JP6460803B2 - Conductive particle, method for producing conductive particle, conductive material, and connection structure - Google Patents

Description

  The present invention relates to a conductive particle in which a conductive part is disposed on the surface of a base particle, and the conductive part has a plurality of protrusions on the outer surface, and a method for producing the conductive particle. The present invention also relates to a conductive material and a connection structure using the conductive particles.

  Anisotropic conductive materials such as anisotropic conductive pastes and anisotropic conductive films are widely known. In these anisotropic conductive materials, conductive particles are dispersed in a binder resin.

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

  As an example of the conductive particles, Patent Document 1 below discloses conductive particles in which nickel or a nickel alloy coating is formed on the surface of core material particles. The conductive particles protrude from the surface of the film and are continuous with the film, and have a large number of protrusions 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.

  Patent Document 2 below discloses a conductive particle in which the surface of a base particle is coated with a conductive film, and the conductive film has protrusions 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, respectively. The particle diameter of the soft metal particles is 1.05 to 6 times the average particle diameter of the hard nonmetal particles.

In the following Patent Document 3, the main component is silver or nickel, the surface is provided with a convex portion, and the inside includes a conductive particle containing metal particles or ceramic particles as a core substance for crystal growth of a conductive material. Powder (conductive particles) is disclosed. In this conductive powder, at least the surface is treated with an organic acid or an organic acid salt. The bulk density of the 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 conductive particles described in Patent Documents 1 to 3, protrusions are formed on the outer surface of the conductive portion. However, development of new conductive particles that are completely different from the conductive particles described in Patent Documents 1 to 3 is desired. For example, if the shape of the protrusion on the outer surface of the conductive portion in the conductive particle is different, different properties may be imparted to the conductive particle.

  In particular, when the electrodes are electrically connected using conductive particles, generally, the conductive particles are disposed between the electrodes, and heating and pressurization are performed. In conventional conductive particles, it may be difficult to efficiently arrange a plurality of conductive particles between electrodes. There is a problem that the conductive particles are easily arranged not only in the line (L) where the electrode is formed but also in the space (S) where the electrode is not formed. For this reason, many conductive particles may have to be used on the assumption that the conductive particles are also arranged in the space. Furthermore, there is a problem that poor insulation is likely to occur as a result of the conductive particles being arranged in the space.

  Further, in the conventional conductive particles, the electrodes may be damaged by the protrusions after the connection between the electrodes.

  An object of the present invention is to provide a conductive particle in which a conductive part is disposed on the surface of a base particle and the conductive part has a plurality of protrusions on the outer surface. It is providing the novel electroconductive particle different from the shape of (1), and the manufacturing method of electroconductive particle.

  In addition, a limited object of the present invention is to provide a conductive particle and a method for producing the conductive particle that can efficiently arrange the conductive particles on the electrode when used for electrical connection between the electrodes. Is to provide.

  In addition, a limited object of the present invention is to provide a conductive particle and a method for manufacturing the conductive particle that can suppress damage to the electrode due to the conductive particle when used for electrical connection between the electrodes. It is.

  According to a wide aspect of the present invention, the method includes a base particle and a conductive portion disposed on a surface of the base particle, the conductive portion having a plurality of protrusions on an outer surface, and the plurality of the protrusions Conductive particles having a polygonal column shape are provided.

  On the specific situation with the electroconductive particle which concerns on this invention, the average height of several said processus | protrusion is 10 nm or more and 500 nm or less.

  On the specific situation with the electroconductive particle which concerns on this invention, the average diameter of the base part of several said processus | protrusion is 10 nm or more and 500 nm or less.

  On the specific situation with the electroconductive particle which concerns on this invention, ratio with respect to the average diameter of the base part of several said processus | protrusion is 0.1 or more and 5 or less.

  On the specific situation with the electroconductive particle which concerns on this invention, the shape of the said protrusion is quadrangular prism shape.

  On the specific situation with the electroconductive particle which concerns on this invention, the said electroconductive part consists of copper, nickel, palladium, cobalt, iron, ruthenium, platinum, silver, rhodium, iridium, gold | metal | money, tungsten, molybdenum, phosphorus, and boron. It includes at least one selected from the group.

  On the specific situation with the electroconductive particle which concerns on this invention, the ratio of the (111) plane in the X-ray diffraction of the said protrusion is 50% or more.

  On the specific situation with the electroconductive particle which concerns on this invention, the said electroconductive particle is further equipped with the insulating substance arrange | positioned on the outer surface of the said electroconductive part.

  According to a wide aspect of the present invention, the method includes a step of forming a conductive layer on the surface of the base particle, and when the conductive portion is formed, the conductive portion has a plurality of protrusions on the outer surface, and Provided is a method for producing conductive particles, in which a conductive portion is formed such that the plurality of protrusions have a polygonal column shape.

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

  According to a wide aspect of the present invention, 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. A connection structure is provided in which the connection portion is formed of the above-described conductive particles or is formed of a conductive material containing the conductive particles and a binder resin.

  The conductive particles according to the present invention include base particles and conductive portions arranged on the surfaces of the base particles, and the conductive portions have a plurality of protrusions on the outer surface, and a plurality of the above Since the shape of the protrusion is a polygonal column, the shape of the protrusion on the outer surface of the conductive portion is different from the conventional shape, and a new effect is exhibited due to the shape of the protrusion being a polygonal column.

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 a front sectional view schematically showing a connection structure using conductive particles according to the first embodiment of the present invention. FIG. 6 is a diagram showing an image of the produced conductive particles. FIG. 7 is a diagram showing an image of the produced conductive particles. FIG. 8 is a diagram showing an image of the produced conductive particles. FIG. 9 is a diagram showing an image of the produced conductive particles. FIG. 10 is a diagram showing an image of the produced conductive particles.

  Details of the present invention will be described below.

  The electroconductive particle which concerns on this invention is equipped with base material particle and the electroconductive part arrange | positioned on the surface of the said base material particle. The conductive portion has a plurality of protrusions on the outer surface. The shape of the plurality of protrusions is a polygonal column.

  Moreover, the manufacturing method of the electroconductive particle which concerns on this invention is equipped with the process of forming a conductive layer on the surface of base material particle. In the method for producing conductive particles according to the present invention, when the conductive portion is formed, the conductive portion has a plurality of protrusions on the outer surface, and the shape of the plurality of protrusions is a polygonal column. Next, a conductive portion is formed.

  In the present invention, the conductive part is disposed on the surface of the base particle, and the conductive part has a plurality of protrusions on the outer surface, and the protrusion on the outer surface of the conductive part has a conventional shape. New conductive particles different from the above are provided. In the conductive particle according to the present invention, the conductive particle exhibits a new effect due to the fact that the shape of the protrusion on the outer surface of the conductive portion is different from the conventional shape and the shape of the protrusion is a polygonal column. .

  For example, a polygonal columnar protrusion is likely to make surface contact with a contact object. For this reason, a contact area can be enlarged. In addition, the polygonal columnar protrusion is not easily broken. The electroconductive particle which concerns on this invention is used suitably for the use as which such performance is calculated | required. For example, when electrically connecting electrodes using conductive particles, generally, conductive particles are arranged between the electrodes, and heating and pressurization are performed. In the conductive particles having a polygonal columnar shape, the protrusions are easily brought into surface contact, so that excessive movement of the conductive particles can be suppressed, and the conductive particles can be efficiently arranged on the electrode. In addition, it is easy to deform the entire conductive particles into a flat shape, and this also makes it possible to efficiently dispose the conductive particles on the electrode. Moreover, when obtaining a connection structure, the electroconductive particle which is not located on an electrode can be effectively moved on an electrode. Moreover, in the conductive material according to the present invention, as a result of being able to efficiently arrange the conductive particles on the electrode, on the premise that the conductive particles are also arranged in the space (S) of the portion where the electrode is not formed, Since it is not necessary to use a large amount of conductive particles, the amount of conductive particles used can be reduced.

  The conductive particles according to the present invention are referred to as conductive particles because a conductive portion is formed on the surface, but the application of the conductive particles according to the present invention is not limited to the conductive connection application. The electroconductive particle which concerns on this invention can be used besides the use as which electroconductivity is calculated | required. For example, the conductive particles according to the present invention can also be used as a gap control material (spacer).

  In recent years, with the downsizing of electronic devices, the distance between the line (L) where the electrode is formed and the space (S) where the electrode is not formed has become narrower. For example, there is an increasing need to electrically connect fine electrodes having L / S of 100 μm or less / 100 μm or less. When electrically connecting electrodes having a small L / S, the conventional conductive particles have a problem that insulation defects are particularly likely to occur because many conductive particles are easily arranged in the space (S).

  In contrast, the use of the conductive particles according to the present invention makes it difficult for the conductive particles to be disposed in the space (S), and it is possible to effectively suppress the occurrence of poor insulation. Since the use of the conductive particles according to the present invention can effectively suppress insulation failure, the distance from the space (S) where the electrode is not formed may be 100 μm or less, and 80 μm or less. It may be 60 μm or less, or 40 μm or less.

  The average height A of the plurality of protrusions having a polygonal columnar shape is preferably 10 nm or more, 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 more than the lower limit, the contact property by the protrusions, the capture rate of conductive particles between the electrodes, the conduction reliability, and the insulation reliability are further increased. When the average height A of the protrusions is not more 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 an average height of the protrusions having a polygonal column shape included in one conductive particle. The height of the projection is a virtual line of the conductive portion (dashed line shown in FIG. 1) on the assumption that there is no projection on the line (dashed line L1 shown in FIG. 1) connecting the center of the conductive particles and the tip of the projection. L2) Indicates the distance from the top (on the outer surface of the spherical conductive particles assuming no projection) to the tip of the projection. 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 diameter B of the base portions of the plurality of protrusions having a polygonal columnar shape is preferably 10 nm or more, more preferably 50 nm or more, preferably 500 nm or less, more preferably 300 nm or less. When the average diameter B is equal to or more than the lower limit, the protrusions are not easily broken. When the average diameter B is not more than the above upper limit, the contact property by the protrusions, the capture rate of the conductive particles between the electrodes, the conduction reliability, and the insulation reliability are further enhanced.

  The average diameter B of the base of the protrusion is an average of the diameters of the bases of the protrusions having a polygonal column shape included in one conductive particle. The diameter of the base is the maximum diameter of each of the bases in the protrusion. For example, if the base is square, the diameter of the base is generally the length of the diagonal. On the line connecting the center of the conductive particle and the tip of the protrusion (broken line L1 shown in FIG. 1), the end of the imaginary line portion (broken line L2 shown in FIG. 1) of the conductive part when assuming no protrusion is The distance between the end portions of the projection and the imaginary line portion (the distance connecting the end portions with a straight line) is the diameter of the base portion.

  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) is preferably 0.1 or more, more preferably 0.5 or more. Preferably it is 5.0 or less, More preferably, it is 3.0 or less. When the ratio (average height A / average diameter B) is not less than the above lower limit, the contact property and penetrability by the protrusions are further enhanced. When the ratio (average height A / average diameter B) is not more than the above upper limit, the protrusions are not easily broken.

  The shape of the protrusion may be a triangular prism shape, a quadrangular prism shape, or a pentagonal prism shape. From the viewpoint of suppressing excessive bending of the protrusions and further improving the contactability and penetrability of the protrusions, the plurality of protrusions preferably have a quadrangular prism shape.

  The number of polygonal columnar protrusions on the outer surface of the conductive portion per one conductive particle is preferably 3 or more, more preferably 5 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. Note that it is not necessary that all the protrusions included in the conductive particles have a polygonal column shape.

  The ratio X of the number of projections in the shape of a polygonal column in the number of projections contained in one conductive particle is preferably 30% or more, more preferably 50% or more, still more preferably 60% or more, and particularly preferably. 70% or more, most preferably 80% or more. As the ratio of the number of the polygonal columnar projections increases, the effect of the polygonal columnar projections can be obtained more effectively.

  The ratio of the surface area on which polygonal columnar protrusions are formed is preferably 10% or more, more preferably 20% or more, still more preferably 30% or more, preferably 90%, out of 100% of the entire surface area of the outer surface of the conductive portion. Below, more preferably 80% or less, and still more preferably 70% or less.

  The proportion of the (111) plane in the X-ray diffraction of the protrusion is preferably 50% or more.

  Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

  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 particles 1 include base material particles 2 and conductive portions 3.

  The conductive portion 3 is disposed on the surface of the base particle 2. The conductive particle 1 is a coated particle in which the surface of the base particle 2 is coated with the conductive portion 3. The conductive part 3 is a continuous film.

  The conductive particle 1 has a plurality of protrusions 1a on a conductive surface. The conductive portion 3 has a plurality of protrusions 3a on the outer surface. The shape of the plurality of protrusions 1a and 3a is a polygonal column, and in this embodiment is a quadrangular column. The conductive portion includes a first portion and a second portion that is thicker than the first portion. A portion excluding the plurality of protrusions 1 a and 3 a is the first portion of the conductive portion 3. The plurality of protrusions 1a and 3a are the second portions where the conductive portion 3 is thick.

  In the conductive particle 1, the average height A of the plurality of protrusions 1a and 3a is smaller than the average diameter B of the base of the plurality of protrusions 1a and 3a.

  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 particle 1 </ b> A includes a base particle 2 and a conductive part 3 </ b> A.

  The conductive portion 3 </ b> A is disposed 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. The shapes of the plurality of protrusions 1Aa and 3Aa are polygonal columnar shapes, and in the present embodiment, are quadrangular columnar shapes.

  In the conductive particle 1A, the average height A of the plurality of protrusions 1Aa and 3Aa is larger than the average diameter B of the base portion of the plurality of protrusions 1a and 3a.

  Like the conductive particles 1 and 1A, the relationship between the average height A of the plurality of protrusions 1Aa and 3Aa and the average diameter B of the bases of the plurality of protrusions 1a and 3a can be changed as appropriate. For example, the relationship with the average diameter B of the base portions of the plurality of protrusions 1a and 3a 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 particle 1 </ b> B includes a base particle 2 and a conductive part 3 </ b> B.

  Only the conductive part is different between the conductive particles 1 and the conductive particles 1B. That is, the conductive particle 1 has the conductive layer 3 having a single-layer structure, whereas the conductive particle 1B has the conductive part 3B having a two-layer structure.

  The conductive part 3B has a first conductive part 3BA and a second conductive part 3BB. The first and second conductive portions 3BA and 3BB are disposed on the surface of the base particle 2. The first conductive portion 3BA is disposed between the base particle 2 and the second conductive portion 3BB. Accordingly, the first conductive portion 3BA is disposed on the surface of the base particle 2, and the second conductive portion 3BB is disposed on the outer surface of the first conductive portion 3BA. The outer shape of the first conductive portion 3BA is spherical. The conductive particles 1B have a plurality of protrusions 1Ba on the conductive surface. The conductive portion 3B has a plurality of protrusions 3Ba on the outer surface. The second conductive portion 3BB has a plurality of protrusions 3BBa on the outer surface. The shape of the plurality of protrusions 3BBa is a polygonal column. The inner first conductive portion may have a plurality of protrusions 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 1 </ b> C includes a base particle 2, a conductive part 3, and an insulating substance 4. The conductive particles 1C have a plurality of protrusions 1Ca on the conductive surface.

  The conductive particles 1 </ b> C are conductive particles in which an insulating material 4 is disposed on the outer surface of the conductive particles 1. An insulating substance 4 is disposed on the outer surface of the conductive portion 3. In this embodiment, the insulating substance 4 is an insulating particle. 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 made of an insulating material. Thus, it is preferable that the electroconductive particle which concerns on this invention has the insulating substance arrange | positioned on the outer surface of an electroconductive part.

  Moreover, the image of the electroconductive particle actually manufactured was shown in FIGS. The conductive particles shown in FIGS. 6 to 10 have a plurality of protrusions on the outer surface of the conductive portion, and the shape of the plurality of protrusions is a polygonal column shape.

  Hereinafter, the conductive particles will be described in more detail.

(Conductive particles)
[Base material particles]
Examples of the substrate particles include resin particles, inorganic particles excluding metal particles, organic-inorganic hybrid particles, and metal particles. The base particle may have a core and a shell disposed on the surface of the core, or may be a core-shell particle. The substrate particles are preferably substrate particles excluding metal particles, and more preferably resin particles, inorganic particles excluding metal particles, or organic-inorganic hybrid particles.

  The substrate particles are more preferably resin particles or organic-inorganic hybrid particles, and may be resin particles or organic-inorganic hybrid particles. By using these preferable base particles, conductive particles more suitable for electrical connection between the electrodes can be obtained.

  When connecting between electrodes using the said electroconductive particle, after arrange | positioning the said electroconductive particle between electrodes, the said electroconductive particle is compressed by crimping | bonding. When the substrate 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. For this reason, the connection resistance between electrodes becomes still lower.

  Various organic materials are suitably 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, polyamideimide, 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. Resin for forming the resin particles can be designed and synthesized, and the hardness of the base particles can be easily controlled within a suitable range, which is suitable for conductive materials and having physical properties at the time of compression. 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 monomer having an ethylenically unsaturated group, the monomer having the ethylenically unsaturated group may be a non-crosslinkable monomer or a crosslinkable monomer. And a polymer.

  Examples of the non-crosslinkable monomer include styrene monomers such as styrene and α-methylstyrene; carboxyl group-containing monomers such as (meth) acrylic acid, maleic acid, and maleic anhydride; (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 and glycidyl (meth) acrylate (Meth) acrylates; nitrile-containing monomers such as (meth) acrylonitrile; vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether; vinyl acids such as vinyl acetate, vinyl butyrate, vinyl laurate, vinyl stearate 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, and 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 And silane-containing monomers such as triallyl trimellitate, divinylbenzene, diallyl phthalate, diallylacrylamide, diallyl ether, γ- (meth) acryloxypropyltrimethoxysilane, trimethoxysilylstyrene, vinyltrimethoxysilane It is done.

  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 polymerizing by swelling a monomer together with a radical polymerization initiator using non-crosslinked seed particles.

  In the case where the substrate particles are inorganic particles or organic-inorganic hybrid particles excluding metal particles, examples of the inorganic material for forming the substrate particles include silica, alumina, barium titanate, zirconia, and carbon black. . The inorganic substance is preferably not a metal. The particles formed by the silica are not particularly limited. For example, after forming a crosslinked polymer particle by hydrolyzing a silicon compound having two or more hydrolyzable alkoxysilyl groups, firing may be performed as necessary. The particle | grains obtained by performing are mentioned. 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 disposed 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 reducing the connection resistance between the electrodes, the base material particles are preferably organic-inorganic hybrid particles having an organic core and an inorganic shell disposed 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 inorganic substances for forming the above-described base material particles. The material for forming the inorganic shell is preferably silica. The inorganic shell is preferably formed on the surface of the core by forming a metal alkoxide into a shell-like material by a sol-gel method and then firing the shell-like material. The metal alkoxide is preferably a silane alkoxide. The inorganic shell is preferably formed of a silane alkoxide.

  The particle size 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, still more preferably 50 μm or less, particularly preferably 20 μm or less, and most preferably 10 μm or less. . When the particle size of the core is not less than the above lower limit and not more than the above upper limit, more suitable conductive particles can be obtained by electrical connection between the electrodes, and the base particles can be suitably used for the use of conductive particles. Become. For example, when the core particle size is not less than the lower limit and not more than the upper limit, when the electrodes are connected using the conductive particles, the contact area between the conductive particles and the electrodes is sufficiently large, and Aggregated conductive particles are hardly formed when the conductive layer is formed. Further, the distance between the electrodes connected via the conductive particles does not become too large, and the conductive layer is difficult to peel from the surface of the base material particles.

  The particle diameter of the core means a diameter when the core is a perfect sphere, and means a maximum diameter when the core is a shape other than a true sphere. Moreover, the particle size of a core means the average particle size which measured the core with the arbitrary particle size measuring apparatus. For example, a particle size distribution measuring machine using principles such as laser light scattering, electrical resistance value 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 the electrodes can be obtained, and the base particles can be suitably used for the use of 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 substrate particles are metal particles, examples of the metal for forming the metal particles include silver, copper, nickel, silicon, gold, and titanium. However, the substrate particles are preferably not metal particles.

  The particle diameter of the substrate particles is preferably 0.1 μm or more, more preferably 0.5 μm or more, still more preferably 1 μm or more, still more preferably 1.5 μm or more, particularly preferably 2 μm or more, preferably 1000 μm or less, More preferably, it is 500 μm or less, still 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, and most preferably 3 μm or less. When the particle diameter of the substrate particles is equal to or greater than the lower limit, the contact area between the conductive particles and the electrodes is increased, 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 is further reduced. Further, when the conductive portion is formed on the surface of the base particle by electroless plating, it becomes difficult to aggregate and the aggregated conductive particles are hardly formed. When the average particle diameter of the substrate particles is not more than the above upper limit, the conductive particles are easily compressed, the connection resistance between the electrodes is further reduced, and the interval between the electrodes is further narrowed.

  The particle diameter of the base particle indicates a diameter when the base particle is a true sphere, and indicates a maximum diameter when the base particle is not a true sphere.

[Conductive part]
The conductive part is preferably a conductive layer. The metal that is the material of the conductive part is not particularly limited. The metal that is the material of the conductive part includes gold, silver, copper, palladium, ruthenium, rhodium, iridium, lithium, platinum, zinc, iron, tin, lead, aluminum, cobalt, indium, nickel, chromium, titanium, antimony Bismuth, thallium, germanium, cadmium, silicon, tungsten, molybdenum and alloys thereof. Examples of the metal include tin-doped indium oxide (ITO) and solder. Especially, since the connection resistance between electrodes can be made still lower, an alloy containing tin, nickel, palladium, copper, or gold is preferable, and nickel, palladium, or copper is more preferable. The conductive part having a polygonal columnar projection is at least one selected from the group consisting of copper, nickel, palladium, cobalt, iron, ruthenium, platinum, silver, rhodium, iridium, gold, tungsten, molybdenum, phosphorus and boron. It is preferable that it contains, and it is more preferable that copper, nickel, and phosphorus or boron are included. The material of the conductive part may be an alloy containing phosphorus and boron. In the conductive part, nickel and tungsten or molybdenum may be alloyed. The melting point of the conductive part is preferably 300 ° C. or higher, more preferably 450 ° C. or higher.

  From the viewpoint of further increasing the hardness of the conductive part, more effectively eliminating the oxide film on the surface of the conductive part and the surface of the electrode when connecting the electrodes, and further reducing the connection resistance between the electrodes, The conductive part having a polygonal columnar projection preferably has a conductive part containing copper or nickel. The conductive part 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 part containing copper. In 100% by weight of the copper-containing layer, the copper content is preferably 75% by weight or more, more preferably 85% by weight or more, and still more preferably 95% by weight or more. When the copper content 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 polygonal columnar protrusion can be easily formed, 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. Or a conductive part containing cobalt, nickel and phosphorus.

  The conductive part having a polygonal columnar projection preferably contains phosphorus or boron, and the conductive part containing nickel preferably contains phosphorus or boron. When the conductive part 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 part containing phosphorus or boron. More preferably, it is 3% by weight or more, preferably 10% by weight or less. When the total content of phosphorus and boron is not more than the above upper limit, the resistance of the conductive portion is further lowered, and the content of metal such as nickel is relatively increased, so that the connection resistance between the electrodes is further increased. It becomes even lower.

  The conductive part may be formed of a single layer or a plurality of layers. That is, the conductive portion may be a single layer or may have a stacked structure of two or more layers. When the conductive portion is formed of 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, and 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 portions, the connection resistance between the electrodes is further reduced. 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 particle is not particularly limited. Examples of the method for forming the conductive part 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 metal powder or a paste containing metal powder and a binder. Can be mentioned. Especially, since formation of an electroconductive part is simple, the method by electroless plating is preferable. Examples of the method by physical vapor deposition include methods such as vacuum vapor deposition, ion plating, and ion sputtering.

  Examples of a method for forming a projection having a polygonal columnar shape on the outer surface of the conductive portion include the following methods.

  A method by electroless high-purity nickel plating using hydrazine as a reducing agent, a method by electroless palladium-nickel alloy using hydrazine as a reducing agent, an electroless CoNiP alloy plating method using a hypophosphite compound as a reducing agent, In addition, a method by electroless copper-nickel-phosphorus alloy plating using a hypophosphorous acid compound as a reducing agent may be used.

  In the method of forming by electroless plating, generally, a catalyzing step and an electroless plating step are performed. Hereinafter, an example of a method for forming a projection having a polygonal columnar shape formed on an outer surface of an alloy plating layer containing copper and nickel and a conductive portion on the surface of 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, after adding the resin particles to a solution containing palladium chloride and tin chloride, the surface of the resin particles is activated with an acid solution or an alkali solution, A method of depositing palladium on the surface of the resin particles, and after adding the resin particles to a solution containing palladium sulfate and aminopyridine, the surface of the resin particles is activated by a solution containing a reducing agent. Examples thereof include a method of depositing palladium on the surface. A phosphorus-containing reducing agent is used as the reducing agent. In addition, 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 using a plating solution containing a copper-containing compound, a complexing agent and a reducing agent, a hypophosphite compound is included as a reducing agent, It is preferable to use a copper-nickel-phosphorus alloy plating solution containing a nickel-containing compound as a reaction initiation metal catalyst and containing a nonionic surfactant.

  By immersing the resin particles in the copper-nickel-phosphorus alloy plating bath, the copper-nickel-phosphorus alloy can be deposited on the surface of the resin particles on which the catalyst is formed. A conductive layer 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, and potassium borohydride.

  The complexing agent is a monocarboxylic acid complexing agent such as sodium acetate or sodium propionate, a dicarboxylic acid complexing agent such as disodium malonate, a tricarboxylic acid complexing agent such as disodium succinate, lactic acid, DL-malic acid, Rochelle salt, hydroxy acid complexing agents such as sodium citrate and sodium gluconate, amino acid complexing agents such as glycine and EDTA, amine complexing agents such as ethylenediamine, and organic acids such as maleic acid 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 and amphoteric surfactants, and nonionic surfactants are particularly suitable. Preferred nonionic surfactants are polyethers containing ether oxygen atoms. Preferred nonionic surfactants include 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 or phenol ethoxylate. As for the said surfactant, only 1 type may be used and 2 or more types may be used together. Polyethylene glycol having a molecular weight of about 1000 (for example, 500 or more and 2000 or less) is particularly preferable.

  In order to form a projection having a polygonal columnar shape on the outer surface of the conductive portion, it is desirable to control the molar ratio of the copper compound and the nickel compound. The amount of the copper compound used is preferably 50 to 500 times in molar ratio to the nickel compound.

  In order to form protrusions having a polygonal column shape, it is preferable to use a nonionic surfactant, and it is particularly preferable to use polyethylene glycol having a molecular weight of about 1000 (for example, 500 or more and 2000 or less).

  The ratio of the average height A of the plurality of protrusions to the average diameter B of the base portions of the plurality of protrusions (average height A / average diameter B) depends on the thickness of the conductive portion, and is the immersion time in the plating bath. Can be controlled. The plating temperature is preferably 30 ° C. or higher, preferably 100 ° C. or lower, and the plating time is preferably 5 minutes or longer. In particular, in order to form protrusions having a polygonal columnar shape, 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. is there.

  Next, an example of a method for forming projections having a polygonal columnar shape on the outer surface 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, after adding the resin particles to a solution containing palladium chloride and tin chloride, the surface of the resin particles is activated with an acid solution or an alkali solution, A method of depositing palladium on the surface of the resin particles, and after adding the resin particles to a solution containing palladium sulfate and aminopyridine, the surface of the resin particles is activated by a solution containing a reducing agent. Examples thereof include a method of depositing palladium on the surface. A phosphorus-containing reducing agent is used as the reducing agent. In addition, 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 nonionic surfactant, and a reducing agent, high-purity nickel containing hydrazine as a reducing agent A plating solution is preferably used.

  By immersing the resin particles in a high-purity nickel plating bath, high-purity nickel plating can be deposited on the surface of the resin particles on which the catalyst is formed, and a 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 agent include monocarboxylic acid complexing agents such as sodium acetate and sodium propionate, dicarboxylic acid complexing agents such as disodium malonate, tricarboxylic acid complexing agents such as disodium succinate, and lactic acid. , DL-malic acid, Rochelle salt, hydroxy acid complexing agents such as sodium citrate and sodium gluconate, amino acid complexing agents such as glycine and EDTA, amine complexing agents such as ethylenediamine, and organic such as maleic acid Examples include acid complexing agents. The complexing agent is preferably an amino acid glycine.

  Examples of the surfactant include anionic, cationic, nonionic and amphoteric surfactants, and nonionic surfactants are particularly suitable. Preferred nonionic surfactants are polyethers containing ether oxygen atoms. Preferred nonionic surfactants include 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 or phenol ethoxylate. As for the said surfactant, only 1 type may be used and 2 or more types may be used together. Polyethylene glycol having a molecular weight of about 1000 (for example, 500 or more and 2000 or less) is particularly preferable.

  In order to form protrusions having a polygonal columnar shape on the outer surface of the conductive part, it is preferable to adjust the pH of the plating solution to 6.0 or higher. An electroless plating solution using hydrazine as a reducing agent is accompanied by a sharp drop in pH when nickel is reduced by an oxidation reaction of hydrazine. In order to suppress the rapid decrease in pH, it is preferable to use a buffering agent such as phosphoric acid, boric acid or carbonic acid. 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 diameter B of the base portions of the plurality of protrusions (average height A / average diameter B) depends on the thickness of the conductive portion, and is the immersion time in the plating bath. Can be controlled. The plating temperature is preferably 30 ° C. or higher, preferably 100 ° C. or lower, and the plating time is preferably 5 minutes or longer. In particular, in order to form protrusions having a polygonal columnar shape, 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. It is.

  Next, an example of a method for forming a palladium-nickel alloy plating layer and a projection having a polygonal columnar shape 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, after adding the resin particles to a solution containing palladium chloride and tin chloride, the surface of the resin particles is activated with an acid solution or an alkali solution, A method of depositing palladium on the surface of the resin particles, and after adding the resin particles to a solution containing palladium sulfate and aminopyridine, the surface of the resin particles is activated by a solution containing a reducing agent. Examples thereof include a method of depositing palladium on the surface. A phosphorus-containing reducing agent is used as the reducing agent. In addition, a conductive layer containing phosphorus can be formed by using a phosphorus-containing reducing agent as the reducing agent.

  In the electroless plating step, as a reducing agent 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 nonionic surfactant, and a reducing agent. A palladium-nickel alloy plating solution containing hydrazine 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 on which the catalyst is formed, 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 dichloroethylenediamine palladium (II), palladium chloride, dichlorodiammine palladium (II), dinitrodiammine palladium (II), tetraammine palladium (II) nitrate, tetraammine palladium (II) sulfate, oxalato diammine. Palladium (II), tetraammine palladium (II) oxalate, tetraammine palladium (II) chloride, etc. are mentioned. The palladium-containing compound is preferably palladium chloride.

  Examples of the stabilizer include lead compounds, bismuth compounds, and thallium compounds. Specific examples of these compounds include sulfates, carbonates, acetates, nitrates, and hydrochlorides of metals (lead, bismuth, thallium) constituting the compounds. Considering the influence on the environment, at least one of bismuth compounds and thallium compounds is preferable.

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

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

  Examples of the surfactant include anionic, cationic, nonionic and amphoteric surfactants, and nonionic surfactants are particularly suitable. Preferred nonionic surfactants are polyethers containing ether oxygen atoms. Preferred nonionic surfactants include 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 or phenol ethoxylate. As for the said surfactant, only 1 type may be used and 2 or more types may be used together. Polyethylene glycol having a molecular weight of about 1000 (for example, 500 or more and 2000 or less) is particularly preferable.

  In order to form a projection having a polygonal columnar shape 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 to 500 times in terms of a molar ratio to the nickel compound.

  In order to form protrusions having a polygonal columnar shape on the outer surface of the conductive part, it is preferable to adjust the pH of the plating solution from 8.0 to 10.0. When the pH is 7.5 or lower, the stability of the plating solution is lowered and bath decomposition is caused. Therefore, the pH is preferably 8.0 or higher.

  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 portion and is controlled by the immersion time in the plating bath. can do. The plating temperature is preferably 30 ° C. or higher, preferably 100 ° C. or lower, and the plating time is preferably 5 minutes or longer. In particular, in order to form protrusions having a polygonal columnar shape, from the viewpoint of suppressing the precipitation reaction rate, the plating time is preferably 30 ° C. or more, preferably 60 ° C. or less, and the plating time is preferably 30 minutes or more. is there.

  Next, an example of a method for forming an alloy plating layer containing cobalt and nickel on the surface of the resin particles and a projection having a polygonal columnar shape on the outer surface of the conductive portion 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, after adding the resin particles to a solution containing palladium chloride and tin chloride, the surface of the resin particles is activated with an acid solution or an alkali solution, A method of depositing palladium on the surface of the resin particles, and after adding the resin particles to a solution containing palladium sulfate and aminopyridine, the surface of the resin particles is activated by a solution containing a reducing agent. Examples thereof include a method of depositing palladium on the surface. A phosphorus-containing reducing agent is used as the reducing agent. In addition, 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 cobalt-nickel-phosphorus alloy plating method using a plating solution containing a cobalt-containing compound, an inorganic additive, a complexing agent, a nonionic surfactant, and a reducing agent, A cobalt-nickel-phosphorus alloy plating solution containing a hypophosphorous acid compound and a cobalt-containing compound as a reaction initiation metal catalyst for the reducing agent is preferably used.

  By immersing the resin particles in the cobalt-nickel-phosphorus alloy plating bath, a cobalt-nickel-phosphorus alloy can be deposited on the surface of the resin particles on which the catalyst is formed. A conductive layer containing 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 more 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, and potassium borohydride.

  The complexing agent is a monocarboxylic acid complexing agent such as sodium acetate or sodium propionate, a dicarboxylic acid complexing agent such as disodium malonate, a tricarboxylic acid complexing agent such as disodium succinate, lactic acid, DL-malic acid, Rochelle salt, hydroxy acid complexing agents such as sodium citrate and sodium gluconate, amino acid complexing agents such as glycine and EDTA, amine complexing agents such as ethylenediamine, and organic acids such as maleic acid 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. The inorganic additive is considered to act to promote precipitation of the electroless cobalt plating layer.

  Examples of the surfactant include anionic, cationic, nonionic and amphoteric surfactants, and nonionic surfactants are particularly suitable. Preferred nonionic surfactants are polyethers containing ether oxygen atoms. Preferred nonionic surfactants include 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 or phenol ethoxylate. As for the said surfactant, only 1 type may be used and 2 or more types may be used together. Polyethylene glycol having a molecular weight of about 1000 (for example, 500 or more and 2000 or less) is particularly preferable.

  In order to form a projection having a polygonal columnar shape 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 to 500 times in terms of a molar ratio to the nickel compound.

  In order to form a projection having a polygonal column shape, an inorganic additive is preferably used, and ammonium sulfate is particularly preferably used.

  The ratio of the average height A of the plurality of protrusions to the average diameter B of the base portions of the plurality of protrusions (average height A / average diameter B) depends on the thickness of the conductive portion, and is the immersion time in the plating bath. Can be controlled. The plating temperature is preferably 30 ° C. or higher, preferably 100 ° C. or lower, and the plating time is preferably 5 minutes or longer. In particular, in order to form protrusions having a polygonal columnar shape, 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. is there.

  The thickness of the entire conductive part in the portion where there is no protrusion is preferably 5 nm or more, more preferably 10 nm or more, still more preferably 20 nm or more, particularly preferably 50 nm or more, preferably 1000 nm or less, more preferably 800 nm or less, and still more preferably. It is 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 not less than the above lower limit, the conductivity of the conductive particles is further improved. When the thickness of the entire conductive part is less than or equal to the above upper limit, the difference in thermal expansion coefficient between the base particle and the conductive part becomes small, and the conductive part is difficult to peel from the base particle. When the conductive part has a plurality of conductive parts (first conductive part and second conductive part), the thickness of the conductive part is the total thickness of the conductive part (total of the first and second conductive parts). Thickness).

  When the conductive part has a plurality of conductive parts, the thickness of the conductive part in the outermost layer where the protrusion is not present is preferably 1 nm or more, more preferably 10 nm or more, preferably 500 nm or less, more preferably 100 nm or less. is there. When the thickness of the conductive portion of the outermost layer is not less than the above lower limit and not more than the above upper limit, the coating with the conductive portion of the outermost layer can be made uniform, the corrosion resistance is sufficiently high, and the connection resistance between the electrodes is sufficiently high Lower. In addition, when the outermost layer is more expensive than the inner-layer conductive portion, the thinner the outermost layer, the lower the cost.

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

[Insulating material]
It is preferable that the electroconductive particle which concerns on this invention is equipped with the insulating substance arrange | positioned on the outer surface of the said electroconductive part. In this case, when the conductive particles are used for connection between the electrodes, a short circuit between adjacent electrodes can be prevented. Specifically, when a plurality of conductive particles are in contact with each other, an insulating material is present between the plurality of electrodes, so that it is possible to prevent a short circuit between electrodes adjacent in the lateral direction instead of between the upper and lower electrodes. Note that the insulating material between the conductive portion and the electrode can be easily removed by pressurizing the conductive particles with the two electrodes when connecting the electrodes. Since the conductive particles have a plurality of protrusions on the outer surface of the conductive portion, the insulating material between the conductive portion of the conductive particles and the electrode can be easily excluded.

  The insulating substance is preferably an insulating particle because the insulating substance can be more easily removed when the electrodes are pressed.

  Specific examples of the insulating resin that is the material of the insulating material include polyolefins, (meth) acrylate polymers, (meth) acrylate copolymers, block polymers, thermoplastic resins, crosslinked thermoplastic resins, heat Examples thereof include curable resins and water-soluble resins.

  Examples of the polyolefins include polyethylene, ethylene-vinyl acetate copolymer, and ethylene-acrylic acid ester copolymer. 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 copolymer, SB type styrene-butadiene block copolymer, SBS type styrene-butadiene block copolymer, and hydrogenated products thereof. Examples of the thermoplastic resin include vinyl polymers and vinyl copolymers. As said thermosetting resin, an epoxy resin, a phenol resin, a melamine resin, etc. are mentioned. Examples of the water-soluble resin include polyvinyl alcohol, polyacrylic acid, polyacrylamide, polyvinyl pyrrolidone, polyethylene oxide, and methyl cellulose. Of these, water-soluble resins are preferable, and polyvinyl alcohol is more preferable.

  From the viewpoint of further increasing the detachability of the insulating particles during thermocompression bonding, the insulating particles are preferably inorganic particles, and are 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 pulverized silica and spherical silica, and spherical silica is preferably used.

  As a method of disposing an insulating material on the surface of the conductive part, a known method can be adopted.

  The average diameter (average particle diameter) of the insulating material 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 material 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 material is equal to or more than the above lower limit, when the conductive particles are dispersed in the binder resin, the conductive portions in the plurality of conductive particles are difficult to contact each other. When the average diameter of the insulating particles is not more than the above upper limit, it is not necessary to make the pressure too high in order to eliminate the insulating material between the electrodes and the conductive particles when the electrodes are connected, There is no need for heating.

  The “average diameter (average particle diameter)” of the insulating material indicates a number average diameter (number average particle diameter). The average diameter of the insulating material is determined 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 a circuit connection material. The binder resin is not particularly limited. As the binder resin, a known insulating resin is used.

  Examples of the binder resin include vinyl resins, thermoplastic resins, curable resins, thermoplastic block copolymers, and elastomers. As for the said binder resin, only 1 type may be used and 2 or more types may be used together.

  Examples of the vinyl resin include vinyl acetate resin, acrylic resin, and styrene resin. Examples of the thermoplastic resin include polyolefin resins, ethylene-vinyl acetate copolymers, and polyamide resins. Examples of the curable resin include an epoxy resin, a urethane resin, a polyimide resin, and an 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 a styrene-butadiene-styrene block copolymer, a styrene-isoprene-styrene block copolymer, a hydrogenated product of a styrene-butadiene-styrene block copolymer, and a styrene-isoprene. -Hydrogenated product of a styrene block copolymer. 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 includes, for example, a filler, an extender, a softener, a plasticizer, a polymerization catalyst, a curing catalyst, a colorant, an antioxidant, a heat stabilizer, and a light stabilizer. Various additives such as an agent, an ultraviolet absorber, a lubricant, an antistatic agent and a flame retardant may be contained.

  The conductive material according to the present invention can be used as a conductive paste and a conductive film. When the conductive material according to the present invention is a conductive film, a film that does not include conductive particles may be laminated on a conductive film that includes conductive particles. The conductive paste is preferably an anisotropic conductive paste. The conductive film is preferably an anisotropic conductive film.

  In 100% by weight of the conductive material, the content of the binder resin is preferably 10% by weight or more, more preferably 30% by weight or more, still more preferably 50% by weight or more, particularly preferably 70% by weight or more, preferably 99.% or more. It is 99 weight% or less, More preferably, it is 99.9 weight% or less. When the content of the binder resin is not less than the above lower limit and not more than the above upper limit, the conductive particles are efficiently arranged between the electrodes, and the connection reliability of the connection target member connected by the conductive material is further 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 or less, More preferably, it is 40% by weight or less, particularly preferably 20% by weight or less, most preferably 10% by weight or less. When the content of the conductive particles is not less than the above lower limit and not more than the above upper limit, the conduction reliability between the electrodes is further enhanced.

(Connection structure)
A connection structure can be obtained by connecting a connection object member using the electrically-conductive material containing the electroconductive particle and binder resin which concern on this invention.

  The connection structure includes a first connection target member, a second connection target member, and a connection portion that connects the first connection target member and the second connection target member. The connection structure is preferably formed of the above-described conductive particles or a conductive material including the above-described conductive particles and a binder resin.

  In FIG. 5, the connection structure using the electroconductive particle which concerns on the 1st Embodiment of this invention is typically shown with front sectional drawing.

  The connection structure 51 shown in FIG. 5 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 and 53. Prepare. The connection portion 54 includes the conductive particles 1 and a binder resin (such as a cured binder resin). The connection part 54 is formed of a conductive material including the conductive particles 1. The connection portion 54 is preferably formed by curing a conductive material. In FIG. 5, the conductive particles 1 are schematically shown for convenience of illustration. Instead of the conductive particles 1, other conductive particles such as the conductive particles 1A, 1B, and 1C 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 surface (lower surface). The first electrode 52 a and the second electrode 53 a 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 manufacturing method of the connection structure is not particularly limited. As an example of the manufacturing method of the connection structure, the conductive material is disposed between the first connection target member and the second connection target member to obtain a laminate, and then the laminate is heated and pressurized. Methods and the like. The pressure of the said pressurization is about 9.8 * 10 < ⁴ > -4.9 * 10 < ⁶ > Pa. The temperature of the said heating is about 120-220 degreeC.

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

  Examples of the electrode provided on the connection target member include metal electrodes such as a gold electrode, a nickel electrode, a tin electrode, an aluminum electrode, a copper electrode, a silver electrode, a molybdenum electrode, and a tungsten electrode. When the connection object member is a flexible printed board, the electrode is preferably a gold electrode, a nickel electrode, a tin electrode, or a copper electrode. When the connection target member is a glass substrate, the electrode is preferably an aluminum electrode, a copper electrode, a molybdenum electrode, or a tungsten electrode. In addition, when the said electrode is an aluminum electrode, the electrode formed only with aluminum may be sufficient and the electrode by which the aluminum layer was laminated | stacked on the surface of the metal oxide layer may be sufficient. Examples of the material for 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 present invention is not limited only to the following examples.

Example 1
The surface of divinylbenzene copolymer resin particles (“Micropearl SP-203” manufactured by Sekisui Chemical Co., Ltd.) having a particle size of 3.0 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 material particles A) were prepared.

  The organic / inorganic hybrid particles were etched and washed with water. Next, organic-inorganic hybrid particles were added to 100 mL of a palladium-catalyzed solution containing 8% by weight of a palladium catalyst and stirred. Then, it filtered and wash | cleaned. Organic / inorganic hybrid particles were added to 0.5 wt% dimethylamine borane solution at pH 6 to obtain organic / inorganic hybrid particles to which palladium was attached.

  The organic-inorganic hybrid particles to which palladium was attached were stirred and dispersed in 300 mL of ion exchange water for 3 minutes to obtain a dispersion. Next, 1 g of nickel particle slurry (including spherical nickel particles and an average particle diameter of nickel as a core material of 100 nm) is added to the dispersion over 3 minutes to include organic-inorganic hybrid particles to which the core material is attached. A suspension was obtained.

  Further, as an electroless copper-nickel-phosphorus alloy plating solution, copper sulfate 150 g / L, nickel sulfate 5 g / L, sodium hypophosphite 100 g / L, sodium citrate 150 g / L, nonionic interface As an activator, a plating solution prepared by adjusting a mixed solution of polyethylene glycol 1000 (molecular weight: 1000) 10 g / L to pH 9 with sodium hydroxide was prepared. 650 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 58 ° C. Thereafter, the mixture was stirred until the pH became stable, and it was confirmed that hydrogen foaming stopped.

  Thereafter, by filtering the suspension, the particles are taken out, washed with water, and dried, whereby a copper-nickel-phosphorus alloy conductive layer (thickness: 101 nm) is formed on the surface of the organic-inorganic hybrid particles to which the core substance is attached. Arranged conductive particles were obtained. The conductive part in the obtained conductive particles had a plurality of polygonal columnar protrusions on the outer surface.

(Example 2)
Divinylbenzene copolymer resin particles (base particle B, “Micropearl SP-203” manufactured by Sekisui Chemical Co., Ltd.) having a particle size of 3.0 μm were prepared.

  Conductive particles were obtained in the same manner as in Example 1 except that the base particle A was changed to the base particle B. Thus, the electroconductive particle by which the copper-nickel-phosphorus alloy conductive layer (thickness: 101 nm) was arrange | positioned on the surface of the resin particle was obtained. The conductive part in the obtained conductive particles had a plurality of polygonal columnar protrusions on the outer surface.

(Example 3)
As an electroless high-purity nickel plating solution, nickel chloride 30 g / L, hydrazine monohydrate 80 g / L, glycine 50 g / L, boric acid 20 g / L, and non-ionic surfactant polyethylene glycol 1000 ( (Molecular weight: 1000) A plating solution in which a mixed solution of 10 g / L was adjusted to pH 10 with sodium hydroxide was prepared. 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 56 ° C. Thereafter, the mixture was stirred until the pH became stable, and it was confirmed that hydrogen foaming stopped.

  Thereafter, the suspension was filtered to take out the particles, washed with water, and dried to place a high-purity Ni conductive layer (thickness: 103 nm) on the surface of the organic-inorganic hybrid particles to which the core substance was attached. Conductive particles were obtained. The conductive part in the obtained conductive particles had a plurality of polygonal columnar protrusions on the outer surface.

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

(Example 4)
As electroless palladium-nickel alloy plating solution, palladium chloride 60g / L, nickel sulfate 3g / L, hydrazine monohydrate 80g / L, ethylenediamine 25g / L, DL-malic acid 30g / L, stable A plating solution was prepared in which a mixed solution of 5 ml / L of an agent and 10 g / L of polyethylene glycol 1000 (molecular weight: 1000) as a nonionic surfactant was adjusted to pH 9 with sodium hydroxide. 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 20 ml / min. The reaction temperature was set at 55 ° C. Thereafter, the mixture was stirred until the pH became stable, and it was confirmed that hydrogen foaming stopped.

  Thereafter, by filtering the suspension, the particles are taken out, washed with water, and dried, whereby a palladium-nickel alloy conductive layer (thickness: 103 nm) is disposed on the surface of the organic-inorganic hybrid particles to which the core substance is attached. Conductive particles were obtained. The conductive part in the obtained conductive particles had a plurality of polygonal columnar protrusions on the outer surface.

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

(Example 5)
As electroless cobalt-nickel-phosphorous alloy plating solution, cobalt sulfate 70 g / L, nickel sulfate 5 g / L, sodium hypophosphite 100 g / L, ammonium sulfate 50 g / L, sodium pyrophosphate 20 g / L, A plating solution in which a mixed solution of polyethylene glycol 1000 (molecular weight: 1000) 10 g / L as a nonionic surfactant was adjusted to pH 10 with sodium hydroxide was prepared. 1000 ml of this plating solution was added dropwise to the suspension through a metering pump at an addition rate of 10 ml / min. The reaction temperature was set to 58 ° C. Thereafter, the mixture was stirred until the pH became stable, and it was confirmed that hydrogen foaming stopped.

  Thereafter, by filtering the suspension, the particles are taken out, washed with water, and dried, whereby a cobalt-nickel-phosphorus alloy conductive layer (thickness: 105 nm) is formed on the surface of the organic-inorganic hybrid particles to which the core substance is attached. Arranged conductive particles were obtained. The outer surface had a plurality of polygonal columnar protrusions.

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

(Example 6)
As an electroless copper-nickel-phosphorus alloy plating solution, copper sulfate 50 g / L, nickel sulfate 2.0 g / L, sodium hypophosphite 100 g / L, sodium citrate 150 g / L, nonionic interface A plating solution prepared by adjusting a mixed solution of polyethylene glycol 1000 (molecular weight: 1000) 20 g / L as an activator to pH 9 with sodium hydroxide was prepared. 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 15 ml / min. The reaction temperature was set to 58 ° C. Thereafter, the mixture was stirred until the pH became stable, and it was confirmed that hydrogen foaming stopped.

  Thereafter, by filtering the suspension, the particles are taken out, washed with water, and dried to form a copper-nickel-phosphorus alloy conductive layer (thickness: 102 nm) on the surface of the organic-inorganic hybrid particles to which the core substance is attached. Arranged conductive particles were obtained. The conductive part in the obtained conductive particles had a plurality of polygonal columnar protrusions on the outer surface.

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

(Example 7)
As an electroless copper-nickel-phosphorus alloy plating solution, copper sulfate 100 g / L, nickel sulfate 3.5 g / L, sodium hypophosphite 100 g / L, sodium citrate 150 g / L, nonionic interface A plating solution in which a mixed solution of polyethylene glycol 1000 (molecular weight: 1000) 15 g / L as an activator was adjusted to pH 9 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 15 ml / min. The reaction temperature was set to 58 ° C. Thereafter, the mixture was stirred until the pH became stable, and it was confirmed that hydrogen foaming stopped.

  Thereafter, by filtering the suspension, the particles are taken out, washed with water, and dried, whereby a copper-nickel-phosphorus alloy conductive layer (thickness: 103 nm) is formed on the surface of the organic-inorganic hybrid particles to which the core substance is attached. Arranged conductive particles were obtained. The conductive part in the obtained conductive particles had a plurality of polygonal columnar protrusions on the outer surface.

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

(Example 8)
As an electroless copper-nickel-phosphorus alloy plating solution, copper sulfate 200 g / L, nickel sulfate 12 g / L, sodium hypophosphite 100 g / L, sodium citrate 150 g / L, and nonionic surfactant As a plating solution, a mixed solution of polyethylene glycol 1000 (molecular weight: 1000) 5 g / L was adjusted to pH 9 with sodium hydroxide. 500 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 60 ° C. Thereafter, the mixture was stirred until the pH became stable, and it was confirmed that hydrogen foaming stopped.

  Thereafter, by filtering the suspension, the particles are taken out, washed with water, and dried to form a copper-nickel-phosphorus alloy conductive layer (thickness: 102 nm) on the surface of the organic-inorganic hybrid particles to which the core substance is attached. Arranged conductive particles were obtained. The conductive part in the obtained conductive particles had a plurality of polygonal columnar protrusions on the outer surface.

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

Example 9
Production of insulating particles:
To a 1000 mL separable flask equipped with a four-neck separable cover, stirring blade, three-way cock, condenser and temperature probe, 100 mmol of methyl methacrylate and N, N, N-trimethyl-N-2-methacryloyloxyethyl 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 under a nitrogen atmosphere. After completion of the reaction, it was freeze-dried to obtain insulating particles having an ammonium group on the surface, an average particle size of 220 nm, and a CV value of 10%.

  The insulating particles were dispersed in ion exchange water under ultrasonic irradiation to obtain a 10 wt% aqueous dispersion of insulating particles.

Production of conductive particles:
10 g of the conductive particles obtained in Example 1 were dispersed in 500 mL of ion exchange water, 4 g of an aqueous dispersion of insulating particles was added, and the mixture was stirred at room temperature for 6 hours. After filtration through a 3 μm mesh filter, the particles were further washed with methanol and dried to obtain conductive particles having insulating particles attached thereto.

  When observed with a scanning electron microscope (SEM), only one coating layer of insulating particles was formed on the surface of the conductive particles. The coverage of the insulating particles with respect to the area of 2.5 μm from the center of the conductive particles by image analysis (that is, the projected area of the particle diameter of the insulating particles) was calculated to be 30%.

(Example 10)
Divinylbenzene copolymer resin particles (base particle B, “Micropearl SP-203” manufactured by Sekisui Chemical Co., Ltd.) having a particle size of 3.0 μm were prepared. After dispersing 10 parts by weight of the resin particles in 100 parts by weight of an alkaline solution containing 5% by weight of a palladium catalyst solution using an ultrasonic disperser, the resin particles were taken out by filtering the solution. 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 surface was activated were sufficiently washed with water, and then added to 500 parts by weight of distilled water and dispersed to obtain a suspension.

  In addition, as an electroless copper-nickel-phosphorus alloy plating solution, copper sulfate 50 g / L, nickel sulfate 1 g / L, sodium hypophosphite 100 g / L, sodium citrate 90 g / L, boric acid 10 g / L A plating solution was prepared in which a mixed solution of L and polyethylene glycol 1000 (molecular weight: 1000) 1 g / L as a nonionic surfactant was adjusted to pH 9 with sodium hydroxide. 1500 ml of this plating solution was added dropwise to the suspension through a metering pump at an addition rate of 10 ml / min. The reaction temperature was set at 55 ° C. Thereafter, the mixture was stirred until the pH became stable, and it was confirmed that hydrogen foaming stopped.

  Thereafter, by filtering the suspension, the particles are taken out, washed with water, and dried to obtain conductive particles having a copper-nickel-phosphorus alloy conductive layer (thickness: 100 nm) disposed on the surface of the resin particles. It was. The conductive part in the obtained conductive particles had a plurality of polygonal columnar protrusions on the outer surface.

(Example 11)
As electroless nickel-copper-phosphorus alloy plating solution, nickel sulfate 80 g / L, copper sulfate 15 g / L, sodium hypophosphite 100 g / L, sodium citrate 100 g / L, boric acid 10 g / L A plating solution was prepared by adjusting a mixed solution of polyethylene glycol 1000 (molecular weight: 1000) 2 g / L as a nonionic surfactant to pH 5 with sodium hydroxide. 2000 ml of this plating solution was added dropwise to the suspension obtained in Example 10 through a metering pump at an addition rate of 5 ml / min. The reaction temperature was set to 45 ° C. Thereafter, the mixture was stirred until the pH became stable, and it was confirmed that hydrogen foaming stopped.

  Thereafter, by filtering the suspension, the particles are taken out, washed with water, and dried to obtain conductive particles having a nickel-copper-phosphorus alloy conductive layer (thickness: 101 nm) disposed on the surface of the resin particles. It was. The conductive part in the obtained conductive particles had a plurality of polygonal columnar protrusions on the outer surface.

  Conductive particles were obtained in the same manner as in Example 10 except that the conductive part was formed by the above plating method.

(Example 12)
As electroless high-purity nickel plating solution, nickel chloride 55 g / L, hydrazine monohydrate 50 g / L, glycine 90 g / L, boric acid 20 g / L, and non-ionic surfactant polyethylene glycol 1000 ( (Molecular weight: 1000) A plating solution in which a mixed solution of 1 g / L was adjusted to pH 11 with sodium hydroxide was prepared. 1500 ml of this plating solution was added dropwise to the suspension obtained in Example 10 through a metering pump at an addition rate of 20 ml / min. The reaction temperature was set to 58 ° C. Thereafter, the mixture was stirred until the pH became stable, and it was confirmed that hydrogen foaming stopped.

  Thereafter, by filtering the suspension, the particles were taken out, washed with water, and dried to obtain conductive particles in which a high-purity Ni conductive layer (thickness: 103 nm) was arranged on the surface of the resin particles. The conductive part in the obtained conductive particles had a plurality of polygonal columnar protrusions on the outer surface.

  Conductive particles were obtained in the same manner as in Example 10 except that the conductive part was formed by the above plating method.

(Example 13)
As electroless palladium-nickel alloy plating solution, palladium chloride 40g / L, nickel sulfate 3g / L, hydrazine monohydrate 50g / L, ethylenediamine 5g / L, DL-malic acid 50g / L, stable A plating solution was prepared in which a mixed solution of 5 ml / L of an agent and 2 g / L of polyethylene glycol 1000 (molecular weight: 1000) as a nonionic surfactant was adjusted to pH 9 with sodium hydroxide. 1500 ml of this plating solution was added dropwise to the suspension obtained in Example 10 through a metering pump at an addition rate of 20 ml / min. The reaction temperature was set to 48 ° C. Thereafter, the mixture was stirred until the pH became stable, and it was confirmed that hydrogen foaming stopped.

  Thereafter, by filtering the suspension, the particles were taken out, washed with water, and dried to obtain conductive particles having a palladium-nickel alloy conductive layer (thickness: 100 nm) disposed on the surface of the resin particles. The conductive part in the obtained conductive particles had a plurality of polygonal columnar protrusions on the outer surface.

  Conductive particles were obtained in the same manner as in Example 10 except that the conductive part was formed by the above plating method.

(Example 14)
As electroless cobalt-nickel-phosphorus alloy plating solution, cobalt sulfate 50 g / L, nickel sulfate 10 g / L, sodium hypophosphite 100 g / L, ammonium sulfate 50 g / L, sodium pyrophosphate 35 g / L, A plating solution was prepared by adjusting a mixed solution of polyethylene glycol 1000 (molecular weight: 1000) 1 g / L as a nonionic surfactant to pH 9 with sodium hydroxide. 1400 ml of this plating solution was added dropwise to the suspension obtained in Example 10 through a metering pump at an addition rate of 20 ml / min. The reaction temperature was set to 60 ° C. Thereafter, the mixture was stirred until the pH became stable, and it was confirmed that hydrogen foaming stopped.

  Thereafter, by filtering the suspension, the particles are taken out, washed with water, and dried to obtain conductive particles in which a cobalt-nickel-phosphorus alloy conductive layer (thickness: 101 nm) is disposed on the surface of the resin particles. It was. The conductive part in the obtained conductive particles had a plurality of polygonal columnar protrusions on the outer surface.

  Conductive particles were obtained in the same manner as in Example 10 except that the conductive layer was formed by the above plating method.

(Example 15)
Core-shell type organic-inorganic hybrid particles (base material particles C) in which the surface of divinylbenzene copolymer resin particles having a particle diameter of 2.5 μm is coated with a silica shell (thickness 250 nm) using a condensation reaction by a sol-gel reaction. Obtained. Conductive particles in which a copper-nickel-phosphorus alloy conductive layer (thickness: 100 nm) is disposed on the surface of the organic-inorganic hybrid particles in the same manner as in Example 10 except that the base particle B is changed to the base particle C. Got. The conductive part in the obtained conductive particles had a plurality of polygonal columnar protrusions on the outer surface.

(Example 16)
Conductive particles were obtained in the same manner as in Example 10 except that the base material particle B was changed to the base material particle D which was different from the base material particle B only in particle size and had a particle size of 2.5 μm. Thus, the electroconductive particle by which the copper- nickel- phosphorus alloy conductive layer (thickness: 103 nm) was arrange | positioned on the surface of the resin particle was obtained. The conductive part in the obtained conductive particles had a plurality of polygonal columnar protrusions on the outer surface.

(Example 17)
Conductive particles were obtained in the same manner as in Example 10 except that the base particle B was changed to the base particle E which was different from the base particle B only in particle size and the particle size was 10.0 μm. Thus, the electroconductive particle by which the copper-nickel-phosphorus alloy conductive layer (thickness: 101 nm) was arrange | positioned on the surface of the resin particle was obtained. The conductive part in the obtained conductive particles had a plurality of polygonal columnar protrusions on the outer surface.

(Example 18)
In a 500 mL reaction vessel equipped with a stirrer and a thermometer, 300 g of a 0.13% by weight aqueous ammonia solution was placed. Next, 4.1 g of methyltrimethoxysilane, 19.2 g of vinyltrimethoxysilane, and 0.7 g of silicone alkoxy oligomer (“X-41-1053” manufactured by Shin-Etsu Chemical Co., Ltd.) in an aqueous ammonia solution in the reaction vessel. The mixture with was added slowly. After the hydrolysis and condensation reaction proceeded with stirring, 2.4 mL of a 25 wt% aqueous ammonia solution was added, and then the particles were isolated from the aqueous ammonia solution, and the resulting particles were subjected to an oxygen partial pressure of 10 ⁻¹⁷ atm. And calcination at 350 ° C. for 2 hours to obtain organic-inorganic hybrid particles (base particle F) having a particle size of 3.0 μm. Except having changed the said base particle B into the said base particle F, it carried out similarly to Example 10, and obtained the electroconductive particle by which the copper- nickel- phosphorus alloy conductive layer was arrange | positioned on the surface of the resin particle. The conductive part in the obtained conductive particles had a plurality of polygonal columnar protrusions on the outer surface.

(Example 19)
As the electroless nickel-boron alloy plating solution for forming the first conductive part, nickel sulfate 100 g / L, dimethylamine borane 80 g / L, plating stabilizer (bismuth compound) 10 ml / L, and sodium citrate 30 g / L A plating solution was prepared by adjusting the mixed solution with L to pH 6 with sodium hydroxide. 250 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 45 ° C. Thereafter, the mixture was stirred until the pH became stable, and it was confirmed that hydrogen foaming stopped.

  Thereafter, by filtering the suspension, the particles are taken out and washed with water, so that the conductive particles in which the nickel-boron alloy conductive layer (thickness: 52 nm) of the first conductive part is arranged on the surface of the resin particles. Obtained. A suspension was obtained by adding and dispersing conductive particles on which the first conductive part nickel-boron alloy conductive layer is disposed in 500 parts by weight of distilled water.

  Next, as an electroless copper-nickel-phosphorus alloy plating solution for forming a second conductive part, copper sulfate 50 g / L, nickel sulfate 5 g / L, sodium hypophosphite 100 g / L, and sodium citrate A plating solution was prepared by adjusting a mixed solution of 90 g / L, boric acid 10 g / L, and polyethylene glycol 1000 (molecular weight: 1000) 1 g / L as a nonionic surfactant to pH 9 with sodium hydroxide. 750 ml of this plating solution was added dropwise to the suspension through a metering pump at an addition rate of 10 ml / min. The reaction temperature was set at 55 ° C. Thereafter, the mixture was stirred until the pH became stable, and it was confirmed that hydrogen foaming stopped.

  Thereafter, by filtering the suspension, the particles are taken out, washed with water, and dried, whereby the copper-nickel-phosphorus alloy conductive layer (thickness: second conductive portion) is formed on the outer surface of the first conductive portion. 50 nm) was obtained. The conductive part in the obtained conductive particles had a plurality of polygonal columnar protrusions on the outer surface.

  Conductive particles were obtained in the same manner as in Example 10 except that the conductive part was formed by the above plating method.

(Example 20)
As the electroless copper plating solution for forming 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 is used as ammonia. A copper plating solution adjusted to pH 10.5 was prepared. 250 ml of this plating solution was added dropwise to the suspension through a metering pump at an addition rate of 10 ml / min. The reaction temperature was set to 65 ° C. Thereafter, the mixture was stirred until the pH became stable, and it was confirmed that hydrogen foaming stopped.

  Thereafter, by filtering the suspension, the particles were taken out and washed with water to obtain conductive particles in which the copper conductive layer (thickness: 53 nm) of the first conductive part was disposed on the surface of the resin particles. Suspension was obtained by adding the electroconductive particle by which the copper electroconductive layer of the 1st electroconductive part was arrange | positioned to 100 weight part of distilled water, and making it disperse | distribute. The suspension is 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 is filtered to obtain a copper conductive layer of the first conductive part. The arranged conductive particles were taken out. Next, the conductive particles on which the copper conductive layer of the first conductive part was disposed 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 part. The conductive particles on which the copper conductive layer of the first conductive part whose surface was activated were sufficiently washed, then added to 500 parts by weight of distilled water and dispersed to obtain a suspension.

  Next, as an electroless copper-nickel-phosphorus alloy plating solution for forming a second conductive part, copper sulfate 50 g / L, nickel sulfate 5 g / L, sodium hypophosphite 100 g / L, and sodium citrate A plating solution was prepared by adjusting a mixed solution of 90 g / L, boric acid 10 g / L, and polyethylene glycol 1000 (molecular weight: 1000) 1 g / L as a nonionic surfactant to pH 9 with sodium hydroxide. 750 ml of this plating solution was added dropwise to the suspension through a metering pump at an addition rate of 10 ml / min. The reaction temperature was set at 55 ° C. Thereafter, the mixture was stirred until the pH became stable, and it was confirmed that hydrogen foaming stopped.

  Thereafter, by filtering the suspension, the particles are taken out, washed with water, and dried, whereby the copper-nickel-phosphorus alloy conductive layer (thickness: second conductive portion) is formed on the outer surface of the first conductive portion. 53 nm) are obtained. The conductive part in the obtained conductive particles had a plurality of polygonal columnar protrusions on the outer surface.

  Conductive particles were obtained in the same manner as in Example 10 except that the conductive part was formed by the above plating method.

(Example 21)
As electroless copper-nickel-phosphorus alloy plating solution for forming the first conductive part, copper sulfate 50 g / L, nickel sulfate 5 g / L, sodium hypophosphite 100 g / L, and sodium citrate 90 g / L Then, a plating solution prepared by adjusting a pH of 9 to 10 g / L of boric acid and 1 g / L of polyethylene glycol 1000 (molecular weight: 1000) as a nonionic surfactant with sodium hydroxide was prepared. 1300 ml of this plating solution was added dropwise to the suspension through a metering pump at an addition rate of 10 ml / min. The reaction temperature was set at 55 ° C. Thereafter, the mixture was stirred until the pH became stable, and it was confirmed that hydrogen foaming stopped.

  Thereafter, the suspension is filtered to take out the particles, and the particles are washed with water, whereby the copper-nickel-phosphorus alloy conductive layer (thickness: 82 nm) of the first conductive part is disposed on the surface of the resin particles. Particles were obtained. A suspension was obtained by adding and dispersing conductive particles in which the copper-nickel-phosphorus alloy conductive layer of the first conductive portion was placed in 500 parts by weight of distilled water.

  Next, potassium gold cyanide 10 g / L, sodium citrate 45 g / L, ethylenediaminetetraacetic acid 5 g / L, and sodium hydroxide 20 g / L are used as the displacement gold plating solution for forming the second conductive portion. 500 ml of a gold plating solution (pH 6.0) was prepared.

  While stirring the resulting suspension at 45 ° C., 500 mL of the above gold plating solution was gradually added dropwise to the suspension to perform displacement gold plating.

  Thereafter, by filtering the suspension, the particles are taken out, washed with water, and dried, whereby the gold conductive layer (thickness: 14 nm) of the second conductive part is disposed on the outer surface of the first conductive part. Conductive particles were obtained. The conductive part in the obtained conductive particles had a plurality of polygonal columnar protrusions on the outer surface.

  Conductive particles were obtained in the same manner as in Example 10 except that the conductive part was formed by the above plating method.

(Example 22)
As electroless copper-nickel-phosphorus alloy plating solution for forming the first conductive part, copper sulfate 50 g / L, nickel sulfate 5 g / L, sodium hypophosphite 100 g / L, and sodium citrate 90 g / L Then, a plating solution prepared by adjusting a pH of 9 to 10 g / L of boric acid and 1 g / L of polyethylene glycol 1000 (molecular weight: 1000) as a nonionic surfactant with sodium hydroxide was prepared. 1300 ml of this plating solution was added dropwise to the suspension through a metering pump at an addition rate of 10 ml / min. The reaction temperature was set at 55 ° C. Thereafter, the mixture was stirred until the pH became stable, and it was confirmed that hydrogen foaming stopped.

  Thereafter, the suspension is filtered to take out the particles, and the particles are washed with water, whereby the copper-nickel-phosphorus alloy conductive layer (thickness: 82 nm) of the first conductive part is disposed on the surface of the resin particles. Particles were obtained. A suspension was obtained by adding and dispersing conductive particles in which the copper-nickel-phosphorus alloy conductive layer of the first conductive portion was placed in 500 parts by weight of distilled water.

  Next, as an electroless palladium plating solution for forming a second conductive part, a mixed solution of 12 g / L of palladium sulfate, 30 ml / L of ethylenediamine, 80 g / L of sodium formate, and 5 mg / L of sodium saccharinate is obtained. 500 ml of a plating solution adjusted to pH 8.0 with sulfuric acid was prepared.

  While stirring the obtained suspension at 50 ° C., 500 mL of the electroless palladium plating solution was gradually added dropwise to the suspension to perform electroless palladium plating.

  Thereafter, by filtering the suspension, the particles are taken out, washed with water, and dried, whereby the palladium conductive layer (thickness: 17 nm) of the second conductive part is disposed on the outer surface of the first conductive part. Conductive particles were obtained. The conductive part in the obtained conductive particles had a plurality of polygonal columnar protrusions on the outer surface.

  Conductive particles were obtained in the same manner as in Example 10 except that the conductive part was formed by the above plating method.

(Example 23)
As electroless copper-nickel-phosphorus alloy plating solution for forming the first conductive part, copper sulfate 50 g / L, nickel sulfate 5 g / L, sodium hypophosphite 100 g / L, and sodium citrate 90 g / L Then, a plating solution prepared by adjusting a pH of 9 to 10 g / L of boric acid and 1 g / L of polyethylene glycol 1000 (molecular weight: 1000) as a nonionic surfactant with sodium hydroxide was prepared. 1300 ml of this plating solution was added dropwise to the suspension through a metering pump at an addition rate of 10 ml / min. The reaction temperature was set at 55 ° C. Thereafter, the mixture was stirred until the pH became stable, and it was confirmed that hydrogen foaming stopped.

  Thereafter, the suspension is filtered, and the particles are taken out and washed with water, whereby a conductive layer in which the copper-nickel-phosphorus alloy conductive layer (thickness: 86 nm) of the first conductive portion is disposed on the surface of the resin particles. Particles were obtained. A suspension was obtained by adding and dispersing conductive particles in which the copper-nickel-phosphorus alloy conductive layer of the first conductive portion was placed in 500 parts by weight of distilled water.

  Next, as an electroless nickel-boron alloy plating solution for forming a second conductive part, nickel sulfate 15 g / L, dimethylamine borane 40 g / L, plating stabilizer (bismuth compound) 2 ml / L, and citric acid A plating solution in which a mixed solution of sodium 15 g / L was adjusted to pH 6 with sodium hydroxide was prepared. 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 45 ° C. Thereafter, the mixture was stirred until the pH became stable, and it was confirmed that hydrogen foaming stopped.

  Thereafter, the suspension is filtered to take out particles, washed with water, and dried to form a nickel-boron alloy conductive layer (thickness: 14 nm) of the second conductive part on the outer surface of the first conductive part. The electroconductive particle by which was arrange | positioned was obtained. The conductive part in the obtained conductive particles had a plurality of polygonal columnar protrusions on the outer surface.

  Conductive particles were obtained in the same manner as in Example 10 except that the conductive part was formed by the above plating method.

(Example 24)
Production of insulating particles:
To a 1000 mL separable flask equipped with a four-neck separable cover, stirring blade, three-way cock, condenser and temperature probe, 100 mmol of methyl methacrylate and N, N, N-trimethyl-N-2-methacryloyloxyethyl 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 under a nitrogen atmosphere. After completion of the reaction, it was freeze-dried to obtain insulating particles having an ammonium group on the surface, an average particle size of 220 nm, and a CV value of 10%.

  The insulating particles were dispersed in ion exchange water under ultrasonic irradiation to obtain a 10 wt% aqueous dispersion of insulating particles.

Production of conductive particles:
10 g of the conductive particles obtained in Example 10 were dispersed in 500 mL of ion exchange water, 4 g of an aqueous dispersion of insulating particles was added, and the mixture was stirred at room temperature for 6 hours. After filtration through a 3 μm mesh filter, the particles were further washed with methanol and dried to obtain conductive particles having insulating particles attached thereto.

  When observed with a scanning electron microscope (SEM), only one coating layer of insulating particles was formed on the surface of the conductive particles. The coverage of the insulating particles with respect to the area of 2.5 μm from the center of the conductive particles by image analysis (that is, the projected area of the particle diameter of the insulating particles) was calculated to be 30%.

(Comparative Example 1)
Organic-inorganic hybrid particles (base particle A) similar to Example 1 were prepared.

  The organic / inorganic hybrid particles were etched and washed with water. Next, organic-inorganic hybrid particles were added to 100 mL of a palladium-catalyzed solution containing 8% by weight of a palladium catalyst and stirred. Then, it filtered and wash | cleaned. Organic / inorganic hybrid particles were added to 0.5 wt% dimethylamine borane solution at pH 6 to obtain organic / inorganic hybrid particles to which palladium was attached.

  The organic-inorganic hybrid particles to which palladium was attached were stirred and dispersed in 300 mL of ion exchange water for 3 minutes to obtain a dispersion. Next, 1 g of nickel particle slurry (including spherical nickel particles and an average particle diameter of nickel as a core material of 100 nm) is added to the dispersion over 3 minutes to include organic-inorganic hybrid particles to which the core material is attached. A suspension was obtained.

  In addition, as an electroless nickel-phosphorus alloy plating solution, a mixed solution of nickel sulfate 450 g / L, sodium hypophosphite 150 g / L, sodium citrate 200 g / L, and plating stabilizer 5 ml / L is used as ammonia. A plating solution adjusted to pH 7 was prepared. 500 ml of this plating solution was added dropwise to the suspension through a metering pump at an addition rate of 15 ml / min. The reaction temperature was set to 60 ° C. Thereafter, the mixture was stirred until the pH became stable, and it was confirmed that hydrogen foaming stopped.

  Thereafter, by filtering the suspension, the particles are taken out, washed with water, and dried, whereby a nickel-phosphorus alloy conductive layer (thickness: 101 nm) is disposed on the surface of the organic-inorganic hybrid particles to which the core substance is attached. Conductive particles were obtained. The shape of the plurality of protrusions in the obtained conductive particles was a partial shape of a sphere.

(Comparative Example 2)
Divinylbenzene copolymer resin particles (base particle B, “Micropearl SP-203” manufactured by Sekisui Chemical Co., Ltd.) having a particle size of 3.0 μm were prepared.

  The divinylbenzene copolymer resin particles were etched and washed with water. Next, resin particles were added to 100 mL of a palladium-catalyzed solution containing 8% by weight of a palladium catalyst and stirred. Then, it filtered and wash | cleaned. Resin particles were added to 0.5 wt% dimethylamine borane solution at pH 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 exchange water for 3 minutes to obtain a dispersion. Next, 1 g of nickel particle slurry (including spherical nickel particles, average particle diameter of nickel as core material of 100 nm) is added to the dispersion over 3 minutes, and the suspension containing resin particles to which the core material is attached is added. A liquid was obtained.

  In addition, as an electroless nickel-phosphorus alloy plating solution, a mixed solution of nickel sulfate 650 g / L, sodium hypophosphite 150 g / L, sodium citrate 200 g / L, and plating stabilizer 5 ml / L is used as ammonia. The pH was adjusted to 7. 500 ml of this plating solution was added dropwise to the suspension through a metering pump at an addition rate of 15 ml / min. The reaction temperature was set to 60 ° C. Thereafter, the mixture was stirred until the pH became stable, and it was confirmed that hydrogen foaming stopped.

  Thereafter, by filtering the suspension, the particles are taken out, washed with water, and dried, whereby a nickel-phosphorus alloy conductive layer (thickness: 102 nm) is disposed on the surface of the organic-inorganic hybrid particles to which the core substance is attached. Conductive particles were obtained. The shape of the plurality of protrusions in the obtained conductive particles was a partial shape of a sphere.

(Comparative Example 3)
Conductive particles were obtained in the same manner as in Example 1 except that no protrusion was formed on the outer surface of the conductive portion and the outer shape of the conductive portion was spherical.

(Comparative Example 4)
Conductive particles were obtained in the same manner as in Example 2 except that no protrusion was formed on the outer surface of the conductive portion and the outer shape of the conductive portion was spherical.

(Evaluation)
(1) Evaluation of surface grating of conductive part Using an X-ray diffractometer ("RINT2500VHF" manufactured by Rigaku Corporation), the peak intensity ratio of diffraction lines specific to the apparatus depending on the diffraction angle was calculated. The ratio of the diffraction peak intensity in the (111) direction occupying the diffraction peak intensity of the entire diffraction line of the gold layer (the ratio of the (111) plane) was determined.

(2) Disposition accuracy (capture rate) of conductive particles on the electrode
The obtained conductive particles were added to “Strectbond XN-5A” manufactured by Mitsui Chemicals Co., Ltd. so as to have a content of 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 the upper surface was prepared. Moreover, the semiconductor chip which has a copper electrode pattern whose L / S is 30 micrometers / 30 micrometers on the lower surface was prepared.

  On the said transparent glass substrate, the anisotropic conductive paste immediately after preparation was applied so that it might become thickness of 30 micrometers, and the anisotropic conductive paste layer was formed. Next, the semiconductor chip was stacked on the anisotropic conductive paste layer so that the electrodes face each other. Then, 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 hardened | cured at 185 degreeC and the connection structure was obtained.

  In the obtained connection structure, the ratio (%) of the number of conductive particles arranged on the electrode was evaluated in 100% by weight of the total number of conductive particles included in the connection portion formed of the conductive material. . The arrangement accuracy of the conductive particles on the electrode was determined according to the following criteria.

[Judgment criteria for placement accuracy of conductive particles on electrode]
○○: The ratio of the number of conductive particles arranged on the electrode is 80% or more ○: The ratio of the number of conductive particles arranged on the electrode is 70% or more and less than 80% Δ: On the electrode Ratio of the number of conductive particles arranged is 60% or more and less than 70% ×: Ratio of the number of conductive particles arranged on the electrode is less than 60%

(3) Conduction reliability The connection resistance between the upper and lower electrodes of the 15 connection structures obtained in the evaluation of (2) above was measured by a four-terminal method. The average value of the two connection resistances was calculated. Note that the connection resistance can be obtained by measuring the voltage when a constant current is passed from the relationship of voltage = current × resistance. From the connection resistance, the conduction reliability was judged according to the following criteria.

[Judgment criteria for conduction reliability (connection resistance)]
○○: Average value of connection resistance is 8.0Ω or less ○: Average value of connection resistance exceeds 8.0Ω and 10.0Ω or less △: Average value of connection resistance exceeds 10.0Ω and 15.0Ω or less × : Average connection resistance exceeds 15.0Ω

(4) Insulation reliability Fifteen connection structures obtained by the evaluation in (2) above were allowed to stand at 85 ° C. and a humidity of 85% for 500 hours. In the connection structure after being allowed to stand, 5 V was applied between adjacent electrodes, the resistance value was measured at 25 locations, and the average value of the insulation resistance was calculated. Insulation reliability was judged according to the following criteria.

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

(5) Measurement of average height A of protrusions The obtained conductive particles were added to Kulzer “Technobit 4000” so that the content was 30% by weight, dispersed, and used for testing conductive particles. An embedding resin was produced. A cross section of the conductive particles was cut out using an ion milling device (“IM4000” manufactured by Hitachi High-Technologies Corporation) so as to pass through the vicinity of the center of the dispersed conductive resin in the test resin.

  Then, using a field emission transmission electron microscope (FE-TEM) (“JEM-ARM200F” manufactured by JEOL Ltd.), the image magnification is set to 50,000 times, and 20 conductive particles are randomly selected, The protrusion part of each electroconductive particle was observed. The height of the protrusions of the protrusions in the obtained conductive particles was measured, and was arithmetically averaged to obtain the average height A of the protrusions.

(6) Measurement of average diameter B of base of protrusions The obtained conductive particles were added to Kulzer's “Technobit 4000” so that the content was 30% by weight, and dispersed to conduct conductive particle inspection. An embedded resin was prepared. A cross section of the conductive particles was cut out using an ion milling device (“IM4000” manufactured by Hitachi High-Technologies Corporation) so as to pass through the vicinity of the center of the dispersed conductive resin in the test resin.

  Then, using a field emission transmission electron microscope (FE-TEM) (“JEM-ARM200F” manufactured by JEOL Ltd.), the image magnification is set to 50,000 times, and 20 conductive particles are randomly selected, The protrusion part of each electroconductive particle was observed. The base diameter of the protrusions of the protrusions in the obtained conductive particles was measured, and this was arithmetically averaged to obtain the average diameter B of the bases of the protrusions.

(7) Measurement of the ratio X of the number of protrusions having a polygonal columnar shape Using a scanning electron microscope (SEM), the image magnification is set to 25000 times, and 20 conductive particles are randomly selected. The protrusions of the conductive particles were observed. All the protrusions are evaluated as to whether or not the protrusion shape is a polygonal column, and are classified into a protrusion that is formed by a polygonal column and a protrusion that is not formed by a polygonal column. did. In this way, 1) the number of projections formed by a polygonal column per conductive particle and 2) the number of projections not formed by a polygonal column were measured. The ratio X of the number of protrusions that are 1) polygonal columns out of the total number of protrusions 1) and 2) was calculated.

  The results are shown in Table 1 below. In Table 1 below, the average height A of the plurality of protrusions, the average diameter B of the bases of the plurality of protrusions, and the number of protrusions in the shape of a polygonal column in the number of protrusions included in one conductive particle. The ratio X of

  In addition, when the electrode of the connection structure using the electroconductive particle of Examples 1-24 obtained by evaluation of said (1) and Comparative Examples 1 and 2 was confirmed, the electroconductive particle of Examples 1-24 was confirmed. The connection structure used was considerably less damaged than the connection structure using the conductive particles of Comparative Examples 1 and 2.

1, 1A, 1B, 1C ... conductive particles 1a, 1Aa, 1Ba, 1Ca ... projections 2 ... substrate particles 3, 3A, 3B ... conductive parts (conductive layers)
3a, 3Aa, 3Ba ... projection 3BA ... first conductive portion 3BB ... second conductive portion 3BBa ... projection 4 ... insulating material 51 ... connection structure 52 ... first connection target member 52a ... first electrode 53 ... 2nd connection object member 53a ... 2nd electrode 54 ... connection part

Claims (11)

Substrate particles,
A conductive portion disposed on the surface of the base particle,
The conductive portion is to have a plurality of protrusions are polygonal shaped on the outer surface, the conductive particles.   The electroconductive particle of Claim 1 whose average height of the said some protrusion is 10 nm or more and 500 nm or less.   The electroconductive particle of Claim 1 or 2 whose average diameter of the base part of several said processus | protrusion is 10 nm or more and 500 nm or less.   4. The conductive particle according to claim 1, wherein a ratio of an average height of the plurality of protrusions to an average diameter of a base portion of the plurality of protrusions is 0.1 or more and 5 or less.   The electroconductive particle of any one of Claims 1-4 whose shape of the said processus | protrusion is square columnar shape.   The conductive portion includes at least one selected from the group consisting of copper, nickel, palladium, cobalt, iron, ruthenium, platinum, silver, rhodium, iridium, gold, tungsten, molybdenum, phosphorus, and boron. The electroconductive particle of any one of -5.   The electroconductive particle of any one of Claims 1-6 whose ratio of the (111) plane in the X-ray diffraction of the said protrusion is 50% or more.   The electroconductive particle of any one of Claims 1-7 further provided with the insulating substance arrange | positioned on the outer surface of the said electroconductive part. A method for producing the conductive particles according to any one of claims 1 to 8,
Comprising a step of forming a conductive layer on the surface of the substrate particles,
A method for producing conductive particles, wherein when forming the conductive part, the conductive part is formed such that the conductive part has a plurality of polygonal columnar protrusions on an outer surface.   The electroconductive material containing the electroconductive particle of any one of Claims 1-8, and binder resin. A first connection target member;
A second connection target member;
A connection portion connecting the first connection target member and the second connection target member;
A connection structure in which the connecting portion is formed of the conductive particles according to any one of claims 1 to 8, or is formed of a conductive material containing the conductive particles and a binder resin.