a portion that covers the surface of the second conductive portion and a portion that covers the surface of the insulating substance. In the conductive particles, it is preferable that the surface of the second conductive portion and the surface of the insulating substance are covered with the continuous film, and the continuous surface of the second conductive portion is covered. It is preferable that the film and the continuous film covering the insulating substance are connected. In this case, it is possible to more effectively prevent the insulating substance from being unintentionally desorbed from the surface of the conductive particles before the conductive connection such as dispersing the conductive particles in the binder resin. As a result, the insulation reliability between adjacent electrodes can be further effectively enhanced.
　電極間の絶縁信頼性をより一層効果的に高める観点、及び電極間の導通信頼性をより一層効果的に高める観点からは、上記連続膜は、無機酸化物膜であることが好ましい。上記連続膜は無機材料により形成されていることが好ましい。この場合には、導電性粒子を用いて電極間を電気的に接続する際に、導電性粒子の表面から絶縁性物質がより一層容易に脱離できる。結果として、電極間の導通信頼性をより一層効果的に高めることができる。 From the viewpoint of further effectively enhancing the insulation reliability between the electrodes and further effectively enhancing the conduction reliability between the electrodes, the continuous film is preferably an inorganic oxide film. The continuous film is preferably formed of an inorganic material. In this case, when the electrodes are electrically connected using the conductive particles, the insulating substance can be more easily desorbed from the surface of the conductive particles. As a result, the conduction reliability between the electrodes can be further effectively enhanced.
　上記無機材料及び上記無機酸化物膜の材料としては、ケイ素、チタニウム、ジルコニウム、及びアルミニウム等の酸化物、並びに、これらの酸化物の複合物等が挙げられる。 Examples of the inorganic material and the material of the inorganic oxide film include oxides such as silicon, titanium, zirconium, and aluminum, and composites of these oxides.
　電極間の絶縁信頼性をより一層効果的に高める観点、及び電極間の導通信頼性をより一層効果的に高める観点からは、上記連続膜の厚みは、好ましくは１ｎｍ以上、より好ましくは１０ｎｍ以上であり、好ましくは５００ｎｍ以下、より好ましくは１００ｎｍ以下である。上記連続膜が２層以上の多層構造である場合には、上記連続膜の厚みは、全ての層の合計の厚みであることが好ましい。 From the viewpoint of further effectively enhancing the insulation reliability between the electrodes and further effectively enhancing the conduction reliability between the electrodes, the thickness of the continuous film is preferably 1 nm or more, more preferably 10 nm or more. It is preferably 500 nm or less, more preferably 100 nm or less. When the continuous film has a multilayer structure of two or more layers, the thickness of the continuous film is preferably the total thickness of all the layers.
　上記連続膜の厚みは、任意の導電性粒子５０個を電子顕微鏡にて観察し、平均値を算出することにより求めることが好ましい。導電性粒子において、連続膜の厚みを測定する場合には、例えば、以下のように測定できる。 The thickness of the continuous film is preferably determined by observing 50 arbitrary conductive particles with an electron microscope and calculating an average value. When measuring the thickness of a continuous film in conductive particles, for example, it can be measured as follows.
　導電性粒子を含有量が３０重量％となるように、Ｋｕｌｚｅｒ社製「テクノビット４０００」に添加し、分散させて、導電性粒子検査用埋め込み樹脂体を作製する。その検査用埋め込み樹脂体中の分散した導電性粒子の中心付近を通るようにイオンミリング装置（日立ハイテクノロジーズ社製「ＩＭ４０００」）を用いて、導電性粒子の断面を切り出す。そして、電界放射型走査型電子顕微鏡（ＦＥ－ＳＥＭ）を用いて、画像倍率５万倍に設定し、５０個の導電性粒子を無作為に選択し、各導電性粒子における連続膜を観察する。各導電性粒子における連続膜の厚みを計測し、それらを算術平均して連続膜の厚みとする。 Conductive particles are added to "Technobit 4000" manufactured by Kulzer so as to have a content of 30% by weight and dispersed to prepare an embedded resin body for conducting conductive particle inspection. A cross section of the conductive particles is cut out using an ion milling device (“IM4000” manufactured by Hitachi High-Technologies Corporation) so as to pass near the center of the dispersed conductive particles in the embedded resin body for inspection. Then, using a field emission scanning electron microscope (FE-SEM), the image magnification is set to 50,000 times, 50 conductive particles are randomly selected, and a continuous film in each conductive particle is observed. .. The thickness of the continuous film in each conductive particle is measured, and they are arithmetically averaged to obtain the thickness of the continuous film.
　上記絶縁性物質が絶縁性粒子である場合に、上記連続膜の厚みの上記絶縁性粒子の粒子径に対する比（連続膜の厚み／絶縁性粒子の粒子径）は、好ましくは０．０１以上、より好ましくは０．０５以上であり、好ましくは１以下、より好ましくは０．１以下である。上記比（連続膜の厚み／絶縁性粒子の粒子径）が、上記下限以上及び上記上限以下であると、電極間の絶縁信頼性をより一層効果的に高めることができ、電極間の導通信頼性をより一層効果的に高めることができる。 When the insulating substance is an insulating particle, the ratio of the thickness of the continuous film to the particle size of the insulating particle (thickness of the continuous film / particle size of the insulating particle) is preferably 0.01 or more. It is more preferably 0.05 or more, preferably 1 or less, and more preferably 0.1 or less. When the above ratio (thickness of continuous film / particle size of insulating particles) is equal to or more than the above lower limit and less than or equal to the above upper limit, the insulation reliability between the electrodes can be further effectively enhanced, and the conduction reliability between the electrodes can be further improved. The sex can be enhanced even more effectively.
　上記第２の導電部の表面及び上記絶縁性物質の表面を上記連続膜で被覆する方法としては、アルコキシドの加水分解反応を用いて、上記第２の導電部の表面及び上記絶縁性物質の表面に絶縁性組成物（金属アルコキシドを含む組成物）をコーティングする方法等が挙げられる。 As a method of coating the surface of the second conductive portion and the surface of the insulating substance with the continuous film, the surface of the second conductive portion and the surface of the insulating substance are used by using an alkoxide hydrolysis reaction. Examples thereof include a method of coating an insulating composition (composition containing a metal alkoxide).
　（防錆処理）
　導電性粒子の腐食を抑え、電極間の接続抵抗をより一層低くする観点からは、上記第２の導電部の外表面は防錆処理されていることが好ましい。 (Rust prevention treatment)
From the viewpoint of suppressing corrosion of the conductive particles and further lowering the connection resistance between the electrodes, it is preferable that the outer surface of the second conductive portion is rust-proofed.
　導通信頼性をより一層高める観点からは、上記第２の導電部の外表面は、炭素数６～２２のアルキル基を有する化合物により、防錆処理されていることが好ましい。上記第２の導電部の外表面は、リンを含まない化合物により防錆処理されていてもよく、炭素数６～２２のアルキル基を有しかつリンを含まない化合物により防錆処理されていてもよい。導通信頼性をより一層高める観点からは、上記第２の導電部の外表面は、アルキルリン酸化合物又はアルキルチオールにより、防錆処理されていることが好ましい。防錆処理により、第２の導電部の外表面に、防錆膜を形成できる。 From the viewpoint of further enhancing the conduction reliability, it is preferable that the outer surface of the second conductive portion is rust-proofed with a compound having an alkyl group having 6 to 22 carbon atoms. The outer surface of the second conductive portion may be rust-proofed with a phosphorus-free compound, or may be rust-proofed with a phosphorus-free compound having an alkyl group having 6 to 22 carbon atoms. May be good. From the viewpoint of further enhancing the conduction reliability, it is preferable that the outer surface of the second conductive portion is rust-proofed with an alkylphosphoric acid compound or an alkylthiol. By the rust preventive treatment, a rust preventive film can be formed on the outer surface of the second conductive portion.
　上記防錆膜は、炭素数６～２２のアルキル基を有する化合物（以下、化合物Ａともいう）により形成されていることが好ましい。上記第２の導電部の外表面は、上記化合物Ａにより表面処理されていることが好ましい。上記アルキル基の炭素数が６以上であると、第２の導電部全体で錆がより一層生じ難くなる。上記アルキル基の炭素数が２２以下であると、導電性粒子の導電性が高くなる。導電性粒子の導電性をより一層高める観点からは、上記化合物Ａにおける上記アルキル基の炭素数は１６以下であることが好ましい。上記アルキル基は直鎖構造を有していてもよく、分岐構造を有していてもよい。上記アルキル基は、直鎖構造を有することが好ましい。 The rust preventive film is preferably formed of a compound having an alkyl group having 6 to 22 carbon atoms (hereinafter, also referred to as compound A). The outer surface of the second conductive portion is preferably surface-treated with the compound A. When the number of carbon atoms of the alkyl group is 6 or more, rust is less likely to occur in the entire second conductive portion. When the number of carbon atoms of the alkyl group is 22 or less, the conductivity of the conductive particles becomes high. From the viewpoint of further increasing the conductivity of the conductive particles, the number of carbon atoms of the alkyl group in the compound A is preferably 16 or less. The alkyl group may have a linear structure or a branched structure. The alkyl group preferably has a linear structure.
　上記化合物Ａは、炭素数６～２２のアルキル基を有していれば特に限定されない。上記化合物Ａは、炭素数６～２２のアルキル基を有するリン酸エステル若しくはその塩、炭素数６～２２のアルキル基を有する亜リン酸エステル若しくはその塩、又は炭素数６～２２のアルキル基を有するアルコキシシランであることが好ましい。上記化合物Ａは、炭素数６～２２のアルキル基を有するアルキルチオール、又は、炭素数６～２２のアルキル基を有するジアルキルジスルフィドであることが好ましい。上記炭素数６～２２のアルキル基を有する化合物Ａは、リン酸エステル若しくはその塩、亜リン酸エステル若しくはその塩、アルコキシシラン、アルキルチオール又はジアルキルジスルフィドであることが好ましい。これらの好ましい化合物Ａの使用により、上記第２の導電部に錆をより一層生じ難くすることができる。錆をより一層生じ難くする観点からは、上記化合物Ａは、上記リン酸エステル若しくはその塩、亜リン酸エステル若しくはその塩、又は、アルキルチオールであることが好ましく、上記リン酸エステル若しくはその塩、又は、亜リン酸エステル若しくはその塩であることがより好ましい。上記化合物Ａは、１種のみが用いられてもよく、２種以上が併用されてもよい。 The compound A is not particularly limited as long as it has an alkyl group having 6 to 22 carbon atoms. The compound A contains a phosphoric acid ester having an alkyl group having 6 to 22 carbon atoms or a salt thereof, a phosphite ester having an alkyl group having 6 to 22 carbon atoms or a salt thereof, or an alkyl group having 6 to 22 carbon atoms. It is preferably an alkoxysilane having. The compound A is preferably an alkyl thiol having an alkyl group having 6 to 22 carbon atoms or a dialkyl disulfide having an alkyl group having 6 to 22 carbon atoms. The compound A having an alkyl group having 6 to 22 carbon atoms is preferably a phosphoric acid ester or a salt thereof, a phosphite ester or a salt thereof, an alkoxysilane, an alkylthiol or a dialkyldisulfide. By using these preferable compounds A, it is possible to make it even more difficult for rust to occur in the second conductive portion. From the viewpoint of making rust less likely to occur, the compound A is preferably a phosphoric acid ester or a salt thereof, a phosphite ester or a salt thereof, or an alkylthiol, and the phosphoric acid ester or a salt thereof. Alternatively, it is more preferably a phosphite ester or a salt thereof. As the compound A, only one kind may be used, or two or more kinds may be used in combination.
　上記化合物Ａは、第２の導電部の外表面と反応可能な反応性官能基を有することが好ましい。上記化合物Ａは、上記絶縁性物質と反応可能な反応性官能基を有することが好ましい。上記防錆膜は、第２の導電部と化学結合していることが好ましい。上記防錆膜は、上記絶縁性物質と化学結合していることが好ましい。上記防錆膜は、上記第２の導電部及び上記絶縁性物質の双方と化学結合していることがより好ましい。上記反応性官能基の存在により、及び上記化学結合により、上記防錆膜の剥離が生じ難くなり、この結果、第２の導電部に錆がより一層生じ難くなり、かつ導電性粒子の表面から絶縁性物質が意図せずにより一層脱離し難くなる。 The compound A preferably has a reactive functional group capable of reacting with the outer surface of the second conductive portion. The compound A preferably has a reactive functional group capable of reacting with the insulating substance. The rust preventive film is preferably chemically bonded to the second conductive portion. The rust preventive film is preferably chemically bonded to the insulating substance. It is more preferable that the rust preventive film is chemically bonded to both the second conductive portion and the insulating substance. Due to the presence of the reactive functional group and the chemical bond, the rust preventive film is less likely to be peeled off, and as a result, rust is less likely to occur on the second conductive portion, and from the surface of the conductive particles. The insulating material becomes more difficult to detach unintentionally.
　上記炭素数６～２２のアルキル基を有するリン酸エステル又はその塩としては、例えば、リン酸ヘキシルエステル、リン酸ヘプチルエステル、リン酸モノオクチルエステル、リン酸モノノニルエステル、リン酸モノデシルエステル、リン酸モノウンデシルエステル、リン酸モノドデシルエステル、リン酸モノトリデシルエステル、リン酸モノテトラデシルエステル、リン酸モノペンタデシルエステル、リン酸モノヘキシルエステルモノナトリウム塩、リン酸モノヘプチルエステルモノナトリウム塩、リン酸モノオクチルエステルモノナトリウム塩、リン酸モノノニルエステルモノナトリウム塩、リン酸モノデシルエステルモノナトリウム塩、リン酸モノウンデシルエステルモノナトリウム塩、リン酸モノドデシルエステルモノナトリウム塩、リン酸モノトリデシルエステルモノナトリウム塩、リン酸モノテトラデシルエステルモノナトリウム塩及びリン酸モノペンタデシルエステルモノナトリウム塩等が挙げられる。上記リン酸エステルのカリウム塩を用いてもよい。 Examples of the phosphoric acid ester having an alkyl group having 6 to 22 carbon atoms or a salt thereof include phosphoric acid hexyl ester, phosphoric acid heptyl ester, phosphoric acid monooctyl ester, phosphoric acid monononyl ester, and phosphoric acid monodecyl ester. Organophosphate monoundecyl ester, phosphate monododecyl ester, phosphate monotridecyl ester, phosphate monotetradecyl ester, phosphate monopentadecyl ester, phosphate monohexyl ester monosodium salt, phosphate monoheptyl ester monosodium Salt, monooctyl phosphate monosodium salt, mononoyl phosphate monosodium salt, monodecyl phosphate monosodium salt, monoundecyl phosphate monosodium salt, monododecyl phosphate monosodium salt, phosphate Examples thereof include a monotridecyl ester monosodium salt, a monotetradecyl phosphate monosodium salt, and a monopentadecyl phosphate monosodium salt. The potassium salt of the above-mentioned phosphoric acid ester may be used.
　上記炭素数６～２２のアルキル基を有する亜リン酸エステル又はその塩としては、例えば、亜リン酸ヘキシルエステル、亜リン酸ヘプチルエステル、亜リン酸モノオクチルエステル、亜リン酸モノノニルエステル、亜リン酸モノデシルエステル、亜リン酸モノウンデシルエステル、亜リン酸モノドデシルエステル、亜リン酸モノトリデシルエステル、亜リン酸モノテトラデシルエステル、亜リン酸モノペンタデシルエステル、亜リン酸モノヘキシルエステルモノナトリウム塩、亜リン酸モノヘプチルエステルモノナトリウム塩、亜リン酸モノオクチルエステルモノナトリウム塩、亜リン酸モノノニルエステルモノナトリウム塩、亜リン酸モノデシルエステルモノナトリウム塩、亜リン酸モノウンデシルエステルモノナトリウム塩、亜リン酸モノドデシルエステルモノナトリウム塩、亜リン酸モノトリデシルエステルモノナトリウム塩、亜リン酸モノテトラデシルエステルモノナトリウム塩及び亜リン酸モノペンタデシルエステルモノナトリウム塩等が挙げられる。上記亜リン酸エステルのカリウム塩を用いてもよい。 Examples of the phosphite ester having an alkyl group having 6 to 22 carbon atoms or a salt thereof include hexyl phosphite ester, heptyl phosphite ester, monooctyl phosphite ester, monononyl phosphite ester, and sub-phosphate. Monodecyl phosphate, monoundecyl phosphite, monododecyl phosphite, monotridecyl phosphite, monotetradecyl phosphite, monopentadecyl phosphite, monohexyl phosphite Ester monosodium salt, phosphite monoheptyl ester monosodium salt, phosphite monooctyl ester monosodium salt, phosphite monononyl ester monosodium salt, phosphite monodecyl ester monosodium salt, phosphite monoun Decyl ester monosodium salt, phosphite monododecyl ester monosodium salt, phosphite monotridecyl ester monosodium salt, phosphite monotetradecyl ester monosodium salt, phosphite monopentadecyl ester monosodium salt, etc. Can be mentioned. The potassium salt of the above phosphite ester may be used.
　上記炭素数６～２２のアルキル基を有するアルコキシシランとしては、例えば、ヘキシルトリメトキシシラン、ヘキシルトリエトキシシラン、ヘプチルトリメトキシシラン、ヘプチルトリエトキシシラン、オクチルトリメトキシシラン、オクチルトリエトキシシラン、ノニルトリメトキシシラン、ノニルトリエトキシシラン、デシルトリメトキシシラン、デシルトリエトキシシラン、ウンデシルトリメトキシシラン、ウンデシルトリエトキシシラン、ドデシルトリメトキシシラン、ドデシルトリエトキシシラン、トリデシルトリメトキシシラン、トリデシルトリエトキシシラン、テトラデシルトリメトキシシラン、テトラデシルトリエトキシシラン、ペンタデシルトリメトキシシラン及びペンタデシルトリエトキシシラン等が挙げられる。 Examples of the alkoxysilane having an alkyl group having 6 to 22 carbon atoms include hexyltrimethoxysilane, hexyltriethoxysilane, heptyltrimethoxysilane, heptyltriethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, and nonyltri. Methoxysilane, nonyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, undecyltrimethoxysilane, undecyltriethoxysilane, dodecyltrimethoxysilane, dodecyltriethoxysilane, tridecyltrimethoxysilane, tridecyltriethoxysilane Examples thereof include silane, tetradecyltrimethoxysilane, tetradecyltriethoxysilane, pentadecyltrimethoxysilane, and pentadecyltriethoxysilane.
　上記炭素数６～２２のアルキル基を有するアルキルチオールとしては、例えば、ヘキシルチオール、ヘプチルチオール、オクチルチオール、ノニルチオール、デシルチオール、ウンデシルチオール、ドデシルチオール、トリデシルチオール、テトラデシルチオール、ペンタデシルチオール及びヘキサデシルチオール等が挙げられる。上記アルキルチオールは、アルキル鎖の末端にチオール基を有することが好ましい。 Examples of the alkyl thiol having an alkyl group having 6 to 22 carbon atoms include hexyl thiol, heptyl thiol, octyl thiol, nonyl thiol, decyl thiol, undecyl thiol, dodecyl thiol, tridecyl thiol, tetradecyl thiol and pentadecyl. Examples thereof include thiols and hexadecylthiols. The alkyl thiol preferably has a thiol group at the end of the alkyl chain.
　上記炭素数６～２２のアルキル基を有するジアルキルジスルフィドとしては、例えば、ジヘキシルジスルフィド、ジヘプチルジスルフィド、ジオクチルジスルフィド、ジノニルジスルフィド、ジデシルジスルフィド、ジウンデシルジスルフィド、ジドデシルジスルフィド、ジトリデシルジスルフィド、ジテトラデシルジスルフィド、ジペンタデシルジスルフィド及びジヘキサデシルジスルフィド等が挙げられる。 Examples of the dialkyl disulfide having an alkyl group having 6 to 22 carbon atoms include dihexyl disulfide, diheptyl disulfide, dioctyl disulfide, dinonyl disulfide, didecyl disulfide, diundecyl disulfide, didodecyl disulfide, ditridecyl disulfide, and ditetra. Examples thereof include decyl disulfide, dipenta decyl disulfide and dihexadecyl disulfide.
　（用途）
　上記導電性粒子は、電極と、上記電極の表面上に配置された保護層とを備える保護層付き電極の導電接続用途に好適に用いることができる。上記導電性粒子は、配線と、上記配線の表面上に配置された保護層とを備える保護層付き配線の導電接続用途に好適に用いることができる。上記電極及び上記配線の材料としては、金、銀又は銅等の貴金属が挙げられる。電極の防錆性をより一層向上させる観点からは、上記保護層は、メルカプト基を有するトリアゾール化合物、メルカプト基を有するテトラゾール化合物、メルカプト基を有するチアジアゾール化合物、アミノ基を有するトリアゾール化合物又はアミノ基を有するテトラゾール化合物を含有することが好ましい。上記保護層付き電極又は上記保護層付き配線の導電接続用途に上記導電性粒子を用いた場合には、電極間の接続抵抗をより一層効果的に低くすることができ、導通信頼性をより一層効果的に高めることができる。 (Use)
The conductive particles can be suitably used for conductive connection of an electrode with a protective layer including an electrode and a protective layer arranged on the surface of the electrode. The conductive particles can be suitably used for conductive connection of wiring with a protective layer including the wiring and a protective layer arranged on the surface of the wiring. Examples of the material of the electrode and the wiring include a precious metal such as gold, silver or copper. From the viewpoint of further improving the rust resistance of the electrode, the protective layer comprises a triazole compound having a mercapto group, a tetrazole compound having a mercapto group, a thiazazole compound having a mercapto group, a triazole compound having an amino group, or an amino group. It is preferable to contain the tetrazole compound having. When the conductive particles are used for the conductive connection of the electrode with the protective layer or the wiring with the protective layer, the connection resistance between the electrodes can be lowered more effectively, and the conduction reliability can be further improved. Can be effectively enhanced.
　また、上記導電性粒子は、フレキシブル部材の電極の導電接続用途に好適に用いることができる。上記フレキシブル部材を用いた接続構造体としては、フレキシブルパネル等が挙げられる。フレキブルパネルは、曲面パネルとして用いることが可能である。上記導電性粒子は、フレキシブルパネルの接続部を形成するために用いられることが好ましく、曲面パネルの接続部を形成するために用いられることが好ましい。 Further, the conductive particles can be suitably used for conductive connection of electrodes of flexible members. Examples of the connection structure using the flexible member include a flexible panel and the like. The flexible panel can be used as a curved panel. The conductive particles are preferably used for forming the connecting portion of the flexible panel, and preferably used for forming the connecting portion of the curved panel.
　（導電材料）
　本発明に係る導電材料は、上述した導電性粒子と、バインダー樹脂とを含む。上記導電性粒子は、バインダー樹脂中に分散され、導電材料として用いられることが好ましい。上記導電材料は、異方性導電材料であることが好ましい。上記導電性粒子及び上記導電材料はそれぞれ、電極間の電気的な接続に用いられることが好ましい。上記導電材料は、回路接続用材料であることが好ましい。 (Conductive material)
The conductive material according to the present invention includes the above-mentioned conductive particles and a binder resin. The conductive particles are preferably dispersed in the binder resin and used as a conductive material. The conductive material is preferably an anisotropic conductive material. It is preferable that the conductive particles and the conductive material are used for electrical connection between the electrodes, respectively. The conductive material is preferably a circuit connection material.
　上記バインダー樹脂は特に限定されない。上記バインダー樹脂として、公知の絶縁性の樹脂が用いられる。 The binder resin is not particularly limited. As the binder resin, a known insulating resin is used.
　上記バインダー樹脂としては、例えば、ビニル樹脂、熱可塑性樹脂、硬化性樹脂、熱可塑性ブロック共重合体及びエラストマー等が挙げられる。上記バインダー樹脂は１種のみが用いられてもよく、２種以上が併用されてもよい。 Examples of the binder resin include vinyl resins, thermoplastic resins, curable resins, thermoplastic block copolymers, and elastomers. Only one kind of the binder resin may be used, or two or more kinds may be used in combination.
　上記ビニル樹脂としては、例えば、酢酸ビニル樹脂、アクリル樹脂及びスチレン樹脂等が挙げられる。上記熱可塑性樹脂としては、例えば、ポリオレフィン樹脂、エチレン－酢酸ビニル共重合体及びポリアミド樹脂等が挙げられる。上記硬化性樹脂としては、例えば、エポキシ樹脂、ウレタン樹脂、ポリイミド樹脂及び不飽和ポリエステル樹脂等が挙げられる。なお、上記硬化性樹脂は、常温硬化型樹脂、熱硬化型樹脂、光硬化型樹脂又は湿気硬化型樹脂であってもよい。上記硬化性樹脂は、硬化剤と併用されてもよい。上記熱可塑性ブロック共重合体としては、例えば、スチレン－ブタジエン－スチレンブロック共重合体、スチレン－イソプレン－スチレンブロック共重合体、スチレン－ブタジエン－スチレンブロック共重合体の水素添加物、及びスチレン－イソプレン－スチレンブロック共重合体の水素添加物等が挙げられる。上記エラストマーとしては、例えば、スチレン－ブタジエン共重合ゴム、及びアクリロニトリル－スチレンブロック共重合ゴム等が挙げられる。 Examples of the vinyl resin include vinyl acetate resin, acrylic resin, styrene resin and the like. Examples of the thermoplastic resin include polyolefin resins, ethylene-vinyl acetate copolymers, and polyamide resins. Examples of the curable resin include epoxy resin, urethane resin, polyimide resin, unsaturated polyester resin and the like. The curable resin may be a room temperature curable resin, a thermosetting resin, a photocurable resin, or a moisture curable resin. The curable resin may be used in combination with a curing agent. Examples of the thermoplastic block copolymer include a styrene-butadiene-styrene block copolymer, a styrene-isoprene-styrene block copolymer, a hydrogenated additive of a styrene-butadiene-styrene block copolymer, and a styrene-isoprene. -Hydrogen additives for styrene block copolymers and the like can be mentioned. Examples of the elastomer include styrene-butadiene copolymer rubber and acrylonitrile-styrene block copolymer rubber.
　上記導電材料及び上記バインダー樹脂は、熱可塑性成分又は熱硬化性成分を含むことが好ましい。上記導電材料及び上記バインダー樹脂は、熱可塑性成分を含んでいてもよく、熱硬化性成分を含んでいてもよい。上記導電材料及び上記バインダー樹脂は、熱硬化性成分を含むことが好ましい。上記熱硬化性成分は、加熱により硬化可能な硬化性化合物と熱硬化剤とを含むことが好ましい。上記熱硬化剤は、熱カチオン硬化開始剤であることが好ましい。上記加熱により硬化可能な硬化性化合物と上記熱硬化剤とは、上記バインダー樹脂が硬化するように適宜の配合比で用いられる。 The conductive material and the binder resin preferably contain a thermoplastic component or a thermosetting component. The conductive material and the binder resin may contain a thermoplastic component or may contain a thermosetting component. The conductive material and the binder resin preferably contain a thermosetting component. The thermosetting component preferably contains a curable compound that can be cured by heating and a thermosetting agent. The thermosetting agent is preferably a thermal cation curing initiator. The curable compound curable by heating and the thermosetting agent are used in an appropriate compounding ratio so that the binder resin is cured.
　上記導電材料は、上記導電性粒子及び上記バインダー樹脂の他に、例えば、充填剤、増量剤、軟化剤、可塑剤、重合触媒、硬化触媒、着色剤、酸化防止剤、熱安定剤、光安定剤、紫外線吸収剤、滑剤、帯電防止剤及び難燃剤等の各種添加剤を含んでいてもよい。 In addition to the conductive particles and the binder resin, the conductive material includes, for example, a filler, a bulking agent, a softening agent, a plasticizer, a polymerization catalyst, a curing catalyst, a colorant, an antioxidant, a heat stabilizer, and a photostabilizer. It may contain various additives such as an agent, an ultraviolet absorber, a lubricant, an antistatic agent and a flame retardant.
　上記バインダー中に上記導電性粒子を分散させる方法は、従来公知の分散方法を用いることができ、特に限定されない。上記バインダー中に上記導電性粒子を分散させる方法としては、上記バインダー中に上記導電性粒子を添加した後、プラネタリーミキサー等で混練して分散させる方法、上記導電性粒子を水又は有機溶剤中にホモジナイザー等を用いて均一に分散させた後、上記バインダー中に添加し、プラネタリーミキサー等で混練して分散させる方法が挙げられる。さらに、上記バインダー中に上記導電性粒子を分散させる方法としては、上記バインダーを水又は有機溶剤等で希釈した後、上記導電性粒子を添加し、プラネタリーミキサー等で混練して分散させる方法等が挙げられる。 The method for dispersing the conductive particles in the binder can be a conventionally known dispersion method and is not particularly limited. Examples of the method of dispersing the conductive particles in the binder include a method of adding the conductive particles to the binder and then kneading and dispersing the conductive particles with a planetary mixer or the like, and a method of dispersing the conductive particles in water or an organic solvent. After uniformly dispersing the particles with a homogenizer or the like, the particles are added to the binder and kneaded with a planetary mixer or the like to disperse the particles. Further, as a method for dispersing the conductive particles in the binder, a method in which the binder is diluted with water or an organic solvent, the conductive particles are added, and the particles are kneaded and dispersed with a planetary mixer or the like. Can be mentioned.
　上記導電材料は、導電ペースト及び導電フィルム等として使用され得る。上記導電材料が、導電フィルムである場合には、導電性粒子を含む導電フィルムに、導電性粒子を含まないフィルムが積層されていてもよい。上記導電ペーストは、異方性導電ペーストであることが好ましい。上記導電フィルムは、異方性導電フィルムであることが好ましい。 The conductive material can be used as a conductive paste, a conductive film, or the like. When the conductive material is a conductive film, a film containing no conductive particles may be laminated on the conductive film containing the conductive particles. The conductive paste is preferably an anisotropic conductive paste. The conductive film is preferably an anisotropic conductive film.
　上記導電材料１００重量％中、上記バインダー樹脂の含有量は好ましくは１０重量％以上、より好ましくは３０重量％以上、さらに好ましくは５０重量％以上、特に好ましくは７０重量％以上であり、好ましくは９９．９９重量％以下、より好ましくは９９．９重量％以下である。上記バインダー樹脂の含有量が、上記下限以上及び上記上限以下であると、電極間に導電性粒子が効率的に配置され、導電材料により接続された接続対象部材の接続信頼性をより一層高くすることができる。 The content of the binder resin in 100% by weight of the conductive material is preferably 10% by weight or more, more preferably 30% by weight or more, still more preferably 50% by weight or more, particularly preferably 70% by weight or more, and preferably 70% by weight or more. It is 99.99% by weight or less, more preferably 99.9% by weight or less. When the content of the binder resin is not less than the above lower limit and not more than the above upper limit, the conductive particles are efficiently arranged between the electrodes, and the connection reliability of the connection target member connected by the conductive material is further improved. be able to.
　上記導電材料１００重量％中、上記導電性粒子の含有量は好ましくは０．０１重量％以上、より好ましくは０．１重量％以上であり、好ましくは８０重量％以下、より好ましくは６０重量％以下、さらに好ましくは４０重量％以下、特に好ましくは２０重量％以下、最も好ましくは１０重量％以下である。上記導電性粒子の含有量が、上記下限以上及び上記上限以下であると、電極間の導通信頼性をより一層高くすることができる。 The content of the conductive particles in 100% by weight of the conductive material is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, preferably 80% by weight or less, and more preferably 60% by weight. Below, it is more preferably 40% by weight or less, particularly preferably 20% by weight or less, and most preferably 10% by weight or less. When the content of the conductive particles is not less than the above lower limit and not more than the above upper limit, the conduction reliability between the electrodes can be further increased.
　（接続構造体）
　上記導電性粒子を用いて、又は上記導電性粒子とバインダー樹脂とを含む上記導電材料を用いて、接続対象部材を接続することにより、接続構造体を得ることができる。 (Connection structure)
A connection structure can be obtained by connecting the members to be connected with the conductive particles or with the conductive material containing the conductive particles and the binder resin.
　上記接続構造体は、第１の接続対象部材と、第２の接続対象部材と、第１，第２の接続対象部材を接続している接続部とを備える。上記接続構造体では、上記接続部の材料が、上述した導電性粒子であるか、又は上記導電性粒子とバインダー樹脂とを含む導電材料であることが好ましい。上記接続部が、上述した導電性粒子により形成されているか、又は上記導電性粒子とバインダー樹脂とを含む導電材料により形成されていることが好ましい。上記接続構造体では、上記第１の電極と上記第２の電極とが、上記導電性粒子により電気的に接続されている。上記接続部の材料として導電性粒子が用いられた場合には、接続部自体が導電性粒子である。すなわち、第１，第２の接続対象部材が上記導電性粒子により接続される。 The connection structure includes a first connection target member, a second connection target member, and a connection portion connecting the first and second connection target members. In the connection structure, it is preferable that the material of the connection portion is the above-mentioned conductive particles or a conductive material containing the above-mentioned conductive particles and a binder resin. It is preferable that the connecting portion is formed of the above-mentioned conductive particles or a conductive material containing the above-mentioned conductive particles and a binder resin. In the connection structure, the first electrode and the second electrode are electrically connected by the conductive particles. When conductive particles are used as the material of the connecting portion, the connecting portion itself is the conductive particles. That is, the first and second connection target members are connected by the conductive particles.
　電極間の接続抵抗をより一層効果的に低くする観点からは、上記接続構造体では、上記第１の導電部における主金属の標準電極電位が、上記第１の電極又は上記第２の電極の外表面の主金属の標準電極電位よりも小さいことが好ましい。 From the viewpoint of further effectively lowering the connection resistance between the electrodes, in the connection structure, the standard electrode potential of the main metal in the first conductive portion is the same as that of the first electrode or the second electrode. It is preferably smaller than the standard electrode potential of the main metal on the outer surface.
　図７に、本発明の第１の実施形態に係る導電性粒子を用いた接続構造体を模式的に正面断面図で示す。 FIG. 7 schematically shows a connection structure using conductive particles according to the first embodiment of the present invention in a front sectional view.
　図７に示す接続構造体５１は、第１の接続対象部材５２と、第２の接続対象部材５３と、第１，第２の接続対象部材５２，５３を接続している接続部５４とを備える。接続部５４は、導電性粒子１を含む導電材料を硬化させることにより形成されている。なお、図７では、導電性粒子１は、図示の便宜上、略図的に示されている。導電性粒子１にかえて、導電性粒子１１，２１及び３１等を用いてもよい。 The connection structure 51 shown in FIG. 7 connects a first connection target member 52, a second connection target member 53, and a connection portion 54 connecting the first and second connection target members 52 and 53. Be prepared. The connecting portion 54 is formed by curing a conductive material containing the conductive particles 1. In FIG. 7, the conductive particles 1 are shown schematically for convenience of illustration. Conductive particles 11, 21, 31 and the like may be used instead of the conductive particles 1.
　第１の接続対象部材５２は表面（上面）に、複数の第１の電極５２ａを有する。第２の接続対象部材５３は表面（下面）に、複数の第２の電極５３ａを有する。第１の電極５２ａと第２の電極５３ａとが、１つ又は複数の導電性粒子１により電気的に接続されている。従って、第１，第２の接続対象部材５２，５３が導電性粒子１により電気的に接続されている。 The first connection target member 52 has a plurality of first electrodes 52a on the surface (upper surface). The second connection target member 53 has a plurality of second electrodes 53a on the surface (lower surface). The first electrode 52a and the second electrode 53a are electrically connected by one or more conductive particles 1. Therefore, the first and second connection target members 52 and 53 are electrically connected by the conductive particles 1.
　上記接続構造体の製造方法は特に限定されない。上記接続構造体の製造方法の一例としては、上記第１の接続対象部材と上記第２の接続対象部材との間に上記導電材料を配置し、積層体を得た後、該積層体を加熱及び加圧する方法等が挙げられる。上記加圧の圧力は９．８×１０４Ｐａ～４．９×１０６Ｐａ程度である。上記加熱の温度は、５０℃～２２０℃程度である。フレキシブルプリント基板の電極、樹脂フィルム上に配置された電極及びタッチパネルの電極を接続するための上記加圧の圧力は９．８×１０４Ｐａ～１．０×１０６Ｐａ程度である。 The method for manufacturing the connection structure is not particularly limited. As an example of the method for manufacturing the connection structure, the conductive material is arranged between the first connection target member and the second connection target member, and after obtaining a laminate, the laminate is heated. And a method of pressurizing and the like. The pressurizing pressure is about 9.8 × 10 4 Pa to 4.9 × 10 6 Pa. The heating temperature is about 50 ° C. to 220 ° C. The pressure of the pressurization for connecting the electrodes of the flexible printed circuit board, the electrodes arranged on the resin film, and the electrodes of the touch panel is about 9.8 × 10 4 Pa to 1.0 × 10 6 Pa.
　上記接続対象部材としては、具体的には、半導体チップ、コンデンサ及びダイオード等の電子部品、並びにプリント基板、フレキシブルプリント基板、ガラスエポキシ基板及びガラス基板等の回路基板が挙げられる。上記接続対象部材は電子部品であることが好ましい。上記導電性粒子は、電子部品における電極の電気的な接続に用いられることが好ましい。 Specific examples of the connection target member include electronic components such as semiconductor chips, capacitors and diodes, and circuit boards such as printed circuit boards, flexible printed circuit boards, glass epoxy boards and glass boards. The connection target member is preferably an electronic component. The conductive particles are preferably used for electrical connection of electrodes in electronic components.
　上記接続対象部材に設けられている電極としては、金電極、ニッケル電極、錫電極、アルミニウム電極、銅電極、銀電極、ＳＵＳ電極、モリブデン電極及びタングステン電極等の金属電極が挙げられる。上記接続対象部材がフレキシブルプリント基板である場合には、上記電極は金電極、ニッケル電極、錫電極又は銅電極であることが好ましい。上記接続対象部材がガラス基板である場合には、上記電極はアルミニウム電極、銅電極、モリブデン電極又はタングステン電極であることが好ましい。なお、上記電極がアルミニウム電極である場合には、アルミニウムのみで形成された電極であってもよく、金属酸化物層の表面にアルミニウム層が積層された電極であってもよい。上記金属酸化物層の材料としては、３価の金属元素がドープされた酸化インジウム及び３価の金属元素がドープされた酸化亜鉛等が挙げられる。上記３価の金属元素としては、Ａｌ及びＧａ等が挙げられる。 Examples of the electrodes provided on the connection target member include metal electrodes such as gold electrodes, nickel electrodes, tin electrodes, aluminum electrodes, copper electrodes, silver electrodes, SUS electrodes, molybdenum electrodes and tungsten electrodes. When the connection target member is a flexible printed substrate, the electrode is preferably a gold electrode, a nickel electrode, a tin electrode, or a copper electrode. When the member to be connected is a glass substrate, the electrode is preferably an aluminum electrode, a copper electrode, a molybdenum electrode, or a tungsten electrode. When the electrode is an aluminum electrode, it may be an electrode formed only of aluminum, or an electrode in which an aluminum layer is laminated on the surface of a metal oxide layer. Examples of the material of the metal oxide layer include indium oxide doped with a trivalent metal element and zinc oxide doped with a trivalent metal element. Examples of the trivalent metal element include Al and Ga.
　以下、実施例及び比較例を挙げて、本発明を具体的に説明する。本発明は、以下の実施例のみに限定されない。 Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. The present invention is not limited to the following examples.
　（標準電極電位）
　実施例及び比較例で使用する第１の導電部、第２の導電部、第１の電極及び第２の電極に用いられる金属に関して、該金属の標準電極電位は、次の通りである。 (Standard electrode potential)
With respect to the metal used for the first conductive portion, the second conductive portion, the first electrode and the second electrode used in Examples and Comparative Examples, the standard electrode potential of the metal is as follows.
　アルミニウム：－１．６６２（Ｖ）
　鉄：－０．４４０（Ｖ）
　コバルト：－０．２８０（Ｖ）
　ニッケル：－０．２５７（Ｖ）
　錫：－０．１３８（Ｖ）
　ルテニウム：＋０．３００（Ｖ）
　銅：＋０．３３７（Ｖ）
　ロジウム：＋０．７５８（Ｖ）
　銀：＋０．７９９（Ｖ）
　パラジウム：＋０．９９０（Ｖ）
　白金：＋１．１８８（Ｖ）
　金：＋１．８３０（Ｖ） Aluminum: -1.662 (V)
Iron: -0.440 (V)
Cobalt: -0.280 (V)
Nickel: -0.257 (V)
Tin: -0.138 (V)
Ruthenium: +0.300 (V)
Copper: +0.337 (V)
Rhodium: +0.758 (V)
Silver: +0.799 (V)
Palladium: +0.990 (V)
Platinum: +1.188 (V)
Gold: +1.830 (V)
　（実施例１）
　（１）導電性粒子の作製（第１の導電部の形成）
　ジビニルベンゼン共重合体樹脂粒子（基材粒子Ａ、積水化学工業社製「ミクロパールＳＰ－２０３」、粒子径３μｍ）を用意した。パラジウム触媒液を５重量％含むアルカリ溶液１００重量部に、上記基材粒子Ａ１０重量部を、超音波分散器を用いて分散させた後、溶液をろ過することにより、基材粒子Ａを取り出した。次いで、基材粒子Ａをジメチルアミンボラン１重量％溶液１００重量部に添加し、基材粒子Ａの表面を活性化させた。表面が活性化された基材粒子Ａを十分に水洗した後、蒸留水５００重量部に加え、分散させることにより、懸濁液を得た。 (Example 1)
(1) Preparation of conductive particles (formation of first conductive portion)
Divinylbenzene copolymer resin particles (base particle A, "Micropearl SP-203" manufactured by Sekisui Chemical Industry Co., Ltd., particle diameter 3 μm) were prepared. After dispersing 10 parts by weight of the base particle A in 100 parts by weight of an alkaline solution containing 5% by weight of a palladium catalyst solution using an ultrasonic disperser, the base particle A was taken out by filtering the solution. .. Next, the base particle A was added to 100 parts by weight of a 1 wt% dimethylamine borane solution to activate the surface of the substrate particle A. The surface-activated substrate particles A were thoroughly washed with water, and then added to 500 parts by weight of distilled water and dispersed to obtain a suspension.
　また、ニッケルめっき液として、硫酸ニッケル０．１４ｍｏｌ／Ｌ、ジメチルアミンボラン０．４６ｍｏｌ／Ｌ及びクエン酸ナトリウム０．２ｍｏｌ／Ｌを含むニッケルめっき液（ｐＨ８．５）を用意した。 Further, as a nickel plating solution, a nickel plating solution (pH 8.5) containing nickel sulfate 0.14 mol / L, dimethylamine borane 0.46 mol / L and sodium citrate 0.2 mol / L was prepared.
　得られた懸濁液を６０℃にて攪拌しながら、上記ニッケルめっき液を懸濁液に、滴下速度３０ｍＬ／分の条件で１０分間滴下した。その後、滴下速度１０ｍＬ／分の条件で４０分間滴下し、さらにその後、滴下速度４ｍＬ／分の条件で８０分間滴下することで、めっき膜中に取り込まれるボロンの含有量を制御しながら、無電解ニッケル－ボロン合金めっきを行った。 While stirring the obtained suspension at 60 ° C., the nickel plating solution was added dropwise to the suspension at a dropping rate of 30 mL / min for 10 minutes. Then, the mixture was added dropwise at a dropping rate of 10 mL / min for 40 minutes, and then dropped at a dropping rate of 4 mL / min for 80 minutes to control the content of boron incorporated in the plating film without electrolessing. Nickel-boron alloy plating was performed.
　その後、上記懸濁液をろ過することにより、粒子を取り出し、水洗し、乾燥することにより、基材粒子Ａの表面上に第１の導電部（ニッケルを含む導電層、厚み０．１μｍ）が配置された粒子を得た。 Then, the particles are taken out by filtering the suspension, washed with water, and dried to form a first conductive portion (conductive layer containing nickel, thickness 0.1 μm) on the surface of the base particle A. Placed particles were obtained.
　（２）導電性粒子の作製（第２の導電部の形成）
　得られた粒子１０ｇを、超音波処理機により、イオン交換水５００ｍＬに分散させて、懸濁液を得た。硫酸パラジウム０．０２ｍｏｌ／Ｌ、錯化剤としてエチレンジアミン０．０４ｍｏｌ／Ｌ、還元剤として蟻酸アンモニウム０．０６ｍｏｌ／Ｌ及び結晶調整剤を含むｐＨ１０．０のめっき液を用意した。得られた懸濁液を５０℃で攪拌しながら、得られためっき液を徐々に添加し、無電解パラジウムめっきを行い、第２の導電部を形成した。第２の導電部の厚みが２０ｎｍになった時点で無電解パラジウムめっきを終了した。上記第１の導電部の表面上に第２の導電部（パラジウム層、厚み０．０２μｍ）が形成された導電性粒子（粒子径３．２４μｍ）を得た。 (2) Fabrication of conductive particles (formation of a second conductive portion)
10 g of the obtained particles were dispersed in 500 mL of ion-exchanged water by an ultrasonic treatment machine to obtain a suspension. A plating solution having a pH of 10.0 containing 0.02 mol / L of palladium sulfate, 0.04 mol / L of ethylenediamine as a complexing agent, 0.06 mol / L of ammonium formic acid as a reducing agent, and a crystal modifier was prepared. While stirring the obtained suspension at 50 ° C., the obtained plating solution was gradually added to perform electroless palladium plating to form a second conductive portion. Electroless palladium plating was completed when the thickness of the second conductive portion reached 20 nm. Conductive particles (particle diameter 3.24 μm) in which a second conductive portion (palladium layer, thickness 0.02 μm) was formed on the surface of the first conductive portion were obtained.
　（３）導電フィルム（異方性導電フィルム）の作製
　熱硬化性化合物であるフェノキシ化合物（Ｉｎｃｈｅｍ社製「ＰＫＨＣ」）３０重量部をＰＧＭＥＡ３５重量部とメチルエチルケトン３５重量部との混合溶媒に入れ、２４時間常温で撹拌してフェノキシ化合物の３０重量％分散液を得た。次に、上記分散液３０重量部と、熱硬化性化合物であるエポキシ化合物（ＤＩＣ社製「ＥＰＩＣＬＯＮ　ＨＰ－４０３２Ｄ」）３０重量部と、潜在型熱硬化剤であるイミダゾールのマイクロカプセル硬化剤（旭化成社製「ノバキュアＨＸＡ３９２２」）３０重量部とを配合した配合物を得た。得られた配合物に、シランカップリング剤（信越化学工業社製「ＫＢＭ－４０３」）１重量部を配合し、さらに得られた導電性粒子を、得られる導電フィルム１００重量％中での含有量が１０重量％となるように添加した。その後、固形分量が５０％となるようにメチルエチルケトンを添加し、遊星式攪拌機を用いて２０００ｒｐｍで５分間攪拌することにより、混合物を得た。得られた混合物を剥離処理されたポリエチレンテレフタレート上に塗布し、溶媒を乾燥させて、厚みが２０μｍである異方性導電フィルムを得た。 (3) Preparation of Conductive Film (Anisically Conductive Film) 30 parts by weight of a phenoxy compound (“PKHC” manufactured by Inchem), which is a thermosetting compound, is placed in a mixed solvent of 35 parts by weight of PGMEA and 35 parts by weight of methyl ethyl ketone, and 24 Stirring at room temperature for a time gave a 30% by weight dispersion of the phenoxy compound. Next, 30 parts by weight of the dispersion liquid, 30 parts by weight of an epoxy compound (“EPICLON HP-4032D” manufactured by DIC) which is a thermosetting compound, and a microcapsule curing agent (Asahi Kasei) of imidazole which is a latent thermosetting agent. A compound containing 30 parts by weight of "Novacure HXA3922") manufactured by the same company was obtained. 1 part by weight of a silane coupling agent (“KBM-403” manufactured by Shin-Etsu Chemical Co., Ltd.) was added to the obtained formulation, and the obtained conductive particles were further contained in 100% by weight of the obtained conductive film. It was added so that the amount was 10% by weight. Then, methyl ethyl ketone was added so that the solid content was 50%, and the mixture was stirred at 2000 rpm for 5 minutes using a planetary stirrer to obtain a mixture. The obtained mixture was applied onto the stripped polyethylene terephthalate, and the solvent was dried to obtain an anisotropic conductive film having a thickness of 20 μm.
　（４）接続構造体の作製
　第１の接続対象部材として、Ｌ／Ｓが１０μｍ／１０μｍの銅電極パターン（第１の電極）を上面に有するプラスチック基板を用意した。また、第２の接続対象部材として、Ｌ／Ｓが１０μｍ／１０μｍの銅電極パターン（第２の電極）を下面に有するフレキシブル基板を用意した。 (4) Preparation of Connection Structure As the first connection target member, a plastic substrate having a copper electrode pattern (first electrode) having an L / S of 10 μm / 10 μm on the upper surface was prepared. Further, as a second connection target member, a flexible substrate having a copper electrode pattern (second electrode) having an L / S of 10 μm / 10 μm on the lower surface was prepared.
　上記プラスチック基板の上面に、作製直後の導電フィルム（異方性導電フィルム）を配置し、導電フィルム層（異方性導電フィルム層）を形成した。次に、導電フィルム層（異方性導電フィルム層）の上面に上記フレキシブル基板を、電極同士が対向するように積層した。その後、導電フィルム層（異方性導電フィルム層）の温度が１００℃となるようにヘッドの温度を調整しながら、フレキシブル基板の上面に加圧加熱ヘッドを載せ、電極面積に対して６０ＭＰａの圧力をかけて導電フィルムを１００℃で硬化させ、接続構造体を得た。 A conductive film (anisotropic conductive film) immediately after production was placed on the upper surface of the plastic substrate to form a conductive film layer (anisotropic conductive film layer). Next, the flexible substrate was laminated on the upper surface of the conductive film layer (anisotropic conductive film layer) so that the electrodes face each other. After that, while adjusting the temperature of the head so that the temperature of the conductive film layer (anisotropic conductive film layer) becomes 100 ° C., the pressure heating head is placed on the upper surface of the flexible substrate, and the pressure is 60 MPa with respect to the electrode area. The conductive film was cured at 100 ° C. to obtain a connecting structure.
　（実施例２）
　第１の導電部を形成する際に、基材粒子Ａの懸濁液に、ニッケル粒子スラリー（平均粒子径１５０ｎｍ）１ｇを添加した。基材粒子Ａの代わりに、基材粒子Ａの表面に芯物質を付着させた粒子を用いたこと以外は、実施例１と同様にして、導電性粒子、導電フィルム及び接続構造体を得た。 (Example 2)
When forming the first conductive portion, 1 g of nickel particle slurry (average particle diameter 150 nm) was added to the suspension of the base particle A. Conductive particles, a conductive film, and a connecting structure were obtained in the same manner as in Example 1 except that particles having a core substance adhered to the surface of the base particles A were used instead of the base particles A. ..
　（実施例３）
　第１の導電部を形成する際に、ニッケル粒子スラリー（平均粒子径１５０ｎｍ）の代わりに、アルミナ粒子スラリー（平均粒子径１５０ｎｍ）を用いたこと以外は、実施例２と同様にして、導電性粒子、導電フィルム及び接続構造体を得た。 (Example 3)
Conductivity in the same manner as in Example 2 except that an alumina particle slurry (average particle diameter 150 nm) was used instead of the nickel particle slurry (average particle diameter 150 nm) when forming the first conductive portion. Particles, conductive film and connecting structure were obtained.
　（実施例４）
　第１の導電部を形成する際に、ニッケル粒子スラリー（平均粒子径１５０ｎｍ）の代わりに、チタニア粒子スラリー（平均粒子径１５０ｎｍ）を用いたこと以外は、実施例２と同様にして、導電性粒子、導電フィルム及び接続構造体を得た。 (Example 4)
Conductivity in the same manner as in Example 2 except that a titania particle slurry (average particle diameter 150 nm) was used instead of the nickel particle slurry (average particle diameter 150 nm) when forming the first conductive portion. Particles, conductive film and connecting structure were obtained.
　（実施例５）
　第１の導電部を形成する際に、基材粒子Ａの粒子径を３μｍから１．５μｍに変更したこと以外は、実施例３と同様にして、導電性粒子、導電フィルム及び接続構造体を得た。 (Example 5)
The conductive particles, the conductive film, and the connecting structure were formed in the same manner as in Example 3 except that the particle size of the base particle A was changed from 3 μm to 1.5 μm when the first conductive portion was formed. Obtained.
　（実施例６）
　第１の導電部を形成する際に、基材粒子Ａの粒子径を３μｍから２０μｍに変更したこと以外は、実施例３と同様にして、導電性粒子、導電フィルム及び接続構造体を得た。 (Example 6)
Conductive particles, a conductive film, and a connecting structure were obtained in the same manner as in Example 3 except that the particle size of the base particle A was changed from 3 μm to 20 μm when the first conductive portion was formed. ..
　（実施例７）
　炭素数６のアルキル基を有する化合物を用いて、得られた導電性粒子を分散させることにより、導電性粒子の外表面を防錆処理したこと以外は、実施例３と同様にして、導電性粒子、導電フィルム及び接続構造体を得た。 (Example 7)
Conductivity in the same manner as in Example 3 except that the outer surface of the conductive particles was rust-proofed by dispersing the obtained conductive particles using a compound having an alkyl group having 6 carbon atoms. Particles, conductive film and connecting structure were obtained.
　（実施例８）
　４つ口セパラブルカバー、攪拌翼、三方コック、冷却管及び温度プローブが取り付けられた１０００ｍＬのセパラブルフラスコに、以下のモノマー組成物を入れ、モノマー組成物の固形分率が５重量％となるようにイオン交換水を秤取した後、２００ｒｐｍで攪拌し、窒素雰囲気下７０℃で２４時間重合を行った。上記モノマー組成物は、メタクリル酸メチル１００ｍｍｏｌと、Ｎ，Ｎ，Ｎ－トリメチル－Ｎ－２－メタクリロイルオキシエチルアンモニウムクロライド１ｍｍｏｌと、２，２’－アゾビス（２－アミジノプロパン）二塩酸塩１ｍｍｏｌとを含む。反応終了後、凍結乾燥して、表面にアンモニウム基を有し、平均粒子径２２０ｎｍ及びＣＶ値１０％の絶縁性粒子を得た。 (Example 8)
The following monomer composition is placed in a 1000 mL separable flask equipped with a 4-port separable cover, stirring blade, three-way cock, cooling tube and temperature probe, and the solid content of the monomer composition becomes 5% by weight. After weighing the ion-exchanged water as described above, the mixture was stirred at 200 rpm and polymerized at 70 ° C. for 24 hours under a nitrogen atmosphere. The above-mentioned monomer composition comprises 100 mmol of methyl methacrylate, 1 mmol of N, N, N-trimethyl-N-2-methacryloyloxyethylammonium chloride, and 1 mmol of 2,2'-azobis (2-amidinopropane) dihydrochloride. Including. After completion of the reaction, the reaction was freeze-dried to obtain insulating particles having an ammonium group on the surface, having an average particle diameter of 220 nm and a CV value of 10%.
　絶縁性粒子を超音波照射下でイオン交換水に分散させ、絶縁性粒子の１０重量％水分散液を得た。 Insulating particles were dispersed in ion-exchanged water under ultrasonic irradiation to obtain a 10% by weight aqueous dispersion of insulating particles.
　実施例３で得られた導電性粒子１０ｇをイオン交換水５００ｍＬに分散させ、絶縁性粒子の水分散液４ｇを添加し、室温で６時間攪拌した。３μｍのメッシュフィルターでろ過した後、更にメタノールで洗浄し、乾燥し、絶縁性粒子が付着した導電性粒子（絶縁性粒子付き導電性粒子）を得た。 10 g of the conductive particles obtained in Example 3 were dispersed in 500 mL of ion-exchanged water, 4 g of an aqueous dispersion of insulating particles was added, and the mixture was stirred at room temperature for 6 hours. After filtering with a 3 μm mesh filter, the mixture was further washed with methanol and dried to obtain conductive particles to which insulating particles were attached (conductive particles with insulating particles).
　走査型電子顕微鏡（ＳＥＭ）により観察したところ、導電性粒子の表面に絶縁性粒子による被覆層が１層のみ形成されていた。画像解析により導電性粒子の中心より２．５μｍの面積に対する絶縁性粒子の被覆面積（即ち絶縁性粒子の粒子径の投影面積）を算出したところ、被覆率は４０％であった。 When observed with a scanning electron microscope (SEM), only one coating layer of insulating particles was formed on the surface of the conductive particles. When the covering area of the insulating particles (that is, the projected area of the particle diameter of the insulating particles) was calculated for an area of 2.5 μm from the center of the conductive particles by image analysis, the covering ratio was 40%.
　導電フィルム（異方性導電フィルム）を作製する際に、導電性粒子の代わりに、絶縁性粒子付き導電性粒子を用いたこと以外は、実施例３と同様にして、導電フィルム及び接続構造体を得た。 The conductive film and the connecting structure are the same as in Example 3 except that the conductive particles with insulating particles are used instead of the conductive particles when the conductive film (anisometric conductive film) is produced. Got
　（実施例９）
　第２の導電部を形成する際に、無電解パラジウムめっきの代わりに、無電解金めっきを施したこと以外は、実施例３と同様にして、導電性粒子、導電フィルム及び接続構造体を得た。 (Example 9)
Conductive particles, a conductive film, and a connecting structure were obtained in the same manner as in Example 3 except that electroless gold plating was applied instead of electroless palladium plating when forming the second conductive portion. It was.
　（実施例１０）
　第２の導電部を形成する際に、無電解パラジウムめっきの代わりに、無電解ルテニウムめっきを施したこと以外は、実施例３と同様にして、導電性粒子、導電フィルム及び接続構造体を得た。 (Example 10)
Conductive particles, a conductive film, and a connecting structure were obtained in the same manner as in Example 3 except that electroless ruthenium plating was applied instead of electroless palladium plating when forming the second conductive portion. It was.
　（実施例１１）
　第２の接続対象部材として、第２の接続対象部材における電極の外表面の主金属が金である電極パターン（第２の電極）を下面に有するフレキシブル基板を用意した。接続構造体を作製する際に、Ｌ／Ｓが１０μｍ／１０μｍの銅電極パターン（第２の電極）を下面に有するフレキシブル基板の代わりに、用意したフレキシブル基板を用いたこと以外は、実施例３と同様にして、接続構造体を得た。 (Example 11)
As the second connection target member, a flexible substrate having an electrode pattern (second electrode) in which the main metal of the outer surface of the electrode in the second connection target member is gold is prepared on the lower surface. Example 3 except that a prepared flexible substrate was used instead of the flexible substrate having a copper electrode pattern (second electrode) having an L / S of 10 μm / 10 μm on the lower surface when producing the connection structure. The connection structure was obtained in the same manner as above.
　（実施例１２）
　第２の接続対象部材として、第２の接続対象部材における電極の外表面の主金属が銀である電極パターン（第２の電極）を下面に有するフレキシブル基板を用意した。接続構造体を作製する際に、Ｌ／Ｓが１０μｍ／１０μｍの銅電極パターン（第２の電極）を下面に有するフレキシブル基板の代わりに、用意したフレキシブル基板を用いたこと以外は、実施例３と同様にして、接続構造体を得た。 (Example 12)
As the second connection target member, a flexible substrate having an electrode pattern (second electrode) on the lower surface in which the main metal of the outer surface of the electrode in the second connection target member is silver was prepared. Example 3 except that the prepared flexible substrate was used instead of the flexible substrate having a copper electrode pattern (second electrode) having an L / S of 10 μm / 10 μm on the lower surface when producing the connection structure. The connection structure was obtained in the same manner as above.
　（実施例１３）
　第１の接続対象部材として、第１の接続対象部材における電極の外表面の主金属が金である電極パターン（第１の電極）を上面に有するプラスチック基板を用意した。また、第２の接続対象部材として、第２の接続対象部材における電極の外表面の主金属が金である電極パターン（第２の電極）を下面に有するフレキシブル基板を用意した。接続構造体を作製する際に、Ｌ／Ｓが１０μｍ／１０μｍの銅電極パターン（第１の電極）を上面に有するプラスチック基板とＬ／Ｓが１０μｍ／１０μｍの銅電極パターン（第２の電極）を下面に有するフレキシブル基板との代わりに、用意した基板を用いたこと以外は、実施例３と同様にして、接続構造体を得た。 (Example 13)
As the first connection target member, a plastic substrate having an electrode pattern (first electrode) on which the main metal of the outer surface of the electrode in the first connection target member is gold was prepared. Further, as the second connection target member, a flexible substrate having an electrode pattern (second electrode) in which the main metal of the outer surface of the electrode in the second connection target member is gold is prepared on the lower surface. When producing the connection structure, a plastic substrate having a copper electrode pattern (first electrode) having an L / S of 10 μm / 10 μm on the upper surface and a copper electrode pattern having an L / S of 10 μm / 10 μm (second electrode) A connection structure was obtained in the same manner as in Example 3 except that the prepared substrate was used instead of the flexible substrate having the above.
　（実施例１４）
　攪拌機及び温度計が取り付けられた５００ｍＬの反応容器内に、０．１３重量％のアンモニア水溶液３００ｇを入れた。次に、反応容器内のアンモニア水溶液中に、メチルトリメトキシシラン１．９ｇと、ビニルトリメトキシシラン１２．７ｇと、シリコーンアルコキシオリゴマーＡ（信越化学工業社製「ＫＲ－５１７」）０．４ｇとの混合物をゆっくりと添加した。撹拌しながら、加水分解及び縮合反応を進行させた後、２５重量％アンモニア水溶液１．６ｍＬ添加した後、アンモニア水溶液中から粒子を単離して、得られた粒子を酸素分圧１０－１０ａｔｍ、３８０℃（焼成温度）で２時間（焼成時間）焼成して、有機無機ハイブリッド粒子（基材粒子Ｂ）を得た。得られた有機無機ハイブリッド粒子（基材粒子Ｂ）の粒子径は３μｍであった。 (Example 14)
300 g of a 0.13 wt% ammonia aqueous solution was placed in a 500 mL reaction vessel equipped with a stirrer and a thermometer. Next, in the aqueous ammonia solution in the reaction vessel, 1.9 g of methyltrimethoxysilane, 12.7 g of vinyltrimethoxysilane, and 0.4 g of silicone alkoxy oligomer A (“KR-517” manufactured by Shinetsu Chemical Industry Co., Ltd.) were added. The mixture of was added slowly. After advancing the hydrolysis and condensation reaction with stirring, 1.6 mL of a 25 wt% aqueous ammonia solution was added, and then the particles were isolated from the aqueous ammonia solution, and the obtained particles were subjected to an oxygen partial pressure of 10-10 atm. Organic-inorganic hybrid particles (base particle B) were obtained by firing at 380 ° C. (baking temperature) for 2 hours (baking time). The particle size of the obtained organic-inorganic hybrid particles (base particle B) was 3 μm.
　導電性粒子を作製する際に、基材粒子Ａの代わりに、基材粒子Ｂを用いたこと以外は、実施例３と同様にして、導電性粒子、導電フィルム及び接続構造体を得た。 Conductive particles, a conductive film, and a connecting structure were obtained in the same manner as in Example 3 except that the base particles B were used instead of the base particles A when producing the conductive particles.
　（実施例１５）
　ニッケルめっき液（１）として、硫酸ニッケル０．１４ｍｏｌ／Ｌ、ジメチルアミンボラン０．４６ｍｏｌ／Ｌ及びクエン酸ナトリウム０．２ｍｏｌ／Ｌを含むニッケルめっき液（ｐＨ８．５）を用意した。また、ニッケルめっき液（２）として、硫酸ニッケル０．１４ｍｏｌ／Ｌ、塩化チタン（ＩＩＩ）０．６０ｍｏｌ／Ｌを含むニッケルめっき液（ｐＨ８．０）を用意した。 (Example 15)
As the nickel plating solution (1), a nickel plating solution (pH 8.5) containing nickel sulfate 0.14 mol / L, dimethylamine borane 0.46 mol / L and sodium citrate 0.2 mol / L was prepared. Further, as the nickel plating solution (2), a nickel plating solution (pH 8.0) containing nickel sulfate 0.14 mol / L and titanium chloride (III) 0.60 mol / L was prepared.
　第１の導電部を形成する際に、得られた懸濁液を６０℃にて攪拌しながら、上記ニッケルめっき液（１）を懸濁液に、滴下速度６ｍＬ／分の条件で１０分間滴下した。その後、滴下速度２ｍＬ／分の条件で４０分間滴下し、さらにその後、滴下速度０．８ｍＬ／分の条件で８０分間滴下することで、めっき膜中に取り込まれるボロンの含有量を制御しながら、基材粒子Ａの表面に無電解ニッケル－ボロン合金めっきを行った（厚み０．０２μｍ）。続いて、液温を７０℃に設定して、上記ニッケルめっき液（２）を徐々に滴下し、無電解ニッケルめっきを行い、懸濁液（２）を得た。 When forming the first conductive portion, the nickel plating solution (1) was added dropwise to the suspension at a dropping rate of 6 mL / min for 10 minutes while stirring the obtained suspension at 60 ° C. did. Then, the particles were added dropwise at a dropping rate of 2 mL / min for 40 minutes, and then dropped at a dropping rate of 0.8 mL / min for 80 minutes to control the content of boron incorporated in the plating film. Electroless nickel-boron alloy plating was performed on the surface of the base particle A (thickness 0.02 μm). Subsequently, the liquid temperature was set to 70 ° C., the nickel plating liquid (2) was gradually added dropwise, electroless nickel plating was performed, and a suspension (2) was obtained.
　その後、懸濁液（２）をろ過することにより、粒子を取り出し、水洗し、乾燥することにより、基材粒子Ａの表面にニッケル－ボロン合金の導電層（厚み０．０２μｍ）と純ニッケル導電層（厚み０．０８μｍ）が配置されたニッケルを主金属とする第１の導電部（厚み０．１μｍ）が形成された粒子を得た。得られた粒子を用いたこと以外は、実施例３と同様にして、導電性粒子、導電フィルム及び接続構造体を得た。 Then, by filtering the suspension (2), the particles are taken out, washed with water, and dried to form a nickel-boron alloy conductive layer (thickness 0.02 μm) and pure nickel conductivity on the surface of the base particle A. Particles on which a first conductive portion (thickness 0.1 μm) having a nickel-based main metal on which a layer (thickness 0.08 μm) was arranged were formed were obtained. Conductive particles, a conductive film, and a connecting structure were obtained in the same manner as in Example 3 except that the obtained particles were used.
　（実施例１６）
　第１の接続対象部材における電極の外表面及び第２の接続対象部材における電極の外表面に、３－メルカプト－トリアゾールを含む保護層を形成したプラスチック基板及びフレキシブル基板を用意した。接続構造体を作製する際に、Ｌ／Ｓが１０μｍ／１０μｍの銅電極パターン（第１の電極）を上面に有するプラスチック基板とＬ／Ｓが１０μｍ／１０μｍの銅電極パターン（第２の電極）を下面に有するフレキシブル基板との代わりに、用意した基板を用いたこと以外は、実施例３と同様にして、接続構造体を得た。 (Example 16)
A plastic substrate and a flexible substrate having a protective layer containing 3-mercapto-triazole formed on the outer surface of the electrode in the first connection target member and the outer surface of the electrode in the second connection target member were prepared. When producing the connection structure, a plastic substrate having a copper electrode pattern (first electrode) having an L / S of 10 μm / 10 μm on the upper surface and a copper electrode pattern having an L / S of 10 μm / 10 μm (second electrode) A connection structure was obtained in the same manner as in Example 3 except that the prepared substrate was used instead of the flexible substrate having the above.
　（実施例１７）
　ニッケルめっき液として、硫酸ニッケル０．１４ｍｏｌ／Ｌ、ジメチルアミンボラン０．４６ｍｏｌ／Ｌ及びクエン酸ナトリウム０．２ｍｏｌ／Ｌを含むニッケルめっき液（ｐＨ８．５）を用意した。 (Example 17)
As the nickel plating solution, a nickel plating solution (pH 8.5) containing nickel sulfate 0.14 mol / L, dimethylamine borane 0.46 mol / L and sodium citrate 0.2 mol / L was prepared.
　第１の導電部を形成する際に、得られた懸濁液を６０℃にて攪拌しながら、上記ニッケルめっき液を懸濁液に、滴下速度３０ｍＬ／分の条件で１０分間滴下し、その後、滴下速度１０ｍＬ／分の条件で４０分間滴下した。さらにその後、上記ニッケルめっき液を硫酸でｐＨ６．８に調整し、反応温度を３０℃以下にしてから上記ニッケルめっき液を滴下速度４ｍＬ／分の条件で８０分間滴下することで、めっき膜中に取り込まれるボロンの含有量を制御しながら、無電解ニッケル－ボロン合金めっきを行い、懸濁液（２）を得た。 When forming the first conductive portion, the nickel plating solution was added dropwise to the suspension at a dropping rate of 30 mL / min for 10 minutes while stirring the obtained suspension at 60 ° C., and then. , The dropping speed was 10 mL / min for 40 minutes. After that, the pH of the nickel plating solution was adjusted to 6.8 with sulfuric acid to reduce the reaction temperature to 30 ° C. or lower, and then the nickel plating solution was added dropwise to the plating film at a dropping rate of 4 mL / min for 80 minutes. Electroless nickel-boron alloy plating was performed while controlling the content of boron to be incorporated to obtain a suspension (2).
　その後、懸濁液（２）をろ過することにより、粒子を取り出し、水洗し、乾燥することにより、基材粒子Ａの表面にニッケルを主金属とする第１の導電部（厚み０．１μｍ）が形成された粒子を得た。得られた粒子における第１の導電部では、第１の導電部の内表面から外側に向かって厚み１／５の領域（Ｒ１）の１００重量％中におけるホウ素の平均含有量が１．０重量％であり、かつ第１の導電部の外表面から内側に向かって厚み１／５の領域（Ｒ２）の１００重量％中におけるホウ素の平均含有量が６．０重量％であった。得られた粒子を用いたこと以外は、実施例３と同様にして、導電性粒子、導電フィルム及び接続構造体を得た。 Then, by filtering the suspension (2), the particles are taken out, washed with water, and dried to form a first conductive portion (thickness 0.1 μm) containing nickel as the main metal on the surface of the base particle A. Obtained the formed particles. In the first conductive portion of the obtained particles, the average content of boron in 100% by weight of the region (R1) having a thickness of 1/5 from the inner surface to the outside of the first conductive portion is 1.0 weight by weight. The average content of boron in 100% by weight of the region (R2) having a thickness of 1/5 from the outer surface to the inside of the first conductive portion was 6.0% by weight. Conductive particles, a conductive film, and a connecting structure were obtained in the same manner as in Example 3 except that the obtained particles were used.
　（比較例１）
　ニッケルめっき液（１）として、硫酸ニッケル０．１４ｍｏｌ／Ｌ、ジメチルアミンボラン０．４６ｍｏｌ／Ｌ及びクエン酸ナトリウム０．４ｍｏｌ／Ｌを含むニッケルめっき液（ｐＨ８．０）を用意した。また、ニッケルめっき液（２）として、硫酸ニッケル０．０５ｍｏｌ／Ｌ、ジメチルアミンボラン０．９５ｍｏｌ／Ｌ及びクエン酸ナトリウム０．８ｍｏｌ／Ｌを含むニッケルめっき液（ｐＨ６．０）を用意した。 (Comparative Example 1)
As the nickel plating solution (1), a nickel plating solution (pH 8.0) containing nickel sulfate 0.14 mol / L, dimethylamine borane 0.46 mol / L and sodium citrate 0.4 mol / L was prepared. Further, as the nickel plating solution (2), a nickel plating solution (pH 6.0) containing nickel sulfate 0.05 mol / L, dimethylamine borane 0.95 mol / L and sodium citrate 0.8 mol / L was prepared.
　第１の導電部を形成する際に、得られた懸濁液を６０℃にて攪拌しながら、上記ニッケルめっき液（１）を懸濁液に、滴下速度５ｍＬ／分の条件で４０分間滴下した。その後、液温を２０℃に設定して、上記ニッケルめっき液（２）（ｐＨ６．０）を徐々に滴下し、無電解ニッケル－ボロン合金めっきを行い、懸濁液（２）を得た。 When forming the first conductive portion, the nickel plating solution (1) was added dropwise to the suspension at a dropping rate of 5 mL / min for 40 minutes while stirring the obtained suspension at 60 ° C. did. Then, the liquid temperature was set to 20 ° C., and the nickel plating liquid (2) (pH 6.0) was gradually added dropwise to perform electroless nickel-boron alloy plating to obtain a suspension (2).
　その後、懸濁液（２）をろ過することにより、粒子を取り出し、水洗し、乾燥することにより、基材粒子Ａの表面上に第１の導電部（ニッケルを含む導電層、厚み０．１μｍ）が配置された粒子を得た。得られた粒子における第１の導電部では、第１の導電部の内表面から外側に向かって厚み１／５の領域の１００重量％中におけるホウ素の平均含有量が０．０５重量％であり、かつ第１の導電部の外表面から内側に向かって厚み１／５の領域の１００重量％中におけるホウ素の平均含有量が１５．０重量％であった。得られた粒子を用いたこと以外は、実施例３と同様にして、導電性粒子、導電フィルム及び接続構造体を得た。 Then, the suspension (2) is filtered to take out the particles, washed with water, and dried to obtain a first conductive portion (conductive layer containing nickel, thickness 0.1 μm) on the surface of the base particle A. ) Was placed. In the first conductive portion of the obtained particles, the average content of boron in 100% by weight of the region having a thickness of 1/5 from the inner surface to the outside of the first conductive portion is 0.05% by weight. Moreover, the average content of boron in 100% by weight of the region having a thickness of 1/5 from the outer surface to the inside of the first conductive portion was 15.0% by weight. Conductive particles, a conductive film, and a connecting structure were obtained in the same manner as in Example 3 except that the obtained particles were used.
　（比較例２）
　ニッケルめっき液として、硫酸ニッケル０．２５ｍｏｌ／Ｌ、次亜リン酸ナトリウム０．２５ｍｏｌ／Ｌ、及びクエン酸ナトリウム０．１５ｍｏｌ／Ｌを含むニッケルめっき液（ｐＨ９．０）を用意した。 (Comparative Example 2)
As the nickel plating solution, a nickel plating solution (pH 9.0) containing nickel sulfate 0.25 mol / L, sodium hypophosphite 0.25 mol / L, and sodium citrate 0.15 mol / L was prepared.
　第１の導電部を形成する際に、得られた懸濁液を６０℃にて攪拌しながら、上記ニッケルめっき液を懸濁液に徐々に滴下し、無電解ニッケルーリン合金めっきを行った。その後、懸濁液をろ過することにより、粒子を取り出し、水洗し、乾燥することにより、基材粒子Ａの表面にニッケル－リン層（厚み０．１μｍ）が配置された粒子を得た。導電層１００重量％中のニッケルの含有量は９７．０重量％、リンの含有量は３．０重量％であった。得られた粒子を用いたこと以外は、実施例３と同様にして、導電性粒子、導電材料及び接続構造体を得た。 When forming the first conductive portion, the nickel plating solution was gradually added dropwise to the suspension while stirring the obtained suspension at 60 ° C. to perform electroless nickel-phosphorus alloy plating. Then, the suspension was filtered to take out the particles, washed with water, and dried to obtain particles in which a nickel-phosphorus layer (thickness 0.1 μm) was arranged on the surface of the base particle A. The nickel content in 100% by weight of the conductive layer was 97.0% by weight, and the phosphorus content was 3.0% by weight. Conductive particles, a conductive material, and a connecting structure were obtained in the same manner as in Example 3 except that the obtained particles were used.
　（比較例３）
　ニッケルめっき液として、硫酸ニッケル０．４０ｍｏｌ／Ｌ、次亜リン酸ナトリウム０．１５ｍｏｌ／Ｌ、及びクエン酸ナトリウム０．１５ｍｏｌ／Ｌを含むニッケルめっき液（ｐＨ１０．０）を用意した。 (Comparative Example 3)
As the nickel plating solution, a nickel plating solution (pH 10.0) containing nickel sulfate 0.40 mol / L, sodium hypophosphite 0.15 mol / L, and sodium citrate 0.15 mol / L was prepared.
　第１の導電部を形成する際に、得られた懸濁液を８０℃にて攪拌しながら、上記ニッケルめっき液を懸濁液に徐々に滴下し、無電解ニッケルーリン合金めっきを行った。その後、懸濁液をろ過することにより、粒子を取り出し、水洗し、乾燥することにより、基材粒子Ａの表面にニッケル－リン層（厚み０．１μｍ）が配置された粒子を得た。導電層１００重量％中のニッケルの含有量は９９．５重量％、リンの含有量は０．５重量％であった。得られた粒子を用いたこと以外は、実施例３と同様にして、導電性粒子、導電材料及び接続構造体を得た。 When forming the first conductive portion, the nickel plating solution was gradually added dropwise to the suspension while stirring the obtained suspension at 80 ° C. to perform electroless nickel-phosphorus alloy plating. Then, the suspension was filtered to take out the particles, washed with water, and dried to obtain particles in which a nickel-phosphorus layer (thickness 0.1 μm) was arranged on the surface of the base particle A. The content of nickel in 100% by weight of the conductive layer was 99.5% by weight, and the content of phosphorus was 0.5% by weight. Conductive particles, a conductive material, and a connecting structure were obtained in the same manner as in Example 3 except that the obtained particles were used.
　（比較例４）
　第１の接続対象部材として、第１の接続対象部材における電極の外表面の主金属が金である電極パターン（第１の電極）を上面に有するプラスチック基板を用意した。また、第２の接続対象部材として、第２の接続対象部材における電極の外表面の主金属が金である電極パターン（第２の電極）を下面に有するフレキシブル基板を用意した。接続構造体を作製する際に、Ｌ／Ｓが１０μｍ／１０μｍの銅電極パターン（第１の電極）を上面に有するプラスチック基板とＬ／Ｓが１０μｍ／１０μｍの銅電極パターン（第２の電極）を下面に有するフレキシブル基板との代わりに、用意した基板を用いたこと以外は、比較例３と同様にして、接続構造体を得た。 (Comparative Example 4)
As the first connection target member, a plastic substrate having an electrode pattern (first electrode) on which the main metal of the outer surface of the electrode in the first connection target member is gold was prepared. Further, as the second connection target member, a flexible substrate having an electrode pattern (second electrode) in which the main metal of the outer surface of the electrode in the second connection target member is gold is prepared on the lower surface. When producing the connection structure, a plastic substrate having a copper electrode pattern (first electrode) having an L / S of 10 μm / 10 μm on the upper surface and a copper electrode pattern having an L / S of 10 μm / 10 μm (second electrode) A connection structure was obtained in the same manner as in Comparative Example 3 except that the prepared substrate was used instead of the flexible substrate having the above.
　（比較例５）
　導電性粒子を作製する際に、第２の導電部を形成しなかったこと以外は、実施例１６と同様にして、導電性粒子、導電材料及び接続構造体を得た。 (Comparative Example 5)
Conductive particles, a conductive material, and a connecting structure were obtained in the same manner as in Example 16 except that the second conductive portion was not formed when the conductive particles were produced.
　（比較例６）
　第２の導電部を形成する際に、無電解コバルトめっきを施したこと以外は、実施例３と同様にして、導電性粒子、導電フィルム及び接続構造体を得た。 (Comparative Example 6)
Conductive particles, a conductive film, and a connecting structure were obtained in the same manner as in Example 3 except that electroless cobalt plating was applied when forming the second conductive portion.
　（導電性粒子の粒子径）
　導電性粒子の粒子径は、レーザー回折式粒度分布測定装置（堀場製作所社製「ＬＡ－９２０」）を用いて測定した。 (Particle diameter of conductive particles)
The particle size of the conductive particles was measured using a laser diffraction type particle size distribution measuring device (“LA-920” manufactured by HORIBA, Ltd.).
　（評価）
　（１）第１の導電部の全体１００重量％中におけるニッケル及びホウ素の平均含有量
　導電性粒子の作製の際に、第１の導電部のみを形成することで、第１の導電部のみが形成された粒子を用意した。６０％硝酸５ｍＬと３７％塩酸１０ｍＬとの混合液に、用意した粒子５ｇを加え、第１の導電部を完全に溶解させ、溶液を得た。得られた溶液を用いて、ニッケル及びホウ素の含有量を高周波誘導結合プラズマイオン源質量分析装置（日立ハイテクサイエンス社製「ＩＣＰ－ＭＳ」）により分析した。なお、上記粒子を５ｇ用意することが困難な場合は、測定に用いる粒子は、５ｇ未満であってもよい。 (Evaluation)
(1) Average content of nickel and boron in 100% by weight of the first conductive portion By forming only the first conductive portion during the production of the conductive particles, only the first conductive portion is formed. The formed particles were prepared. 5 g of the prepared particles were added to a mixed solution of 5 mL of 60% nitric acid and 10 mL of 37% hydrochloric acid, and the first conductive portion was completely dissolved to obtain a solution. Using the obtained solution, the contents of nickel and boron were analyzed by a high-frequency inductively coupled plasma ion source mass spectrometer (“ICP-MS” manufactured by Hitachi High-Tech Science Co., Ltd.). If it is difficult to prepare 5 g of the above particles, the amount of particles used for the measurement may be less than 5 g.
　（２）第１の導電部の厚み方向におけるニッケル及びホウ素の平均含有量
　第１の導電部の厚み方向における、ニッケル及びホウ素の含有量の分布を測定した。 (2) Average content of nickel and boron in the thickness direction of the first conductive portion The distribution of the content of nickel and boron in the thickness direction of the first conductive portion was measured.
　集束イオンビームを用いて、得られた導電性粒子の薄膜切片を作製した。電界放射型透過電子顕微鏡（日本電子社製「ＪＥＭ－２０１０ＦＥＦ」）を用いて、エネルギー分散型Ｘ線分析装置（ＥＤＳ）により、第１の導電部の厚み方向におけるニッケル及びホウ素の各含有量を測定した。この結果から、第１の導電部の内表面から外側に向かって厚み１／５までの上記領域（Ｒ１）（内表面側の厚み２０％の領域）、及び第１の導電部の外表面から内側に向かって厚み１／５までの上記領域（Ｒ２）（外表面側の厚み２０％の領域）の１００重量％中におけるニッケル（Ｎｉ）及びホウ素（Ｂ）の平均含有量を求めた。得られた結果から、上記領域（Ｒ１）の１００重量％中におけるホウ素の平均含有量と、上記領域（Ｒ２）の１００重量％中におけるホウ素の平均含有量との差の絶対値（ホウ素の平均含有量の差の絶対値）を算出した。 A thin film section of the obtained conductive particles was prepared using a focused ion beam. Using a field emission transmission electron microscope (“JEM-2010FEF” manufactured by JEOL Ltd.), the energy dispersive X-ray analyzer (EDS) was used to determine the content of nickel and boron in the thickness direction of the first conductive portion. It was measured. From this result, from the above-mentioned region (R1) (the region having a thickness of 20% on the inner surface side) up to 1/5 of the thickness from the inner surface of the first conductive portion to the outside, and from the outer surface of the first conductive portion. The average contents of nickel (Ni) and boron (B) in 100% by weight of the above region (R2) (region having a thickness of 20% on the outer surface side) up to 1/5 of the thickness toward the inside were determined. From the obtained results, the absolute value of the difference between the average content of boron in 100% by weight of the region (R1) and the average content of boron in 100% by weight of the region (R2) (average of boron). The absolute value of the difference in content) was calculated.
　（３）接続抵抗Ａ（初期）
　得られた接続構造体の対向する電極間の接続抵抗Ａを４端子法により測定した。なお、電圧＝電流×抵抗の関係から、一定の電流を流した時の電圧を測定することにより接続抵抗を求めることができる。また、接続抵抗Ａを下記の基準で判定した。 (3) Connection resistor A (initial)
The connection resistance A between the opposing electrodes of the obtained connection structure was measured by the 4-terminal method. From the relationship of voltage = current x resistance, the connection resistance can be obtained by measuring the voltage when a constant current is passed. Further, the connection resistance A was determined according to the following criteria.
　［接続抵抗Ａの評価基準］
　○○○：接続抵抗Ａが２．０Ω以下
　○○：接続抵抗Ａが２．０Ωを超え３．０Ω以下
　○：接続抵抗Ａが３．０Ωを超え５．０Ω以下
　△：接続抵抗Ａが５．０Ωを超え１０Ω以下
　×：接続抵抗Ａが１０Ωを超える [Evaluation criteria for connection resistance A]
○ ○ ○: Connection resistance A is 2.0Ω or less ○○: Connection resistance A is more than 2.0Ω and 3.0Ω or less ○: Connection resistance A is more than 3.0Ω and 5.0Ω or less △: Connection resistance A is 5 More than 0.0Ω and less than 10Ω ×: Connection resistance A exceeds 10Ω
　（４）接続抵抗Ｂ（信頼性試験後）
　上記（１）初期の接続抵抗の評価で得られた接続構造体を、８５℃及び相対湿度８５％の条件で放置した。放置開始から１０００時間後に、上記（３）接続抵抗Ａの評価と同様に電極間の接続抵抗Ｂを４端子法により測定した。また、接続抵抗Ｂを下記の基準で判定した。 (4) Connection resistor B (after reliability test)
The connection structure obtained in the above (1) initial evaluation of connection resistance was left to stand under the conditions of 85 ° C. and 85% relative humidity. After 1000 hours from the start of leaving, the connection resistance B between the electrodes was measured by the 4-terminal method in the same manner as in the evaluation of the connection resistance A in (3) above. Further, the connection resistance B was determined according to the following criteria.
　［接続抵抗Ｂの判定基準］
　○○○：接続抵抗Ｂが、接続抵抗Ａの１．２５倍未満
　○○：接続抵抗Ｂが、接続抵抗Ａの１．２５倍以上１．５倍未満
　○：接続抵抗Ｂが、接続抵抗Ａの１．５倍以上２倍未満
　△：接続抵抗Ｂが、接続抵抗Ａの２倍以上３倍未満
　×：接続抵抗Ｂが、接続抵抗Ａの３倍以上 [Criteria for connection resistance B]
○ ○ ○: Connection resistance B is less than 1.25 times the connection resistance A ○ ○: Connection resistance B is 1.25 times or more and less than 1.5 times the connection resistance A ○: Connection resistance B is the connection resistance A 1.5 times or more and less than 2 times Δ: Connection resistance B is 2 times or more and less than 3 times of connection resistance A ×: Connection resistance B is 3 times or more of connection resistance A
　（５）導電部の割れ（初期）
　得られた導電性粒子１ｇと、トルエン２０ｇと、直径０．５ｍｍのジルコニアボール４５ｇとを混合し、直径３ｃｍの攪拌羽根で４００ｒｐｍの条件で２分間撹拌した。固液分離した粒子を乾燥した後、ＳＥＭ観察を行った。導電性粒子１０００個中、導電部に割れが生じた導電性粒子の個数をカウントして、導電部の割れを下記の基準で判定した。なお、導電部の割れの評価に用いる上記導電性粒子の使用量は、１０００個観察できるのであれば１ｇ未満であってもよい。 (5) Cracking of conductive part (initial)
1 g of the obtained conductive particles, 20 g of toluene, and 45 g of zirconia balls having a diameter of 0.5 mm were mixed and stirred with a stirring blade having a diameter of 3 cm at 400 rpm for 2 minutes. After the solid-liquid separated particles were dried, SEM observation was performed. Of the 1000 conductive particles, the number of conductive particles in which the conductive portion was cracked was counted, and the crack in the conductive portion was determined according to the following criteria. The amount of the conductive particles used for evaluating the cracking of the conductive portion may be less than 1 g as long as 1000 particles can be observed.
　［導電部の割れ（初期）の判定基準］
　○○○：導電部に割れが生じた導電性粒子の個数の割合が、３％未満
　○○：導電部に割れが生じた導電性粒子の個数の割合が、３％以上１０％未満
　○：導電部に割れが生じた導電性粒子の個数の割合が、１０％以上２０％未満
　△：導電部に割れが生じた導電性粒子の個数の割合が、２０％以上３０％未満
　×：導電部に割れが生じた導電性粒子の個数の割合が、３０％以上 [Criteria for cracking (initial) of conductive parts]
○○○: The ratio of the number of conductive particles with cracks in the conductive part is less than 3% ○○: The ratio of the number of conductive particles with cracks in the conductive part is 3% or more and less than 10% ○: The ratio of the number of conductive particles with cracks in the conductive part is 10% or more and less than 20% Δ: The ratio of the number of conductive particles with cracks in the conductive part is 20% or more and less than 30% ×: Conductive part The ratio of the number of conductive particles with cracks is 30% or more.
　（６）導電部の割れ（信頼性試験後）
　得られた導電性粒子を、８５℃及び相対湿度８５％の条件で放置した。放置開始から１０００時間後に、放置した導電性粒子１ｇと、トルエン２０ｇと、直径０．５ｍｍのジルコニアボール４５ｇとを混合し、直径３ｃｍの攪拌羽根で４００ｒｐｍの条件で２分間撹拌した。固液分離した粒子を乾燥した後、ＳＥＭ観察を行った。導電性粒子１０００個中、導電部に割れが生じた導電性粒子の個数をカウントして、導電部の割れを下記の基準で判定した。なお、導電部の割れの評価に用いる上記導電性粒子の使用量は、１０００個観察できるのであれば１ｇ未満であってもよい。 (6) Cracking of conductive part (after reliability test)
The obtained conductive particles were left at 85 ° C. and 85% relative humidity. After 1000 hours from the start of standing, 1 g of the left conductive particles, 20 g of toluene, and 45 g of zirconia balls having a diameter of 0.5 mm were mixed and stirred with a stirring blade having a diameter of 3 cm at 400 rpm for 2 minutes. After the solid-liquid separated particles were dried, SEM observation was performed. Of the 1000 conductive particles, the number of conductive particles in which the conductive portion was cracked was counted, and the crack in the conductive portion was determined according to the following criteria. The amount of the conductive particles used for evaluating the cracking of the conductive portion may be less than 1 g as long as 1000 particles can be observed.
　［導電部の割れ（信頼性試験後）の判定基準］
　○○○：導電部に割れが生じた導電性粒子の個数の割合が、５％未満
　○○：導電部に割れが生じた導電性粒子の個数の割合が、５％以上１５％未満
　○：導電部に割れが生じた導電性粒子の個数の割合が、１５％以上２５％未満
　△：導電部に割れが生じた導電性粒子の個数の割合が、２５％以上３５％未満
　×：導電部に割れが生じた導電性粒子の個数の割合が、３５％以上 [Criteria for cracking conductive parts (after reliability test)]
○ ○ ○: The ratio of the number of conductive particles with cracks in the conductive part is less than 5% ○ ○: The ratio of the number of conductive particles with cracks in the conductive part is 5% or more and less than 15% ○: The ratio of the number of conductive particles with cracks in the conductive part is 15% or more and less than 25% Δ: The ratio of the number of conductive particles with cracks in the conductive part is 25% or more and less than 35% ×: Conductive part The ratio of the number of conductive particles with cracks is 35% or more.
　導電性粒子の詳細及び結果を下記の表１～４に示す。 Details and results of the conductive particles are shown in Tables 1 to 4 below.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004
　１，１１，２１，３１…導電性粒子
　２…基材粒子
　３，１３，２３，３３…第１の導電部
　４，２４，３４…第２の導電部
　１３Ａ，１３Ｂ…導電部
　２５…芯物質
　２６…絶縁性物質
　２１Ａ，２３Ａ，２４Ａ…突起
　３１Ａ，３３Ａ，３４Ａ…突起
　５１…接続構造体
　５２…第１の接続対象部材
　５２ａ…第１の電極
　５３…第２の接続対象部材
　５３ａ…第２の電極
　５４…接続部 1,11,21,31 ... Conductive particles 2 ... Base particles 3,13,23,33 ... First conductive parts 4,24,34 ... Second conductive parts 13A, 13B ... Conductive parts 25 ... Core material 26 ... Insulating material 21A, 23A, 24A ... Projection 31A, 33A, 34A ... Projection 51 ... Connection structure 52 ... First connection target member 52a ... First electrode 53 ... Second connection target member 53a ... Second Electrode 54 ... Connection

Claims (18)

  1. 　基材粒子と、
    　前記基材粒子の表面上に配置された第１の導電部と、
    　前記第１の導電部の表面上に配置された第２の導電部とを備え、
    　前記第１の導電部が、ニッケルとホウ素とを含み、かつ、リンを含まず、
    　前記第１の導電部の内表面から外側に向かって厚み１／５の領域の１００重量％中におけるホウ素の平均含有量と、前記第１の導電部の外表面から内側に向かって厚み１／５の領域の１００重量％中におけるホウ素の平均含有量との差の絶対値が、０重量％以上１０重量％以下であり、
    　前記第１の導電部における主金属の標準電極電位が、前記第２の導電部における主金属の標準電極電位よりも小さい、導電性粒子。     With base particles
    A first conductive portion arranged on the surface of the base particle and
    It is provided with a second conductive portion arranged on the surface of the first conductive portion.
    The first conductive portion contains nickel and boron and does not contain phosphorus.
    The average content of boron in 100% by weight of the region having a thickness of 1/5 from the inner surface of the first conductive portion to the outside, and the thickness of 1/5 from the outer surface of the first conductive portion to the inside. The absolute value of the difference from the average content of boron in 100% by weight of the region 5 is 0% by weight or more and 10% by weight or less.
    A conductive particle in which the standard electrode potential of the main metal in the first conductive portion is smaller than the standard electrode potential of the main metal in the second conductive portion.
  2. 　前記第１の導電部における主金属の標準電極電位と、前記第２の導電部における主金属の標準電極電位との差の絶対値が、０．０５Ｖ以上３Ｖ以下である、請求項１に記載の導電性粒子。 The first aspect of claim 1, wherein the absolute value of the difference between the standard electrode potential of the main metal in the first conductive portion and the standard electrode potential of the main metal in the second conductive portion is 0.05 V or more and 3 V or less. Conductive particles.
  3. 　前記第１の導電部の内表面から外側に向かって厚み１／５の領域の１００重量％中におけるホウ素の平均含有量が、０重量％以上１０重量％以下であり、
    　前記第１の導電部の外表面から内側に向かって厚み１／５の領域の１００重量％中におけるホウ素の平均含有量が、０重量％以上１０重量％以下である、請求項１又は２に記載の導電性粒子。     The average content of boron in 100% by weight of the region having a thickness of 1/5 from the inner surface to the outside of the first conductive portion is 0% by weight or more and 10% by weight or less.
    According to claim 1 or 2, the average content of boron in 100% by weight of the region having a thickness of 1/5 from the outer surface to the inside of the first conductive portion is 0% by weight or more and 10% by weight or less. The conductive particles described.
  4. 　前記第１の導電部の全体１００重量％中におけるニッケルの平均含有量が、５０重量％以上９９．９重量％以下である、請求項１～３のいずれか１項に記載の導電性粒子。 The conductive particles according to any one of claims 1 to 3, wherein the average content of nickel in 100% by weight of the first conductive portion is 50% by weight or more and 99.9% by weight or less.
  5. 　前記第１の導電部の全体１００重量％中におけるホウ素の平均含有量が、０．００１重量％以上１０重量％以下である、請求項１～４のいずれか１項に記載の導電性粒子。 The conductive particles according to any one of claims 1 to 4, wherein the average content of boron in 100% by weight of the first conductive portion is 0.001% by weight or more and 10% by weight or less.
  6. 　前記第２の導電部における主金属が、錫、銅、パラジウム、ルテニウム、白金、銀、ロジウム、イリジウム又は金である、請求項１～５のいずれか１項に記載の導電性粒子。 The conductive particle according to any one of claims 1 to 5, wherein the main metal in the second conductive portion is tin, copper, palladium, ruthenium, platinum, silver, rhodium, iridium or gold.
  7. 　前記第２の導電部の外表面が防錆処理されている、請求項１～６のいずれか１項に記載の導電性粒子。 The conductive particle according to any one of claims 1 to 6, wherein the outer surface of the second conductive portion is rust-proofed.
  8. 　前記第２の導電部の外表面が、炭素数６～２２のアルキル基を有する化合物により防錆処理されている、請求項７に記載の導電性粒子。 The conductive particles according to claim 7, wherein the outer surface of the second conductive portion is rust-proofed with a compound having an alkyl group having 6 to 22 carbon atoms.
  9. 　前記基材粒子の粒子径が、０．１μｍ以上１００μｍ以下である、請求項１～８のいずれか１項に記載の導電性粒子。 The conductive particle according to any one of claims 1 to 8, wherein the base particle has a particle size of 0.1 μm or more and 100 μm or less.
  10. 　前記第１の導電部又は前記第２の導電部の外表面に複数の突起を有する、請求項１～９のいずれか１項に記載の導電性粒子。 The conductive particle according to any one of claims 1 to 9, which has a plurality of protrusions on the outer surface of the first conductive portion or the second conductive portion.
  11. 　前記第１の導電部又は前記第２の導電部の内部又は内側において、複数の前記突起を形成するように、前記第１の導電部又は前記第２の導電部の表面を隆起させている複数の芯物質を備える、請求項１０に記載の導電性粒子。 A plurality of raised surfaces of the first conductive portion or the second conductive portion so as to form a plurality of the protrusions inside or inside the first conductive portion or the second conductive portion. The conductive particle according to claim 10, further comprising the core material of the above.
  12. 　前記第１の導電部又は前記第２の導電部の内部又は内側において、複数の前記突起を形成するように、前記第１の導電部又は前記第２の導電部の表面を隆起させている複数の芯物質を備えていない、請求項１０に記載の導電性粒子。 A plurality of raised surfaces of the first conductive portion or the second conductive portion so as to form a plurality of the protrusions inside or inside the first conductive portion or the second conductive portion. The conductive particle according to claim 10, which does not include the core material of the above.
  13. 　前記第２の導電部の外表面上に配置された絶縁性物質を備える、請求項１～１２のいずれか１項に記載の導電性粒子。 The conductive particle according to any one of claims 1 to 12, comprising an insulating substance arranged on the outer surface of the second conductive portion.
  14. 　電極と、上記電極の表面上に配置された保護層とを備える保護層付き電極の導電接続用途に用いられる、請求項１～１３のいずれか１項に記載の導電性粒子。 The conductive particle according to any one of claims 1 to 13, which is used for conductive connection of an electrode with a protective layer including an electrode and a protective layer arranged on the surface of the electrode.
  15. 　フレキシブル部材の電極の導電接続用途に用いられる、請求項１～１３のいずれか１項に記載の導電性粒子。 The conductive particle according to any one of claims 1 to 13, which is used for conductive connection of electrodes of flexible members.
  16. 　請求項１～１３のいずれか１項に記載の導電性粒子と、バインダー樹脂とを含む、導電材料。 A conductive material containing the conductive particles according to any one of claims 1 to 13 and a binder resin.
  17. 　第１の電極を表面に有する第１の接続対象部材と、
    　第２の電極を表面に有する第２の接続対象部材と、
    　前記第１の接続対象部材と、前記第２の接続対象部材とを接続している接続部とを備え、
    　前記接続部が、請求項１～１３のいずれか１項に記載の導電性粒子により形成されているか、又は前記導電性粒子とバインダー樹脂とを含む導電材料により形成されており、
    　前記第１の電極と前記第２の電極とが、前記導電性粒子により電気的に接続されている、接続構造体。     A first connection target member having a first electrode on its surface,
    A second connection target member having a second electrode on the surface,
    A connecting portion connecting the first connection target member and the second connection target member is provided.
    The connecting portion is formed of the conductive particles according to any one of claims 1 to 13, or is formed of a conductive material containing the conductive particles and a binder resin.
    A connection structure in which the first electrode and the second electrode are electrically connected by the conductive particles.
  18. 　前記第１の導電部における主金属の標準電極電位が、前記第１の電極又は前記第２の電極の外表面の主金属の標準電極電位よりも小さい、請求項１７に記載の接続構造体。 The connection structure according to claim 17, wherein the standard electrode potential of the main metal in the first conductive portion is smaller than the standard electrode potential of the main metal on the outer surface of the first electrode or the second electrode.
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