JP2021057189A - Conductive particle, conductive material and connection structure - Google Patents

Abstract

To provide a conductive particle that can effectively reduce initial connection resistance after conductive connection and can improve conduction reliability after long-term use.SOLUTION: A conductive particle 1 has a conductive part 3 disposed on the surface of a base particle 2, and has at least two kinds of organic silicon functional groups on the external surface of the conductive part.EFFECT: As a result, the dispersibility of the conductive particle in a binder resin is improved, the entry of moisture is prevented, initial connection resistance is effectively reduced, and conduction reliability after long-term use is improved.SELECTED DRAWING: Figure 1

Description

The present invention relates to conductive particles that can be used for electrical connection between electrodes and the like. The present invention also relates to a conductive material and a connecting structure using the above conductive particles.

Anisotropic conductive materials such as anisotropic conductive pastes and anisotropic conductive films are widely known. In the anisotropic conductive material, conductive particles are dispersed in the binder resin. Further, as the conductive particles, conductive particles having a base material particles and a conductive portion arranged on the surface of the base material particles may be used.

The anisotropic conductive material is used to obtain various connection structures. Connections using the anisotropic conductive material include a connection between a flexible printed circuit board and a glass substrate (FOG (Film on Glass)), a connection between a semiconductor chip and a flexible printed circuit board (COF (Chip on Film)), and a semiconductor chip. The connection between the glass substrate and the glass substrate (COG (Chip on Glass)), the connection between the flexible printed circuit board and the glass epoxy substrate (FOB (Film on Board)), and the like can be mentioned.

The conductive particles that can be used for the anisotropic conductive material are disclosed in Patent Documents 1 to 3 below.

Patent Document 1 below discloses conductive particles including base particles and a conductive layer provided on the surface of the base particles. The conductive layer has a structure in which a metal layer containing nickel and a conductive layer containing gold or palladium are sequentially laminated. The thickness of the conductive layer is 10 nm or less. The conductive particles have an alkyl group having 6 to 22 carbon atoms on the surface. Since the conductive particles have an alkyl group having 6 to 22 carbon atoms on the surface, the surface of the conductive particles is hydrophobic. Patent Document 1 describes that even if the nickel-containing metal layer is exposed, the metal layer is less likely to be corroded and the connection resistance of the conductive particles is prevented from increasing.

Patent Document 2 below includes a conductive particle main body having resin particles, a conductive layer provided on the surface of the resin particles, and a coating layer covering the surface of the conductive particle main body. Conductive particles are disclosed. The coating layer is formed by cross-linking an organic silicon compound. Patent Document 2 describes that the hydrophilicity of the surface of the conductive particles can be enhanced, and that the dispersibility of the conductive particles can be enhanced with respect to an oxygen-containing resin such as an epoxy resin. ..

Patent Document 3 below discloses conductive particles having at least particles whose surface is a conductive portion and a coating film arranged on the outer surface of the conductive portion. The coating has a non-polar group and a polar group. In Patent Document 3, when the electrodes are connected using the conductive particles, the conduction reliability between the electrodes can be improved, and the conductive particles can be well dispersed in the binder resin. It is stated that it can be done.

Japanese Unexamined Patent Publication No. 2010-0866664 Japanese Unexamined Patent Publication No. 2012-003917 Japanese Unexamined Patent Publication No. 2013-214509

In Patent Document 1, since the surface of the conductive particles has an alkyl group having 6 to 22 carbon atoms on the surface, the surface of the conductive particles is hydrophobic, so that the initial connection resistance after the conductive connection is lowered to some extent. It is possible to further improve the conductivity reliability after long-term use to some extent. Further, in Patent Documents 2 and 3, since the dispersibility of the conductive particles can be improved, the initial connection resistance after the conductive connection can be lowered to some extent, and the conduction reliability after long-term use can be improved to some extent. be able to.

However, in recent years, the density and performance of electronic devices have been increasing, and further reduction of connection resistance and further improvement of conduction reliability are required.

In Patent Document 1, since the dispersibility of the conductive particles in the binder resin is low, it is difficult to considerably improve the conduction reliability. The reason for this is that moisture easily penetrates into the interface between the conductive particles and the binder resin.

Even in Patent Documents 2 and 3, it is difficult to achieve both a considerably low initial connection resistance and a considerably high conduction reliability.

An object of the present invention is to provide conductive particles capable of enhancing conduction reliability after long-term use. A limited object of the present invention is to provide conductive particles capable of effectively lowering the initial connection resistance after conductive connection and further enhancing conduction reliability after long-term use. Another object of the present invention is to provide a conductive material and a connecting structure using the above conductive particles.

According to a broad aspect of the present invention, conductive particles having a conductive portion and having at least two kinds of organic silicon functional groups on the outer surface of the conductive portion are provided.

In a specific aspect of the conductive particles according to the present invention, the outer surface of the conductive portion has an organic silicon functional group having a (meth) acryloyl group.

In a specific aspect of the conductive particles according to the present invention, the outer surface of the conductive portion has an organic silicon functional group having an epoxy group.

In a specific aspect of the conductive particles according to the present invention, the outer surface of the conductive portion has an organic silicon functional group having an alkyl group having 1 or more and 22 or less carbon atoms.

In a specific aspect of the conductive particles according to the present invention, the outer surface of the conductive portion has an organic silicon functional group having a rust preventive effect.

In a specific aspect of the conductive particles according to the present invention, the organic silicon functional group having a rust preventive effect is an organic silicon functional group having a benzotriazole group.

In a specific aspect of the conductive particles according to the present invention, the outer surface of the conductive portion has an organic silicon functional group having a rust preventive effect, an organic silicon functional group having a (meth) acryloyl group, and an organic having an epoxy group. It has at least one organic silicon functional group among the silicon functional groups.

In a specific aspect of the conductive particles according to the present invention, the organic silicon functional group having the (meth) acryloyl group and the organic silicon functional group having the epoxy group of the number of the organic silicon functional groups having the rust preventive effect. The ratio to the total number of is 0.05 or more and 0.95 or less.

In a specific aspect of the conductive particles according to the present invention, the outer surface of the conductive portion has an organic silicon functional group having a (meth) acryloyl group and an organic silicon functional group having an epoxy group.

In a specific aspect of the conductive particles according to the present invention, the surface area covered with at least two kinds of organic silicon functional groups is 60% or more and 100% or less in the surface area of the conductive portion.

In a specific aspect of the conductive particles according to the present invention, the conductive particles include a base material particle and a conductive portion arranged on the surface of the base material particle.

In certain aspects of the conductive particles according to the present invention, the conductive particles have protrusions on the outer surface of the conductive portion.

In certain aspects of the conductive particles according to the present invention, the conductive particle body comprises an insulating material disposed on the outer surface of the conductive portion.

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

According to a broad aspect of the present invention, a first connection target member having a first electrode on the surface, a second connection target member having a second electrode on the surface, the first connection target member, and the above. It is provided with a connecting portion connecting the second connection target member, and the material of the connecting portion is the above-mentioned conductive particles or a conductive material containing the conductive particles and a binder resin. Provided is a connection structure in which the first electrode and the second electrode are electrically connected by the conductive particles.

The conductive particles according to the present invention have a conductive portion and have at least two kinds of organic silicon functional groups on the outer surface of the conductive portion. Since the conductive particles according to the present invention have the above-mentioned structure, the conduction reliability after long-term use can be improved.

FIG. 1 is a cross-sectional view showing conductive particles according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view showing conductive particles according to a second embodiment of the present invention. FIG. 3 is a cross-sectional view showing conductive particles according to a third embodiment of the present invention. FIG. 4 is a cross-sectional view showing conductive particles according to a 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.

The details of the present invention will be described below.

(Conductive particles)
The conductive particles according to the present invention have a conductive portion, and have at least two kinds of organic silicon functional groups on the outer surface of the conductive portion.

Since the conductive particles according to the present invention have the above-mentioned structure, the initial connection resistance can be effectively lowered after the conductive connection, and the conduction reliability after long-term use can be improved. ..

The "organic silicon functional group" includes a carbon atom and a silicon atom. The organic silicon functional group is represented by, for example, the following formula (1).

In the above formula (1), X1, X2 and X3 independently represent a non-hydrolyzable group, a hydrolyzable group, another organic silicon functional group or a hydrogen atom. Also, at least one of X1, X2 and X3 is a non-hydrolyzable group. When X1, X2 or X3 is an organic silicon functional group, for example, two silicons are connected via a siloxane bond in which two Sis are connected via −O− or a chemical bond such as −Si−Si−. It refers to a state in which different organic silicon functional groups are connected starting from an atom. X1, X2 and X3 may be the same or different. Further, the remaining bonds that are not bonded to any of the Si atoms X1, X2, and X3 are bonded to the outer surface of the conductive portion itself or a substance (coating or the like) arranged on the outer surface of the conductive portion.

Examples of the hydrolyzable group include an alkoxy group and the like. Specific examples of the alkoxy group include an alkoxy group having 1 to 6 carbon atoms. Examples of the alkoxy group having 1 to 6 carbon atoms include a methoxy group, an ethoxy group and a propoxy group.

The hydrolyzable group may be a hydrolyzable group other than the alkoxy group. Specific examples of the hydrolyzable group other than the alkoxy group include a halogen group such as chlorine or bromine, an acetyl group, a hydroxyl group and an isocyanate group.

Examples of the non-hydrolyzable organic group include an organic group having 1 to 30 carbon atoms, which is a stable hydrophobic group that is difficult to be hydrolyzed.

Examples of the organic group having 1 to 30 carbon atoms include an alkyl group having 1 to 30 carbon atoms, an alkyl halide group, an aromatic substituted alkyl group, an aryl group, an organic group containing a vinyl group, and an organic group containing an epoxy group. Meta) Examples thereof include an organic group containing an acryloyl group, an organic group containing a benzotriazole group, an organic group containing an amino group, and an organic group containing a thiol group.

Examples of the alkyl group having 1 to 30 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, a cyclohexyl group, an octyl group, a pentyl group, a decyl group, a dodecyl group, a tetradecyl group, a hexadecyl group and an octadecyl group. And an eikosyl group and the like. Examples of the alkyl halide group include a fluorinated group of an alkyl group, a chlorinated group of an alkyl group, and a brominated group of an alkyl group. Specific examples of the above alkyl halide group include, for example, 3-chloropropyl group, 6-chloropropyl group, 6-chlorohexyl group, 6,6,6-trifluorohexyl group and the like. Examples of the aromatic-substituted alkyl group include a benzyl group and a halogen-substituted benzyl group. Examples of the halogen-substituted benzyl group include a 4-chlorobenzyl group and a 4-bromobenzyl group. Examples of the aryl group include a phenyl group, a tolyl group, a mesityl group, a naphthyl group and the like.

At least two kinds of the organic silicon functional groups can be introduced by using at least two kinds of organic silicon compounds. At least two kinds of the above-mentioned organic silicon functional groups may be introduced by reacting at least two kinds of organic silicon compounds respectively. Using the first organic silicon compound and the second organic silicon compound, a first organic silicon functional group derived from the first organic silicon compound and a second organic silicon derived from the second organic silicon compound are used. A functional group may be introduced. The first organic silicon compound, the second organic silicon compound, and the third organic silicon compound are used to form a first organic silicon functional group derived from the first organic silicon compound and a second organic silicon compound. A second organic silicon functional group derived from the organic silicon functional group and a third organic silicon functional group derived from the third organic silicon compound may be introduced. A first organic silicon compound, a second organic silicon compound, a third organic silicon compound, and a fourth organic silicon compound may be used. In this case, the first organic silicon functional group derived from the first organic silicon compound, the second organic silicon functional group derived from the second organic silicon compound, and the second organic silicon functional group derived from the third organic silicon compound. The organic silicon functional group of 3 and the 4th organic silicon functional group derived from the 4th organic silicon compound may be introduced. The first organic silicon functional group and the second organic silicon functional group may be a reaction product of the first organic silicon compound and the second organic silicon compound. The first organic silicon functional group, the second organic silicon functional group, and the third organic silicon functional group are a reaction product of the first organic silicon compound, the second organic silicon compound, and the third organic silicon compound. It may be. The first organic silicon functional group, the second organic silicon functional group, the third organic silicon functional group, and the fourth organic silicon functional group are the first organic silicon compound, the second organic silicon compound, and the third organic silicon compound. It may be a reaction product of an organic silicon compound and a fourth organic silicon compound.

Specific examples of the organic silicon compound include triphenylethoxysilane, trimethylethoxysilane, triethylethoxysilane, triphenylmethoxysilane, triethylmethoxysilane, ethyldimethylmethoxysilane, methyldiethylmethoxysilane, ethyldimethylethoxysilane, and methyl. Diethylethoxysilane, phenyldimethylmethoxysilane, phenyldiethylmethoxysilane, phenyldimethylethoxysilane, phenyldiethylethoxysilane, methyldiphenylmethoxysilane, ethyldiphenylmethoxysilane, methyldiphenylethoxysilane, ethyldiphenylethoxysilane, tert-butoxytrimethylsilane, Butoxytrimethylsilane, dimethylethoxysilane, methoxydimethylvinylsilane, ethoxydimethylvinylsilane, diphenyldiethoxylan, phenyldiethoxysilane, dimethyldimethoxysilane, diacetoxymethylsilane, diethoxymethylsilane, 3-chloropropyldimethoxymethylsilane, chloromethyl Diethoxymethylsilane, diethoxydimethylsilane, diacetoxymethylvinylsilane, diethoxymethylvinylsilane, diethoxydiethylsilane, dimethyldipropoxysilane, dimethoxymethylphenylsilane, methyltrimethoxysilane, methyltriethoxysilane, methyl-tri-n -Propoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyl-tri-n-propoxysilane, propyltrimethoxysilane, propyltriethoxysilane, propyl-tri-n-propoxysilane, butyltrimethoxysilane, butyltriethoxy Silane, butyltripropoxysilane, isobutyltrimethoxysilane, isobutyltriethoxysilane, isobutyltripropoxysilane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, n-hexyltripropoxysilane, cyclohexyltrimethoxysilane, cyclohexyltri Ethoxysilane, cyclohexyltripropoxysilane, octyltrimethoxysilane, octyltriethoxysilane, octyllipopoxysilane, dodecyltrimethoxysilane, dodecyltriethoxysilane, dodecyltripropoxysilane, tetradecyltrimethoxysilane, tetradecyltriethoxysilane, Tetradecyltripropoxysilane, hexa Decyltrimethoxysilane, hexadecyltriethoxysilane, hexadecyltripropoxysilane, octadecyltrimethoxysilane, octadecyltriethoxysilane, octadecyltripropoxysilane, eicosyldecyltrimethoxysilane, eicosyltriethoxysilane, eicosyltripropoxysilane , 6-Chlorohexyltrimethoxysilane, 6,6,6-trifluorohexyltrimethoxysilane, benzyltrimethoxysilane, 4-chlorobenzyltrimethoxysilane, 4-bromobenzyltri-n-propoxysilane, phenyltrimethoxysilane , Phenyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxy Silane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacry Loxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N -2- (Aminoethyl) -3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propyl Amin, N-phenyl-3-aminopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-isocyanabyl Triethoxysilane, triethoxysilane, trimethoxysilane, triisopropoxysilane, tri-n-propoxysilane, triacetoxysilane, tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetraisopropoxysilane and tetraacetoxy Examples include silane.

At least two kinds of the organic silicon functional groups may be bonded to each other. At least two kinds of the organic silicon functional groups may be linked by a siloxane bond.

In a binder resin containing an acrylic resin as a main component, from the viewpoint of improving the adhesion at the interface between the conductive particles and the binder resin and further enhancing the connection reliability, the conductive particles are the outer surface of the conductive portion. It is preferable to have an organic silicon functional group having a (meth) acryloyl group. In this case, the conductive particles further have an organic silicon functional group other than the organic silicon functional group having a (meth) acryloyl group on the outer surface of the conductive portion. The organic silicon functional group having a (meth) acryloyl group is preferably introduced by an organic silicon compound having a (meth) acryloyl group. The organic silicon functional group having a (meth) acryloyl group is preferably an organic silicon functional group derived from an organic silicon compound having a (meth) acryloyl group. The organic silicon functional group having a (meth) acryloyl group preferably has a (meth acryloyl group) bonded to a silicon atom.

Examples of the organic silicon compound having a (meth) acryloyl group include 3-methacryloxypropyltrimethoxysilane, 3-acryloxytrimethoxysilane, and 8-methacryloxytrimethoxysilane.

In a binder resin containing an epoxy resin as a main component, from the viewpoint of improving the adhesion at the interface between the conductive particles and the binder resin and further enhancing the connection reliability, the conductive particles are the outer surface of the conductive portion. It is preferable to have an organic silicon functional group having an epoxy group. In this case, the conductive particles further have an organic silicon functional group other than the organic silicon functional group having an epoxy group on the outer surface of the conductive portion. The organic silicon functional group having an epoxy group is preferably introduced by an organic silicon compound having an epoxy group. The organic silicon functional group having an epoxy group is preferably an organic silicon functional group derived from an organic silicon compound having an epoxy group. The organic silicon functional group having an epoxy group preferably has an epoxy group bonded to a silicon atom.

Examples of the organic silicon compound having an epoxy group include 3-glycidoxypropyltrimethoxysilane, 2- (3,4-epoxidecyclohexyl) ethyltrimethoxysilane, and 8-glycidoxyoctyltrimethoxysilane.

In a binder resin containing an acrylic resin and an epoxy resin, the conductive particles are outside the conductive portion from the viewpoint of improving the adhesion at the interface between the conductive particles and the binder resin and further enhancing the connection reliability. It is preferable to have an organic silicon functional group having a (meth) acryloyl group and an organic silicon functional group having an epoxy group on the surface.

From the viewpoint of further improving the connection reliability by improving the corrosion resistance on the surface of the conductive particles and preventing deterioration, the conductive particles have an alkyl group having 1 or more and 22 or less carbon atoms on the outer surface of the conductive portion. It is preferable to have an organic silicon functional group having. In this case, the conductive particles further have an organic silicon functional group other than the organic silicon functional group having an alkyl group having 1 to 22 carbon atoms or less on the outer surface of the conductive portion. In the organic silicon functional group having an alkyl group having 1 or more and 22 or less carbon atoms, the alkyl group has 1 or more and 22 or less carbon atoms. From the viewpoint of further improving the corrosion resistance on the surface of the conductive particles and further enhancing the conduction reliability after long-term use by preventing deterioration, the number of carbon atoms of the alkyl group is preferably 3 or more, preferably 18 or less.

From the viewpoint of further improving the conductivity reliability after long-term use by improving the corrosion resistance on the surface of the conductive particles and preventing deterioration, the conductive particles are organic silicon having a rust preventive effect on the outer surface of the conductive portion. It preferably has a functional group. In this case, the conductive particles further have an organic silicon functional group other than the organic silicon functional group having a rust preventive effect on the outer surface of the conductive portion. The organic silicon functional group having a rust preventive effect is preferably introduced by an organic silicon compound having a group having a rust preventive effect. The organic silicon functional group having a rust preventive effect is preferably an organic silicon functional group derived from an organic silicon compound having a group having a rust preventive effect. The organic silicon functional group having a rust preventive effect preferably has a group having a rust preventive effect bonded to a silicon atom.

Examples of the organic silicon compound having a group having a rust preventive effect include benzotriazolemethyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, and trifluoropropyltrimethoxysilane.

Examples of the group having a rust preventive effect include a benzotriazole group, a mercapto group, a trifluoroalkyl group and the like.

From the viewpoint of further enhancing the conduction reliability after long-term use, the organic silicon functional group having a rust preventive effect is preferably an organic silicon functional group having a benzotriazole group. The organic silicon functional group having a benzotriazole group is preferably introduced by an organic silicon compound having a benzotriazole group. The organic silicon functional group having a benzotriazole group is preferably an organic silicon functional group derived from an organic silicon compound having a benzotriazole group. The organic silicon functional group having a benzotriazole group preferably has a benzotriazole group bonded to a silicon atom.

From the viewpoint of improving the adhesion of the interface between the conductive particles and the binder resin, improving the corrosion resistance on the surface of the conductive particles and further improving the conduction reliability after long-term use by preventing deterioration, the conductive particles are used. On the outer surface of the conductive portion, an organic silicon functional group having a rust preventive effect, and at least one of an organic silicon functional group having a (meth) acryloyl group and an organic silicon functional group having an epoxy group are used. It is preferable to have.

The ratio of the number of organic silicon functional groups having a rust preventive effect to the total number of the organic silicon functional groups having the (meth) acryloyl group and the organic silicon functional groups having the epoxy group is defined as the ratio (X). .. The ratio (X) is preferably 0.05 or more, more preferably 0.10 or more, from the viewpoint of further improving the corrosion resistance on the surface of the conductive particles and further improving the conduction reliability after long-term use by preventing deterioration. It is preferably 0.95 or less, more preferably 0.90 or less.

The ratio of the number of the organic silicon functional groups having the benzotriazole group to the total number of the organic silicon functional groups having the (meth) acryloyl group and the organic silicon functional groups having the epoxy group is defined as the ratio (X1). .. From the viewpoint of further improving the connection reliability by improving the corrosion resistance on the surface of the conductive particles and preventing deterioration, the above ratio (X1) is preferably 0.05 or more, more preferably 0.10 or more, preferably 0. It is .95 or less, more preferably 0.90 or less.

Among the above-mentioned organic silicon functional groups, the organic silicon functional group having a benzotriazole group mainly plays a role of improving corrosion resistance and preventing deterioration on the surface of conductive particles, and enhances conduction reliability after long-term use. ..

Among the above-mentioned organic silicon functional groups, the organic silicon functional group having a (meth) acryloyl group or an epoxy group mainly plays a role of improving the adhesion between the surface of the conductive particles and the interface of the binder resin, and connects them. Increase reliability.

By introducing an organic silicon functional group having a different role, the initial connection resistance can be further effectively lowered after the conductive connection, and the conduction reliability after long-term use can be further improved.

From the viewpoint of further lowering the initial connection resistance after the conductive connection and further enhancing the conduction reliability after long-term use, the surface area of the conductive portion is 100% covered with at least two kinds of the organic silicon functional groups. The surface area is preferably 60% or more, more preferably 80% or more, and preferably 100% or less. Of the 100% surface area of the conductive portion, the surface area covered with at least two kinds of organic silicon functional groups may be 97.5% or less, or 95% or less.

The particle size of the conductive particles is preferably 0.1 μm or more, more preferably 1 μm or more, preferably 1000 μm or less, more preferably 100 μm or less, still more preferably 10 μm or less. When the particle diameter of the conductive particles is equal to or greater than the above lower limit and equal to or less than the above upper limit, the contact area between the conductive particles and the electrodes becomes sufficiently large when the electrodes are connected using the conductive particles. Moreover, it becomes difficult to form agglomerated conductive particles when forming the conductive portion. In addition, the distance between the electrodes connected via the conductive particles does not become too large, and the conductive portion does not easily peel off from the surface of the substrate particles.

The particle size of the conductive particles is preferably an average particle size, and preferably a number average particle size. For the particle size of the conductive particles, for example, 50 arbitrary conductive particles are observed with an electron microscope or an optical microscope, the average value of the particle size of each conductive particle is calculated, or a particle size distribution measuring device is used. Obtained using. In observation with an electron microscope or an optical microscope, the particle size of each conductive particle is determined as the particle size in a circle-equivalent diameter. In observation with an electron microscope or an optical microscope, the average particle diameter of any 50 conductive particles in a circle-equivalent diameter is substantially equal to the average particle diameter in a sphere-equivalent diameter. In the particle size distribution measuring device, the particle size of each conductive particle is obtained as the particle size in the equivalent diameter of a sphere. The average particle size of the conductive particles is preferably calculated using a particle size distribution measuring device.

The coefficient of variation (CV value) of the particle size of the conductive particles is preferably 10% or less, more preferably 5% or less. When the coefficient of variation of the particle size of the conductive particles is not more than the above upper limit, the conduction reliability and the insulation reliability between the electrodes can be further effectively improved.

The coefficient of variation (CV value) can be measured as follows.

CV value (%) = (ρ / Dn) × 100
ρ: Standard deviation of particle size of conductive particles Dn: Mean value of particle size of conductive particles

The shape of the conductive particles is not particularly limited. The shape of the conductive particles may be spherical, non-spherical, flat or the like.

Hereinafter, the present invention will be specifically described with reference to the drawings. In addition, in FIG. 1 and the figure described later, different parts can be replaced with each other.

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

The conductive particle 1 shown in FIG. 1 has a base particle 2 and a conductive portion 3. The conductive portion 3 is arranged on the surface of the base particle 2. In the first embodiment, the conductive portion 3 is in contact with the surface of the base particle 2. The conductive particles 1 are coated particles in which the surface of the base particle 2 is coated with the conductive portion 3.

In the conductive particles 1, the conductive portion 3 is a single-layer conductive layer. In the conductive particles, the conductive portion may cover the entire surface of the base material particles, or the conductive portion may cover a part of the surface of the base material particles. In the conductive particles, the conductive portion may be a single-layer conductive layer or a multi-layer conductive layer composed of two or more layers.

The conductive particles 1 do not have a core substance, unlike the conductive particles 11 and 21 described later. The conductive particles 1 have no protrusions on the surface. The conductive particles 1 are spherical. The conductive portion 3 has no protrusion on the outer surface. As described above, the conductive particles according to the present invention do not have to have protrusions on the conductive surface, and may be spherical. Further, the conductive particles 1 do not have an insulating substance, unlike the conductive particles 11 and 21 described later. However, the conductive particles 1 may have an insulating substance arranged on the outer surface of the conductive portion 3.

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

The conductive particle 11 shown in FIG. 2 has a base particle 2, a conductive portion 12, a plurality of core substances 13, and a plurality of insulating substances 14. The conductive portion 12 is arranged on the surface of the base particle 2 so as to be in contact with the base particle 2.

In the conductive particles 11, the conductive portion 12 is a single-layer conductive layer. In the conductive particles, the conductive portion may cover the entire surface of the base material particles, or the conductive portion may cover a part of the surface of the base material particles. In the conductive particles, the conductive portion may be a single-layer conductive layer or a multi-layer conductive layer composed of two or more layers.

The conductive particles 11 have a plurality of protrusions 11a on the conductive surface. The conductive portion 12 has a plurality of protrusions 12a on the outer surface. A plurality of core substances 13 are arranged on the surface of the base particle 2. The plurality of core substances 13 are embedded in the conductive portion 12. The core material 13 is arranged inside the protrusions 11a and 12a. The conductive portion 12 covers a plurality of core substances 13. The outer surface of the conductive portion 12 is raised by the plurality of core substances 13, and protrusions 11a and 12a are formed.

The conductive particles 11 have an insulating substance 14 arranged on the outer surface of the conductive portion 12. At least a part of the outer surface of the conductive portion 12 is covered with the insulating substance 14. The insulating substance 14 is formed of an insulating material and is an insulating particle. As described above, the conductive particles according to the present invention may have an insulating substance arranged on the outer surface of the conductive portion. However, the conductive particles according to the present invention do not necessarily have an insulating substance.

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

The conductive particle 21 shown in FIG. 3 has a base particle 2, a conductive portion 22, a plurality of core substances 13, and a plurality of insulating substances 14. As a whole, the conductive portion 22 has a first conductive portion 22A on the base particle 2 side and a second conductive portion 22B on the side opposite to the base particle 2 side.

Only the conductive portion is different between the conductive particles 11 and the conductive particles 21. That is, in the conductive particles 11, the conductive portion 12 having a one-layer structure is formed, whereas in the conductive particles 21, the first conductive portion 22A and the second conductive portion 22B having a two-layer structure are formed. ing. The first conductive portion 22A and the second conductive portion 22B are formed as separate conductive portions.

The first conductive portion 22A is arranged on the surface of the base particle 2. The first conductive portion 22A is arranged between the base particle 2 and the second conductive portion 22B. The first conductive portion 22A is in contact with the base particle 2. The second conductive portion 22B is in contact with the first conductive portion 22A. Therefore, the first conductive portion 22A is arranged on the surface of the base particle 2, and the second conductive portion 22B is arranged on the surface of the first conductive portion 22A. The conductive particles 21 have a plurality of protrusions 21a on the conductive surface. The conductive portion 22 has a plurality of protrusions 22a on the outer surface. The first conductive portion 22A has a plurality of protrusions 22Aa on the outer surface. The second conductive portion 22B has a plurality of protrusions 22Ba on the outer surface.

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

The conductive particles 31 shown in FIG. 4 are entirely conductive portions. Both the central portion and the surface portion of the conductive particles 31 are formed by conductive portions. The conductive particles 31 do not have base particles.

The conductive particles 1, 11 and 21 have at least two kinds of organic silicon functional groups on the outer surfaces of the conductive portions 3, 12 and 22. The conductive particle 31 which is a conductive portion has at least two kinds of organic silicon functional groups on the outer surface. At least two kinds of organic silicon functional groups may be formed as a film arranged on the outer surface of the conductive portion.

Hereinafter, other details of the conductive particles will be described.

(Base particles)
The material of the base particle is not particularly limited. The material of the base particle may be an organic material or an inorganic material. Examples of the base particle formed from the organic material alone include resin particles and the like. Examples of the base particle formed only of the above-mentioned inorganic material include inorganic particles excluding metal. Examples of the base particle formed by both the organic material and the inorganic material include organic-inorganic hybrid particles. From the viewpoint of further lowering the initial connection resistance and further increasing the conduction reliability, the base material particles are preferably resin particles or organic-inorganic hybrid particles, and more preferably resin particles.

The base material particles do not have to be metal particles.

Examples of the organic material include polyolefin resins such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyisobutylene and polybutadiene; acrylic resins such as polymethylmethacrylate and polymethylacrylate; polycarbonate, polyamide, phenolformaldehyde resin and melamine. Formaldehyde resin, benzoguanamine formaldehyde resin, urea formaldehyde resin, phenol resin, melamine resin, benzoguanamine resin, urea resin, epoxy resin, unsaturated polyester resin, saturated polyester resin, polyethylene terephthalate, polysulfone, polyphenylene oxide, polyacetal, polyimide, polyamideimide, Examples thereof include polyether ether ketone, polyether sulfone, divinylbenzene polymer, and divinylbenzene copolymer. Examples of the divinylbenzene copolymer and the like include a divinylbenzene-styrene copolymer and a divinylbenzene- (meth) acrylic acid ester copolymer. Since the compression characteristics of the base particle can be easily controlled within a suitable range, the material of the base particle is a polymer obtained by polymerizing one or more polymerizable monomers having an ethylenically unsaturated group. Is preferable.

When the base material particles are obtained by polymerizing a polymerizable monomer having an ethylenically unsaturated group, the polymerizable monomer having an ethylenically unsaturated group is crosslinked with a non-crosslinkable monomer. Examples include sex monomers.

Examples of the non-crosslinkable monomer include styrene monomers such as styrene, α-methylstyrene, and chlorostyrene; vinyl ether compounds such as methylvinyl ether, ethylvinyl ether, and propylvinyl ether; vinyl acetate, vinyl butyrate, and the like. Acid vinyl ester compounds such as vinyl laurate and vinyl stearate; halogen-containing monomers such as vinyl chloride and vinyl fluoride; as (meth) acrylic compounds, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) ) Acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate and other alkyl ( Meta) acrylate compound; oxygen atom-containing (meth) acrylate compound such as 2-hydroxyethyl (meth) acrylate, glycerol (meth) acrylate, polyoxyethylene (meth) acrylate, glycidyl (meth) acrylate; Nitrile-containing monomer; Halogen-containing (meth) acrylate compound such as trifluoromethyl (meth) acrylate and pentafluoroethyl (meth) acrylate; As α-olefin compound, olefin such as diisobutylene, isobutylene, linearene, ethylene and propylene Compound: Examples of the conjugated diene compound include isoprene and butadiene.

Examples of the crosslinkable monomer include vinyl monomers such as divinylbenzene, 1,4-dibinyloxybutane, and divinylsulfone as vinyl compounds; and tetramethylolmethanetetra (meth) acrylate as (meth) acrylic compounds. , Polytetramethylene glycol diacrylate, Tetramethylolmethanetri (meth) acrylate, Tetramethylolmethanedi (meth) acrylate, Trimethylolpropanetri (meth) acrylate, Dipentaerythritol hexa (meth) acrylate, Dipentaerythritol penta (meth) ) Acrylic, glycerol tri (meth) acrylate, glycerol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, polytetramethylene glycol di (meth) acrylate, 1,4-butanediol di Polyfunctional (meth) acrylate compounds such as (meth) acrylate; as allyl compounds, triallyl (iso) cyanurate, triallyl trimellitate, diallylphthalate, diallylacrylamide, diallyl ether; as silane compounds, tetramethoxysilane, tetraethoxysilane , Methyltrimethoxysilane, Methyltriethoxysilane, Ethyltrimethoxysilane, Ethyltriethoxysilane, Isopropyltrimethoxysilane, Isobutyltrimethoxysilane, Cyclohexyltrimethoxysilane, n-hexyltrimethoxysilane, n-octyltriethoxysilane, n-decyltrimethoxysilane, phenyltrimethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diisopropyldimethoxysilane, trimethoxysilylstyrene, γ- (meth) acryloxipropyltrimethoxysilane, 1,3-divinyltetramethyldi Silane alkoxide compounds such as siloxane, methylphenyldimethoxysilane, diphenyldimethoxysilane; vinyltrimethoxysilane, vinyltriethoxysilane, dimethoxymethylvinylsisilane, dimethoxyethylvinylsilane, diethoxymethylvinylsilane, diethoxyethylvinylsilane, ethylmethyldivinylsilane , Methylvinyldimethoxysilane, ethylvinyldimethoxysilane, methylvinyldiethoxysilane, ethylvinyldiethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethi Polymeric double bond-containing silane alkoxides such as rudimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxipropyltrimethoxysilane Cyclic siloxane such as decamethylcyclopentasiloxane; Modified (reactive) silicone oil such as one-terminal modified silicone oil, double-ended silicone oil, side chain type silicone oil; (meth) acrylic acid, maleic acid, maleic anhydride, etc. Examples thereof include a carboxyl group-containing monomer of.

The base material particles can be obtained by polymerizing the polymerizable monomer having an ethylenically unsaturated group. The above polymerization method is not particularly limited, and examples thereof include known methods such as radical polymerization, ionic polymerization, polycondensation (condensation polymerization, polycondensation polymerization), addition condensation, living polymerization, and living radical polymerization. Further, as another polymerization method, suspension polymerization in the presence of a radical polymerization initiator can be mentioned.

Examples of the inorganic material include silica, alumina, barium titanate, zirconia, carbon black, silicate glass, borosilicate glass, lead glass, soda-lime glass and alumina silicate glass.

The base particle may be an organic-inorganic hybrid particle. The base material particles may be core-shell particles. When the base particle is an organic-inorganic hybrid particle, examples of the inorganic substance that is the material of the base particle include silica, alumina, barium titanate, zirconia, and carbon black. It is preferable that the inorganic substance is not a metal. The base particle formed of the silica is not particularly limited, but after hydrolyzing a silicon compound having two or more hydrolyzable alkoxysilyl groups to form crosslinked polymer particles, firing is performed if necessary. Examples thereof include substrate particles obtained by carrying out the process. Examples of the organic-inorganic hybrid particles include organic-inorganic hybrid particles formed of a crosslinked alkoxysilyl polymer and an acrylic resin.

The organic-inorganic hybrid particles are preferably core-shell type organic-inorganic hybrid particles having a core and a shell arranged on the surface of the core. It is preferable that the core is an organic core. It is preferable that the shell is an inorganic shell. The base material particles are preferably organic-inorganic hybrid particles having an organic core and an inorganic shell arranged on the surface of the organic core.

Examples of the organic core material include the organic materials described above.

Examples of the material of the inorganic shell include the above-mentioned inorganic substances as the material of the base particle. The material of the inorganic shell is preferably silica. The inorganic shell is preferably formed by forming a metal alkoxide into a shell-like material by a sol-gel method on the surface of the core and then firing the shell-like material. The metal alkoxide is preferably a silane alkoxide. The inorganic shell is preferably formed of silane alkoxide.

The particle size of the base material particles can be selected in consideration of the particle size of the conductive particles. The particle size of the base particles is preferably 0.1 μm or more, more preferably 1 μm or more. The particle size of the base particles is preferably 1000 μm or less, more preferably 500 μm or less, still more preferably 300 μm or less, still more preferably 50 μm or less, and even more preferably 10 μm or less. When the particle size of the base material particles is equal to or larger than the above lower limit, the contact area between the conductive particles and the electrodes becomes large, so that the conduction reliability between the electrodes can be further improved, and the conductive particles are connected via the conductive particles. The connection resistance between the electrodes can be further reduced. Further, when the conductive portion is formed on the surface of the base material particles by electroless plating, it is possible to make it difficult for the agglomerated conductive particles to be formed. When the particle size of the base material particles is not more than the above upper limit, the conductive particles are easily sufficiently compressed, the connection resistance between the electrodes can be further reduced, and the distance between the electrodes can be further reduced. it can.

The particle size of the base particles is particularly preferably 1 μm or more and 3 μm or less. When the particle size of the base material particles is within the range of 1 μm or more and 3 μm or less, it becomes difficult to agglomerate when forming a conductive portion on the surface of the base material particles, and it becomes difficult to form agglomerated conductive particles.

The particle size of the base particles is preferably an average particle size, and preferably a number average particle size. As for the particle size of the base particle, 50 arbitrary base particles are observed with an electron microscope or an optical microscope, the average value of the particle size of each base particle is calculated, or a particle size distribution measuring device is used. Is required. In observation with an electron microscope or an optical microscope, the particle size of each substrate particle is determined as the particle size in a circle-equivalent diameter. In observation with an electron microscope or an optical microscope, the average particle diameter of any 50 substrate particles in a circle-equivalent diameter is substantially equal to the average particle diameter in a sphere-equivalent diameter. In the particle size distribution measuring device, the particle size of each base particle is determined as the particle size in the equivalent sphere diameter. The average particle size of the base particles is preferably calculated using a particle size distribution measuring device. When measuring the particle size of the base material particles in the conductive particles, for example, the measurement can be performed as follows.

An embedded resin for conducting a conductive particle inspection is prepared by adding and dispersing the conductive particles to "Technobit 4000" manufactured by Kulzer so that the content of the conductive particles is 30% by weight. A cross section of the conductive particles is cut out using an ion milling device (“IM4000” manufactured by Hitachi High-Technologies Corporation) so as to pass near the center of the conductive particles dispersed in the embedded resin for inspection. Then, using a field emission scanning electron microscope (FE-SEM), the image magnification is set to 25000 times, 50 conductive particles are randomly selected, and the base particles of each conductive particle are observed. To do. The particle size of the base material particles in each conductive particle is measured, and they are arithmetically averaged to obtain the particle size of the base material particles.

(Conductive part)
The conductive particles according to the present invention have a conductive portion. The conductive particles according to the present invention may include base particles and conductive portions arranged on the surface of the base particles. The conductive portion preferably contains a metal. The metal constituting the conductive portion is not particularly limited.

The metals constituting the conductive portion include gold, silver, palladium, copper, platinum, zinc, iron, tin, lead, aluminum, cobalt, indium, nickel, chromium, titanium, antimony, bismuth, tarium, germanium, cadmium, and the like. Examples thereof include silicon, tungsten, molybdenum and alloys thereof. Examples of the metal constituting the conductive portion include tin-doped indium oxide (ITO) and solder. Only one kind of metal constituting the conductive portion may be used, or two or more kinds may be used in combination.

From the viewpoint of further effectively lowering the connection resistance between the electrodes, the conductive portion preferably contains nickel, gold, palladium, silver, or copper, and more preferably nickel, gold, or palladium. It is particularly preferable to contain nickel.

The content of nickel in 100% by weight of the conductive portion containing nickel is preferably 10% by weight or more, more preferably 50% by weight or more, still more preferably 60% by weight or more, still more preferably 70% by weight or more, and particularly preferably. Is 90% by weight or more. The content of nickel in 100% by weight of the conductive portion containing nickel may be 97% by weight or more, 97.5% by weight or more, 98% by weight or more, 100% by weight. It may be% by weight.

In addition, hydroxyl groups are often present on the surface of the conductive portion due to oxidation. Generally, a hydroxyl group is present on the surface of a conductive portion formed of nickel due to oxidation. An insulating substance can be arranged on the surface of the conductive portion having such a hydroxyl group (the surface of the conductive particles) via a chemical bond.

The conductive portion may be formed by one layer. The conductive portion may be formed of a plurality of layers. That is, the conductive portion may have a laminated structure of two or more layers. When the conductive portion is formed of a plurality of layers, the metal constituting the outermost layer is preferably gold, nickel, palladium, copper or an alloy containing tin and silver, and is preferably gold. More preferred. When the metal constituting the outermost layer is these preferred metals, the connection resistance between the electrodes becomes even lower. Further, when the metal constituting the outermost layer is gold, the corrosion resistance is further enhanced. The metal constituting the outermost layer may be nickel.

The method of forming the conductive portion on the surface of the base particle is not particularly limited. Examples of the method for forming the conductive portion include a method by electroless plating, a method by electroplating, a method by physical collision, a method by mechanochemical reaction, a method by physical vapor deposition or physical adsorption, and a metal powder or metal powder. Examples thereof include a method of coating the surface of the substrate particles with a paste containing the binder and the binder. The method for forming the conductive portion is preferably a method by electroless plating, electroplating or physical collision. Examples of the method by physical vapor deposition include methods such as vacuum vapor deposition, ion plating, and ion sputtering. Further, as the method by the above physical collision, a sheeter composer (manufactured by Tokuju Kosakusho Co., Ltd.) or the like is used.

The thickness of the conductive portion is preferably 0.005 μm or more, more preferably 0.01 μm or more, preferably 10 μm or less, more preferably 1 μm or less, still more preferably 0.3 μm or less. The thickness of the conductive portion is the thickness of the entire conductive portion when the conductive portion has multiple layers. When the thickness of the conductive portion is at least the above lower limit and at least the above upper limit, sufficient conductivity can be obtained, and the conductive particles are not too hard and the conductive particles are sufficiently deformed at the time of connection between the electrodes. Can be made to.

When the conductive portion is formed of a plurality of layers, the thickness of the conductive portion of the outermost layer is preferably 0.001 μm or more, more preferably 0.01 μm or more, preferably 0.5 μm or less, more preferably. Is 0.1 μm or less. When the thickness of the conductive portion of the outermost layer is equal to or higher than the lower limit and lower than the upper limit, the coating by the conductive portion of the outermost layer becomes uniform, the corrosion resistance becomes sufficiently high, and the connection resistance between the electrodes is sufficient. Can be lowered to. Further, when the metal constituting the outermost layer is gold, the thinner the outermost layer, the lower the cost.

The thickness of the conductive portion can be measured by observing the cross section of the conductive particles using, for example, a transmission electron microscope (TEM). Regarding the thickness of the conductive portion, it is preferable to calculate the average value of the thickness of any of the conductive portions at five points as the thickness of the conductive portion of one conductive particle, and the average value of the thickness of the entire conductive portion is one. It is more preferable to calculate as the thickness of the conductive portion of the conductive particles. The thickness of the conductive portion is preferably obtained by calculating the average value of the thickness of the conductive portion of each conductive particle for 10 arbitrary conductive particles.

(Core material and protrusions)
The conductive particles preferably have protrusions on the outer surface of the conductive portion. It is preferable that the number of the protrusions is plurality. An oxide film is often formed on the surface of the electrode connected by the conductive particles. When conductive particles having protrusions on the surface of the conductive portion are used, the oxide film can be effectively removed by the protrusions by arranging the conductive particles between the electrodes and crimping them. Therefore, the electrodes and the conductive portion come into contact with each other more reliably, and the connection resistance between the electrodes becomes even lower. Further, when the conductive particles include an insulating substance, or when the conductive particles are dispersed in a binder resin and used as a conductive material, the protrusions of the conductive particles provide insulation between the conductive particles and the electrode. The sex substance or the binder resin can be eliminated more effectively. Therefore, the connection resistance between the electrodes can be further reduced.

It is preferable that the conductive particles include a plurality of core substances in which the surface of the conductive portion is raised so as to form the plurality of protrusions in the conductive portion.

As a method of forming the above-mentioned protrusions, a method of forming a conductive portion by electroless plating after adhering a core substance to the surface of the base material particles, and a method of forming a conductive portion by electroless plating on the surface of the base material particles. After that, a method of adhering a core substance and further forming a conductive portion by electroless plating can be mentioned. Further, the core material may not be used to form the protrusions.

Examples of other methods for forming the protrusions include a method of adding a core substance in the middle of forming a conductive portion on the surface of the base particle. Further, in order to form protrusions, a conductive portion is formed on the base material particles by electroless plating without using the above-mentioned core substance, and then plating is deposited in a protrusion shape on the surface of the conductive portion, and further electroless plating is performed. You may use a method of forming a conductive portion by the above method.

As a method of adhering the core substance to the surface of the base particle, the core substance is added to the dispersion liquid of the base particle, and the core substance is accumulated and adhered to the surface of the base particle by van der Waals force. Examples thereof include a method in which a core substance is added to a container containing the base material particles, and the core substance is adhered to the surface of the base material particles by a mechanical action such as rotation of the container. From the viewpoint of controlling the amount of the core substance to be adhered, the method of adhering the core substance to the surface of the base material particles is a method of accumulating and adhering the core substance to the surface of the base material particles in the dispersion liquid. preferable.

Examples of the substance constituting the core substance include a conductive substance and a non-conductive substance. Examples of the conductive substance include metals, metal oxides, conductive non-metals such as graphite, and conductive polymers. Examples of the conductive polymer include polyacetylene and the like. Examples of the non-conductive substance include silica, alumina and zirconia. From the viewpoint of removing the oxide film more effectively, the core material is preferably hard. From the viewpoint of further effectively lowering the connection resistance between the electrodes, the core material is preferably a metal.

The metal is not particularly limited. Examples of the metals include metals such as gold, silver, copper, platinum, zinc, iron, lead, tin, aluminum, cobalt, indium, nickel, chromium, titanium, antimony, bismuth, germanium and cadmium, and tin-lead alloys. Examples thereof include alloys composed of two or more kinds of metals such as tin-copper alloy, tin-silver alloy, tin-lead-silver alloy and tungsten carbide. From the viewpoint of further effectively lowering the connection resistance between the electrodes, the metal is preferably nickel, copper, silver or gold. The metal may be the same as or different from the metal constituting the conductive portion (conductive layer).

The shape of the core substance is not particularly limited. The shape of the core material is preferably lumpy. Examples of the core material include particulate lumps, agglomerates in which a plurality of fine particles are agglomerated, and amorphous lumps.

The particle size of the core substance is preferably 0.001 μm or more, more preferably 0.05 μm or more, preferably 0.9 μm or less, and more preferably 0.2 μm or less. When the particle size of the core substance is not less than the above lower limit and not more than the upper limit, the connection resistance between the electrodes can be further effectively reduced.

The particle size of the core material is preferably an average particle size, and more preferably a number average particle size. The particle size of the core substance can be obtained by observing 50 arbitrary core substances with an electron microscope or an optical microscope, calculating the average value of the particle size of each core substance, or using a particle size distribution measuring device. In observation with an electron microscope or an optical microscope, the particle size of each core substance is determined as the particle size in a circle-equivalent diameter. In observation with an electron microscope or an optical microscope, the average particle diameter of any 50 core materials in the equivalent circle diameter is substantially equal to the average particle diameter in the equivalent diameter of the sphere. In the particle size distribution measuring device, the particle size of each core substance is obtained as the particle size in the equivalent diameter of a sphere. The average particle size of the core material is preferably calculated using a particle size distribution measuring device.

From the viewpoint of further lowering the initial connection resistance and further enhancing the conduction reliability under high temperature and high humidity, the surface area of the portion having the protrusion is preferably 100% of the total surface area of the outer surface of the conductive portion. It is 25% or more, more preferably 30% or more, still more preferably 50% or more. The surface area of the portion having the protrusions may be 95% or less, 90% or less, or 80% or less.

The number of the protrusions per one conductive particle is preferably 3 or more, and more preferably 5 or more. The upper limit of the number of the protrusions is not particularly limited. The upper limit of the number of protrusions can be appropriately selected in consideration of the particle size of the conductive particles and the like. When the number of the protrusions is at least the above lower limit, the connection resistance between the electrodes can be further effectively reduced.

The number of the protrusions can be calculated by observing arbitrary conductive particles with an electron microscope or an optical microscope. The number of protrusions is preferably determined by observing 50 arbitrary conductive particles with an electron microscope or an optical microscope and calculating the average value of the number of protrusions in each conductive particle.

The height of the protrusion is preferably 0.001 μm or more, more preferably 0.05 μm or more, preferably 0.9 μm or less, and more preferably 0.2 μm or less. When the height of the protrusion is equal to or higher than the lower limit and lower than the upper limit, the connection resistance between the electrodes can be further effectively reduced.

The height of the protrusions can be calculated by observing the protrusions on any conductive particle with an electron microscope or an optical microscope. The height of the protrusions is preferably calculated by calculating the average value of the heights of all the protrusions per conductive particle as the height of the protrusions of one conductive particle. It is preferable that the height of the protrusions is obtained by calculating the average value of the heights of the protrusions of each conductive particle for 50 arbitrary conductive particles.

(Insulating substance)
From the viewpoint of further enhancing the conductivity, the conductive particles do not have to include an insulating substance arranged on the outer surface of the conductive portion. From the viewpoint of further enhancing the insulation reliability, it is preferable that the conductive particles include an insulating substance arranged on the outer surface of the conductive portion. In this case, if the conductive particles are used for the connection between the electrodes, a short circuit between adjacent electrodes can be prevented more effectively. Specifically, when a plurality of conductive particles come into contact with each other, an insulating substance exists between the plurality of electrodes, so that it is possible to prevent a short circuit between the electrodes adjacent to each other in the lateral direction rather than between the upper and lower electrodes. By pressurizing the conductive particles with the two electrodes at the time of connection between the electrodes, the insulating substance between the conductive portion of the conductive particles and the electrodes can be easily removed. Further, in the case of the conductive particles having protrusions on the outer surface of the conductive portion, the insulating substance between the conductive portion of the conductive portion and the electrode can be more easily removed.

Examples of the insulating substance include an insulating layer and insulating particles. The insulating substance is preferably insulating particles because the insulating substance can be more easily removed during crimping between the electrodes.

Examples of the material of the insulating substance include the above-mentioned organic material, the above-mentioned inorganic material, and the above-mentioned inorganic substance as the material of the base particle. The material of the insulating substance is preferably the organic material described above.

Other materials of the insulating substance include polyolefin compounds, (meth) acrylate polymers, (meth) acrylate copolymers, block polymers, thermoplastic resins, crosslinked products of thermoplastic resins, thermosetting resins and water-soluble materials. Examples include resin. As the material of the insulating substance, only one kind may be used, or two or more kinds may be used in combination.

Examples of the polyolefin compound include polyethylene, ethylene-vinyl acetate copolymer and ethylene-acrylic acid ester copolymer. Examples of the (meth) acrylate polymer include polymethyl (meth) acrylate, polydodecyl (meth) acrylate, and polystearyl (meth) acrylate. Examples of the block polymer include polystyrene, styrene-acrylic acid ester copolymer, SB type styrene-butadiene block copolymer, SBS type styrene-butadiene block copolymer, and hydrogenated products thereof. Examples of the thermoplastic resin include vinyl polymers and vinyl copolymers. Examples of the thermosetting resin include epoxy resin, phenol resin, melamine resin and the like. Examples of the crosslinked product of the thermoplastic resin include the introduction of polyethylene glycol methacrylate, alkoxylated trimethylolpropane methacrylate, alkoxylated pentaerythritol methacrylate and the like. Examples of the water-soluble resin include polyvinyl alcohol, polyacrylic acid, polyacrylamide, polyvinylpyrrolidone, polyethylene oxide, methyl cellulose and the like. Further, a chain transfer agent may be used to adjust the degree of polymerization. Examples of the chain transfer agent include thiols and carbon tetrachloride.

Examples of the method of arranging the insulating substance on the surface of the conductive portion include a chemical method and a physical or mechanical method. Examples of the chemical method include an interfacial polymerization method, a suspension polymerization method in the presence of particles, and an emulsion polymerization method. Examples of the physical or mechanical method include spray drying, hybridization, electrostatic adhesion method, spraying method, dipping and vacuum deposition method. From the viewpoint of further effectively enhancing the insulation reliability and the conduction reliability when the electrodes are electrically connected, the method of arranging the insulating substance on the surface of the conductive portion is a physical method. It is preferable to have.

The outer surface of the conductive portion and the outer surface of the insulating substance may each be coated with a compound having a reactive functional group. The outer surface of the conductive portion and the outer surface of the insulating substance may not be directly chemically bonded, or may be indirectly chemically bonded by a compound having a reactive functional group. After introducing a carboxyl group into the outer surface of the conductive portion, the carboxyl group may be chemically bonded to a functional group on the outer surface of the insulating substance via a polymer electrolyte such as polyethyleneimine.

When the insulating substance is an insulating particle, the particle size of the insulating particle can be appropriately selected depending on the particle size of the conductive particle, the use of the conductive particle, and the like. The particle size of the insulating particles is preferably 10 nm or more, more preferably 100 nm or more, further preferably 300 nm or more, particularly preferably 500 nm or more, preferably 4000 nm or less, more preferably 2000 nm or less, still more preferably 1500 nm or less. , Especially preferably 1000 nm or less. When the particle size of the insulating particles is at least the above lower limit, it becomes difficult for the conductive portions of the plurality of conductive particles to come into contact with each other when the conductive particles are dispersed in the binder resin. When the particle size of the insulating particles is not more than the above upper limit, it is not necessary to increase the pressure too much in order to eliminate the insulating particles between the electrodes and the conductive particles when connecting the electrodes, and the temperature is high. There is no need to heat it.

The particle size of the insulating particles is preferably an average particle size, and preferably a number average particle size. For the particle size of the insulating particles, observe 50 arbitrary insulating particles with an electron microscope or an optical microscope, calculate the average value of the particle size of each insulating particle, or use a particle size distribution measuring device. Desired. In observation with an electron microscope or an optical microscope, the particle size of each insulating particle is determined as the particle size in a circle-equivalent diameter. In observation with an electron microscope or an optical microscope, the average particle diameter of any 50 insulating particles in a circle-equivalent diameter is substantially equal to the average particle diameter in a sphere-equivalent diameter. In the particle size distribution measuring device, the particle size of each insulating particle is obtained as the particle size in the equivalent diameter of a sphere. The average particle size of the insulating particles is preferably calculated using a particle size distribution measuring device. When measuring the particle size of the insulating particles in the conductive particles, for example, the measurement can be performed as follows.

Conductive particles are added to "Technobit 4000" manufactured by Kulzer so as to have a content of 30% by weight and dispersed to prepare an embedded resin for conducting conductive particle inspection. A cross section of the conductive particles is cut out using an ion milling device (“IM4000” manufactured by Hitachi High-Technologies Corporation) so as to pass near the center of the dispersed conductive particles in the embedded resin for inspection. Then, using a field emission scanning electron microscope (FE-SEM), the image magnification was set to 50,000 times, 50 conductive particles were randomly selected, and the insulating particles of each conductive particle were observed. To do. The particle size of the insulating particles in each conductive particle is measured, and they are arithmetically averaged to obtain the particle size of the insulating particles.

The ratio of the particle size of the conductive particles to the particle size of the insulating particles (particle size of the conductive particles / particle size of the insulating particles) is preferably 4 or more, more preferably 8 or more, and preferably 8. It is 200 or less, more preferably 100 or less. When the above ratio (particle size of conductive particles / particle size of insulating particles) is equal to or more than the above lower limit and less than or equal to the above upper limit, the insulation reliability and conduction reliability are further improved when the electrodes are electrically connected. It can be enhanced more effectively.

(Conductive material)
The conductive material according to the present invention includes the above-mentioned conductive particles and a binder resin. The conductive particles are preferably dispersed in the binder resin and used, and preferably dispersed in the binder resin and used as the conductive material. The conductive material is preferably an anisotropic conductive material. The conductive material is preferably used for electrical connection between electrodes. The conductive material is preferably a conductive material for circuit connection. Since the above-mentioned conductive particles are used in the above-mentioned conductive material, the connection resistance between the electrodes can be lowered more effectively, and the occurrence of aggregation between the conductive particles can be further effectively suppressed. be able to. Since the above-mentioned conductive particles are used in the above-mentioned conductive material, the insulation reliability between the electrodes can be further effectively enhanced.

The binder resin is not particularly limited. As the binder resin, a known insulating resin is used. The binder resin preferably contains a thermoplastic component (thermoplastic compound) or a curable component, and more preferably contains a curable component. Examples of the curable component include a photocurable component and a thermosetting component. The photocurable component preferably contains a photocurable compound and a photopolymerization initiator. The thermosetting component preferably contains a thermosetting compound and a thermosetting agent.

Examples of the binder resin include vinyl resins, thermoplastic resins, curable resins, thermoplastic block copolymers, and elastomers. Only one kind of the binder resin may be used, or two or more kinds may be used in combination.

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 epoxy resin, urethane resin, polyimide resin, and unsaturated polyester resin. The curable resin may be a room temperature curable resin, a thermosetting resin, a photocurable resin, or a moisture curable resin. The curable resin may be used in combination with a curing agent. Examples of the thermoplastic block copolymer include a styrene-butadiene-styrene block copolymer, a styrene-isoprene-styrene block copolymer, a hydrogenated additive of a styrene-butadiene-styrene block copolymer, and a styrene-isoprene-styrene. Examples include a hydrogenated additive of a 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, a bulking agent, a softener, a plasticizer, a polymerization catalyst, a curing catalyst, a colorant, an antioxidant, a heat stabilizer, and a photostabilizer. It may contain various additives such as an agent, an ultraviolet absorber, a lubricant, an antistatic agent and a flame retardant.

As a method for dispersing the conductive particles in the binder resin, a conventionally known dispersion method can be used and is not particularly limited. Examples of the method for dispersing the conductive particles in the binder resin include the following methods. A method in which the conductive particles are added to the binder resin and then kneaded and dispersed with a planetary mixer or the like. A method in which the conductive particles are uniformly dispersed in water or an organic solvent using a homogenizer or the like, added to the binder resin, and kneaded and dispersed by a planetary mixer or the like. A method in which the binder resin is diluted with water or an organic solvent, the conductive particles are added, and the binder resin is kneaded and dispersed with a planetary mixer or the like.

The viscosity (η25) of the conductive material at 25 ° C. is preferably 30 Pa · s or more, more preferably 50 Pa · s or more, preferably 400 Pa · s or less, and more preferably 300 Pa · s or less. When the viscosity of the conductive material at 25 ° C. is equal to or higher than the lower limit and lower than the upper limit, the insulation reliability between the electrodes can be further effectively enhanced, and the conduction reliability between the electrodes is further effective. Can be enhanced to. The viscosity (η25) can be appropriately adjusted depending on the type and amount of the compounding components.

The viscosity (η25) can be measured at 25 ° C. and 5 rpm using, for example, an E-type viscometer (“TVE22L” manufactured by Toki Sangyo Co., Ltd.).

The conductive material according to the present invention can be used as a conductive paste, a conductive film, or the like. When the conductive material according to the present invention is a conductive film, a film containing no conductive particles may be laminated on the conductive film containing the conductive particles. The conductive paste is preferably an anisotropic conductive paste. The conductive film is preferably an anisotropic conductive film.

The content of the binder resin in 100% by weight of the conductive material is preferably 10% by weight or more, more preferably 30% by weight or more, still more preferably 50% by weight or more, and particularly preferably 70% by weight or more. Is 99.99% by weight or less, more preferably 99.9% by weight or less. When the content of the binder resin is not less than the above lower limit and not more than the above upper limit, the conductive particles are efficiently arranged between the electrodes, and the connection reliability of the connection target member connected by the conductive material is further enhanced. Can be done.

The content of the conductive particles in 100% by weight of the conductive material is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, preferably 80% by weight or less, more preferably 60% by weight. % Or less, more preferably 40% by weight or less, particularly preferably 20% by weight or less, and most preferably 10% by weight or less. When the content of the conductive particles is not less than the above lower limit and not more than the above upper limit, the connection resistance between the electrodes can be further effectively lowered. 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 and the insulation reliability between the electrodes can be further improved.

(Connection structure)
The connection structure according to the present invention includes a first connection target member having a first electrode on the surface, a second connection target member having a second electrode on the surface, the first connection target member, and the above. It includes a connecting portion that connects to the second connection target member. In the connection structure according to the present invention, the material of the connection portion is the above-mentioned conductive particles or a conductive material containing the above-mentioned conductive particles and a binder resin. In the connection structure according to the present invention, the first electrode and the second electrode are electrically connected by the conductive particles.

The connection structure includes a step of arranging the conductive particles or the conductive material between the first connection target member and the second connection target member, and a step of conducting a conductive connection by thermocompression bonding. Can be obtained through. When the conductive particles have the insulating substance, it is preferable that the insulating substance is desorbed from the conductive particles at the time of thermocompression bonding.

When the conductive particles are used alone, the connecting portion itself is the conductive particles. That is, the first connection target member and the second connection target member are connected by the conductive particles. The conductive material used to obtain the connection structure is preferably an anisotropic conductive material.

FIG. 5 is a front sectional view schematically showing a connection structure using conductive particles according to the first embodiment of the present invention.

The connection structure 51 shown in FIG. 5 connects a first connection target member 52, a second connection target member 53, and a connection portion 54 connecting the first and second connection target members 52 and 53. Be prepared. The connecting portion 54 is formed by curing a conductive material containing the conductive particles 1. In FIG. 5, the conductive particles 1 are shown schematicly for convenience of illustration. Instead of the conductive particles 1, other conductive particles such as conductive particles 11 and 21 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 52a and the second electrode 53a are electrically connected by one or more conductive particles 1. Therefore, the first and second connection target members 52 and 53 are electrically connected by the conductive particles 1.

The method for manufacturing the connection structure is not particularly limited. As an example of a method for manufacturing a connection structure, the conductive material is arranged between a first connection target member and a second connection target member, and after obtaining a laminate, the laminate is heated and pressurized. The method and the like can be mentioned. The thermocompression bonding pressure is preferably 40 MPa or more, more preferably 60 MPa or more, preferably 90 MPa or less, and more preferably 70 MPa or less. The heating temperature of the thermocompression bonding is preferably 80 ° C. or higher, more preferably 100 ° C. or higher, preferably 140 ° C. or lower, and more preferably 120 ° C. or lower. When the pressure and temperature of the thermocompression bonding are at least the above lower limit and at least the above upper limit, the conduction reliability and insulation reliability between the electrodes can be further improved. Further, when the conductive particles have the insulating particles, the insulating particles can be easily separated from the surface of the conductive particles at the time of conductive connection.

When the conductive particles have the insulating particles, they are present between the conductive particles and the first electrode and the second electrode when the laminate is heated and pressurized. The above insulating particles can be eliminated. For example, during the heating and pressurization, the insulating particles existing between the conductive particles and the first electrode and the second electrode are released from the surface of the conductive particles. Easy to detach. During the heating and pressurization, some of the insulating particles may be separated from the surface of the conductive particles, and the surface of the conductive portion may be partially exposed. When the exposed surface of the conductive portion comes into contact with the first electrode and the second electrode, the first electrode and the second electrode are electrically connected via the conductive particles. can do.

The first connection target member and the second connection target member are not particularly limited. Specific examples of the first connection target member and the second connection target member include electronic components such as semiconductor chips, semiconductor packages, LED chips, LED packages, capacitors and diodes, resin films, printed circuit boards, and flexible devices. Examples thereof include electronic components such as printed circuit boards, flexible flat cables, rigid flexible boards, glass epoxy boards, and circuit boards such as glass boards. The first connection target member and the second connection target member are preferably electronic components.

Examples of the electrode provided on the connection target member include a gold electrode, a nickel electrode, a tin electrode, an aluminum electrode, a copper electrode, a molybdenum electrode, a silver electrode, a SUS electrode, and a metal electrode such as a tungsten electrode. When the connection target member is a flexible printed substrate, the electrode is preferably a gold electrode, a nickel electrode, a tin electrode, a silver electrode, or a copper electrode. When the member to be connected is a glass substrate, the electrodes are preferably aluminum electrodes, copper electrodes, molybdenum electrodes, silver electrodes or tungsten electrodes. When the electrode is an aluminum electrode, it may be an electrode formed only of aluminum, or an electrode in which an aluminum layer is laminated on the surface of a metal oxide layer. Examples of the material of the metal oxide layer include indium oxide doped with a trivalent metal element and zinc oxide doped with a trivalent metal element. Examples of the trivalent metal element include 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 to the following examples.

In order to introduce the following organic silicon functional groups into the obtained conductive particles, the following organic silicon compounds were used.

A: Organic silicon compound for introducing an organic silicon functional group having an alkyl group having 10 carbon atoms Decyltrimethoxysilane (organic silicon compound A)
B: Organic silicon compound for introducing an organic silicon functional group having a benzotriazole group Bentriazole methyltrimethoxysilane (a compound in which a benzotriazole group is added to the methyl group of methyltrimethoxysilane) (organic silicon compound B)
C: Organic silicon compound for introducing an organic silicon functional group having a (meth) acryloyl group 3-methacryloxypropyltrimethoxysilane (organic silicon compound C)
D: Organic silicon compound for introducing an organic silicon functional group having an epoxy group 3-glycidoxypropyltrimethoxysilane (organic silicon compound D)

In the obtained conductive particles, the following compounds were used for surface treatment of the conductive portion.

Phosphoric acid compound: Phosphoric acid monohexyl ester Benzotriazole compound: 1,2,3-benzotriazole Thiazol compound: 2-Mercaptobenzotriazole

(Example 1)
(1) Preparation of Conductive Particles Divinylbenzene copolymer resin particles (base particle A, “Micropearl SP-203” manufactured by Sekisui Chemical Co., Ltd., particle diameter 3 μm) were prepared as the base particle A. The base particle A was dispersed in 100 parts by weight of an alkaline solution containing 5% by weight of a palladium catalyst solution using an ultrasonic disperser, and then the base particle A was taken out by filtering the solution. .. Next, the base particle A was added to 100 parts by weight of a 1% by weight solution of dimethylamine borane to activate the surface of the base particle A. The surface-activated substrate particles A were thoroughly washed with water, and then added to 500 parts by weight of distilled water and dispersed to obtain a dispersion liquid.

Next, 1 part by weight of an alumina particle slurry (average particle size 150 nm) was added to the dispersion liquid over 3 minutes to obtain a suspension containing the base particle A to which the core substance was attached.

Further, as the nickel plating solution, a nickel plating solution (pH 8.5) containing nickel sulfate 0.14 mol / L, dimethylamine borane 0.46 mol / L, and sodium citrate 0.2 mol / L was prepared.

While stirring the obtained suspension at 60 ° C., the nickel plating solution was added dropwise to the suspension at a dropping rate of 30 mL / min for 10 minutes. Then, the mixture was added dropwise at a dropping rate of 10 mL / min for 40 minutes, and then dropped at a dropping rate of 4 mL / min for 80 minutes to control the content of boron incorporated in the plating film without electrolessing. Nickel-boron alloy plating was performed.

Then, by filtering the suspension, the particles are taken out, washed with water, and dried to form a first conductive portion (conductive layer containing nickel, thickness 0.1 μm) on the surface of the base particle A. Placed particles were obtained.

5 parts by weight of the obtained particles were dispersed in 100 parts by weight of ethanol to obtain a particle dispersion liquid.

To 50 parts by weight of ethanol, 10 parts by weight of water, 0.8 parts by weight of acetic acid, and 1.5 parts by weight of the organic silicon compound A were added, and the mixture was stirred at room temperature for 200 minutes to obtain a solution A. To 50 parts by weight of ethanol, 10 parts by weight of water, 0.8 parts by weight of acetic acid, and 1.5 parts by weight of the organic silicon compound D were added, and the mixture was stirred at room temperature for 200 minutes to obtain a solution D.

The solution A and the solution D were placed in the particle dispersion, heated to 50 ° C. and stirred to obtain conductive particles whose surface was modified with the organic silicon compounds A and D.

(2) Preparation of conductive material 60 parts by weight of phenoxy resin (Nippon Steel Chemical & Materials Co., Ltd. "YP-50"), 40 parts by weight of epoxy resin (Mitsubishi Chemical Co., Ltd. "jER828"), and cationic curing agent (3) 2 parts by weight of "SI-60L" manufactured by Shin Kagaku Kogyo Co., Ltd.) was blended to obtain an insulating adhesive. The obtained conductive particles were added to the insulating adhesive so that the content in 100% by weight of the obtained conductive film was 5% by weight to obtain a first mixture. Then, methyl ethyl ketone was added to the first mixture so that the solid content was 50% by weight, and the mixture was stirred at 2000 rpm for 5 minutes using a planetary stirrer to obtain a second mixture. The obtained second mixture was applied onto the stripped polyethylene terephthalate, and the solvent was dried to obtain an anisotropic conductive film having a thickness of 20 μm.

(3) Preparation of Connection Structure A polyimide substrate (flexible printed circuit board) having an Al—Ti 4% electrode pattern (Al—Ti 4% electrode thickness 1 μm) having an L / S of 20 μm / 20 μm on the upper surface was prepared. Further, a semiconductor chip having a gold electrode pattern (gold electrode thickness 20 μm) having an L / S of 20 μm / 20 μm on the lower surface was prepared. The prepared anisotropic conductive film was attached to the upper surface of the polyimide substrate at 80 ° C. and 0.98 MPa (10 kgf / cm2), and then the separator was peeled off to bond the bumps of the chip with gold bumps and the Al—Ti circuit. Alignment was performed. Next, a pressure heating head was placed on the upper surface of the semiconductor chip, and the anisotropic conductive material layer was cured at 180 ° C. while applying a low pressure of 1 MPa calculated from the crimping area to obtain a connection structure.

(Example 2)
As the base particle A, divinylbenzene copolymer resin particles (base particle A, “Micropearl SP-203” manufactured by Sekisui Chemical Co., Ltd., particle diameter 3 μm) were prepared. The base particle A was dispersed in 100 parts by weight of an alkaline solution containing 5% by weight of a palladium catalyst solution using an ultrasonic disperser, and then the base particle A was taken out by filtering the solution. .. Next, the base particle A was added to 100 parts by weight of a 1% by weight solution of dimethylamine borane to activate the surface of the base particle A. The surface-activated base particle A was thoroughly washed with water, and then added to 500 parts by weight of distilled water and dispersed to obtain a suspension containing the base particle A to which the core substance was not attached. Conductive particles were obtained in the same manner as in Example 1 except that the obtained suspension was used.

A conductive film and a connecting structure were obtained in the same manner as in Example 1 except that the obtained conductive particles were used.

(Example 3)
Conductive particles were obtained in the same manner as in Example 1 except that a nickel particle slurry (average particle size 150 nm) was used instead of the alumina particle slurry (average particle size 150 nm).

A conductive film and a connecting structure were obtained in the same manner as in Example 1 except that the obtained conductive particles were used.

(Example 4)
Conductive particles were obtained in the same manner as in Example 1 except that a titania particle slurry (average particle size 150 nm) was used instead of the alumina particle slurry (average particle size 150 nm).

A conductive film and a connecting structure were obtained in the same manner as in Example 1 except that the obtained conductive particles were used.

(Example 5)
Conductive particles were obtained in the same manner as in Example 1 except that the base particles B, which differed only in particle size from the base particles A and had a particle size of 1.5 μm, were used.

A conductive film and a connecting structure were obtained in the same manner as in Example 1 except that the obtained conductive particles were used.

(Example 6)
Conductive particles were obtained in the same manner as in Example 1 except that the base particles C, which differed only in particle size from the base particles A and had a particle size of 20 μm, were used.

A conductive film and a connecting structure were obtained in the same manner as in Example 1 except that the obtained conductive particles were used.

(Example 7)
The following monomer composition is placed in a 1000 mL separable flask equipped with a four-neck separable cover, a stirring blade, a three-way cock, a cooling tube and a temperature probe, and the solid content of the monomer composition becomes 5% by weight. After weighing the ion-exchanged water as described above, the mixture was stirred at 200 rpm and polymerized at 70 ° C. for 24 hours under a nitrogen atmosphere. The above-mentioned monomer composition contains 100 mmol of methyl methacrylate, 1 mmol of N, N, N-trimethyl-N-2-methacryloyloxyethylammonium chloride, and 1 mmol of 2,2'-azobis (2-amidinopropane) dihydrochloride. Including. After completion of the reaction, the reaction was freeze-dried to obtain insulating particles having an ammonium group on the surface, having an average particle size of 220 nm and a CV value of 10%.

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

10 g of the conductive particles obtained in Example 1 was dispersed in 500 mL of ion-exchanged water, 4 g of an aqueous dispersion of insulating particles was added, and the mixture was stirred at room temperature for 6 hours. After filtering with a 3 μm mesh filter, the mixture was further washed with methanol and dried to obtain conductive particles to which insulating particles were attached (conductive particles with insulating particles).

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

A conductive film and a connecting structure were obtained in the same manner as in Example 1 except that the obtained conductive particles (conductive particles with insulating particles) were used.

(Example 8)
300 g of a 0.13 wt% ammonia aqueous solution was placed in a 500 mL reaction vessel equipped with a stirrer and a thermometer. Next, in the aqueous ammonia solution in the reaction vessel, 1.9 g of methyltrimethoxysilane, 12.7 g of vinyltrimethoxysilane, and 0.4 g of silicone alkoxy oligomer A (“KR-517” manufactured by Shin-Etsu Chemical Co., Ltd.) were added. The mixture of was added slowly. After advancing the hydrolysis and condensation reaction with stirring, 1.6 mL of a 25 wt% aqueous ammonia solution was added, and then the particles were isolated from the aqueous ammonia solution, and the obtained particles were subjected to an oxygen partial pressure of ^10-10 atm. Organic-inorganic hybrid particles (base particle D) were obtained by firing at 380 ° C. (baking temperature) for 2 hours (baking time). The particle size of the obtained organic-inorganic hybrid particles (base particle D) was 3 μm.

Conductive particles were obtained in the same manner as in Example 1 except that the base particles D were used instead of the base particles A.

A conductive film and a connecting structure were obtained in the same manner as in Example 1 except that the obtained conductive particles were used.

(Example 9)
A suspension similar to that of Example 1 was prepared.

As the nickel plating solution (1), a nickel plating solution (pH 8.5) containing nickel sulfate 0.14 mol / L, dimethylamine borane 0.46 mol / L, and sodium citrate 0.2 mol / L was prepared.

Further, as the nickel plating solution (2), a nickel plating solution (pH 8.0) containing nickel sulfate 0.14 mol / L and titanium chloride (III) 0.60 mol / L was prepared.

While stirring the obtained suspension at 60 ° C., the nickel plating solution (1) was added dropwise to the suspension at a dropping rate of 6 mL / min for 5 minutes. Then, the particles were added dropwise at a dropping rate of 2 mL / min for 20 minutes, and then dropped at a dropping rate of 0.8 mL / min for 40 minutes to control the content of boron incorporated in the plating film. The surface of the base particle A was plated with an electroless nickel-boron alloy (thickness: 0.05 μm). Subsequently, the liquid temperature was set to 70 ° C., the nickel plating liquid (2) was gradually added dropwise, electroless nickel plating was performed, and a suspension (2) was obtained.

Then, by filtering the suspension (2), the particles are taken out, washed with water, and dried to form a nickel-boron alloy conductive layer (thickness: 0.05 μm) and pure on the surface of the base particle A. Particles were obtained in which a first conductive portion (main metal: nickel, thickness 0.1 μm) including a nickel conductive layer (thickness 0.05 μm) was arranged.

Conductive particles were obtained in the same manner as in Example 1 except that the obtained particles were used.

A conductive film and a connecting structure were obtained in the same manner as in Example 1 except that the obtained conductive particles were used.

(Example 10)
A particle dispersion similar to that of Example 1 was prepared.

To 50 parts by weight of ethanol, 10 parts by weight of water, 0.8 parts by weight of acetic acid, and 1.5 parts by weight of the organic silicon compound A were added, and the mixture was stirred at room temperature for 200 minutes to obtain a solution A. To 50 parts by weight of ethanol, 10 parts by weight of water, 0.8 parts by weight of acetic acid, and 1.5 parts by weight of organic silicon compound B were added, and the mixture was stirred at room temperature for 200 minutes to obtain a solution B. To 50 parts by weight of ethanol, 10 parts by weight of water, 0.8 parts by weight of acetic acid, and 1.5 parts by weight of the organic silicon compound D were added, and the mixture was stirred at room temperature for 200 minutes to obtain a solution D.

The solution A, the solution B, and the solution D are placed in the particle dispersion, heated to 50 ° C., and stirred to obtain conductive particles whose surface is modified with the organic silicon compounds A, B, and D. Obtained.

A conductive film and a connecting structure were obtained in the same manner as in Example 1 except that the obtained conductive particles were used.

(Example 11)
A particle dispersion similar to that of Example 1 was prepared.

To 50 parts by weight of ethanol, 10 parts by weight of water, 0.8 parts by weight of acetic acid, and 1.5 parts by weight of the organic silicon compound A were added, and the mixture was stirred at room temperature for 200 minutes to obtain a solution A. To 50 parts by weight of ethanol, 10 parts by weight of water, 0.8 parts by weight of acetic acid, and 1.5 parts by weight of organic silicon compound C were added, and the mixture was stirred at room temperature for 200 minutes to obtain a solution C. To 50 parts by weight of ethanol, 10 parts by weight of water, 0.8 parts by weight of acetic acid, and 1.5 parts by weight of the organic silicon compound D were added, and the mixture was stirred at room temperature for 200 minutes to obtain a solution D.

The solution A, the solution C, and the solution D are placed in the particle dispersion, heated to 50 ° C., and stirred to obtain conductive particles whose surface is modified with the organic silicon compounds A, C, and D. Obtained.

Copolymer of phenoxy resin (“PKHC” manufactured by Union Carbide) and acrylic rubber (40 parts by weight of butyl acrylate, 30 parts by weight of ethyl acrylate, 30 parts by weight of acrylonitrile, and 3 parts by weight of glycidyl methacrylate, weight average molecular weight: 850,000 ) And prepared. 30 g of the phenoxy resin and 15 g of the acrylic rubber were dissolved in 20 g of ethyl acetate to obtain a solution having a total concentration of the phenoxy resin and the acrylic rubber of 30% by weight. To this solution, 30 g of a liquid epoxy resin containing a microcapsule type latent curing agent (epoxy equivalent 185, "Novacure HX-3941" manufactured by Asahi Kasei Epoxy Co., Ltd.) was added and stirred to prepare an insulating adhesive solution. The obtained conductive particles were added to the insulating adhesive solution so that the content in 100% by weight of the obtained conductive film was 5% by weight to obtain a first mixture. Then, methyl ethyl ketone was added to the first mixture so that the solid content was 50%, and the mixture was stirred at 2000 rpm for 5 minutes using a planetary stirrer to obtain a second mixture. The obtained second mixture was applied onto the stripped polyethylene terephthalate, and the solvent was dried to obtain an anisotropic conductive film having a thickness of 20 μm.

A connection structure was obtained in the same manner as in Example 1 except that the obtained conductive film was used.

(Example 12)
A particle dispersion similar to that of Example 1 was prepared.

To 50 parts by weight of ethanol, 10 parts by weight of water, 0.8 parts by weight of acetic acid, and 1.5 parts by weight of the organic silicon compound A were added, and the mixture was stirred at room temperature for 200 minutes to obtain a solution A. To 50 parts by weight of ethanol, 10 parts by weight of water, 0.8 parts by weight of acetic acid, and 1.5 parts by weight of organic silicon compound B were added, and the mixture was stirred at room temperature for 200 minutes to obtain a solution B. To 50 parts by weight of ethanol, 10 parts by weight of water, 0.8 parts by weight of acetic acid, and 1.5 parts by weight of organic silicon compound C were added, and the mixture was stirred at room temperature for 200 minutes to obtain a solution C. To 50 parts by weight of ethanol, 10 parts by weight of water, 0.8 parts by weight of acetic acid, and 1.5 parts by weight of the organic silicon compound D were added, and the mixture was stirred at room temperature for 200 minutes to obtain a solution D.

The surface of the particles is modified with the organic silicon compounds A and B and C and D by putting the solution A, the solution B, the solution C and the solution D in the particle dispersion, heating the particles to 50 ° C. and stirring them. The obtained conductive particles were obtained.

A conductive film and a connecting structure were obtained in the same manner as in Example 1 except that the obtained conductive particles were used.

Copolymer of phenoxy resin (“PKHC” manufactured by Union Carbide) and acrylic rubber (40 parts by weight of butyl acrylate, 30 parts by weight of ethyl acrylate, 30 parts by weight of acrylonitrile, and 3 parts by weight of glycidyl methacrylate, weight average molecular weight: 850,000 ) And prepared. 30 g of the phenoxy resin and 15 g of the acrylic rubber were dissolved in 20 g of ethyl acetate to obtain a solution having a total concentration of the phenoxy resin and the acrylic rubber of 30% by weight. To this solution, 30 g of a liquid epoxy resin containing a microcapsule type latent curing agent (epoxy equivalent 185, "Novacure HX-3941" manufactured by Asahi Kasei Epoxy Co., Ltd.) was added and stirred to prepare an insulating adhesive solution. The obtained conductive particles were added to the insulating adhesive solution so that the content in 100% by weight of the obtained conductive film was 5% by weight to obtain a first mixture. Then, methyl ethyl ketone was added to the first mixture so that the solid content was 50%, and the mixture was stirred at 2000 rpm for 5 minutes using a planetary stirrer to obtain a second mixture. The obtained second mixture was applied onto the stripped polyethylene terephthalate, and the solvent was dried to obtain an anisotropic conductive film having a thickness of 20 μm.

A connection structure was obtained in the same manner as in Example 1 except that the obtained conductive film was used.

(Example 13)
A particle dispersion similar to that of Example 1 was prepared.

To 50 parts by weight of ethanol, 10 parts by weight of water, 0.8 parts by weight of acetic acid, and 1.5 parts by weight of organic silicon compound B were added, and the mixture was stirred at room temperature for 200 minutes to obtain a solution B. To 50 parts by weight of ethanol, 10 parts by weight of water, 0.8 parts by weight of acetic acid, and 1.5 parts by weight of the organic silicon compound D were added, and the mixture was stirred at room temperature for 200 minutes to obtain a solution D.

The solution B and the solution D were placed in the particle dispersion, heated to 50 ° C. and stirred to obtain conductive particles whose surface was modified with the organic silicon compounds B and D.

A conductive film and a connecting structure were obtained in the same manner as in Example 1 except that the obtained conductive particles were used.

(Example 14)
The same particles as in Example 1, that is, particles in which the first conductive portion (conductive layer containing nickel, thickness 0.1 μm) was arranged on the surface of the base particle A was prepared.

10 parts by weight of the obtained particles were dispersed in 500 parts by weight of ion-exchanged water by an ultrasonic treatment machine to obtain a suspension.

A palladium plating solution (pH 10.0) containing 0.02 mol / L of palladium sulfate, 0.04 mol / L of ethylenediamine as a complexing agent, 0.06 mol / L of ammonium formic acid as a reducing agent, and a crystal modifier was prepared.

While stirring the obtained suspension at 50 ° C., the palladium plating solution was gradually added to perform electroless palladium plating to form a second conductive portion. Electroless palladium plating was completed when the thickness of the second conductive portion reached 20 nm. Conductive particles (particle diameter 3.24 μm) in which the second conductive portion (palladium layer, thickness 0.02 μm) was arranged on the surface of the first conductive portion were obtained.

A conductive film and a connecting structure were obtained in the same manner as in Example 1 except that the obtained conductive particles were used.

(Example 15)
Conductive particles were obtained in the same manner as in Example 14 except that electroless gold plating was performed instead of electroless palladium plating when forming the second conductive portion.

A conductive film and a connecting structure were obtained in the same manner as in Example 1 except that the obtained conductive particles were used.

(Example 16)
Conductive particles were obtained in the same manner as in Example 14 except that electroless silver plating was applied instead of electroless palladium plating when forming the second conductive portion.

A conductive film and a connecting structure were obtained in the same manner as in Example 1 except that the obtained conductive particles were used.

(Example 17)
Conductive particles were obtained in the same manner as in Example 14 except that electroless ruthenium plating was applied instead of electroless palladium plating when forming the second conductive portion.

A conductive film and a connecting structure were obtained in the same manner as in Example 1 except that the obtained conductive particles were used.

(Example 18)
A suspension similar to that of Example 1 was prepared.

As the nickel plating solution (1), a nickel plating solution (pH 8.5) containing nickel sulfate 0.14 mol / L, dimethylamine borane 0.46 mol / L, and sodium citrate 0.2 mol / L was prepared.

Further, as the nickel plating solution (2), a nickel plating solution (pH 8.0) containing nickel sulfate 0.14 mol / L and titanium chloride (III) 0.60 mol / L was prepared.

While stirring the obtained suspension at 60 ° C., the nickel plating solution (1) was added dropwise to the suspension at a dropping rate of 6 mL / min for 10 minutes. Then, the particles were added dropwise at a dropping rate of 2 mL / min for 40 minutes, and then dropped at a dropping rate of 0.8 mL / min for 80 minutes to control the content of boron incorporated in the plating film. The surface of the base particle A was plated with an electroless nickel-boron alloy (thickness 0.02 μm). Subsequently, the liquid temperature was set to 70 ° C., the nickel plating liquid (2) was gradually added dropwise, electroless nickel plating was performed, and a suspension (2) was obtained.

Then, by filtering the suspension (2), the particles are taken out, washed with water, and dried to form a nickel-boron alloy conductive layer (thickness 0.02 μm) and pure on the surface of the base particle A. Particles were obtained in which a first conductive portion (main metal: nickel, thickness 0.1 μm) including a nickel conductive layer (thickness 0.08 μm) was arranged.

10 parts by weight of the obtained particles were dispersed in 500 parts by weight of ion-exchanged water by an ultrasonic treatment machine to obtain a suspension.

A plating solution (pH 10.0) containing 0.02 mol / L of palladium sulfate, 0.04 mol / L of ethylenediamine as a complexing agent, 0.06 mol / L of ammonium formic acid as a reducing agent, and a crystal modifier was prepared.

While stirring the obtained suspension at 50 ° C., the palladium plating solution was gradually added to perform electroless palladium plating to form a second conductive portion. Electroless palladium plating was completed when the thickness of the second conductive portion reached 20 nm. Conductive particles (particle diameter 3.24 μm) in which the second conductive portion (palladium layer, thickness 0.02 μm) was arranged on the surface of the first conductive portion were obtained.

A conductive film and a connecting structure were obtained in the same manner as in Example 1 except that the obtained conductive particles were used.

(Comparative Example 1)
Particles in which the first conductive portion (conductive layer containing nickel, thickness 0.1 μm) was arranged on the surface of the base particle A similar to that in Example 1 were prepared as the conductive particles of Comparative Example 1. In addition, unlike Example 1, the surface treatment with the organic silicon compound was not performed.

A conductive film and a connecting structure were obtained in the same manner as in Example 1 except that the obtained conductive particles were used.

(Comparative Example 2)
Particles in which the first conductive portion (conductive layer containing nickel, thickness 0.1 μm) was arranged on the surface of the base particle A similar to that in Example 1 were prepared.

10 parts by weight of the particles and 0.5 part by weight of phosphoric acid monohexyl ester were placed in a mixed solution of 25 parts by weight of pure water and 25 parts by weight of ethanol, and the mixture was stirred at 50 ° C. for 1 hour. Then, it was filtered and dried at 100 ° C. for 8 hours by a vacuum dryer to obtain conductive particles having a film formed of a phosphoric acid monohexyl ester on the outer surface of the conductive layer.

A conductive film and a connecting structure were obtained in the same manner as in Example 1 except that the obtained conductive particles were used.

(Comparative Example 3)
Particles in which the first conductive portion (conductive layer containing nickel, thickness 0.1 μm) was arranged on the surface of the base particle A similar to that in Example 1 were prepared.

10 parts by weight of the particles and 0.5 part by weight of 1,2,3-benzotriazole were placed in a mixed solution of 25 parts by weight of pure water and 25 parts by weight of ethanol, and the mixture was stirred at 50 ° C. for 1 hour. Then, it was filtered and dried at 100 ° C. for 8 hours by a vacuum dryer to obtain conductive particles having a film formed of 1,2,3-benzotriazole on the outer surface of the conductive layer.

A conductive film and a connecting structure were obtained in the same manner as in Example 1 except that the obtained conductive particles were used.

(Comparative Example 4)
Particles in which the first conductive portion (conductive layer containing nickel, thickness 0.1 μm) was arranged on the surface of the base particle A similar to that in Example 1 were prepared.

10 parts by weight of the particles and 0.5 part by weight of 2-mercaptobenzothiazole were placed in a mixed solution of 25 parts by weight of pure water and 25 parts by weight of ethanol, and the mixture was stirred at 50 ° C. for 1 hour. Then, it was filtered and dried at 100 ° C. for 8 hours by a vacuum dryer to obtain conductive particles having a film formed by 2-mercaptobenzothiazole on the outer surface of the conductive layer.

A conductive film and a connecting structure were obtained in the same manner as in Example 1 except that the obtained conductive particles were used.

(Comparative Example 5)
A particle dispersion similar to that of Example 1 was prepared.

To 50 parts by weight of ethanol, 10 parts by weight of water, 0.8 parts by weight of acetic acid, and 1.5 parts by weight of the organic silicon compound A were added, and the mixture was stirred at room temperature for 200 minutes to obtain a solution A.

The particle dispersion was added to the solution A, heated to 50 ° C. and stirred to obtain conductive particles whose surface was modified with the organic silicon compound A.

A conductive film and a connecting structure were obtained in the same manner as in Example 1 except that the obtained conductive particles were used.

(Evaluation)
(1) Initial connection resistance A
The connection resistance A between the opposing electrodes of the obtained connection structure was measured by the 4-terminal method. From the relationship of voltage = current x resistance, the connection resistance can be obtained by measuring the voltage when a constant current is passed. Further, the connection resistance A was determined according to the following criteria.

[Evaluation criteria for connection resistance A]
○ ○ ○: Connection resistance A is 2.0Ω or less ○○: Connection resistance A is more than 2.0Ω and 3.0Ω or less ○: Connection resistance A is more than 3.0Ω and 5.0Ω or less △: Connection resistance A is 5 More than 0.0Ω and less than 10Ω ×: Connection resistance A exceeds 10Ω

(2) Connection resistance B after reliability test
The connection structure obtained in the above (1) initial evaluation of connection resistance was left to stand under the conditions of 85 ° C. and 85% relative humidity. After 1000 hours from the start of leaving, the connection resistance B between the electrodes was measured by the 4-terminal method in the same manner as in the evaluation of the connection resistance A in (3) above. Further, the connection resistance B was determined according to the following criteria.

[Criteria for connection resistance B]
○ ○ ○: Connection resistance B is less than 1.25 times the connection resistance A ○ ○: Connection resistance B is 1.25 times or more and less than 1.5 times the connection resistance A ○: Connection resistance B is the connection resistance A 1.5 times or more and less than 2 times Δ: Connection resistance B is 2 times or more and less than 3 times of connection resistance A ×: Connection resistance B is 3 times or more of connection resistance A

(3) Short-circuit occurrence rate As an IC for evaluating the short-circuit occurrence rate, the following IC (comb tooth TEG (test element group) having a space 2.5 times the particle size of the conductive particles) was prepared.

Outer diameter: 1.5 x 13 mm
Thickness: 0.5 mm

Bump specifications: Gold plating, height 15 μm, size 25 × 140 μm, space between bumps 2.5 times the particle size of conductive particles (8.0 μm when the conductive particles are 3.2 μm)
The obtained anisotropic conductive film is sandwiched between an IC for evaluating the short circuit occurrence rate and a glass substrate having a pattern corresponding to the evaluation IC, and heated and pressed under the same connection conditions as for producing a connection structure. I got a connection. The short circuit occurrence rate in the obtained connection was calculated. The short circuit occurrence rate is calculated by "the number of short circuits / total number of spaces". From the viewpoint of manufacturing a practical connection structure, the short circuit occurrence rate is preferably less than 1 ppm.

Details and results are shown in Tables 1 to 3 below.

In Tables 1 and 2 above, the types of organic silicon functional groups are as follows.

A: Organic silicon functional group having an alkyl group having 10 carbon atoms B: Organic silicon functional group having a benzotriazole group C: Organic silicon functional group having a (meth) acryloyl group D: Organic silicon functional group having an epoxy group

1 ... Conductive particles 2 ... Substrate particles 3 ... Conductive parts 11 ... Conductive particles 11a ... Protrusions 12 ... Conductive parts 12a ... Protrusions 13 ... Core material 14 ... Insulating material 21 ... Conductive particles 21a ... Protrusions 22 ... Conductive parts 22a ... Protrusion 22A ... First conductive part 22Aa ... Protrusion 22B ... Second conductive part 22Ba ... Protrusion 31 ... Conductive particles 51 ... Connection structure 52 ... First connection target member 52a ... First electrode 53 ... First 2 Connection target member 53a ... Second electrode 54 ... Connection portion

Claims (15)

Has a conductive part
Conductive particles having at least two kinds of organic silicon functional groups on the outer surface of the conductive portion. The conductive particle according to claim 1, which has an organic silicon functional group having a (meth) acryloyl group on the outer surface of the conductive portion. The conductive particle according to claim 1, which has an organic silicon functional group having an epoxy group on the outer surface of the conductive portion. The conductive particle according to any one of claims 1 to 3, which has an organic silicon functional group having an alkyl group having 1 or more and 22 or less carbon atoms on the outer surface of the conductive portion. The conductive particle according to any one of claims 1 to 4, which has an organic silicon functional group having a rust preventive effect on the outer surface of the conductive portion. The conductive particle according to claim 5, wherein the organic silicon functional group having a rust preventive effect is an organic silicon functional group having a benzotriazole group. On the outer surface of the conductive portion, at least one of the organic silicon functional group having a rust preventive effect, the organic silicon functional group having a (meth) acryloyl group, and the organic silicon functional group having an epoxy group The conductive particle according to claim 5 or 6, having the above. The total number of the organic silicon functional groups having the rust preventive effect, at least one of the organic silicon functional groups having the (meth) acryloyl group and the organic silicon functional groups having the epoxy group. The conductive particle according to claim 7, wherein the ratio to the number is 0.05 or more and 0.95 or less. The conductive particle according to any one of claims 1 to 8, which has an organic silicon functional group having a (meth) acryloyl group and an organic silicon functional group having an epoxy group on the outer surface of the conductive portion. The conductivity according to any one of claims 1 to 9, wherein the surface area covered with at least two kinds of organic silicon functional groups in 100% of the surface area of the conductive portion is 60% or more and 100% or less. particle. The conductive particle according to any one of claims 1 to 10, further comprising a base particle and a conductive portion arranged on the surface of the base particle. The conductive particle according to any one of claims 1 to 11, which has a protrusion on the outer surface of the conductive portion. The conductive particle according to any one of claims 1 to 12, comprising an insulating substance arranged on the outer surface of the conductive portion. A conductive material containing the conductive particles according to any one of claims 1 to 13 and a binder resin. A first connection target member having a first electrode on its surface,
A second connection target member having a second electrode on the surface,
The first connection target member and the connection portion connecting the second connection target member are provided.
The material of the connecting portion is the conductive particles according to any one of claims 1 to 13, or is a conductive material containing the conductive particles and a binder resin.
A connection structure in which the first electrode and the second electrode are electrically connected by the conductive particles.

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