JP2020061376A - Conductive particle, conductive material and connection structure - Google Patents

Abstract

To provide a conductive particle which can improve conduction reliability when electrically connecting electrodes together.SOLUTION: A conductive particle 1 has a base particle 2, and a conductive part 3 disposed on the surface of the base particle 2, the conductive part 3 has a plurality of projections 3a on its external surface, a ratio of (111) faces of the projections 3a in X-ray diffraction is 50% or more, and an average maximum diameter of bases of the projections 3a is 1 nm or more and 500 nm or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a conductive particle in which a conductive portion is arranged on the surface of a base particle and the conductive portion has a plurality of protrusions on the outer surface. The present invention also relates to a conductive material and a connection structure using the above conductive particles.

  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.

  The anisotropic conductive material is used to electrically connect electrodes of various members to be connected such as a flexible printed circuit (FPC), a glass substrate and a semiconductor chip to obtain a connection structure. In addition, as the conductive particles, conductive particles having base particles and conductive portions arranged on the surface of the base particles may be used.

  In order to obtain various connection structures, the anisotropic conductive material is, for example, connected to a flexible printed circuit board and a glass substrate (FOG (Film on Glass)), or connected to a semiconductor chip and a flexible printed circuit board (COF ( Chip on Film)), connection between a semiconductor chip and a glass substrate (COG (Chip on Glass)), and connection between a flexible printed circuit board and a glass epoxy substrate (FOB (Film on Board)).

  As an example of the above-mentioned conductive particles, the following Patent Document 1 discloses conductive particles in which a nickel or nickel alloy film is formed on the surface of core material particles. The conductive particles have a large number of protrusions protruding from the surface of the film, being continuous with the film, and having an aspect ratio of 1 or more. The ratio of the protrusions having an aspect ratio of 1 or more is 40% or more with respect to the total number of protrusions.

  The following Patent Document 2 discloses a conductive particle in which the surface of the base material particle is covered with a conductive film, and the conductive film has a protrusion protruding on the surface. The raised protrusions on the surface of the conductive film have soft metal particles and hard non-metal particles as core materials. The particle size of the soft metal particles is 1.05 to 6 times the average particle size of the hard non-metal particles.

In Patent Document 3 below, conductive powder (conductive particles) whose main component is silver or nickel is provided with a convex portion on the surface, and a metallic material is used as a nuclear substance for crystal growth of a conductive material inside. A conductive powder (conductive particles) containing particles or ceramic particles is disclosed. At least the surface of this conductive powder is treated with an organic acid or an organic acid salt. The bulk density of this conductive powder is a value within the range of 0.5 to 2.5 g / cm ³ .

WO2010 / 044388A1 JP 2006-216388 A JP, 2009-277403, A

  In the conventional conductive particles described in Patent Documents 1 to 3, the protrusions may be broken. Therefore, when conductive particles are used to electrically connect the upper and lower electrodes, the connection resistance may increase.

  In addition, in the conventional conductive particles, electrodes that are not adjacent to each other and are laterally adjacent to each other may be electrically connected to each other.

  In recent years, the electrode width and the interelectrode width (L / S) have become smaller. When L / S is small, it is difficult to secure sufficient insulation reliability. On the other hand, if the particle size of the conductive particles is reduced, the insulation reliability can be improved to some extent. However, when the particle diameter of the conductive particles is small, the conductive particles are likely to aggregate, and the conductive particles are in contact with each other, whereby the protrusions are easily broken.

  The conventional conductive particles may not be able to improve the conduction reliability, and particularly when the particle diameter of the conductive particles is small, it may not be possible to improve both the conduction reliability and the insulation reliability.

  It is an object of the present invention to provide conductive particles that can improve conduction reliability when electrodes are electrically connected. Moreover, the objective of this invention is providing the electrically-conductive material and connection structure which used the said electrically-conductive particle.

  According to a broad aspect of the present invention, it comprises a base particle and a conductive portion arranged on the surface of the base particle, the conductive portion has a plurality of protrusions on the outer surface, X of the protrusion. Provided is a conductive particle having a ratio of (111) plane of 50% or more in line diffraction and an average maximum diameter of the base of the protrusion of 1 nm or more and 500 nm or less.

  In a specific aspect of the conductive particles according to the present invention, the particle size is 0.5 μm or more and less than 5 μm.

  In a specific aspect of the conductive particle according to the present invention, the ratio of the number of protrusions having a maximum diameter of the base portion of 200 nm or less is 10% or more in 100% of the total number of protrusions.

  In a specific aspect of the conductive particles according to the present invention, the particle diameter is 5 μm or more and less than 20 μm.

  In a specific aspect of the conductive particles according to the present invention, the ratio of the number of the protrusions having the maximum diameter of the base of 10% or less of the particle diameter of the conductive particles is 10% or more in 100% of the total number of the protrusions. is there.

  In a particular aspect of the conductive particles according to the present invention, the core substance is not arranged inside the protrusion, the conductive portion having a plurality of the protrusion, the first portion and the first portion Also has a thick second portion, and the plurality of protrusions is the second portion having a thick conductive portion.

  In one specific aspect of the conductive particle according to the present invention, the ratio of the average height of the plurality of protrusions to the average maximum diameter of the bases of the plurality of protrusions is 0.1 or more and 5 or less.

  In a specific aspect of the conductive particle according to the present invention, the ratio of the average maximum diameter of the base of the protrusion to the average minimum diameter of the base of the protrusion is 10 or less.

  In one specific aspect of the conductive particle according to the present invention, the surface area of the portion having the protrusion is 30% or more in 100% of the total surface area of the outer surface of the conductive portion.

  In a particular aspect of the conductive particles according to the present invention, the conductive portion is copper, nickel, palladium, ruthenium, platinum, gold, silver, rhodium, iridium, lithium, cobalt, iron, tungsten, molybdenum, phosphorus and boron. At least one selected from the group consisting of:

  In a specific aspect of the conductive particle according to the present invention, the conductive portion is a multilayer conductive portion, and the conductive portion positioned on the outermost side of the conductive portion has a plurality of protrusions on the outer surface.

  In a specific aspect of the conductive particle according to the present invention, the conductive particle further includes an insulating substance disposed on the outer surface of the conductive portion.

  According to a broad aspect of the present invention, there is provided a conductive material including the conductive particles described above and a binder resin.

  According to a broad aspect of the present invention, a first connection target member, a second connection target member, and a connecting portion connecting the first connection target member and the second connection target member are provided. A connection structure is provided, in which the material of the connection portion is the above-mentioned conductive particles or a conductive material containing the conductive particles and a binder resin.

  The conductive particle according to the present invention comprises a base particle and a conductive portion disposed on the surface of the base particle, the conductive portion having a plurality of protrusions on the outer surface, X of the protrusion. The proportion of the (111) plane in line diffraction is 50% or more, and the average maximum diameter of the base of the protrusion is 1 nm or more and 500 nm or less. Therefore, the conductive particles according to the present invention are used to electrically connect between electrodes. It is possible to improve the conduction reliability when connected to.

FIG. 1 is a cross-sectional view schematically showing conductive particles according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing conductive particles according to the second embodiment of the present invention. FIG. 3 is a cross-sectional view schematically showing conductive particles according to the third embodiment of the present invention. FIG. 4 is a cross-sectional view schematically showing conductive particles according to the fourth embodiment of the present invention. FIG. 5: is sectional drawing which shows the electroconductive particle which concerns on the 5th Embodiment of this invention typically. FIG. 6 is a front sectional view schematically showing a connection structure using the conductive particles according to the first embodiment of the present invention. FIGS. 7A and 7B are views showing images of the produced conductive particles. FIGS. 8A and 8B are views showing images of the produced conductive particles. 9A and 9B are views showing images of the produced conductive particles.

  Hereinafter, the details of the present invention will be described.

(Conductive particles)
The conductive particles according to the present invention include base particles and conductive portions arranged on the surfaces of the base particles. The conductive portion has a plurality of protrusions on the outer surface. The proportion of the (111) plane in X-ray diffraction of the protrusion is 50% or more. The average maximum diameter of the base of the protrusion is 1 nm or more and 500 nm or less.

  By adopting the above-mentioned configuration in the conductive particles according to the present invention, it is possible to improve the conduction reliability when the electrodes are electrically connected by using the conductive particles according to the present invention.

  The particle diameter of the conductive particles according to the present invention is preferably 0.5 μm or more and 30 μm or less. When the conductive particles having a small particle diameter are adopted, the particle diameter of the conductive particles is preferably less than 5 μm, more preferably less than 3 μm, and further preferably 2.8 μm or less. When the particle size of the conductive particles is small, the insulation reliability can be improved. Further, in the present invention, even if the particle size of the conductive particles is small, the specific projections are formed, so that the conduction reliability can be improved. Regarding the particle size, conductive particles having a large particle size and a particle size of 5 μm or more may be adopted depending on the intended use. Further, regarding the conductive particles having a large particle diameter, the particle diameter of the conductive particles is preferably less than 20 μm.

  The particle size of the conductive particles indicates the diameter when the conductive particles are spherical, and indicates the maximum diameter when the conductive particles are not spherical.

  The average height A of the plurality of protrusions is preferably 5 nm or more, more preferably 10 nm or more, still more preferably 50 nm or more, preferably 500 nm or less, more preferably 300 nm or less. When the average height A of the protrusions is equal to or higher than the lower limit, the contactability and penetrability of the protrusions are further enhanced. For example, when an oxide film is formed on the outer surface of the conductive portion and the surface of the electrode, the protrusions easily penetrate the oxide film. As a result, the connection resistance becomes low. When the average height A of the protrusions is equal to or less than the upper limit, the protrusions are not easily broken. Note that the broken protrusion may increase the connection resistance between the electrodes.

  The average height A of the protrusions is the average height of the protrusions contained in one conductive particle. The height of the protrusion is a virtual line of the conductive portion (the broken line shown in FIG. 1) on the line connecting the center of the conductive particle and the tip of the protrusion (broken line L1 shown in FIG. 1) assuming that there is no protrusion. L2) Shows the distance from the top (on the outer surface of the spherical conductive particle assuming no protrusion) to the tip of the protrusion. That is, in FIG. 1, the distance from the intersection of the broken line L1 and the broken line L2 to the tip of the protrusion is shown.

  The average maximum diameter B of the bases of the plurality of protrusions is preferably 5 nm or more, more preferably 10 nm or more, still more preferably 50 nm or more, preferably 500 nm or less, more preferably 300 nm or less. When the average maximum diameter B is equal to or more than the lower limit, the protrusions are less likely to break. When the average maximum diameter B is equal to or less than the upper limit, the contactability and penetrability by the protrusions are further enhanced.

  The average maximum diameter B of the base of the protrusion is the average of the maximum diameters of the bases of the protrusions contained in one conductive particle. The maximum diameter of the base is the maximum diameter of each of the bases in the protrusion. The end of the phantom line portion (broken line L2 shown in FIG. 1) of the conductive portion on the line connecting the center of the conductive particle and the tip of the protrusion (broken line L1 shown in FIG. 1) is assumed to have no protrusion. Is the base of the protrusion, and the distance between the ends of the imaginary line portion is the diameter of the base.

  The ratio of the average height A of the plurality of protrusions to the average maximum diameter B of the bases of the plurality of protrusions (average height A / average maximum diameter B) is preferably 0.1 or more, more preferably 0.5. It is above, preferably 5 or less, more preferably 3 or less. When the ratio (average height A / average maximum diameter B) is at least the above lower limit, the contactability and penetrability of the protrusions will be further enhanced. When the above ratio (average height A / average maximum diameter B) is not more than the above upper limit, the protrusions are not easily broken. Further, when the ratio (average height A / average maximum diameter B) is not more than the upper limit, when the upper and lower electrodes to be connected are electrically connected, they are adjacent to each other in the lateral direction that should not be connected. It is difficult to electrically connect the electrodes.

  The number of protrusions on the outer surface of the conductive portion per one conductive particle is preferably 3 or more, more preferably 5 or more, further preferably 50 or more, and particularly preferably 100 or more. The upper limit of the number of protrusions is not particularly limited. The upper limit of the number of protrusions can be appropriately selected in consideration of the particle diameter of the conductive particles and the like.

  The ratio X of the number of protrusions having the maximum diameter of the base portion (maximum diameter of the base portion in one protrusion) of 200 nm or less is preferably 10% in 100% of the total number of protrusions contained in one conductive particle. The above is more preferably 30% or more, further preferably 50% or more, further preferably 60% or more, particularly preferably 70% or more, and most preferably 80% or more. The larger the ratio of the number of protrusions, the more effectively the effect of the protrusions is obtained.

  Of 100% of the total number of protrusions contained in one conductive particle, the maximum diameter of the base portion (the maximum diameter of the base portion in one protrusion) is 10% or less of the particle diameter of the conductive particles. The ratio Z is preferably 10% or more. The larger the ratio of the number of protrusions, the more effectively the effect of the protrusions is obtained.

  The ratio Y of the surface area on which the projections are formed is preferably 10% or more, more preferably 20% or more, further preferably 30% or more, and preferably 90% in 100% of the total surface area of the outer surface of the conductive portion. Or less, more preferably 80% or less, still more preferably 70% or less.

  From the viewpoint of further lowering the connection resistance between the electrodes, the proportion of the (111) plane in the X-ray diffraction of the protrusion is preferably 60% or more, more preferably 80% or more, and further preferably 90% or more. By satisfying such a ratio of the (111) plane, the projection is more difficult to break and the conductive portion is more difficult to break. As a result, the connection resistance between the electrodes becomes even lower.

  Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. Note that different partial configurations in each embodiment can be appropriately replaced and combined.

  FIG. 1 is a cross-sectional view schematically showing conductive particles according to the first embodiment of the present invention.

  As shown in FIG. 1, the conductive particle 1 includes a base material particle 2 and a conductive portion 3.

  The conductive portion 3 is arranged on the surface of the base particle 2. The conductive portion 3 is in contact with the base material particles 2. The conductive particle 1 is a coated particle in which the surface of the base material particle 2 is coated with the conductive portion 3. The conductive portion 3 is a continuous film.

  The conductive particle 1 has a plurality of protrusions 1a on the conductive surface. The conductive portion 3 has a plurality of protrusions 3a on the outer surface.

  The conductive portion 3 has a first portion and a second portion that is thicker than the first portion. The portion excluding the plurality of protrusions 1a and 3a is the first portion of the conductive portion 3. The plurality of protrusions 1a and 3a are the second portions in which the conductive portion 3 has a large thickness.

  FIG. 2 is a cross-sectional view schematically showing conductive particles according to the second embodiment of the present invention.

  As shown in FIG. 2, the conductive particles 1A include base material particles 2 and conductive portions 3A.

  The conductive portion 3A is arranged on the surface of the base particle 2. The conductive particles 1A have a plurality of protrusions 1Aa on the conductive surface. The conductive portion 3A has a plurality of protrusions 3Aa on the outer surface.

  In the conductive particle 1A, the average height A of the protrusions 1Aa and 3Aa is larger than the average maximum diameter B of the bases of the protrusions 1Aa and 3Aa.

  Like the conductive particles 1, 1A, the relationship between the average height A of the plurality of protrusions 1a, 3a, 1Aa, 3Aa and the average maximum diameter B of the bases of the plurality of protrusions 1a, 3a, 1Aa, 3Aa is appropriately determined. Can be changed. For example, the relationship with the average maximum diameter B of the bases of the plurality of protrusions 1a, 3a, 1Aa, 3Aa can be controlled by the degree of plating growth.

  FIG. 3 is a cross-sectional view schematically showing conductive particles according to the third embodiment of the present invention.

  As shown in FIG. 3, the conductive particles 1B include base particles 2 and conductive portions 3B.

  Only the conductive part is different between the conductive particles 1 and the conductive particles 1B. That is, in the conductive particle 1, the conductive portion 3 having a one-layer structure is formed, whereas in the conductive particle 1B, a multilayer (two layers) conductive portion 3B is formed.

  The conductive portion 3B has a first conductive portion 3BA and a second conductive portion 3BB. The first and second conductive parts 3BA, 3BB are arranged on the surface of the base particle 2. The first conductive portion 3BA is arranged between the base particle 2 and the second conductive portion 3BB. Therefore, the first conductive portion 3BA is arranged on the surface of the base material particle 2, and the second conductive portion 3BB is arranged on the surface of the first conductive portion 3BA. The outer shape of the first conductive portion 3BA is spherical. The conductive particle 1B has a plurality of protrusions 1Ba on its conductive surface. The conductive portion 3B has a plurality of protrusions 3Ba on its outer surface. The second conductive portion 3BB has a plurality of protrusions 3BBa on the outer surface.

  FIG. 4 is a cross-sectional view schematically showing conductive particles according to the fourth embodiment of the present invention.

  As shown in FIG. 4, the conductive particle 1C includes a base material particle 2, a conductive portion 3, and an insulating substance 4. The conductive particles 1C have a plurality of protrusions 1Ca on the conductive surface.

  The conductive particle 1C is a conductive particle in which the insulating material 4 is arranged on the outer surface of the conductive particle 1. The insulating material 4 is disposed on the outer surface of the conductive portion 3. In the present embodiment, the insulating substance 4 is insulating particles. At least a part of the outer surface of the conductive portion 3 is covered with the insulating substance 4. The insulating substance 4 is formed of an insulating material. As described above, it is preferable that the conductive particles according to the present invention have the insulating substance arranged on the outer surface of the conductive portion.

  FIG. 5: is sectional drawing which shows the electroconductive particle which concerns on the 5th Embodiment of this invention typically.

  As shown in FIG. 5, the conductive particle 1D includes a base material particle 2 and a conductive portion 3D.

  The conductive portion 3D is arranged on the surface of the base particle 2. The conductive particle 1D has a plurality of protrusions 1Da on its conductive surface. The conductive portion 3D has a plurality of protrusions 3Da on the outer surface.

  The conductive particles 1D have a plurality of core substances 5D on the surface of the base material particles 2. The conductive portion 3D covers the base material particles 2 and the core substance 5D. Since the conductive material 3D covers the core material 5D, the conductive particles 1D have a plurality of protrusions 1Da on the surface. The surface of the conductive portion 3D is raised by the core substance 5D, and a plurality of protrusions 3Da are formed.

  As described above, the core substance may be used to form the protrusion, but it is preferable that the core substance is not used. It is preferable that the core substance is not arranged inside the protrusion. By forming the protrusion of the conductive portion integrally with the portion of the conductive portion that does not have the protrusion, the protrusion becomes more difficult to break.

  Further, FIGS. 7 to 9 (a) and (b) show images of the conductive particles actually manufactured. The conductive particles shown in FIGS. 7 to 9 (a) and (b) have a plurality of protrusions on the outer surface of the conductive portion. The proportion of the (111) plane in X-ray diffraction of the protrusion is 50% or more. The average maximum diameter of the base of the protrusion is within the above specific range.

  Hereinafter, the conductive particles will be described in more detail. In the following description, “(meth) acrylic” means one or both of “acrylic” and “methacrylic”, and “(meth) acrylate” means one or both of “acrylate” and “methacrylate”. means.

(Conductive particles)
[Base material particles]
Examples of the base particles include resin particles, inorganic particles other than metal particles, organic-inorganic hybrid particles, and metal particles. The base 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 particle may have a core and a shell arranged on the surface of the core, or may be a core-shell particle. The core may be an organic core and the shell may be an inorganic shell.

  The base particles are more preferably resin particles or organic-inorganic hybrid particles, and may be resin particles or organic-inorganic hybrid particles. The use of these preferred substrate particles results in conductive particles that are even more suitable for electrical connection between electrodes.

  When connecting the electrodes using the conductive particles, the conductive particles are arranged between the electrodes and then pressure-bonded to compress the conductive particles. When the base 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 is increased. Therefore, the connection resistance between the electrodes is further reduced.

  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 polymethyl methacrylate and polymethyl acrylate; Alkylene terephthalate, 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, polysulfone, polyphenylene Oxide, polyacetal, polyimide, polyamide imide, polyether ether Tons, polyethersulfone, and polymers such as obtained by a variety of polymerizable monomer having an ethylenically unsaturated group is polymerized with one or more thereof. A resin for forming the above resin particles, since resin particles having arbitrary physical properties at the time of compression suitable for a conductive material can be designed and synthesized, and the hardness of the base material particles can be easily controlled within a suitable range. Is preferably a polymer obtained by polymerizing one or more polymerizable monomers having a plurality of ethylenically unsaturated groups.

  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 a non-crosslinkable monomer. And a crosslinkable monomer.

  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; methyl ( (Meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl ( Alkyl (meth) acrylates such as (meth) acrylate and isobornyl (meth) acrylate; oxygen such as 2-hydroxyethyl (meth) acrylate, glycerol (meth) acrylate, polyoxyethylene (meth) acrylate, glycidyl (meth) acrylate Child-containing (meth) acrylates; nitrile-containing monomers such as (meth) acrylonitrile; vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether; vinyl acetate, vinyl butyrate, vinyl laurate, vinyl stearate, etc. Esters; 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 Is mentioned.

  Examples of the crosslinkable monomer include tetramethylolmethane tetra (meth) acrylate, tetramethylolmethane tri (meth) acrylate, tetramethylolmethane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, dipenta Erythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, glycerol tri (meth) acrylate, glycerol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) Polyfunctional (meth) acrylates such as acrylate, (poly) tetramethylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate; triallyl (iso) cyanure , Silane-containing monomers such as triallyl trimellitate, divinylbenzene, diallyl phthalate, diallyl acrylamide, diallyl ether, γ- (meth) acryloxypropyltrimethoxysilane, trimethoxysilylstyrene, and vinyltrimethoxysilane. To be

  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 a monomer together with a radical polymerization initiator using non-crosslinked seed particles to perform polymerization.

  When the base particles are inorganic particles excluding metal particles or organic-inorganic hybrid particles, examples of the inorganic material for forming the base 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 above-mentioned 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 optionally performed. Particles obtained by carrying out are included. 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. The core is preferably an organic core. The shell is preferably an inorganic shell. From the viewpoint of effectively lowering the connection resistance between the electrodes, the base particle is preferably an organic-inorganic hybrid particle 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 inorganic shell include the inorganic materials for forming the base particles described above. 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 silane alkoxide. The inorganic shell is preferably made of silane alkoxide.

  The particle diameter of the core is preferably 0.5 μm or more, more preferably 1 μm or more, preferably 500 μm or less, more preferably 100 μm or less, further preferably 50 μm or less, particularly preferably 20 μm or less, most preferably 10 μm or less. Is. When the particle size of the core is not less than the lower limit and not more than the upper limit, conductive particles more suitable for electrical connection between electrodes can be obtained, and the base particles can be suitably used for the purpose of the conductive particles. Become. For example, when the particle diameter of the core is not less than the lower limit and not more than the upper limit, the contact area between the conductive particles and the electrode becomes sufficiently large when the electrodes are connected using the conductive particles, and Aggregated conductive particles are less likely to be formed when the conductive layer is formed. In addition, the distance between the electrodes connected via the conductive particles does not become too large, and the conductive layer does not easily peel off from the surface of the base material particles.

  The particle size of the core means the diameter when the core has a true spherical shape, and means the maximum diameter when the core has a shape other than the true spherical shape. The particle size of the core means the average particle size of the core measured by an arbitrary particle size measuring device. For example, a particle size distribution measuring instrument using principles such as laser light scattering, electric resistance change, and image analysis after imaging can be used.

  The thickness of the shell is preferably 100 nm or more, more preferably 200 nm or more, preferably 5 μm or less, 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, conductive particles more suitable for electrical connection between electrodes can be obtained, and the base particles can be preferably used for the purpose of the conductive particles. . The thickness of the shell is an average thickness per base particle. The thickness of the shell can be controlled by controlling the sol-gel method.

  When the base particles are metal particles, examples of the metal for forming the metal particles include silver, copper, nickel, silicon, gold and titanium. However, it is preferable that the base particles are not metal particles.

  The particle diameter of the base particles is preferably 0.1 μm or more, more preferably 0.5 μm or more, even more preferably 1 μm or more, still more preferably 1.5 μm or more, particularly preferably 2 μm or more, preferably 1000 μm. It is preferably 500 μm or less, more preferably 300 μm or less, still more preferably 100 μm or less, still more preferably 50 μm or less, still more preferably 30 μm or less, particularly preferably 5 μm or less, most preferably 3 μm or less. When the particle diameter of the base material particles is equal to or more than the above lower limit, the contact area between the conductive particles and the electrode becomes large, so that the conduction reliability between the electrodes is further increased, and the conductive particles are connected via the conductive particles. The connection resistance between the electrodes becomes even lower. Furthermore, when the electroconductive portion is formed on the surface of the base material particle by electroless plating, it is difficult for the particles to aggregate, and the aggregated conductive particles are less likely to be formed. When the average particle size of the base particles is not more than the above upper limit, the conductive particles are easily compressed, the connection resistance between the electrodes is further lowered, and the distance between the electrodes is further narrowed.

  The particle size of the base particles indicates the diameter when the base particles are spherical, and indicates the maximum diameter when the base particles are not spherical.

[Conductive part]
The conductive part is preferably a conductive layer. The metal that is the material of the conductive portion is not particularly limited. Examples of the metal that is the material of the conductive portion include gold, silver, copper, palladium, platinum, ruthenium, rhodium, iridium, vanadium, niobium, tantalum, zinc, iron, tin, lead, aluminum, cobalt, indium, nickel, chromium. , Lithium, tellurium, selenium, titanium, antimony, bismuth, thallium, germanium, cadmium, silicon, tungsten, molybdenum, and alloys thereof. Further, examples of the metal include tin-doped indium oxide (ITO) and solder. Among them, an alloy containing tin, nickel, palladium, copper or gold is preferable, and nickel, palladium or copper is more preferable, because the connection resistance between the electrodes can be further reduced. The conductive portion having a protrusion is at least one selected from the group consisting of copper, nickel, palladium, cobalt, iron, tungsten, molybdenum, ruthenium, platinum, gold, silver, rhodium, iridium, lithium, phosphorus and boron. It is preferable to include, more preferably at least one selected from the group consisting of copper, nickel, palladium, cobalt, iron, tungsten, molybdenum, ruthenium, platinum, gold, phosphorus and boron, and copper and nickel. More preferably, phosphorus, or boron. The material of the conductive portion may be an alloy containing phosphorus and boron. In the conductive portion, nickel may be alloyed with tungsten or molybdenum. The melting point of the conductive portion is preferably 300 ° C. or higher, more preferably 450 ° C. or higher.

  From the viewpoint of further increasing the hardness of the conductive portion and, when connecting between the electrodes, more effectively eliminating the oxide film on the surface of the conductive portion and the surface of the electrode, further lowering the connection resistance between the electrodes, The conductive portion preferably has a conductive portion containing copper or nickel. The conductive portion containing copper preferably contains copper as a main metal. The content of copper is preferably 50% by weight or more in 100% by weight of the conductive portion containing copper. In 100% by weight of the layer containing copper, the content of copper is preferably 75% by weight or more, more preferably 85% by weight or more, still more preferably 95% by weight or more. When the content of copper is at least the above lower limit, the oxide film on the surface of the conductive portion and the surface of the electrode is more effectively removed, and the connection resistance between the electrodes is further reduced.

  Since the protrusion can be easily formed, whether the conductive portion is a conductive portion containing nickel, copper and phosphorus, a conductive portion containing nickel and palladium, or a conductive portion containing nickel and iron. A conductive part containing cobalt, nickel, and phosphorus is preferable.

  It is preferable that the conductive portion having the projection contains phosphorus or boron, and the conductive portion containing nickel contains phosphorus or boron. When the conductive portion contains phosphorus or boron, the total content of phosphorus and boron is preferably 0.1% by weight or more, more preferably 1% by weight, in 100% by weight of the conductive portion containing phosphorus or boron. As described above, the content is more preferably 3% by weight or more, and preferably 10% by weight or less. When the total content of phosphorus and boron is less than or equal to the above upper limit, the resistance of the conductive portion is further reduced, and the content of metal such as nickel is relatively large, so that the connection resistance between the electrodes is more increased. It gets even lower.

  The conductive portion may be formed of one layer or a plurality of layers (multilayer). That is, the conductive portion may be a single layer or may have a laminated structure of two or more layers. When the conductive part is a multi-layered conductive part, the conductive part located on the outermost side of the conductive part has a plurality of protrusions on the outer surface. When the conductive portion is formed by a plurality of layers, the outermost layer is preferably a gold layer, a nickel layer, a palladium layer, a copper layer or an alloy layer containing tin and silver, the gold layer or the palladium layer. Is more preferable, and a gold layer is particularly preferable. When the outermost layer is these preferable conductive parts, the connection resistance between the electrodes becomes even lower. Moreover, when the outermost layer is a gold layer, the corrosion resistance is further enhanced.

  The method for forming the conductive portion on the surface of the particles is not particularly limited. Examples of the method for forming the conductive portion include a method by electroless plating, a method by electroplating, a method by physical vapor deposition, and a method of coating the surface of particles with a metal powder or a paste containing a metal powder and a binder. Can be mentioned. Among them, the method of electroless plating is preferable because the formation of the conductive portion is simple. Examples of the physical vapor deposition method include vacuum vapor deposition, ion plating, and ion sputtering.

  The following method may be mentioned as a method for forming the projections on the outer surface of the conductive portion.

  Using crystal modifiers of sulfur compounds and metal compounds, electroless nickel alloy plating method by controlling plating growth rate in vertical and horizontal directions, electroless high-purity nickel plating method using hydrazine as a reducing agent, reduction Method using electroless palladium-nickel alloy using hydrazine as an agent, electroless CoNiP alloy plating method using a hypophosphite compound as a reducing agent, and electroless copper-nickel using a hypophosphite compound as a reducing agent Examples thereof include a method using alloy plating.

  In the method of forming by electroless plating, generally, a catalyzing step and an electroless plating step are performed. Hereinafter, by using a crystal modifier of a sulfur compound and a metal compound by electroless plating, by controlling the plating growth rate in the vertical and horizontal directions, the electroless nickel alloy plating layer on the substrate surface and the protrusions on the outer surface of the conductive part An example of a method of forming the will be described.

  In the catalyzing step, a catalyst serving as a starting point for forming a plating layer by electroless plating is formed on the surface of the resin particles.

  As a method of forming the catalyst on the surface of the resin particles, for example, a solution containing palladium chloride and tin chloride, after adding the resin particles, by activating the surface of the resin particles with an acid solution or an alkaline solution, Method of precipitating palladium on the surface of resin particles, and to the solution containing palladium sulfate and aminopyridine, after adding the resin particles, activate the surface of the resin particles with a solution containing a reducing agent, Examples include a method of depositing palladium on the surface. A phosphorus-containing reducing agent is used as the reducing agent. Moreover, a conductive layer containing phosphorus can be formed by using a phosphorus-containing reducing agent as the reducing agent.

  In the electroless plating step, in the electroless nickel alloy plating method using a plating solution containing a nickel-containing compound, a complexing agent, a buffering agent and a reducing agent, a hypophosphite compound is contained as a reducing agent, and a crystal modifier. It is preferable to use a nickel-phosphorus alloy plating solution containing a sulfur compound and a metal compound and containing a nonionic surfactant.

  By immersing the resin particles in the electroless nickel-phosphorus alloy plating bath, the catalyst can deposit nickel-phosphorus alloy on the surface of the resin particles formed on the surface, thereby forming a conductive layer containing nickel and phosphorus. Can be formed.

  Examples of the nickel-containing compound include nickel sulfate, nickel chloride, nickel carbonate, nickel sulfamate, and nickel nitrate. The nickel-containing compound is preferably nickel sulfate.

  Examples of the phosphorus-containing reducing agent include hypophosphorous acid and sodium hypophosphite. In addition to the phosphorus-containing reducing agent, a boron-containing reducing agent may be used. Examples of the boron-containing reducing agent include dimethylamine borane, sodium borohydride, potassium borohydride and the like.

  The complexing agent is sodium acetate, monocarboxylic acid type complexing agent such as sodium propionate, dicarboxylic acid type complexing agent such as disodium malonate, tricarboxylic acid type complexing agent such as disodium succinate, lactic acid, DL-malic acid, Rochelle salt, sodium citrate, sodium gluconate and other hydroxy acid complexing agents, glycine, EDTA and other amino acid complexing agents, ethylenediamine and other amine complexing agents, maleic acid and other organic acids It is preferable to contain a complexing agent and at least one complexing agent selected from the group consisting of these salts.

  Examples of the surfactant include anionic, cationic, nonionic or amphoteric surfactants, and nonionic surfactants are particularly preferable. Preferred nonionic surfactants are polyethers containing ether oxygen atoms. Preferred nonionic surfactants are polyoxyethylene lauryl ether, polyethylene glycol, polypropylene glycol, polyoxyethylene alkyl ether, polyoxyethylene polyoxypropylene glycol, polyoxyethylene nonylphenyl ether, polyoxyethylene polyoxypropylene alkyl. Examples include amines and polyoxyalkylene adducts of ethylenediamine. Preferred are polyoxyethylene monoalkyl ethers such as polyoxyethylene monobutyl ether, polyoxypropylene monobutyl ether, polyoxyethylene polyoxypropylene glycol monobutyl ether, polyethylene glycol and phenol ethoxylate. As for the said surfactant, only 1 type may be used and 2 or more types may be used together. Polyethylene glycol with a molecular weight of 1000 is particularly preferred.

  The crystal modifier of the metal compound has an effect of promoting anisotropic growth. Examples of the crystal modifier include a crystal modifier containing one or more metal ions such as lead, bismuth, thallium, antimony and tellurium. For example, lead nitrate, lead acetate, lead sulfate, lead chloride, bismuth acetate, bismuth nitrate, bismuth sulfate, thallium sulfate, thallium nitrate, antimony chloride, potassium antimony tartrate, telluric acid, tellurium chloride, tellurium dioxide, and the like. It is preferable to use a crystal modifier of at least one metal compound selected from the group consisting of salts of

Further, in addition to the crystal modifier of the metal compound, it is preferable to use a sulfur compound as a crystal modifier having an anisotropic growth promoting effect. Examples of the crystal modifier of a sulfur compound include -SH (mercapto group), -S- (thioether group),> C = S (thioaldehyde group, thioketone group), -COSH (thiocarboxyl group), -CSH. (dithio carboxyl group), - CSNH ₂ (thioamide group), - SCN (thiocyanate group, isothiocyanate group) sulfur compounds having one or more groups consisting of. The sulfur compound may be an organic sulfur compound or an inorganic sulfur compound. Specifically, for example, thioglycolic acid, thiodiglycolic acid, cysteine, saccharin, thiamine nitrate, N, N-diethyl-sodium dithiocarbamate, 1,3-diethyl-2-thiourea, dipyridine, N-thiazole- 2-sulfamyl amide, 1,2,3-benzotriazole-2-thiazoline-2-thiol, thiazole, thiourea, ethylenethiourea, 2-mercapto-1-methylimidazole, thiozole, sodium thioindoxylate, o -Sulfonamide benzoic acid, sulfanilic acid, orange-2, methyl orange, naphthoic acid, naphthalene-α-sulfonic acid, 2-mercaptobenzothiazole, 1-naphthol-4-sulfonic acid, shefferic acid, sulfadiazine, rhodanammon , Rodancari, Rodan soda, Ro Nin, ammonium sulfide, sodium sulfide, ammonium sulfate and the like as well, it is preferable to use a crystalline modifier of at least one sulfur compound selected from the group consisting of salts.

  In order to form protrusions on the outer surface of the conductive portion, it is desirable to control the molar ratio of the crystal modifier of the metal compound and the crystal modifier of the sulfur compound. The amount of the above sulfur compound used is preferably 2 to 500 times the molar ratio of the metal compound.

  The ratio of the average height A of the plurality of protrusions to the average maximum diameter B of the bases of the plurality of protrusions (average height A / average maximum diameter B) depends on the thickness of the conductive portion and is immersed in the plating bath. It can be controlled in time. The plating temperature is preferably 30 ° C. to 100 ° C., and the plating time is preferably 5 minutes or longer. From the viewpoint of suppressing the precipitation reaction rate, the plating temperature is preferably 30 ° C. or higher, preferably 60 ° C. or lower, and the plating time is preferably 30 minutes or longer.

  Next, an example of a method of forming protrusions on the outer surfaces of the high-purity nickel plating layer and the conductive portion on the surface of the resin particles by electroless plating will be described.

  In the catalyzing step, a catalyst serving as a starting point for forming a plating layer by electroless plating is formed on the surface of the resin particles.

  As a method of forming the catalyst on the surface of the resin particles, for example, a solution containing palladium chloride and tin chloride, after adding the resin particles, activate the surface of the resin particles with an acid solution or an alkaline solution, Method of precipitating palladium on the surface of resin particles, and to the solution containing palladium sulfate and aminopyridine, after adding the resin particles, activate the surface of the resin particles with a solution containing a reducing agent, Examples include a method of depositing palladium on the surface. A phosphorus-containing reducing agent is used as the reducing agent. Moreover, a conductive layer containing phosphorus can be formed by using a phosphorus-containing reducing agent as the reducing agent.

  In the electroless plating step, in the electroless high-purity nickel plating method using a plating solution containing a nickel-containing compound, a complexing agent, a buffer, a nonionic surfactant, and a reducing agent, hydrazine as a reducing agent, crystals A high-purity nickel plating solution containing a sulfur compound and a metal compound as a modifier is preferably used.

  By immersing the resin particles in the high-purity nickel plating bath, the high-purity nickel plating can be deposited on the surface of the resin particles on which the catalyst is formed, and the conductive layer of high-purity nickel can be formed.

  Examples of the nickel-containing compound include nickel sulfate, nickel chloride, nickel carbonate, nickel sulfamate, and nickel nitrate. The nickel-containing compound is preferably nickel chloride.

  Examples of the reducing agent include hydrazine monohydrate, hydrazine hydrochloride, and hydrazine sulfate. The reducing agent is preferably hydrazine monohydrate.

  Examples of the complexing agents include sodium acetate, monocarboxylic acid complexing agents such as sodium propionate, dicarboxylic acid complexing agents such as disodium malonate, tricarboxylic acid complexing agents such as disodium succinate, and lactic acid. , DL-malic acid, Rochelle salt, sodium citrate, sodium gluconate and other hydroxy acid complexing agents, glycine, EDTA and other amino acid complexing agents, ethylenediamine and other amine complexing agents, maleic acid and other organic compounds Examples thereof include acid-based complexing agents. The complexing agent is preferably an amino acid-based glycine.

  Examples of the surfactant include anionic, cationic, nonionic or amphoteric surfactants, and nonionic surfactants are particularly preferable. Preferred nonionic surfactants are polyethers containing ether oxygen atoms. Preferred nonionic surfactants are polyoxyethylene lauryl ether, polyethylene glycol, polypropylene glycol, polyoxyethylene alkyl ether, polyoxyethylene polyoxypropylene glycol, polyoxyethylene nonylphenyl ether, polyoxyethylene polyoxypropylene alkyl. Examples include amines and polyoxyalkylene adducts of ethylenediamine. Preferred are polyoxyethylene monoalkyl ethers such as polyoxyethylene monobutyl ether, polyoxypropylene monobutyl ether, polyoxyethylene polyoxypropylene glycol monobutyl ether, polyethylene glycol and phenol ethoxylate. As for the said surfactant, only 1 type may be used and 2 or more types may be used together. Polyethylene glycol with a molecular weight of 1000 is particularly preferred.

  The crystal modifier of the metal compound has an effect of promoting anisotropic growth. Examples of the crystal modifier include a crystal modifier containing one or more metal ions such as lead, bismuth, thallium, antimony and tellurium. For example, lead nitrate, lead acetate, lead sulfate, lead chloride, bismuth acetate, bismuth nitrate, bismuth sulfate, thallium sulfate, thallium nitrate, antimony chloride, potassium antimony tartrate, telluric acid, tellurium chloride, tellurium dioxide, and the like. It is preferable to use a crystal modifier of at least one metal compound selected from the group consisting of salts of

Further, in addition to the crystal modifier of the metal compound, it is preferable to use a sulfur compound as a crystal modifier having an anisotropic growth promoting effect. Examples of the crystal modifier of a sulfur compound include -SH (mercapto group), -S- (thioether group),> C = S (thioaldehyde group, thioketone group), -COSH (thiocarboxyl group), -CSH. (dithio carboxyl group), - CSNH ₂ (thioamide group), - SCN (thiocyanate group, isothiocyanate group) sulfur compounds having one or more groups consisting of. The sulfur compound may be an organic sulfur compound or an inorganic sulfur compound. Specifically, for example, thioglycolic acid, thiodiglycolic acid, cysteine, saccharin, thiamine nitrate, N, N-diethyl-sodium dithiocarbamate, 1,3-diethyl-2-thiourea, dipyridine, N-thiazole- 2-sulfamyl amide, 1,2,3-benzotriazole-2-thiazoline-2-thiol, thiazole, thiourea, ethylenethiourea, 2-mercapto-1-methylimidazole, thiozole, sodium thioindoxylate, o -Sulfonamide benzoic acid, sulfanilic acid, orange-2, methyl orange, naphthoic acid, naphthalene-α-sulfonic acid, 2-mercaptobenzothiazole, 1-naphthol-4-sulfonic acid, shefferic acid, sulfadiazine, rhodanammon , Rodancari, Rodan soda, Ro Nin, ammonium sulfide, sodium sulfide, ammonium sulfate and the like as well, it is preferable to use a crystalline modifier of at least one sulfur compound selected from the group consisting of salts.

  In order to form protrusions on the outer surface of the conductive portion, it is desirable to control the molar ratio of the crystal modifier of the metal compound and the crystal modifier of the sulfur compound. The amount of the above sulfur compound used is preferably 2 to 500 times the molar ratio of the metal compound.

  In order to form protrusions on the outer surface of the conductive portion, it is preferable to adjust the pH of the plating solution to 6.0 or higher. In the electroless plating solution using hydrazine as the reducing agent, the pH is drastically lowered when nickel is reduced by the oxidation reaction of hydrazine. It is preferable to use a buffering agent such as phosphoric acid, boric acid, carbonic acid or the like in order to suppress the sharp decrease in pH. The buffering agent is preferably boric acid having a buffering effect at pH 8.0 or higher.

  The ratio of the average height A of the plurality of protrusions to the average maximum diameter B of the bases of the plurality of protrusions (average height A / average maximum diameter B) depends on the thickness of the conductive portion and is immersed in the plating bath. It can be controlled in time. The plating temperature is preferably 30 ° C. or higher, preferably 100 ° C. or lower, and the plating time is preferably 5 minutes or longer. From the viewpoint of suppressing the precipitation reaction rate, the plating temperature is preferably 30 ° C. or higher, preferably 60 ° C. or lower, and the plating time is preferably 30 minutes or longer.

  Next, an example of a method of forming the palladium-nickel alloy plating layer and the protrusion of the conductive portion on the surface of the resin particle by electroless plating will be described.

  In the catalyzing step, a catalyst serving as a starting point for forming a plating layer by electroless plating is formed on the surface of the resin particles.

  As a method of forming the catalyst on the surface of the resin particles, for example, a solution containing palladium chloride and tin chloride, after adding the resin particles, by activating the surface of the resin particles with an acid solution or an alkaline solution, Method of precipitating palladium on the surface of resin particles, and to the solution containing palladium sulfate and aminopyridine, after adding the resin particles, activate the surface of the resin particles with a solution containing a reducing agent, Examples include a method of depositing palladium on the surface. A phosphorus-containing reducing agent is used as the reducing agent. Moreover, a conductive layer containing phosphorus can be formed by using a phosphorus-containing reducing agent as the reducing agent.

  In the electroless plating step, in the electroless palladium-nickel plating method using a plating solution containing a nickel-containing compound, a palladium compound, a stabilizer, a complexing agent, a buffering agent, a nonionic surfactant, and a reducing agent, A palladium-nickel alloy plating solution containing hydrazine as a reducing agent and a sulfur compound and a metal compound as a crystal modifier is preferably used.

  By immersing the resin particles in a palladium-nickel alloy plating bath, palladium-nickel alloy plating can be deposited on the surface of the resin particles having the catalyst formed on the surface, and a conductive layer of palladium-nickel can be formed. .

  Examples of the nickel-containing compound include nickel sulfate, nickel chloride, nickel carbonate, nickel sulfamate, and nickel nitrate. The nickel-containing compound is preferably nickel sulfate.

  Examples of the palladium-containing compound include dichloroethylenediaminepalladium (II), palladium chloride, dichlorodiamminepalladium (II), dinitrodiamminepalladium (II), tetraamminepalladium (II) nitrate, tetraamminepalladium (II) sulfate, oxalatatodiammine. Palladium (II), tetraamminepalladium (II) oxalate, tetraamminepalladium (II) chloride and the like can be mentioned. The palladium-containing compound is preferably palladium chloride.

  Examples of the reducing agent include hydrazine monohydrate, hydrazine hydrochloride, and hydrazine sulfate. The reducing agent is preferably hydrazine monohydrate.

  Examples of the complexing agents include sodium acetate, monocarboxylic acid complexing agents such as sodium propionate, dicarboxylic acid complexing agents such as disodium malonate, tricarboxylic acid complexing agents such as disodium succinate, and lactic acid. , DL-malic acid, Rochelle salt, sodium citrate, sodium gluconate and other hydroxy acid complexing agents, glycine, EDTA and other amino acid complexing agents, ethylenediamine and other amine complexing agents, maleic acid and other organic compounds Examples thereof include acid-based complexing agents. The complexing agent is preferably an amino acid-based ethylenediamine.

  Examples of the surfactant include anionic, cationic, nonionic or amphoteric surfactants, and nonionic surfactants are particularly preferable. Preferred nonionic surfactants are polyethers containing ether oxygen atoms. Preferred nonionic surfactants are polyoxyethylene lauryl ether, polyethylene glycol, polypropylene glycol, polyoxyethylene alkyl ether, polyoxyethylene polyoxypropylene glycol, polyoxyethylene nonylphenyl ether, polyoxyethylene polyoxypropylene alkyl. Examples include amines and polyoxyalkylene adducts of ethylenediamine. Preferred are polyoxyethylene monoalkyl ethers such as polyoxyethylene monobutyl ether, polyoxypropylene monobutyl ether, polyoxyethylene polyoxypropylene glycol monobutyl ether, polyethylene glycol and phenol ethoxylate. As for the said surfactant, only 1 type may be used and 2 or more types may be used together. Polyethylene glycol with a molecular weight of 1000 is particularly preferred.

  The crystal modifier of the metal compound has an effect of promoting anisotropic growth. Examples of the crystal modifier include a crystal modifier containing one or more metal ions such as lead, bismuth, thallium, antimony and tellurium. For example, lead nitrate, lead acetate, lead sulfate, lead chloride, bismuth acetate, bismuth nitrate, bismuth sulfate, thallium sulfate, thallium nitrate, antimony chloride, potassium antimony tartrate, telluric acid, tellurium chloride, tellurium dioxide, and the like. It is preferable to use a crystal modifier of at least one metal compound selected from the group consisting of salts of

Further, in addition to the crystal modifier of the metal compound, it is preferable to use a sulfur compound as a crystal modifier having an anisotropic growth promoting effect. Examples of the crystal modifier of a sulfur compound include -SH (mercapto group), -S- (thioether group),> C = S (thioaldehyde group, thioketone group), -COSH (thiocarboxyl group), -CSH. (dithio carboxyl group), - CSNH ₂ (thioamide group), - SCN (thiocyanate group, isothiocyanate group) sulfur compounds having one or more groups consisting of. The sulfur compound may be an organic sulfur compound or an inorganic sulfur compound. Specifically, for example, thioglycolic acid, thiodiglycolic acid, cysteine, saccharin, thiamine nitrate, N, N-diethyl-sodium dithiocarbamate, 1,3-diethyl-2-thiourea, dipyridine, N-thiazole- 2-sulfamyl amide, 1,2,3-benzotriazole-2-thiazoline-2-thiol, thiazole, thiourea, thiozole, sodium thioindoxylate, o-sulfonamide benzoic acid, sulfanilic acid, orange-2 , Methyl orange, naphthoic acid, naphthalene-α-sulfonic acid, 2-mercaptobenzothiazole, 1-naphthol-4-sulfonic acid, shefferic acid, sulfadiazine, rodanammon, rodancali, rhodaninsoda, rhodanin, ammonium sulfide, sodium sulfide. , Ammonium sulfate, etc. It is preferable to use a crystalline modifier of at least one sulfur compound selected from the group consisting et salt.

  In order to form protrusions on the outer surface of the conductive portion, it is desirable to control the molar ratio of the crystal modifier of the metal compound and the crystal modifier of the sulfur compound. The amount of the above sulfur compound used is preferably 2 to 500 times the molar ratio of the metal compound.

  In order to form protrusions on the outer surface of the conductive portion, it is desirable to control the molar ratio of the palladium compound and the nickel compound. The amount of the palladium compound used is preferably 50 times to 500 times the molar ratio of the nickel compound.

  In order to form protrusions on the outer surface of the conductive part, it is preferable to adjust the pH of the plating solution to 8.0 to 10.0. When the pH is 7.5 or less, the stability of the plating solution is lowered and the decomposition of the bath is caused. Therefore, the pH is preferably set to 8.0 or more.

  The ratio of the average height A of the plurality of protrusions to the average maximum diameter B of the bases of the plurality of protrusions (average height A / average maximum diameter B) depends on the thickness of the conductive portion and is immersed in the plating bath. It can be controlled in time. The plating temperature is preferably 30 ° C. or higher, preferably 100 ° C. or lower, and the plating time is preferably 5 minutes or longer. From the viewpoint of suppressing the precipitation reaction rate, the plating temperature is preferably 30 ° C. or higher, preferably 60 ° C. or lower, and the plating time is preferably 30 minutes or longer.

  Next, an example of a method of forming protrusions on the outer surface of the alloy plating layer containing cobalt and nickel and the conductive portion on the surface of the resin particles by electroless plating will be described.

  In the catalyzing step, a catalyst serving as a starting point for forming a plating layer by electroless plating is formed on the surface of the resin particles.

  As a method of forming the catalyst on the surface of the resin particles, for example, a solution containing palladium chloride and tin chloride, after adding the resin particles, by activating the surface of the resin particles with an acid solution or an alkaline solution, Method of precipitating palladium on the surface of resin particles, and to the solution containing palladium sulfate and aminopyridine, after adding the resin particles, activate the surface of the resin particles with a solution containing a reducing agent, Examples include a method of depositing palladium on the surface. A phosphorus-containing reducing agent is used as the reducing agent. Moreover, a conductive layer containing phosphorus can be formed by using a phosphorus-containing reducing agent as the reducing agent.

  In the electroless plating step, in an electroless cobalt-nickel-phosphorus alloy plating method using a plating solution containing a cobalt-containing compound, an inorganic additive, a complexing agent, a buffer, a nonionic surfactant, and a reducing agent. A cobalt-nickel-phosphorus alloy plating solution containing a hypophosphorous acid compound as a reducing agent, a cobalt-containing compound as a reaction-starting metal catalyst of a reducing agent, and a sulfur compound and a metal compound as a crystal modifier is preferably used. To be

  By immersing the resin particles in a cobalt-nickel-phosphorus alloy plating bath, the cobalt-nickel-phosphorus alloy can be deposited on the surface of the resin particles having the catalyst formed on the surface thereof. Can be formed.

  The cobalt-containing compound is preferably cobalt sulfate, cobalt chloride, cobalt nitrate, cobalt acetate, or cobalt carbonate. The cobalt-containing compound is preferably cobalt sulfate.

  Examples of the nickel-containing compound include nickel sulfate, nickel chloride, nickel carbonate, nickel sulfamate, and nickel nitrate. The nickel-containing compound is preferably nickel sulfate.

  Examples of the phosphorus-containing reducing agent include hypophosphorous acid and sodium hypophosphite. In addition to the phosphorus-containing reducing agent, a boron-containing reducing agent may be used. Examples of the boron-containing reducing agent include dimethylamine borane, sodium borohydride, potassium borohydride and the like.

  The complexing agent is sodium acetate, monocarboxylic acid type complexing agent such as sodium propionate, dicarboxylic acid type complexing agent such as disodium malonate, tricarboxylic acid type complexing agent such as disodium succinate, lactic acid, DL-malic acid, Rochelle salt, sodium citrate, sodium gluconate and other hydroxy acid complexing agents, glycine, EDTA and other amino acid complexing agents, ethylenediamine and other amine complexing agents, maleic acid and other organic acids It is preferable to contain a complexing agent and at least one complexing agent selected from the group consisting of these salts.

  The inorganic additive is preferably at least one selected from the group consisting of ammonium sulfate, ammonium chloride, and boric acid. It is considered that the above-mentioned inorganic additive acts to accelerate the deposition of the electroless cobalt plating layer.

  Examples of the surfactant include anionic, cationic, nonionic or amphoteric surfactants, and nonionic surfactants are particularly preferable. Preferred nonionic surfactants are polyethers containing ether oxygen atoms. Preferred nonionic surfactants are polyoxyethylene lauryl ether, polyethylene glycol, polypropylene glycol, polyoxyethylene alkyl ether, polyoxyethylene polyoxypropylene glycol, polyoxyethylene nonylphenyl ether, polyoxyethylene polyoxypropylene alkyl. Examples include amines and polyoxyalkylene adducts of ethylenediamine. Preferred are polyoxyethylene monoalkyl ethers such as polyoxyethylene monobutyl ether, polyoxypropylene monobutyl ether, polyoxyethylene polyoxypropylene glycol monobutyl ether, polyethylene glycol and phenol ethoxylate. As for the said surfactant, only 1 type may be used and 2 or more types may be used together. Polyethylene glycol with a molecular weight of 1000 is particularly preferred.

  The crystal modifier of the metal compound has an effect of promoting anisotropic growth. Examples of the crystal modifier include a crystal modifier containing one or more metal ions such as lead, bismuth, thallium, antimony and tellurium. For example, lead nitrate, lead acetate, lead sulfate, lead chloride, bismuth acetate, bismuth nitrate, bismuth sulfate, thallium sulfate, thallium nitrate, antimony chloride, potassium antimony tartrate, telluric acid, tellurium chloride, tellurium dioxide, and the like. It is preferable to use a crystal modifier of at least one metal compound selected from the group consisting of salts of

Further, in addition to the crystal modifier of the metal compound, it is preferable to use a sulfur compound as a crystal modifier having an anisotropic growth promoting effect. Examples of the crystal modifier of a sulfur compound include -SH (mercapto group), -S- (thioether group),> C = S (thioaldehyde group, thioketone group), -COSH (thiocarboxyl group), -CSH. (dithio carboxyl group), - CSNH ₂ (thioamide group), - SCN (thiocyanate group, isothiocyanate group) sulfur compounds having one or more groups consisting of. The sulfur compound may be an organic sulfur compound or an inorganic sulfur compound. Specifically, for example, thioglycolic acid, thiodiglycolic acid, cysteine, saccharin, thiamine nitrate, N, N-diethyl-sodium dithiocarbamate, 1,3-diethyl-2-thiourea, dipyridine, N-thiazole- 2-sulfamyl amide, 1,2,3-benzotriazole-2-thiazoline-2-thiol, thiazole, thiourea, ethylenethiourea, 2-mercapto-1-methylimidazole, thiozole, sodium thioindoxylate, o -Sulfonamide benzoic acid, sulfanilic acid, orange-2, methyl orange, naphthoic acid, naphthalene-α-sulfonic acid, 2-mercaptobenzothiazole, 1-naphthol-4-sulfonic acid, shefferic acid, sulfadiazine, rhodanammon , Rodancari, Rodan soda, Ro Nin, ammonium sulfide, sodium sulfide, ammonium sulfate and the like as well, it is preferable to use a crystalline modifier of at least one sulfur compound selected from the group consisting of salts.

  In order to form protrusions on the outer surface of the conductive portion, it is desirable to control the molar ratio of the crystal modifier of the metal compound and the crystal modifier of the sulfur compound. The amount of the above sulfur compound used is preferably 2 to 500 times the molar ratio of the metal compound.

  In order to form protrusions on the outer surface of the conductive portion, it is desirable to control the molar ratio of the cobalt compound and the nickel compound. The amount of the cobalt compound used is preferably 50 times to 500 times the molar ratio of the nickel compound.

  Further, an inorganic additive is preferably used to form the protrusions, and ammonium sulfate is particularly preferably used.

  The ratio of the average height A of the plurality of protrusions to the average maximum diameter B of the bases of the plurality of protrusions (average height A / average maximum diameter B) depends on the thickness of the conductive portion and is immersed in the plating bath. It can be controlled in time. The plating temperature is preferably 30 ° C. or higher, preferably 100 ° C. or lower, and the plating time is preferably 5 minutes or longer. From the viewpoint of suppressing the precipitation reaction rate, the plating temperature is preferably 30 ° C. or higher, preferably 60 ° C. or lower, and the plating time is preferably 30 minutes or longer.

  Next, an example of a method for forming protrusions on the outer surface of the alloy plating layer containing copper and nickel and the conductive portion on the surface of the resin particles by electroless plating will be described.

  In the catalyzing step, a catalyst serving as a starting point for forming a plating layer by electroless plating is formed on the surface of the resin particles.

  As a method of forming the catalyst on the surface of the resin particles, for example, a solution containing palladium chloride and tin chloride, after adding the resin particles, by activating the surface of the resin particles with an acid solution or an alkaline solution, Method of precipitating palladium on the surface of resin particles, and to the solution containing palladium sulfate and aminopyridine, after adding the resin particles, activate the surface of the resin particles with a solution containing a reducing agent, Examples include a method of depositing palladium on the surface. A phosphorus-containing reducing agent is used as the reducing agent. Moreover, a conductive layer containing phosphorus can be formed by using a phosphorus-containing reducing agent as the reducing agent.

  In the electroless plating step, in the electroless copper-nickel-phosphorus alloy plating method containing a copper-containing compound, a complexing agent, a buffering agent, and a reducing agent, a hypophosphorous acid compound is used as a reducing agent, and a reducing agent is further used. A copper-nickel-phosphorus alloy plating solution containing a nickel-containing compound as the reaction-starting metal catalyst, a sulfur compound and a metal compound as the crystal modifier, and a nonionic surfactant is preferably used.

  By immersing the resin particles in a copper-nickel-phosphorus alloy plating bath, the catalyst can deposit copper-nickel-phosphorus alloy on the surface of the resin particles formed on the surface, and copper, nickel and phosphorus are added. A conductive layer containing the same can be formed.

  Examples of the copper-containing compound include copper sulfate, cupric chloride, and copper nitrate. The copper-containing compound is preferably copper sulfate.

  Examples of the nickel-containing compound include nickel sulfate, nickel chloride, nickel carbonate, nickel sulfamate, and nickel nitrate. The nickel-containing compound is preferably nickel sulfate.

  Examples of the phosphorus-containing reducing agent include hypophosphorous acid and sodium hypophosphite. In addition to the phosphorus-containing reducing agent, a boron-containing reducing agent may be used. Examples of the boron-containing reducing agent include dimethylamine borane, sodium borohydride, potassium borohydride and the like.

  The complexing agent is sodium acetate, monocarboxylic acid type complexing agent such as sodium propionate, dicarboxylic acid type complexing agent such as disodium malonate, tricarboxylic acid type complexing agent such as disodium succinate, lactic acid, DL-malic acid, Rochelle salt, sodium citrate, sodium gluconate and other hydroxy acid complexing agents, glycine, EDTA and other amino acid complexing agents, ethylenediamine and other amine complexing agents, maleic acid and other organic acids It is preferable to contain a complexing agent and at least one complexing agent selected from the group consisting of these salts.

  Examples of the surfactant include anionic, cationic, nonionic or amphoteric surfactants, and nonionic surfactants are particularly preferable. A preferred nonionic surfactant is a polyether containing an ether oxygen atom in one molecule. For example, polyoxyethylene lauryl ether, polyethylene glycol, polypropylene glycol, polyoxyethylene alkyl ether, polyoxyethylene polyoxypropylene glycol, polyoxyethylene nonylphenyl ether, polyoxyethylene polyoxypropylene alkylamine, polyoxyalkylene addition of ethylenediamine. Examples thereof include polyoxyethylene monoalkyl ethers such as polyoxyethylene monobutyl ether, polyoxypropylene monobutyl ether, polyoxyethylene polyoxypropylene glycol monobutyl ether, polyethylene glycol and phenol ethoxylate. As for such a surfactant, only 1 type may be used and 2 or more types may be used together. It is particularly preferable to use polyethylene glycol having a molecular weight of 1000.

  The crystal modifier of the metal compound has an effect of promoting anisotropic growth. Examples of the crystal modifier include a crystal modifier containing one or more metal ions such as lead, bismuth, thallium, antimony and tellurium. For example, lead nitrate, lead acetate, lead sulfate, lead chloride, bismuth acetate, bismuth nitrate, bismuth sulfate, thallium sulfate, thallium nitrate, antimony chloride, potassium antimony tartrate, telluric acid, tellurium chloride, tellurium dioxide, and the like. It is preferable to use a crystal modifier of at least one metal compound selected from the group consisting of salts of

Further, in addition to the crystal modifier of the metal compound, it is preferable to use a sulfur compound as a crystal modifier having an anisotropic growth promoting effect. Examples of the crystal modifier of a sulfur compound include -SH (mercapto group), -S- (thioether group),> C = S (thioaldehyde group, thioketone group), -COSH (thiocarboxyl group), -CSH. (dithio carboxyl group), - CSNH ₂ (thioamide group), - SCN (thiocyanate group, isothiocyanate group) sulfur compounds having one or more groups consisting of. The sulfur compound may be an organic sulfur compound or an inorganic sulfur compound. Specifically, for example, thioglycolic acid, thiodiglycolic acid, cysteine, saccharin, thiamine nitrate, N, N-diethyl-sodium dithiocarbamate, 1,3-diethyl-2-thiourea, dipyridine, N-thiazole- 2-sulfamyl amide, 1,2,3-benzotriazole-2-thiazoline-2-thiol, thiazole, thiourea, ethylenethiourea, 2-mercapto-1-methylimidazole, thiozole, sodium thioindoxylate, o -Sulfonamide benzoic acid, sulfanilic acid, orange-2, methyl orange, naphthoic acid, naphthalene-α-sulfonic acid, 2-mercaptobenzothiazole, 1-naphthol-4-sulfonic acid, shefferic acid, sulfadiazine, rhodanammon , Rodancari, Rodan soda, Ro Nin, ammonium sulfide, sodium sulfide, ammonium sulfate and the like as well, it is preferable to use a crystalline modifier of at least one sulfur compound selected from the group consisting of salts.

  In order to form protrusions on the outer surface of the conductive portion, it is desirable to control the molar ratio of the crystal modifier of the metal compound and the crystal modifier of the sulfur compound. The amount of the above sulfur compound used is preferably 2 to 500 times the molar ratio of the metal compound.

  In order to form protrusions on the outer surface of the conductive part, it is desirable to control the molar ratio of the copper compound and the nickel compound. The copper compound is preferably 50 to 500 times in molar ratio with respect to the nickel compound.

  The ratio of the average height A of the plurality of protrusions to the average diameter B of the bases of the plurality of protrusions (average height A / average diameter B) depends on the thickness of the conductive layer and depends on the immersion time in the plating bath. You can control it. The plating temperature is preferably about 30 ° C. to 100 ° C., and the plating time is preferably 5 minutes or longer. In particular, in order to form protrusions having a polygonal columnar shape, the plating temperature is more preferably 30 ° C. to 60 ° C., and the plating time is more preferably 30 minutes or more in order to suppress the precipitation reaction rate.

  The thickness of the entire conductive portion in the portion having no protrusion is preferably 5 nm or more, more preferably 10 nm or more, further preferably 20 nm or more, particularly preferably 50 nm or more, preferably 1000 nm or less, more preferably 800 nm or less, It is preferably 500 nm or less, particularly preferably 400 nm or less, and most preferably 300 nm or less. When the thickness of the entire conductive portion is at least the above lower limit, the conductivity of the conductive particles will be further improved. When the thickness of the entire conductive portion is equal to or less than the above upper limit, the difference in coefficient of thermal expansion between the base material particles and the conductive portion is small, and the conductive portion is less likely to be separated from the base material particles. When the conductive portion has a plurality of conductive portions (first conductive portion and second conductive portion), the thickness of the conductive portion is the total thickness of the conductive portion (total of the first and second conductive portions). Thickness).

  When the conductive portion has a plurality of conductive portions, the thickness of the conductive portion in the portion of the outermost layer without the protrusion is preferably 1 nm or more, more preferably 10 nm or more, preferably 500 nm or less, more preferably 100 nm. It is the following. When the thickness of the conductive portion of the outermost layer is equal to or higher than the lower limit and equal to or lower than the upper limit, it is possible to uniformly coat the conductive portion of the outermost layer, the corrosion resistance is sufficiently high, and the connection resistance between the electrodes is sufficient. Get lower. Further, when the outermost layer is more expensive than the conductive portion of the inner layer, the thinner the outermost layer, the lower the cost.

  The thickness of the conductive portion can be measured by observing the cross section of the conductive particles using, for example, a transmission electron microscope (TEM).

[Insulating material]
The conductive particles according to the present invention preferably include an insulating substance disposed on the outer surface of the conductive portion. In this case, if conductive particles are used to connect the electrodes, a short circuit between adjacent electrodes can be prevented. Specifically, when a plurality of conductive particles come into contact with each other, the insulating substance exists between the plurality of electrodes, so that a short circuit between adjacent electrodes in the lateral direction, not between the upper and lower electrodes, can be prevented. It should be noted that, when the electrodes are connected to each other, the insulating particles between the conductive portion and the electrodes can be easily eliminated by pressing the conductive particles with the two electrodes. Since the conductive particles have a plurality of protrusions on the outer surface of the conductive portion, the insulating substance between the conductive portion of the conductive particles and the electrode can be easily removed.

  The insulating substance is preferably insulating particles because the insulating substance can be more easily removed during pressure bonding between the electrodes.

  Specific examples of the insulating resin that is a material of the insulating substance include polyolefins, (meth) acrylate polymers, (meth) acrylate copolymers, block polymers, thermoplastic resins, crosslinked products of thermoplastic resins, and A curable resin, a water-soluble resin, etc. are mentioned.

  Examples of the above-mentioned polyolefins include polyethylene, ethylene-vinyl acetate copolymer, ethylene-acrylic acid ester copolymer and the like. Examples of the (meth) acrylate polymer include polymethyl (meth) acrylate, polyethyl (meth) acrylate, and polybutyl (meth) acrylate. Examples of the block polymer include polystyrene, styrene-acrylic acid ester copolymers, SB type styrene-butadiene block copolymers, SBS type styrene-butadiene block copolymers, 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 and melamine resin. Examples of the water-soluble resin include polyvinyl alcohol, polyacrylic acid, polyacrylamide, polyvinylpyrrolidone, polyethylene oxide and methyl cellulose. Of these, water-soluble resins are preferable, and polyvinyl alcohol is more preferable.

  From the viewpoint of further enhancing the detachability of the insulating particles during thermocompression bonding, the insulating particles are preferably inorganic particles, and preferably silica particles. Examples of the inorganic particles include shirasu particles, hydroxyapatite particles, magnesia particles, zirconium oxide particles and silica particles. Examples of the silica particles include ground silica and spherical silica, and spherical silica is preferably used.

  As a method of disposing the insulating substance on the surface of the conductive portion, a known method can be adopted.

  The average diameter (average particle diameter) of the insulating substance can be appropriately selected depending on the particle diameter of the conductive particles, the use of the conductive particles, and the like. The average diameter (average particle diameter) of the insulating substance is preferably 0.005 μm or more, more preferably 0.01 μm or more, preferably 1 μm or less, more preferably 0.5 μm or less. When the average diameter of the insulating substance is not less than 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 average diameter of the insulating particles is less than or equal to the above upper limit, at the time of connection between the electrodes, in order to eliminate the insulating material between the electrodes and the conductive particles, it is not necessary to increase the pressure too high, high temperature There is no need to heat it.

  The “average diameter (average particle diameter)” of the insulating substance means the number average diameter (number average particle diameter). The average diameter of the insulating substance can be obtained by using a particle size distribution measuring device or the like.

(Conductive material)
The conductive material according to the present invention includes the conductive particles described above and a binder resin. The conductive particles are preferably dispersed in a binder resin and used as a conductive material. The conductive material is preferably an anisotropic conductive material. The conductive material is preferably used for electrical connection of electrodes. The conductive material is preferably a circuit connecting material.

  The binder resin is not particularly limited. The binder resin preferably contains a thermoplastic component (thermoplastic compound) or a curable component, and more preferably contains a curable component. Examples of the curable component include a photocurable component and a thermosetting component. The photocurable component preferably contains a photocurable compound and a photopolymerization initiator. The thermosetting component preferably contains a thermosetting compound and a thermosetting agent. A known insulating resin is used as the binder resin. Examples of the binder resin include vinyl resins, thermoplastic resins, curable resins, thermoplastic block copolymers and elastomers. As the binder resin, only one kind may be used, or two or more kinds may be used in combination.

  Examples of the vinyl resin include vinyl acetate resin, acrylic resin and styrene resin. Examples of the thermoplastic resin include polyolefin resin, ethylene-vinyl acetate copolymer, and polyamide resin. Examples of the curable resin include epoxy resin, urethane resin, polyimide resin and unsaturated polyester resin. 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 styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, hydrogenated product of styrene-butadiene-styrene block copolymer, and styrene-isoprene. -Styrene block copolymer hydrogenated products and the like can be mentioned. Examples of the elastomer include styrene-butadiene copolymer rubber and acrylonitrile-styrene block copolymer rubber.

  In addition to the conductive particles and the binder resin, the conductive material may be, for example, a filler, a filler, a softener, a plasticizer, a polymerization catalyst, a curing catalyst, a colorant, an antioxidant, a heat stabilizer, or a light stabilizer. Various additives such as agents, ultraviolet absorbers, lubricants, antistatic agents and flame retardants may be included.

  The conductive material according to the present invention can be used as a conductive paste, a conductive film or the like. When the conductive material according to the present invention is a conductive film, a film containing no conductive particles may be laminated on a conductive film containing 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, further preferably 50% by weight or more, particularly preferably 70% by weight or more, and preferably 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 lower limit and not more than the 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 increased.

  In 100% by weight of the conductive material, the content of the conductive particles is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, preferably 80% by weight or less, more preferably 60% by weight. It is preferably 40% by weight or less, more preferably 20% by weight or less, and most preferably 10% by weight or less. When the content of the conductive particles is equal to or higher than the lower limit and equal to or lower than the upper limit, conduction reliability between the electrodes is further enhanced.

(Connection structure)
The connection structure can be obtained by connecting the connection target members using the conductive material containing the conductive particles and the binder resin according to the present invention. It is preferable that the connecting portion is formed of the above-mentioned conductive particles or a conductive material including the above-mentioned conductive particles and a binder resin.

  The connection structure includes a first connection target member, a second connection target member, and a connection portion connecting the first connection target member and the second connection target member, It is preferable that the material is the above-mentioned conductive particles or the connection structure is a conductive material containing the above-mentioned conductive particles and a binder resin. It is preferable that the connection part is formed of the above-mentioned conductive particles or a connection structure formed of a conductive material containing the above-mentioned conductive particles and a binder resin.

  FIG. 6 is a front sectional view schematically showing a connection structure using the conductive particles according to the first embodiment of the present invention.

  The connection structure 51 shown in FIG. 6 includes 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, 53. Prepare The connection portion 54 includes the conductive particles 1 and a binder resin (hardened binder resin or the like). The connection portion 54 is formed of a conductive material containing the conductive particles 1. The connection portion 54 is preferably formed by curing a conductive material. In addition, in FIG. 6, the conductive particles 1 are schematically illustrated for convenience of illustration. Instead of the conductive particles 1, other conductive particles such as conductive particles 1A, 1B, 1C and 1D may be used.

  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 front surface (lower surface). The first electrode 52a and the second electrode 53a are electrically connected by one or a plurality of 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. 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 to obtain a laminated body, and then the laminated body is heated and pressed. Methods and the like. The pressure applied is about 9.8 × 10 ^{4 to} 4.9 × 10 ⁶ Pa. The heating temperature is about 120 to 220 ° C.

  Specific examples of the connection target member include electronic components such as semiconductor chips, capacitors and diodes, and electronic components such as printed circuit boards, flexible printed circuit boards, glass epoxy substrates, and circuit boards such as glass substrates. The connection target member is preferably an electronic component. The conductive particles are preferably used for electrical connection of electrodes in electronic parts.

  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 member to be connected is a flexible printed board, 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 of only 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 Sn, Al and Ga.

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. The invention is not limited to the following examples.

(Example 1)
Divinylbenzene copolymer resin particles (base particle A, "Micropearl SP-203" manufactured by Sekisui Chemical Co., Ltd.) having a particle diameter of 2.5 µm were prepared. 10 parts by weight of the above resin particles were dispersed in 100 parts by weight of an alkaline solution containing 5% by weight of a palladium catalyst solution using an ultrasonic disperser, and then the solution was filtered to take out the resin particles. Next, the resin particles were added to 100 parts by weight of a 1% by weight dimethylamine borane solution to activate the surface of the resin particles. After thoroughly washing the surface-activated resin particles with water, 500 parts by weight of distilled water was added and dispersed to obtain a suspension (also used in Examples described later).

  Further, as an electroless nickel-phosphorus alloy plating solution, nickel sulfate 100 g / L, bismuth nitrate 1 mg / L, 2-mercapto-1-methylimidazole 10 mg / L, sodium hypophosphite 100 g / L, and quench Sodium acid 10 g / L, glycine 35 g / L, boric acid 10 g / L, and a mixed solution of polyethylene glycol 1000 (molecular weight: 1000) 10 mg / L as a nonionic surfactant, pH 6 with sodium hydroxide. The plating solution adjusted to was prepared.

  500 ml of this plating solution was added dropwise to the suspension through a metering pump at an addition rate of 2 ml / min. The reaction temperature was set to 55 ° C. Then, the mixture was stirred until the pH became stable, and it was confirmed that hydrogen bubbling stopped.

  Then, the suspension was filtered to take out the particles, washed with water, and dried to obtain conductive particles in which a nickel-phosphorus alloy conductive layer (thickness: 102 nm) was arranged on the surface of the resin particles. The conductive portion of the obtained conductive particles had a plurality of protrusions on the outer surface.

(Example 2)
As an electroless copper-nickel-phosphorus alloy plating solution, copper sulfate 150 g / L, nickel sulfate 5 g / L, bismuth nitrate 0.5 mg / L, 2-mercapto-1-methylimidazole 5 mg / L, Sodium hydroxide 100 g / L, sodium citrate 35 g / L, boric acid 10 g / L, and polyethylene glycol 1000 (molecular weight: 1000) 10 mg / L as a nonionic surfactant were mixed with sodium hydroxide. A plating solution adjusted to pH 8 was prepared.

  150 ml of this plating solution was added dropwise to the suspension obtained in Example 1 through a metering pump at an addition rate of 5 ml / min. The reaction temperature was set to 55 ° C. Then, the mixture was stirred until the pH became stable, and it was confirmed that hydrogen bubbling stopped.

  Then, the suspension is filtered to take out the particles, washed with water, and dried to obtain conductive particles in which a copper-nickel-phosphorus alloy conductive layer (thickness: 101 nm) is arranged on the surface of the resin particles. It was The conductive portion of the obtained conductive particles had a plurality of protrusions on the outer surface.

  Conductive particles were obtained in the same manner as in Example 1 except that the conductive portion was formed by the above plating method.

(Example 3)
As an electroless high-purity nickel plating solution, nickel chloride 40 g / L, bismuth nitrate 0.5 mg / L, 2-mercapto-1-methylimidazole 5 mg / L, hydrazine monohydrate 80 g / L, and glycine 50 g / L, boric acid 20 g / L, and a mixed solution of polyethylene glycol 1000 (molecular weight: 1000) 10 mg / L as a nonionic surfactant were adjusted to pH 10 with sodium hydroxide to prepare a plating solution.

  2000 ml of this plating solution was added dropwise to the suspension obtained in Example 1 through a metering pump at an addition rate of 20 ml / min. The reaction temperature was set to 60 ° C. Then, the mixture was stirred until the pH became stable, and it was confirmed that hydrogen bubbling stopped.

  Then, the suspension was filtered to take out the particles, washed with water, and dried to obtain conductive particles in which a high-purity nickel conductive layer (thickness: 103 nm) was arranged on the surface of the resin particles. The conductive portion of the obtained conductive particles had a plurality of protrusions on the outer surface.

  Conductive particles were obtained in the same manner as in Example 1 except that the conductive portion was formed by the above plating method.

(Example 4)
As an electroless palladium-nickel alloy plating solution, 60 g / L of palladium chloride, 3 g / L of nickel sulfate, 0.1 mg / L of bismuth nitrate, 2-mercapto-1-methylimidazole 1 mg / L, and hydrazine monohydrate. 80 g / L, ethylenediamine 25 g / L, DL-malic acid 30 g / L, lithium acetate dihydrate 6 g / L, and polyethylene glycol 1000 (molecular weight: 1000) 10 mg / L as a nonionic surfactant. A plating solution having a pH of 8 adjusted with sodium hydroxide was prepared.

  1000 ml of this plating solution was added dropwise to the suspension obtained in Example 1 through a metering pump at an addition rate of 10 ml / min. The reaction temperature was set to 50 ° C. Then, the mixture was stirred until the pH became stable, and it was confirmed that hydrogen bubbling stopped.

  Then, the suspension was filtered to take out the particles, washed with water, and dried to obtain conductive particles in which the palladium-nickel alloy conductive layer was arranged on the surface of the resin particles. The conductive portion of the obtained conductive particles had a plurality of protrusions on the outer surface.

  Conductive particles were obtained in the same manner as in Example 1 except that the conductive portion was formed by the above plating method.

(Example 5)
As an electroless cobalt-nickel-phosphorus alloy plating solution, cobalt sulfate 70 g / L, nickel sulfate 5 g / L, bismuth nitrate 0.8 mg / L, 2-mercapto-1-methylimidazole 8 mg / L, and hypochlorous acid Sodium hydroxide was mixed with 100 g / L of sodium phosphate, 50 g / L of ammonium sulfate, 20 g / L of sodium pyrophosphate, and 10 mg / L of polyethylene glycol 1000 (molecular weight: 1000) as a nonionic surfactant. A plating solution adjusted to pH 10 was prepared.

  1000 ml of this plating solution was added dropwise to the suspension obtained in Example 1 through a metering pump at an addition rate of 10 ml / min. The reaction temperature was set to 55 ° C. Then, the mixture was stirred until the pH became stable, and it was confirmed that hydrogen bubbling stopped.

  Then, the suspension is filtered to remove the particles, washed with water, and dried to obtain conductive particles in which a cobalt-nickel-phosphorus alloy conductive layer (thickness: 100 nm) is arranged on the surface of the resin particles. It was It had a plurality of protrusions on the outer surface.

  Conductive particles were obtained in the same manner as in Example 1 except that the conductive portion was formed by the above plating method.

(Example 6)
As the electroless nickel-tungsten-phosphorus alloy plating solution for the first conductive portion, nickel sulfate 100 g / L, sodium hypophosphite 50 g / L, sodium tungstate 2 g / L, and sodium succinate 20 g / L. A plating solution in which the pH of the mixed solution was adjusted to 6 with sodium hydroxide was prepared.

  250 ml of this plating solution was added dropwise to the suspension obtained in Example 1 through a metering pump at an addition rate of 5 ml / min. The reaction temperature was set to 40 ° C. Then, the mixture was stirred until the pH became stable, and it was confirmed that hydrogen bubbling stopped.

  After that, the suspension is filtered to take out the particles, and the particles are washed with water to have a conductivity in which the nickel-tungsten-phosphorus alloy conductive layer (thickness: 51 nm) of the first conductive portion is arranged on the surface of the resin particles. The particles were obtained. A second suspension was obtained by adding and dispersing the conductive particles in which the nickel-tungsten-phosphorus alloy conductive layer of the first conductive portion was arranged to 500 parts by weight of distilled water.

  Next, as an electroless nickel-phosphorus alloy plating solution for the second conductive part, nickel sulfate 100 g / L, bismuth nitrate 1 mg / L, 2-mercapto-1-methylimidazole 10 mg / L, and hypophosphorous acid. A mixed solution of 100 g / L of sodium, 10 g / L of sodium citrate, 35 g / L of glycine, 10 g / L of boric acid, and 10 mg / L of polyethylene glycol 1000 (molecular weight: 1000) as a nonionic surfactant. A plating solution adjusted to pH 6 with sodium hydroxide was prepared.

  250 ml of this plating solution was added dropwise to the above second suspension through a metering pump at an addition rate of 5 ml / min. The reaction temperature was set to 55 ° C. Then, the mixture was stirred until the pH became stable, and it was confirmed that hydrogen bubbling stopped.

  Then, the suspension is filtered to remove the particles, washed with water, and dried to form a nickel-phosphorus alloy conductive layer (thickness: 53 nm) of the second conductive portion on the surface of the first conductive portion. The arranged conductive particles were obtained. The conductive portion of the obtained conductive particles had a plurality of protrusions on the outer surface.

  Conductive particles were obtained in the same manner as in Example 1 except that the conductive portion was formed by the above plating method.

(Example 7)
Mixing 100 g / L of nickel sulfate, 80 g / L of dimethylamine borane, 2 g / L of sodium tungstate, and 30 g / L of sodium citrate as an electroless nickel-tungsten-boron alloy plating solution for the first conductive portion. A plating solution whose pH was adjusted to 6 with sodium hydroxide was prepared.

  250 ml of this plating solution was added dropwise to the suspension obtained in Example 1 through a metering pump at an addition rate of 5 ml / min. The reaction temperature was set to 45 ° C. Then, the mixture was stirred until the pH became stable, and it was confirmed that hydrogen bubbling stopped.

  Then, the suspension is filtered to take out the particles, and the particles are washed with water to have a conductivity in which the nickel-tungsten-boron alloy conductive layer (thickness: 50 nm) of the first conductive portion is arranged on the surface of the resin particles. The particles were obtained. A second suspension was obtained by adding and dispersing the conductive particles in which the nickel-tungsten-boron alloy conductive layer of the first conductive portion was arranged to 500 parts by weight of distilled water.

  Next, as an electroless nickel-phosphorus alloy plating solution for the second conductive part, nickel sulfate 100 g / L, bismuth nitrate 1 mg / L, 2-mercapto-1-methylimidazole 10 mg / L, and hypophosphorous acid. A mixed solution of 100 g / L of sodium, 5 g / L of sodium citrate, 25 g / L of glycine, 10 g / L of boric acid, and 10 mg / L of polyethylene glycol 1000 (molecular weight: 1000) as a nonionic surfactant. A plating solution adjusted to pH 6 with sodium hydroxide was prepared.

  250 ml of this plating solution was added dropwise to the above second suspension through a metering pump at an addition rate of 5 ml / min. The reaction temperature was set to 55 ° C. Then, the mixture was stirred until the pH became stable, and it was confirmed that hydrogen bubbling stopped.

  Then, by filtering the suspension, the particles are taken out, washed with water, and dried to form a nickel-phosphorus alloy conductive layer (thickness: 52 nm) of the second conductive portion on the surface of the first conductive portion. The arranged conductive particles were obtained. The conductive portion of the obtained conductive particles had a plurality of protrusions on the outer surface.

  Conductive particles were obtained in the same manner as in Example 1 except that the conductive portion was formed by the above plating method.

(Example 8)
As an electroless copper plating solution for the first conductive part, a mixed solution of 200 g / L of copper sulfate, 150 g / L of ethylenediaminetetraacetic acid, 100 g / L of sodium gluconate, and 50 g / L of formaldehyde was added to give a pH value of 10 with ammonia. A copper plating solution adjusted to 0.5 was prepared.

  250 ml of this plating solution was added dropwise to the suspension obtained in Example 1 through a metering pump at an addition rate of 10 ml / min. The reaction temperature was set to 65 ° C. Then, the mixture was stirred until the pH became stable, and it was confirmed that hydrogen bubbling stopped.

  Then, the suspension was filtered to take out the particles and washed with water to obtain conductive particles in which the copper conductive layer (thickness: 51 nm) of the first conductive portion was arranged on the surface of the resin particles. A conductive particle in which the copper conductive layer of the first conductive portion was arranged was added to 100 parts by weight of distilled water and dispersed to obtain a suspension. The above suspension was dispersed in 100 parts by weight of an acidic solution containing 5% by weight of a palladium catalyst solution using an ultrasonic disperser, and then the solution was filtered to obtain a copper conductive layer of the first conductive portion. The arranged conductive particles were taken out. Next, the conductive particles in which the copper conductive layer of the first conductive portion was arranged were added to 100 parts by weight of a 1% by weight dimethylamine borane solution to activate the surface of the copper conductive layer of the first conductive portion. After sufficiently washing the conductive particles in which the copper conductive layer of the first conductive portion whose surface has been activated is disposed, with water, 500 parts by weight of distilled water is added and dispersed to obtain a second suspension. It was

  Next, as an electroless nickel-phosphorus alloy plating solution for the second conductive part, nickel sulfate 100 g / L, bismuth nitrate 1 mg / L, 2-mercapto-1-methylimidazole 10 mg / L, and hypophosphorous acid. A mixed solution of 100 g / L of sodium, 10 g / L of sodium citrate, 35 g / L of glycine, 10 g / L of boric acid, and 10 mg / L of polyethylene glycol 1000 (molecular weight: 1000) as a nonionic surfactant. A plating solution adjusted to pH 6 with sodium hydroxide was prepared.

  250 ml of this plating solution was added dropwise to the above second suspension through a metering pump at an addition rate of 5 ml / min. The reaction temperature was set to 55 ° C. Then, the mixture was stirred until the pH became stable, and it was confirmed that hydrogen bubbling stopped.

  Then, by filtering the suspension, the particles are taken out, washed with water, and dried to form a nickel-phosphorus alloy conductive layer (thickness: 50 nm) of the second conductive portion on the surface of the first conductive portion. The arranged conductive particles were obtained. The conductive portion of the obtained conductive particles had a plurality of protrusions on the outer surface.

  Conductive particles were obtained in the same manner as in Example 1 except that the conductive portion was formed by the above plating method.

(Example 9)
Mixing 100 g / L of nickel sulfate, 80 g / L of dimethylamine borane, 2 g / L of sodium tungstate, and 30 g / L of sodium citrate as an electroless nickel-tungsten-boron alloy plating solution for the first conductive portion. A plating solution whose pH was adjusted to 6 with sodium hydroxide was prepared.

  450 ml of this plating solution was added dropwise to the suspension obtained in Example 1 through a metering pump at an addition rate of 5 ml / min. The reaction temperature was set to 45 ° C. Then, the mixture was stirred until the pH became stable, and it was confirmed that hydrogen bubbling stopped.

  Then, the suspension is filtered to take out the particles, and the particles are washed with water to have a conductivity in which the nickel-tungsten-boron alloy conductive layer (thickness: 90 nm) of the first conductive portion is arranged on the surface of the resin particles. The particles were obtained. A second suspension was obtained by adding and dispersing the conductive particles in which the nickel-tungsten-boron alloy conductive layer of the first conductive portion was arranged to 500 parts by weight of distilled water.

  Next, as a displacement gold plating solution for the second conductive portion, a mixed solution of potassium gold cyanide 10 g / L, sodium citrate 45 g / L, ethylenediaminetetraacetic acid 5 g / L, and sodium hydroxide 20 g / L. To prepare a plating solution adjusted to pH 6 with sodium hydroxide.

  700 ml of this plating solution was added dropwise to the above-mentioned second suspension through a metering pump at an addition rate of 5 ml / min. The reaction temperature was set to 45 ° C. Then, the mixture was stirred until the pH became stable.

  Then, the suspension was filtered to take out the particles, washed with water, and dried to arrange the gold conductive layer (thickness: 21 nm) of the second conductive portion on the surface of the first conductive portion. Conductive particles were obtained. The conductive portion of the obtained conductive particles had a plurality of protrusions on the outer surface.

  Conductive particles were obtained in the same manner as in Example 1 except that the conductive portion was formed by the above plating method.

(Example 10)
Mixing 100 g / L of nickel sulfate, 80 g / L of dimethylamine borane, 2 g / L of sodium tungstate, and 30 g / L of sodium citrate as an electroless nickel-tungsten-boron alloy plating solution for the first conductive portion. A plating solution whose pH was adjusted to 6 with sodium hydroxide was prepared.

  450 ml of this plating solution was added dropwise to the suspension obtained in Example 1 through a metering pump at an addition rate of 5 ml / min. The reaction temperature was set to 45 ° C. Then, the mixture was stirred until the pH became stable, and it was confirmed that hydrogen bubbling stopped.

  Then, the suspension is filtered to take out the particles, and the particles are washed with water to have a conductivity in which the nickel-tungsten-boron alloy conductive layer (thickness: 90 nm) of the first conductive portion is arranged on the surface of the resin particles. The particles were obtained. A second suspension was obtained by adding and dispersing the conductive particles in which the nickel-tungsten-boron alloy conductive layer of the first conductive portion was arranged to 500 parts by weight of distilled water.

  Next, as a displacement silver plating solution for the second conductive part, a mixed solution of potassium cyanide 10 g / L, potassium cyanide 80 g / L, ethylenediaminetetraacetic acid 5 g / L, and sodium hydroxide 20 g / L was prepared. A plating solution adjusted to pH 6 with sodium hydroxide was prepared.

  700 ml of this plating solution was added dropwise to the above-mentioned second suspension through a metering pump at an addition rate of 5 ml / min. The reaction temperature was set to 35 ° C. Then, the mixture was stirred until the pH became stable.

  Then, the suspension is filtered to take out the particles, washed with water, and dried to arrange the silver conductive layer (thickness: 20 nm) of the second conductive portion on the surface of the first conductive portion. Conductive particles were obtained. The conductive portion of the obtained conductive particles had a plurality of protrusions on the outer surface.

  Conductive particles were obtained in the same manner as in Example 1 except that the conductive portion was formed by the above plating method.

(Example 11)
Mixing 100 g / L of nickel sulfate, 80 g / L of dimethylamine borane, 2 g / L of sodium tungstate, and 30 g / L of sodium citrate as an electroless nickel-tungsten-boron alloy plating solution for the first conductive portion. A plating solution whose pH was adjusted to 6 with sodium hydroxide was prepared.

  450 ml of this plating solution was added dropwise to the suspension obtained in Example 1 through a metering pump at an addition rate of 5 ml / min. The reaction temperature was set to 45 ° C. Then, the mixture was stirred until the pH became stable, and it was confirmed that hydrogen bubbling stopped.

  Then, the suspension is filtered to take out the particles, and the particles are washed with water to have a conductivity in which the nickel-tungsten-boron alloy conductive layer (thickness: 90 nm) of the first conductive portion is arranged on the surface of the resin particles. The particles were obtained. A second suspension was obtained by adding and dispersing the conductive particles in which the nickel-tungsten-boron alloy conductive layer of the first conductive portion was arranged to 500 parts by weight of distilled water.

  Next, a mixture of palladium sulfate 12 g / L, ethylenediamine 30 ml / L, sodium formate 80 g / L, and sodium saccharinate 5 mg / L was added to ammonia as an electroless palladium plating solution for the second conductive portion. A plating solution adjusted to pH 8 was prepared.

  600 ml of this plating solution was added dropwise to the above second suspension through a metering pump at an addition rate of 5 ml / min. The reaction temperature was set to 50 ° C. Then, the mixture was stirred until the pH became stable.

  Then, the suspension was filtered to take out the particles, washed with water, and dried, whereby the palladium conductive layer (thickness: 19 nm) of the second conductive portion was arranged on the surface of the first conductive portion. Conductive particles were obtained. The conductive portion of the obtained conductive particles had a plurality of protrusions on the outer surface.

  Conductive particles were obtained in the same manner as in Example 1 except that the conductive portion was formed by the above plating method.

(Example 12)
Mixing 100 g / L of nickel sulfate, 80 g / L of dimethylamine borane, 2 g / L of sodium tungstate, and 30 g / L of sodium citrate as an electroless nickel-tungsten-boron alloy plating solution for the first conductive portion. A plating solution whose pH was adjusted to 6 with sodium hydroxide was prepared.

  450 ml of this plating solution was added dropwise to the suspension obtained in Example 1 through a metering pump at an addition rate of 5 ml / min. The reaction temperature was set to 45 ° C. Then, the mixture was stirred until the pH became stable, and it was confirmed that hydrogen bubbling stopped.

  Then, the suspension is filtered to take out the particles, and the particles are washed with water to have a conductivity in which the nickel-tungsten-boron alloy conductive layer (thickness: 90 nm) of the first conductive portion is arranged on the surface of the resin particles. The particles were obtained. A second suspension was obtained by adding and dispersing the conductive particles in which the nickel-tungsten-boron alloy conductive layer of the first conductive portion was arranged to 500 parts by weight of distilled water.

  Next, as an electroless high-purity nickel plating solution for the second conductive part, a mixed solution of nickel sulfate 40 g / L, hydrazine monohydrate 80 g / L, glycine 50 g / L, and boric acid 20 g / L. Was prepared to a pH of 9 with sodium hydroxide.

  400 ml of this plating solution was added dropwise to the above-mentioned second suspension through a metering pump at an addition rate of 5 ml / min. The reaction temperature was set to 70 ° C. Then, the mixture was stirred until the pH became stable.

  Then, the suspension is filtered to remove the particles, washed with water, and dried to dispose the high-purity nickel conductive layer (thickness: 21 nm) of the second conductive portion on the surface of the first conductive portion. The obtained conductive particles were obtained. The conductive portion of the obtained conductive particles had a plurality of protrusions on the outer surface.

  Conductive particles were obtained in the same manner as in Example 1 except that the conductive portion was formed by the above plating method.

(Example 13)
The base material particle A was changed to a base material particle B (resin particle) having a particle diameter of 2.0 μm, which was different from the base material particle A only.

  10 parts by weight of the above resin particles were dispersed in 100 parts by weight of an alkaline solution containing 5% by weight of a palladium catalyst solution using an ultrasonic disperser, and then the solution was filtered to take out the resin particles. Next, the resin particles were added to 100 parts by weight of a 1% by weight dimethylamine borane solution to activate the surface of the resin particles. The resin particles whose surfaces were activated were thoroughly washed with water, then added to 500 parts by weight of distilled water and dispersed to obtain a suspension.

  In addition, as an electroless nickel-phosphorus alloy plating solution, nickel sulfate 250 g / L, bismuth nitrate 5 mg / L, 2-mercapto-1-methylimidazole 50 mg / L, sodium hypophosphite 100 g / L, and quench A mixed solution of 10 g / L of sodium acidate, 35 g / L of glycine, 10 g / L of boric acid, and 10 mg / L of polyethylene glycol 1000 (molecular weight: 1000) as a nonionic surfactant was adjusted to pH 6 with sodium hydroxide. The plating solution adjusted to was prepared.

  1000 ml of this plating solution was added dropwise to the above suspension through a metering pump at an addition rate of 2 ml / min. The reaction temperature was set to 50 ° C. Then, the mixture was stirred until the pH became stable, and it was confirmed that hydrogen bubbling stopped.

  Then, the suspension was filtered to take out the particles, washed with water, and dried to obtain conductive particles in which a nickel-phosphorus alloy conductive layer (thickness: 102 nm) was arranged on the surface of the resin particles. The conductive portion of the obtained conductive particles had a plurality of protrusions on the outer surface.

  Conductive particles were obtained in the same manner as in Example 1 except that the base material particles B were used and the conductive portions were formed by the plating method described above.

(Example 14)
The base particle A was changed to a base particle C (resin particle) having a particle diameter of 4.5 μm, which was different from the base particle A only.

  10 parts by weight of the above resin particles were dispersed in 100 parts by weight of an alkaline solution containing 5% by weight of a palladium catalyst solution using an ultrasonic disperser, and then the solution was filtered to take out the resin particles. Next, the resin particles were added to 100 parts by weight of a 1% by weight dimethylamine borane solution to activate the surface of the resin particles. The resin particles whose surfaces were activated were thoroughly washed with water, then added to 500 parts by weight of distilled water and dispersed to obtain a suspension.

  Further, as an electroless nickel-phosphorus alloy plating solution, nickel sulfate 50 g / L, bismuth nitrate 0.1 mg / L, 2-mercapto-1-methylimidazole 1 mg / L, and sodium hypophosphite 100 g / L. , Sodium citrate 10 g / L, glycine 35 g / L, boric acid 10 g / L, and polyethylene glycol 1000 (molecular weight: 1000) 10 mg / L as a nonionic surfactant were added to sodium hydroxide. A plating solution adjusted to pH 7 was prepared.

  500 ml of this plating solution was added dropwise to the above suspension through a metering pump at an addition rate of 2 ml / min. The reaction temperature was set to 60 ° C. Then, the mixture was stirred until the pH became stable, and it was confirmed that hydrogen bubbling stopped.

  Then, the suspension was filtered to take out the particles, washed with water, and dried to obtain conductive particles having a nickel-phosphorus alloy conductive layer (thickness: 101 nm) arranged on the surface of the resin particles. The conductive portion of the obtained conductive particles had a plurality of protrusions on the outer surface.

  Conductive particles were obtained in the same manner as in Example 1 except that the base material particles C were used and the conductive portions were formed by the plating method described above.

(Example 15)
The surface of divinylbenzene copolymer resin particles (“Micropearl SP-202” manufactured by Sekisui Chemical Co., Ltd.) having a particle diameter of 2.0 μm was coated with a silica shell (thickness: 250 nm) using a condensation reaction by a sol-gel reaction. Core-shell type organic-inorganic hybrid particles (base particle D) were obtained.

  Conductive particles were obtained in the same manner as in Example 1 except that the base particle A was changed to the base particle D. Thus, conductive particles in which the nickel-phosphorus alloy conductive layer (thickness: 100 nm) was arranged on the surface of the resin particles were obtained.

(Example 16)
In a 500 mL reaction vessel equipped with a stirrer and a thermometer, 300 g of a 0.13 wt% aqueous ammonia solution was placed. Next, in an aqueous ammonia solution in the reaction vessel, 4.1 g of methyltrimethoxysilane, 19.2 g of vinyltrimethoxysilane, and 0.7 g of a silicone alkoxy oligomer (“X-41-1053” manufactured by Shin-Etsu Chemical Co., Ltd.). Was slowly added. After the hydrolysis and condensation reaction proceeded with stirring, 2.4 mL of 25 wt% ammonia aqueous solution was added, and then the particles were isolated from the ammonia aqueous solution, and the obtained particles had an oxygen partial pressure of 10 ⁻¹⁷ atm. By firing at 350 ° C. for 2 hours, organic-inorganic hybrid particles (base particle E) having a particle diameter of 2.5 μm were obtained.

  Conductive particles having a nickel-phosphorus alloy conductive layer (thickness: 102 nm) arranged on the surface of resin particles were obtained in the same manner as in Example 1 except that the base particles A were changed to the base particles E. It was

(Example 17)
Conductive particles were obtained in the same manner as in Example 1 except that the base material particle A was different from the base material particle A only in the particle diameter and was changed to the base material particle F having a particle diameter of 10.0 μm. In this way, conductive particles in which the nickel-phosphorus alloy conductive layer (thickness: 101 nm) was arranged on the surface of the resin particles were obtained. The conductive portion of the obtained conductive particles had a plurality of polyhedral projections instead of polygonal columns on the outer surface.

(Example 18)
In a 1000 mL separable flask equipped with a 4-neck separable cover, a stirring blade, a three-way cock, a condenser and a temperature probe, 100 mmol of methyl methacrylate and N, N, N-trimethyl-N-2-methacryloyloxyethyl were used. A monomer composition containing 1 mmol of ammonium chloride and 1 mmol of 2,2′-azobis (2-amidinopropane) dihydrochloride was weighed in ion-exchanged water so that the solid content was 5% by weight, and then at 200 rpm. The mixture was stirred and polymerized at 70 ° C. for 24 hours in a nitrogen atmosphere. After the reaction was completed, it was freeze-dried to obtain insulating particles having an ammonium group on the surface and having an average particle diameter of 220 nm and a CV value of 10%.

  The insulating particles were dispersed in ion-exchanged water under ultrasonic irradiation to obtain a 10% by weight aqueous dispersion of insulating particles.

  10 g of the conductive particles obtained in Example 1 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 0.3 μm mesh filter, the particles were further washed with methanol and dried to obtain conductive particles to which insulating particles were attached.

  Observation with a scanning electron microscope (SEM) revealed that only one coating layer of insulating particles was formed on the surface of the conductive particles. When the coating area of the insulating particles with respect to the area of 2.5 μm from the center of the conductive particles (that is, the projected area of the particle diameter of the insulating particles) was calculated by image analysis, the coverage was 40%.

(Comparative Example 1)
Divinylbenzene copolymer resin particles (base particle A, "Micropearl SP-203" manufactured by Sekisui Chemical Co., Ltd.) having a particle diameter of 2.5 µm were prepared.

  The divinylbenzene copolymer resin particles were etched and washed with water. Next, the resin particles were added to 100 mL of the palladium catalyzed liquid containing 8% by weight of the palladium catalyst and stirred. Then, it filtered and wash | cleaned. Resin particles were added to a 0.5 wt% dimethylamine borane solution having a pH of 6 to obtain resin particles to which palladium was attached.

  The resin particles to which palladium was attached were stirred and dispersed in 300 mL of ion-exchanged water for 3 minutes to obtain a dispersion liquid. Next, 1 g of nickel particle slurry (average particle size of nickel, which is a core substance, including spherical nickel particles, 100 nm) was added to the above dispersion liquid over 3 minutes to obtain a suspension containing resin particles to which the core substance was attached. A liquid was obtained.

  Further, as an electroless nickel-phosphorus plating solution, a mixed solution of 200 g / L of nickel sulfate, 50 g / L of sodium hypophosphite, 10 ml / L of plating stabilizer (bismuth compound), and 20 g / L of sodium succinate. To prepare a plating solution adjusted to pH 6 with sodium hydroxide. 500 ml of this plating solution was added dropwise to the suspension through a metering pump at an addition rate of 5 ml / min. The reaction temperature was set to 60 ° C. Then, the mixture was stirred until the pH became stable, and it was confirmed that hydrogen bubbling stopped.

  After that, the suspension is filtered to take out the particles, washed with water, and dried to obtain a conductive layer having a nickel-phosphorus alloy conductive layer (thickness: 105 nm) arranged on the surface of the resin particles to which the core substance is attached. Particles were obtained.

(Comparative example 2)
Conductive particles were obtained in the same manner as in Example 1 except that the conductive portion had a spherical outer shape without forming protrusions on the outer surface of the conductive portion.

(Evaluation)
(1) Evaluation of surface lattice of conductive part An X-ray diffractometer ("RINT2500VHF" manufactured by Rigaku Denki Co., Ltd.) was used to calculate the peak intensity ratio of the diffraction line, which is unique to the device and depends on the diffraction angle. The ratio of the diffraction peak intensity in the (111) direction to the total diffraction peak intensity of the gold layer (the ratio of the (111) plane) was determined.

(2) Continuity reliability (connection resistance)
The conductive particles thus obtained were added to "Structbond XN-5A" manufactured by Mitsui Chemicals Co., Inc. so that the content was 10% by weight, and dispersed to prepare an anisotropic conductive paste.

  A transparent glass substrate having an ITO electrode pattern having an L / S of 30 μm / 30 μm on its upper surface was prepared. Further, a semiconductor chip having a copper electrode pattern having an L / S of 30 μm / 30 μm on the lower surface was prepared.

  On the transparent glass substrate, an anisotropic conductive paste immediately after preparation was applied so as to have a thickness of 30 μm to form an anisotropic conductive paste layer. Next, the semiconductor chip was laminated on the anisotropic conductive paste layer so that the electrodes face each other. Thereafter, while adjusting the temperature of the head so that the temperature of the anisotropic conductive paste layer becomes 185 ° C., a pressure heating head is placed on the upper surface of the semiconductor chip and a pressure of 3 MPa is applied to form the anisotropic conductive paste layer. It was cured at 185 ° C. to obtain a connection structure.

  The connection resistance between the upper and lower electrodes of the obtained 15 connection structures was measured by the 4-terminal method. The average value of the two connection resistances was calculated. From the relationship of voltage = current × resistance, the connection resistance can be obtained by measuring the voltage when a constant current is applied. The connection resistance was judged according to the following criteria.

[Criteria for connection resistance]
○ ○ ○: Connection resistance is 5.0Ω or less ○ ○: Connection resistance is more than 5.0Ω and 8.0Ω or less ○: Connection resistance is more than 8.0Ω and 10.0Ω or less △: Connection resistance is 10.0Ω Over 15.0Ω or less ×: Connection resistance exceeds 15.0Ω

(3) Insulation Reliability The 15 connection structures obtained in the evaluation in (2) above were left at 85 ° C. and 85% humidity for 500 hours. In the connection structure after standing, 5 V was applied between the adjacent electrodes, the resistance value was measured at 25 points, and the average value of the insulation resistance was calculated. The insulation reliability was judged according to the following criteria.

[Criteria for insulation reliability]
○ ○ ○: Insulation resistance is 1000 MΩ or more ○ ○: Insulation resistance is 500 MΩ or more and less than 1000 MΩ ○: Insulation resistance is 100 MΩ or more and less than 500 MΩ △: Insulation resistance is 10 MΩ or more and less than 100 MΩ ×: Insulation resistance is less than 10 MΩ

  The results are shown in Table 1 below. In addition, in Table 1 below, the average height A of the plurality of protrusions, the average maximum diameter B of the bases of the plurality of protrusions, and the maximum of the bases in 100% of the total number of protrusions included in one conductive particle. Ratio X of the number of protrusions having a diameter of 200 nm or less, and the number of protrusions in which the maximum diameter of the base is 10% or less of the particle diameter of the conductive particles in 100% of the total number of protrusions contained in one conductive particle And the ratio Y of the surface area where the protrusions are formed in 100% of the total surface area of the outer surface of the conductive portion.

1, 1A, 1B, 1C, 1D ... Conductive particles 1a, 1Aa, 1Ba, 1Ca, 1Da ... Protrusions 2 ... Base material particles 3, 3A, 3B, 3D ... Conductive part (conductive layer)
3a, 3Aa, 3Ba, 3Da ... Protrusion 3BA ... 1st electroconductive part 3BB ... 2nd electroconductive part 3BBa ... Protrusion 4 ... Insulating substance 5D ... Core substance 51 ... Connection structure 52 ... 1st connection object member 52a ... First electrode 53 ... Second connection target member 53a ... Second electrode 54 ... Connection part

Claims (14)

Base particles,
And a conductive portion arranged on the surface of the base particles,
The conductive portion has a plurality of protrusions on the outer surface,
The ratio of the (111) plane in X-ray diffraction of the protrusion is 50% or more,
The conductive particles, wherein the average maximum diameter of the base of the protrusion is 1 nm or more and 500 nm or less.   The conductive particle according to claim 1, wherein the particle diameter is 0.5 μm or more and less than 5 μm.   The conductive particle according to claim 1, wherein the ratio of the number of protrusions having a maximum diameter of the base portion of 200 nm or less is 10% or more in 100% of the total number of protrusions.   The conductive particle according to claim 1, wherein the particle diameter is 5 μm or more and less than 20 μm.   The ratio of the number of protrusions whose maximum diameter of the base is 10% or less of the particle diameter of the conductive particles is 10% or more in 100% of all the numbers of said protrusions. Conductive particles. No core material is placed inside the protrusions,
The conductive portion having a plurality of protrusions has a first portion and a second portion having a thickness thicker than the first portion, and the plurality of protrusions has a second portion having a thick conductive portion. The conductive particle according to any one of claims 1 to 5, which is a part of.   The conductive particles according to claim 1, wherein a ratio of an average height of the plurality of protrusions to an average maximum diameter of a base portion of the plurality of protrusions is 0.1 or more and 5 or less. .   The conductive particle according to any one of claims 1 to 7, wherein a ratio of an average maximum diameter of a base portion of the protrusion to an average minimum diameter of a base portion of the protrusion is 10 or less.   The conductive particles according to any one of claims 1 to 8, wherein a surface area of a portion having the protrusion is 30% or more in a total surface area of 100% of an outer surface of the conductive portion.   The conductive portion includes at least one selected from the group consisting of copper, nickel, palladium, ruthenium, platinum, gold, silver, rhodium, iridium, lithium, cobalt, iron, tungsten, molybdenum, phosphorus, and boron. Item 10. The conductive particles according to any one of items 1 to 9. The conductive portion is a multilayer conductive portion,
The conductive particle according to any one of claims 1 to 10, wherein the outermost conductive portion of the conductive portion has a plurality of protrusions on its outer surface.   The conductive particle according to claim 1, further comprising an insulating substance disposed on the outer surface of the conductive portion.   An electrically conductive material comprising the electrically conductive particles according to claim 1 and a binder resin. A first connection target member;
A second connection target member;
It has a connection part which connects the 1st connection object member and the 2nd connection object member, The material of the connection part is a conductive particle given in any 1 paragraph of Claims 1-12. Or a conductive material containing the conductive particles and a binder resin.