KR102674579B1 - Conductive particles having insulating particles, method for producing conductive particles having insulating particles, electrically conductive material, and bonded structure - Google Patents

Abstract

Provided are conductive particles having insulating particles that can effectively increase insulation reliability when electrically connecting electrodes. The electrically conductive particle having an insulating particle according to the present invention includes an electrically conductive particle having an electrically conductive portion at least on the surface, and a plurality of insulating particles disposed on the surface of the electrically conductive particle, wherein the insulating particle is a polymer of a polymerizable compound. , the polymerizable compound includes a compound having a first functional group and a compound having a second functional group different from the first functional group, and the polymer has the first functional group and the second functional group.

Description

Conductive particles having insulating particles, method for producing conductive particles having insulating particles, electrically conductive material, and bonded structure

The present invention relates to conductive particles having insulating particles in which insulating particles are disposed on the surface of the conductive particles, and a method for producing conductive particles having insulating particles. Furthermore, this invention relates to an electrically-conductive material and a bonded structure using electrically conductive particles having the above insulating particles.

Anisotropic conductive materials such as anisotropic conductive paste and anisotropic conductive film are widely known. In the anisotropic conductive material, conductive particles are dispersed in the binder resin. Additionally, as the conductive particles, conductive particles to which insulation treatment was applied to the surface of the conductive layer may be used.

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

Additionally, as the conductive particles, conductive particles having insulating particles in which insulating particles are disposed on the surface of the conductive particles may be used. Additionally, covered conductive particles in which an insulating layer is disposed on the surface of the conductive layer may be used.

As an example of the above-described insulating particles, Patent Document 1 below discloses resin particles that exist on the surface of the conductive particles and insulate the conductive particles. The resin particles contain a copolymer of polymerizable components that essentially contain at least alkyl (meth)acrylate and polyhydric (meth)acrylate. The polyvalent (meth)acrylate is a compound in which each (meth)acrylic group is bonded to each other through three or more carbon atoms.

Patent Document 2 below discloses insulating coated conductive particles having conductive particles having conductive surfaces and insulating fine particles adhering to the surfaces of the conductive particles. In the above insulating fine particles, the surface of the core particle containing the polymer component derived from the crosslinkable monomer is covered with a film layer containing the polymer component derived from the crosslinkable monomer. In the insulating fine particles, the crosslinking degree defined by the following formula (1) of the core particles is 7 or more. In the insulating fine particles, the crosslinking degree defined by the following formula (1) of the core particles is higher than the crosslinking degree defined by the following formula (1) of the coating layer.

Degree of crosslinking = Number of polymerizable functional groups in crosslinkable monomers × (number of moles of crosslinkable monomers/number of moles of total monomers) × 100 Equation (1)

Japanese Patent Publication No. 2012-72324 Japanese Patent Publication No. 2010-86665

In the case of conventional conductive particles having insulating particles, when producing an anisotropic conductive material by mixing the conductive particles having insulating particles and a binder resin, the insulating particles may detach from the surface of the conductive particles. In particular, in conventional insulating particles such as those described in Patent Document 1, a crosslinkable monomer (crosslinking agent) is sometimes used to increase solvent resistance. As the content of the crosslinkable monomer (crosslinking agent) increases, the solvent resistance of the resulting insulating particles can be improved. On the other hand, since the obtained insulating particles are hard and lack flexibility, it is difficult to sufficiently increase the adhesion to the surface of the conductive particles, and it may be difficult to prevent the insulating particles from detaching from the surface of the conductive particles. As a result, during conductive connection using an anisotropic conductive material, it may be difficult to significantly increase the insulation reliability between horizontally adjacent electrodes that should not be connected.

In order to solve the above problems, for example, as described in Patent Document 2, etc., a method of using insulating particles as a core-shell structure and adjusting the degree of cross-linking on the surface of the core and the degree of cross-linking on the surface of the shell has been proposed. . However, in the conventional method, when the degree of crosslinking of the shell is low, adhesion or aggregation may occur to a large extent when conductive particles containing insulating particles come into contact with each other. Additionally, when an anisotropic conductive material is produced using a binder resin and conductive particles having insulating particles in which agglomeration has occurred, the dispersibility of the conductive particles having insulating particles may be lowered. When such an anisotropic conductive material is used, after application of the anisotropic conductive material, conductive particles may not be disposed with significantly high uniformity between the upper and lower electrodes to be connected. Additionally, aggregated conductive particles may cause short circuits between horizontally adjacent electrodes that should not be connected. In the case of conductive particles having conventional insulating particles, it is sometimes difficult to significantly increase the reliability of conduction between upper and lower electrodes that should be connected and the reliability of insulation between horizontally adjacent electrodes that should not be connected.

An object of the present invention is to provide conductive particles with insulating particles that can effectively increase insulation reliability when electrically connecting electrodes, and a method for producing conductive particles with insulating particles. Furthermore, the purpose of the present invention is to provide an electrically-conductive material and a bonded structure using electrically conductive particles having the above-described insulating particles.

According to a broad aspect of the present invention, there is provided a conductive particle having an electrically conductive portion at least on the surface, and a plurality of insulating particles disposed on the surface of the conductive particle, wherein the insulating particle is a polymer of a polymerizable compound, and the polymerizable The compound includes a compound having a first functional group and a compound having a second functional group different from the first functional group, and the polymer includes conductive particles having insulating particles having the first functional group and the second functional group. provided.

In a specific aspect of the conductive particles having insulating particles according to the present invention, the polymerizable compound does not contain a crosslinking agent, or contains 10% by weight or less of a crosslinking agent in 100% by weight of the polymerizable compound.

In a certain situation of the electroconductive particle which has the insulating particle which concerns on this invention, the said 1st functional group and the said 2nd functional group have the property which can react with a stimulus.

In a specific situation of the conductive particles having insulating particles according to the present invention, the stimulus is heating or irradiation of light.

According to a broad aspect of the present invention, there is provided a conductive particle having an electrically conductive portion at least on the surface, and a plurality of insulating particles disposed on the surface of the conductive particle, wherein the insulating particle is a polymer of a polymerizable compound, and the polymerizable Insulating property, wherein the compound includes a compound having a first functional group and a compound having a second functional group different from the first functional group, and the polymer includes a structure in which the first functional group and the second functional group reacted. Conductive particles having particles are provided.

In a specific aspect of the conductive particles having insulating particles according to the present invention, the polymerizable compound does not contain a crosslinking agent, or contains 10% by weight or less of a crosslinking agent in 100% by weight of the polymerizable compound.

In a certain situation of the electroconductive particle which has insulating particle which concerns on this invention, the crosslinking degree of the said insulating particle calculated|required by the following formula (1) is 10 or more.

Degree of crosslinking = A × [(B/D) × 100] + [(C/D) × 100] Formula (1)

In the formula (1), A is the number of polymerizable functional groups of the crosslinking agent, B is the number of moles of the crosslinking agent, C is the total number of moles of the compound having the first functional group and the compound having the second functional group, and D is the number of moles of the above It is the total number of moles of polymerizable compounds.

In a specific aspect of the conductive particles having insulating particles according to the present invention, the first functional group is a cyclic ether group, an isocyanate group, an aldehyde group, or a nitrile group.

In a specific aspect of the conductive particles having insulating particles according to the present invention, the cyclic ether group is an epoxy group or an oxetanyl group.

In a certain situation of the electroconductive particle which has the insulating particle which concerns on this invention, the said 2nd functional group is an amide group, a hydroxyl group, a carboxyl group, an imide group, or an amino group.

In a specific situation of the conductive particles having insulating particles according to the present invention, the particle size of the conductive particles is 1 μm or more and 5 μm or less.

According to a broad aspect of the present invention, conductive particles having conductive portions at least on the surface and a plurality of insulating particles are used, and a placement step of arranging the insulating particles on the surface of the conductive particles is provided, wherein the insulating particles are, A method for producing conductive particles having insulating particles is provided, which is a polymer of a polymerizable compound, wherein the polymerizable compound includes a compound having a first functional group and a compound having a second functional group different from the first functional group. .

In a specific aspect of the method for producing conductive particles having insulating particles according to the present invention, the polymerizable compound does not contain a crosslinking agent, or contains 10% by weight or less of a crosslinking agent in 100% by weight of the polymerizable compound.

In a specific aspect of the method for producing electrically conductive particles having insulating particles according to the present invention, the temperature of the batch process is less than 50° C., and the polymer is electrically conductive having insulating particles having the first functional group and the second functional group. get particles.

In a certain aspect of the method for producing conductive particles having insulating particles according to the present invention, a heating step of heating the conductive particles having insulating particles is provided after the batch step, and the heating temperature of the heating step is 70° C. or higher. and the heating time of the heating process is 1 hour or more, and the polymer obtains conductive particles having insulating particles containing a structure in which the first functional group and the second functional group react.

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

According to a broad aspect of the present invention, there is provided a first connection target member having a first electrode on its surface, a second connection target member having a second electrode on its surface, the first connection target member, and the second connection target member. It is provided with a connection part that connects, and the material of the connection part is conductive particles having the above-described insulating particles, or is a conductive material containing the conductive particles having the insulating particles and a binder resin, and the first electrode and the second electrode are provided. A bonded structure is provided in which two electrodes are electrically connected by the conductive portion in the conductive particles having the insulating particles.

The electrically conductive particle having an insulating particle according to the present invention includes an electrically conductive particle having an electrically conductive portion at least on the surface, and a plurality of insulating particles disposed on the surface of the electrically conductive particle. In the conductive particles having insulating particles according to the present invention, the insulating particles are polymers of a polymerizable compound. In the conductive particle having the insulating particle according to the present invention, the polymerizable compound includes a compound having a first functional group and a compound having a second functional group different from the first functional group. In the conductive particle having the insulating particle according to the present invention, the polymer has the first functional group and the second functional group. Since the conductive particles having the insulating particles according to the present invention have the above-described structure, when electrically connecting electrodes, the insulation reliability can be effectively improved.

The electrically conductive particle having an insulating particle according to the present invention includes an electrically conductive particle having an electrically conductive portion at least on the surface, and a plurality of insulating particles disposed on the surface of the electrically conductive particle. In the conductive particles having insulating particles according to the present invention, the insulating particles are polymers of a polymerizable compound. In the conductive particle having the insulating particle according to the present invention, the polymerizable compound includes a compound having a first functional group and a compound having a second functional group different from the first functional group. In the conductive particle having the insulating particle according to the present invention, the coating portion contains a structure in which the first functional group and the second functional group reacted. Since the conductive particles having the insulating particles according to the present invention have the above-described structure, when electrically connecting electrodes, the insulation reliability can be effectively improved.

The method for producing conductive particles having insulating particles according to the present invention includes a placement step of disposing the insulating particles on the surface of the conductive particles using conductive particles having conductive portions at least on the surface and a plurality of insulating particles. do. In the method for producing conductive particles having insulating particles according to the present invention, the insulating particles are polymers of a polymerizable compound. In the method for producing conductive particles having insulating particles according to the present invention, the polymerizable compound includes a compound having a first functional group and a compound having a second functional group different from the first functional group. Since the method for producing conductive particles having insulating particles according to the present invention has the above-mentioned structure, when electrically connecting electrodes, insulation reliability can be effectively improved.

1 is a cross-sectional view showing conductive particles having insulating particles according to a first embodiment of the present invention.
Fig. 2 is a cross-sectional view showing conductive particles having insulating particles according to the second embodiment of the present invention.
Fig. 3 is a cross-sectional view showing conductive particles having insulating particles according to the third embodiment of the present invention.
Fig. 4 is a cross-sectional view schematically showing a bonded structure using conductive particles having insulating particles according to the first embodiment of the present invention.

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

(Conductive particles having insulating particles and method for producing conductive particles having insulating particles)

The electrically conductive particle having an insulating particle according to the present invention includes an electrically conductive particle having an electrically conductive portion at least on the surface, and a plurality of insulating particles disposed on the surface of the electrically conductive particle. In the conductive particles having insulating particles according to the present invention, the insulating particles are polymers of a polymerizable compound. In the conductive particle having the insulating particle according to the present invention, the polymerizable compound includes a compound having a first functional group and a compound having a second functional group different from the first functional group. In the conductive particle having the insulating particle according to the present invention, the polymer has the first functional group and the second functional group.

Since the conductive particles having the insulating particles according to the present invention have the above-described structure, when electrically connecting electrodes, the insulation reliability can be effectively improved.

In this specification, both particles before the first functional group and the second functional group react and particles after the first functional group and the second functional group react are disclosed.

In the conductive particles having the insulating particles according to the present invention, the polymer has the first functional group and the second functional group, and the first functional group and the second functional group do not react. The conductive particles having this insulating particle are particles before the first functional group and the second functional group react. In the conductive particle having the insulating particle according to the present invention, the first functional group and the second functional group do not react, so the insulating particle has a low degree of crosslinking, has flexibility, and can increase the adhesion between the surfaces of the insulating particle and the conductive particle. there is.

The electrically conductive particle having an insulating particle according to the present invention includes an electrically conductive particle having an electrically conductive portion at least on the surface, and a plurality of insulating particles disposed on the surface of the electrically conductive particle. In the conductive particles having insulating particles according to the present invention, the insulating particles are polymers of a polymerizable compound. In the conductive particle having the insulating particle according to the present invention, the polymerizable compound includes a compound having a first functional group and a compound having a second functional group different from the first functional group. In the conductive particles having the insulating particles according to the present invention, the polymer contains a structure in which the first functional group and the second functional group reacted.

Since the conductive particles having the insulating particles according to the present invention have the above-described structure, when electrically connecting electrodes, the insulation reliability can be effectively improved.

In the conductive particles having the insulating particles according to the present invention, the polymer contains a structure in which the first functional group and the second functional group reacted. The conductive particles having this insulating particle are particles after the first functional group and the second functional group reacted. The conductive particles having this insulating particle are preferably obtained by reacting the first functional group with the second functional group before being incorporated into the binder resin. In the conductive particles having insulating particles before being incorporated into the binder resin, it is preferable that the first functional group and the second functional group are reacting. In the conductive particles having the insulating particles according to the present invention, the first functional group and the second functional group react, so that the degree of crosslinking of the insulating particles can be increased and the solvent resistance of the insulating particles can be improved.

In the case of conventional conductive particles having insulating particles, the insulating particles sometimes detach from the surface of the conductive particles when producing an anisotropic conductive material by mixing the conductive particles having insulating particles with a binder resin. In particular, in conventional insulating particles, a crosslinkable monomer (crosslinking agent) is sometimes used to increase solvent resistance. Therefore, since conventional insulating particles are hard and lack flexibility, it is difficult to sufficiently increase the adhesion between the surfaces of the insulating particles and the conductive particles, and it is difficult to prevent the insulating particles from detaching from the surface of the conductive particles. There is. As a result, during conductive connection using an anisotropic conductive material, it may be difficult to significantly increase the insulation reliability between horizontally adjacent electrodes that should not be connected.

The present inventors found that by using conductive particles having specific insulating particles, both adhesion to the surface of the conductive particles and solvent resistance can be achieved with respect to the insulating particles. In the present invention, since the above-mentioned structure is provided, it is possible to prevent the insulating particles from detaching from the surface of the conductive particles. As a result, the insulation reliability between adjacent transverse electrodes that should not be connected can be effectively improved.

Furthermore, in the present invention, since the degree of crosslinking of the insulating particles can be increased, adhesion or agglomeration of the conductive particles having the insulating particles can be prevented, and the dispersibility of the conductive particles having the insulating particles in the anisotropic conductive material can be improved. there is. As a result, a sufficient amount of conductive particles disposed between the upper and lower electrodes to be connected can be secured, and the conduction reliability between the upper and lower electrodes to be connected can be effectively increased.

In the present invention, in order to obtain the above effects, the use of conductive particles having specific insulating particles contributes greatly.

From the viewpoint of more effectively improving the conduction reliability and insulation reliability between electrodes, the coefficient of variation (CV value) of the particle diameter of the conductive particles having the above insulating particles is preferably 10% or less, more preferably 5% or less.

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

CV value (%) = (ρ/Dn) × 100

ρ: Standard deviation of particle diameter of conductive particles having insulating particles

Dn: Average value of particle diameter of conductive particles having insulating particles

The shape of the electrically conductive particles having the above insulating particles is not particularly limited. The shape of the conductive particles having the above insulating particles may be spherical, may be of a shape other than spherical, may be flat, etc.

The electrically conductive particles having the insulating particles are dispersed in a binder resin and are suitably used to obtain an electrically conductive material.

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

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

The electrically conductive particle 1 having insulating particles shown in FIG. 1 includes an electrically conductive particle 2 and a plurality of insulating particles 3 disposed on the surface of the electrically conductive particle 2. The insulating particles 3 are formed of a material having insulating properties.

The electroconductive particle 2 has the substrate particle 11 and the electroconductive part 12 arrange|positioned on the surface of the substrate particle 11. In the conductive particles 1 having insulating particles, the conductive portion 12 is a conductive layer. The conductive portion 12 covers the surface of the substrate particle 11. The conductive particles 2 are coated particles in which the surface of the substrate particle 11 is covered with the conductive portion 12. The conductive particles 2 have conductive portions 12 on the surface. In the said electroconductive particle, the said electroconductive part may cover the entire surface of the said substrate particle, and the said electroconductive part may cover a part of the surface of the said substrate particle. In the conductive particles having the insulating particles, it is preferable that the insulating particles are disposed on the surface of the conductive part.

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

The conductive particle 21 having insulating particles shown in FIG. 2 includes the conductive particle 22 and a plurality of insulating particles 3 arranged on the surface of the conductive particle 22.

The electroconductive particle 22 has the substrate particle 11 and the electrically conductive part 31 arrange|positioned on the surface of the substrate particle 11. In the conductive particles 21 containing insulating particles, the conductive portion 31 is a conductive layer. The electroconductive particle 22 has a plurality of core substances 32 on the surface of the substrate particle 11. The conductive portion 31 covers the substrate particles 11 and the core material 32. Since the conductive portion 31 covers the core material 32, the conductive particles 22 have a plurality of protrusions 33 on the surface. In the conductive particles 22, the surface of the conductive portion 31 is raised by the core material 32, and a plurality of protrusions 33 are formed. In the said electroconductive particle, the said electroconductive part may cover the entire surface of the said substrate particle, and the said electroconductive part may cover a part of the surface of the said substrate particle. In the conductive particles having the insulating particles, it is preferable that the insulating particles are disposed on the surface of the conductive part.

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

The electrically conductive particle 41 having insulating particles shown in FIG. 3 includes the electrically conductive particle 42 and a plurality of insulating particles 3 disposed on the surface of the electrically conductive particle 42 .

The electroconductive particle 42 has the substrate particle 11 and the electrically conductive part 51 arrange|positioned on the surface of the substrate particle 11. In the conductive particles 41 containing insulating particles, the conductive portion 51 is a conductive layer. The conductive particles 42 do not have a core material like the conductive particles 22 . The conductive portion 51 has a first portion and a second portion that is thicker than the first portion. The conductive particles 42 have a plurality of protrusions 52 on the surface. The portion excluding the plurality of projections 52 is the first portion of the conductive portion 51. The plurality of protrusions 52 are the second portion of the conductive portion 51 where the thickness is thick. In the said electroconductive particle, the said electroconductive part may cover the entire surface of the said substrate particle, and the said electroconductive part may cover a part of the surface of the said substrate particle. In the conductive particles having the insulating particles, it is preferable that the insulating particles are disposed on the surface of the conductive part.

Next, the manufacturing method of the electroconductive particle concerning this invention is demonstrated.

The method for producing conductive particles having insulating particles according to the present invention includes a placement step of disposing the insulating particles on the surface of the conductive particles using conductive particles having conductive portions at least on the surface and a plurality of insulating particles. do. In the method for producing conductive particles having insulating particles according to the present invention, the insulating particles are polymers of a polymerizable compound. In the method for producing conductive particles having insulating particles according to the present invention, the polymerizable compound includes a compound having a first functional group and a compound having a second functional group different from the first functional group. It is preferable that the obtained conductive particles having insulating particles are particles before the first functional group and the second functional group react.

Since the method for producing conductive particles having insulating particles according to the present invention has the above-mentioned structure, when electrically connecting electrodes, insulation reliability can be effectively improved.

In the method for producing conductive particles having insulating particles according to the present invention, the temperature of the batch process is preferably less than 50°C, and it is more preferable that the temperature of the batch process is 40°C or less. In the method for producing conductive particles with insulating particles according to the present invention, in the conductive particles with insulating particles after the arrangement step, it is preferable that the polymer has the first functional group and the second functional group. In the method for producing conductive particles having insulating particles according to the present invention, it is preferable that the first functional group and the second functional group do not react in the conductive particles having insulating particles after the batch process. In the method for producing conductive particles having insulating particles according to the present invention, in the conductive particles having insulating particles after the batch process, the first functional group does not react with the second functional group, so the degree of crosslinking of the insulating particles is low, It has flexibility and can improve the adhesion between the surfaces of the insulating particles and the conductive particles.

In the method for producing conductive particles having insulating particles according to the present invention, it is preferable to provide a heating step of heating the conductive particles having insulating particles after the arrangement step. In the method for producing conductive particles having insulating particles according to the present invention, the heating temperature in the heating step is preferably 70°C or higher, and it is more preferable that the heating temperature in the heating step is 90°C or higher. In the method for producing conductive particles having insulating particles according to the present invention, it is preferable that the heating time of the heating step is 1 hour or more, and it is more preferable that the heating time of the heating step is 2 hours or more. In the method for producing conductive particles having insulating particles according to the present invention, in the conductive particles having insulating particles after the heating step, it is preferable that the polymer contains a structure in which the first functional group and the second functional group reacted. do. In the method for producing conductive particles having insulating particles according to the present invention, it is preferable that the first functional group and the second functional group are reacting in the conductive particles having insulating particles after the heating step. It is preferable that the conductive particles having the insulating particles after the heating process are particles after the first functional group and the second functional group reacted. In the method for producing conductive particles having insulating particles according to the present invention, in the conductive particles having insulating particles after the heating step, the first functional group and the second functional group react, so that the degree of crosslinking of the insulating particles can be increased. And, the solvent resistance of the insulating particles can be improved.

In the method for producing conductive particles having insulating particles according to the present invention, the heating step is provided after the placing step, so that both adhesion to the surface of the conductive particles and solvent resistance can be achieved with respect to the insulating particles. there is. As a result, when electrically connecting electrodes using conductive particles having insulating particles, the insulation reliability between adjacent electrodes in the lateral direction, which should not be connected, can be more effectively improved.

In the method for producing conductive particles having insulating particles according to the present invention, the degree of crosslinking of the insulating particles can be increased, so that adhesion or aggregation of the conductive particles having insulating particles can be prevented, and the insulating particles in the anisotropic conductive material can be prevented. The dispersibility of the conductive particles can be improved. As a result, the conduction reliability between the upper and lower electrodes to be connected can be improved more effectively.

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

Conductive particles:

It is preferable that the said electroconductive particle has a substrate particle and an electroconductive part arrange|positioned on the surface of the said substrate particle. The conductive part may have a single-layer structure or a two-layer or more multi-layer structure.

The particle diameter of the conductive particles is preferably 0.5 μm or more, more preferably 1 μm or more, preferably 100 μm or less, more preferably 60 μm or less, even more preferably 30 μm or less, even more preferably is 10 μm or less, particularly preferably 5 μm or less. If the particle size of the conductive particles is equal to or greater than the lower limit and equal to or less than the upper limit, when connecting electrodes using the conductive particles, the contact area between the conductive particles and the electrode becomes sufficiently large, and the conductivity aggregated when forming the conductive portion is sufficiently increased. It becomes difficult for particles to form. Additionally, the gap between electrodes connected via the conductive particles does not become too large, and it becomes difficult for the conductive portion to peel off from the surface of the substrate particle.

The particle diameter of the conductive particles is preferably an average particle diameter, and more preferably a number average particle diameter. The particle diameter of the conductive particles is determined, for example, by observing 50 arbitrary conductive particles with an electron microscope or an optical microscope, calculating the average value of the particle diameter of each conductive particle, or performing laser diffraction particle size distribution measurement. In observation using an electron microscope or an optical microscope, the particle size of each conductive particle is determined as the particle size in the equivalent circle diameter. In observation using an electron microscope or an optical microscope, the average particle diameter in the equivalent circle diameter of any 50 conductive particles becomes almost equal to the average particle diameter in the equivalent sphere diameter. In laser diffraction particle size distribution measurement, the particle size of each conductive particle is determined as the particle size in the equivalent sphere diameter. The particle size of the conductive particles is preferably calculated by laser diffraction particle size distribution measurement.

The coefficient of variation (CV value) of the particle diameter of the conductive particles is preferably 10% or less, more preferably 5% or less. If the coefficient of variation of the particle diameter of the conductive particles is below the upper limit, the reliability of conduction and insulation between electrodes can be improved more effectively.

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

CV value (%) = (ρ/Dn) × 100

ρ: Standard deviation of particle diameter of conductive particles

Dn: Average value of particle diameter of conductive particles

The shape of the conductive particles is not particularly limited. The shape of the electrically conductive particles may be spherical, may be of a shape other than spherical, may be flat, etc.

Base particles:

Examples of the substrate particles include resin particles, inorganic particles excluding metal particles, organic-inorganic hybrid particles, and metal particles. It is preferable that the said substrate particle is a substrate particle excluding a metal particle, and it is more preferable that it is a resin particle, an inorganic particle except a metal particle, or an organic-inorganic hybrid particle. The base particle may be a core-shell particle including a core and a shell disposed on the surface of the core. The core may be an organic core, and the shell may be an inorganic shell.

As materials for the resin particles, various organic substances are suitably used. Examples of materials for the resin particles include polyolefin resins such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyisobutylene, and polybutadiene; Acrylic resins such as polymethyl methacrylate and polymethyl acrylate; Polycarbonate, polyamide, phenol formaldehyde resin, melamine formaldehyde resin, benzoguanamine formaldehyde resin, urea formaldehyde resin, phenol resin, melamine resin, benzoguanamine resin, urea resin, epoxy resin, unsaturated polyester. Resin, saturated polyester resin, polyethylene terephthalate, polysulfone, polyphenylene oxide, polyacetal, polyimide, polyamideimide, polyetheretherketone, polyethersulfone, divinylbenzene polymer, and divinylbenzene-based copolymer. etc. can be mentioned. Examples of the divinylbenzene-based copolymer include divinylbenzene-styrene copolymer and divinylbenzene-(meth)acrylic acid ester copolymer. Since the hardness of the resin particles can be easily controlled to an appropriate range, the material of the resin particles is preferably a polymer obtained by polymerizing one or two or more types of polymerizable monomers having an ethylenically unsaturated group.

When the resin particles are obtained by polymerizing a polymerizable monomer having an ethylenically unsaturated group, examples of the polymerizable monomer having an ethylenically unsaturated group include non-crosslinkable monomers and crosslinkable monomers.

Examples of the non-crosslinkable monomer include styrene-based monomers such as styrene and α-methylstyrene; Carboxyl group-containing monomers such as (meth)acrylic acid, maleic acid, and maleic anhydride; Methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, cetyl (meth) alkyl (meth)acrylate compounds such as acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, and isobornyl (meth)acrylate; oxygen atom-containing (meth)acrylate compounds such as 2-hydroxyethyl (meth)acrylate, glycerol (meth)acrylate, polyoxyethylene (meth)acrylate, and glycidyl (meth)acrylate; Nitrile-containing monomers such as (meth)acrylonitrile; Vinyl ether compounds such as methyl vinyl ether, ethyl vinyl ether, and propyl vinyl ether; Acid vinyl ester compounds such as vinyl acetate, vinyl butyrate, vinyl laurate, and vinyl stearate; unsaturated hydrocarbons such as ethylene, propylene, isoprene, and butadiene; and halogen-containing monomers such as trifluoromethyl (meth)acrylate, pentafluoroethyl (meth)acrylate, vinyl chloride, vinyl fluoride, and chlorostyrene.

Examples of the crosslinkable monomer include tetramethylolmethane tetra(meth)acrylate, tetramethylolmethane tri(meth)acrylate, tetramethylolmethane di(meth)acrylate, and trimethylolpropane tri(meth)acrylate. Latex, dipentaerythritol hexa(meth)acrylate, dipentaerythritol penta(meth)acrylate, glycerol tri(meth)acrylate, glycerol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate polyfunctional (meth)acrylate compounds such as polyester, (poly)propylene glycol di(meth)acrylate, (poly)tetramethylene glycol di(meth)acrylate, and 1,4-butanediol di(meth)acrylate; Triallyl (iso)cyanurate, triallyl trimellitate, divinylbenzene, diallyl phthalate, diallyl acrylamide, diallyl ether, and γ-(meth)acryloxypropyltrimethoxysilane, trimethoxy and silane-containing monomers such as silyl styrene and vinyl trimethoxysilane.

The term “(meth)acrylate” refers to acrylate and methacrylate. The term “(meth)acrylic” refers to acrylic and methacryl. The term “(meth)acryloyl” refers to acryloyl and methacryloyl.

The resin particles can be obtained by polymerizing the polymerizable monomer having an ethylenically unsaturated group by a known method. Examples of this method include a method of performing suspension polymerization in the presence of a radical polymerization initiator, and a method of polymerizing the monomer by swelling it with a radical polymerization initiator using non-crosslinked seed particles.

When the substrate particles are inorganic particles other than metal or organic-inorganic hybrid particles, examples of the inorganic material for forming the substrate particles include silica, alumina, barium titanate, zirconia, and carbon black. It is preferable that the inorganic material is not a metal. The particles formed from the above silica are not particularly limited, but examples include particles obtained by hydrolyzing a silicon compound having two or more hydrolyzable alkoxysilyl groups to form crosslinked polymer particles, and then performing baking as necessary. You can. Examples of the organic-inorganic hybrid particles include organic-inorganic hybrid particles formed of a crosslinked alkoxysilyl polymer and an acrylic resin.

The organic-inorganic hybrid particles are preferably core-shell type organic-inorganic hybrid particles having a core and a shell disposed on the surface of the core. It is preferred that the core is an organic core. It is preferred that the shell is an inorganic shell. From the viewpoint of effectively lowering the connection resistance between electrodes, it is preferable that the substrate particles are organic-inorganic hybrid particles having an organic core and an inorganic shell disposed on the surface of the organic core.

Materials for the organic core include the resin particle materials described above.

Examples of the material of the inorganic shell include the inorganic substances cited as materials for the substrate particles described above. 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 baking the shell-like material. The metal alkoxide is preferably a silane alkoxide. The inorganic shell is preferably formed of silane alkoxide.

When the substrate particles are metal particles, examples of metals used as materials for the metal particles include silver, copper, nickel, silicon, gold, and titanium.

The particle diameter of the substrate particles is preferably 0.5 μm or more, more preferably 1 μm or more, further preferably 2 μm or more, preferably 100 μm or less, more preferably 60 μm or less, even more preferably It is 50㎛ or less. If the particle size of the substrate particle is more than the above-mentioned lower limit and below the above-mentioned upper limit, the space between electrodes becomes small, and even if the thickness of the conductive layer is increased, small electroconductive particles are obtained. Moreover, when forming an electrically conductive part on the surface of a substrate particle, it becomes difficult to aggregate, and it becomes difficult for the aggregated electrically conductive particle to be formed.

It is especially preferable that the particle diameter of the said substrate particle is 2 micrometers or more and 50 micrometers or less. If the particle diameter of the said substrate particle is within the range of 2 micrometers or more and 50 micrometers or less, it becomes difficult to aggregate when forming an electrically conductive part on the surface of a substrate particle, and it becomes difficult for aggregated electroconductive particles to form.

The particle diameter of the substrate particle represents the diameter when the substrate particle is spherical, and represents the maximum diameter when the substrate particle is not spherical.

The particle diameter of the substrate particles represents the number average particle diameter. The particle diameter of the substrate particles is determined using a particle size distribution measuring device or the like. The particle diameter of the substrate particles is preferably determined by observing 50 arbitrary substrate particles with an electron microscope or an optical microscope and calculating the average value. In observation using an electron microscope or an optical microscope, the particle diameter of each substrate particle is determined as the particle diameter in the equivalent circle diameter. In observation using an electron microscope or an optical microscope, the average particle diameter in the equivalent circle diameter of any 50 substrate particles becomes almost equal to the average particle diameter in the equivalent sphere diameter. In a particle size distribution measuring device, the particle diameter of each substrate particle is determined as the particle diameter in the equivalent sphere diameter. It is preferable to calculate the particle diameter of the substrate particles using a particle size distribution measuring device. In the case of electroconductive particles, when measuring the particle diameter of the substrate particles, it can be measured as follows, for example.

It is added to "Technobit 4000" manufactured by Kulzer and dispersed so that the content of the conductive particles is 30% by weight, and an embedding resin for conductive particle inspection is produced. Using an ion milling device (“IM4000” manufactured by Hitachi High Technologies), a cross section of the conductive particles is cut so as to pass near the center of the conductive particles dispersed in the embedding resin for inspection. Then, using a field emission scanning electron microscope (FE-SEM), the image magnification is set to 25,000 times, 50 conductive particles are randomly selected, and the substrate particles of each conductive particle are observed. The particle diameter of the substrate particle in each electroconductive particle is measured, and they are arithmetic averaged to obtain the particle diameter of the substrate particle.

Challenge section:

In the present invention, the electrically conductive particles have an electrically conductive portion at least on the surface. The electrically conductive portion preferably contains metal. The metal constituting the conductive portion is not particularly limited. Examples of the metal include gold, silver, copper, platinum, palladium, zinc, lead, aluminum, cobalt, indium, nickel, chromium, titanium, antimony, bismuth, germanium and cadmium, and alloys thereof. . Additionally, as the metal, tin-doped indium oxide (ITO) may be used. Only one type of the said metal may be used, and two or more types may be used together. From the viewpoint of further lowering the connection resistance between electrodes, the metal is preferably an alloy containing tin, nickel, palladium, copper, or gold, and nickel or palladium is more preferable.

Additionally, from the viewpoint of effectively increasing conduction reliability, it is preferable that the conductive portion and the outer surface portion of the conductive portion contain nickel. The nickel content in 100% by weight of the conductive part containing nickel is preferably 10% by weight or more, more preferably 50% by weight or more, even more preferably 60% by weight or more, and even more preferably 70% by weight or more. , especially preferably 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, or 98% by weight or more.

Additionally, hydroxyl groups often exist on the surface of the conductive part due to oxidation. Generally, hydroxyl groups exist on the surface of the conductive part formed of nickel due to oxidation. Insulating particles can be placed on the surface of the conductive part (surface of the conductive particle) having such a hydroxyl group through chemical bonding.

The conductive portion may be formed of one layer. The conductive portion may be formed of multiple layers. That is, the conductive portion may have a laminated structure of two or more layers. When the conductive portion is formed of multiple layers, the metal constituting the outermost layer is preferably gold, nickel, palladium, copper, or an alloy containing tin and silver, and more preferably gold. When the metal constituting the outermost layer is one of these preferred metals, the connection resistance between electrodes is further lowered. Additionally, when the metal constituting the outermost layer is gold, corrosion resistance is further improved.

The method of forming the conductive portion on the surface of the substrate particle is not particularly limited. Methods for forming the conductive portion include, for example, 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 method of coating the surface of a base particle with a metal powder or a paste containing a metal powder and a binder can be mentioned. The method of forming the conductive portion is preferably electroless plating, electroplating, or physical collision. Examples of the physical vapor deposition method include vacuum deposition, ion plating, and ion sputtering. In addition, in the method using physical collision, for example, a sheeter composer (manufactured by Tokuju Kosakusho Co., Ltd.) 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, and still more preferably 0.3 μm or less. If the thickness of the conductive portion is equal to or greater than the lower limit and equal to or less than the upper limit, sufficient conductivity is obtained, and the conductive particles do not become too hard, and the conductive particles can be sufficiently deformed during connection between electrodes.

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, and more preferably 0.1 μm or more. It is less than ㎛. If the thickness of the electrically conductive portion of the outermost layer is equal to or greater than the lower limit and equal to or smaller than the upper limit, the electrically conductive portion of the outermost layer becomes uniform, corrosion resistance is sufficiently increased, and connection resistance between electrodes can be sufficiently low.

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

Core Material:

The electrically conductive particles preferably have a plurality of protrusions on the outer surface of the electrically conductive part. An oxide film is often formed on the surface of an electrode connected by conductive particles having insulating particles. When conductive particles having insulating particles having protrusions are used on the surface of the conductive portion, the oxide film can be effectively removed by the protrusions by placing the conductive particles having insulating particles between electrodes and pressing them. For this reason, the electrode and the conductive part contact more reliably, and the connection resistance between the electrodes is further lowered. Additionally, when connecting electrodes, insulating particles between the conductive particles and the electrodes can be effectively excluded by the protrusions of the conductive particles. For this reason, the reliability of conduction between electrodes is further improved.

Methods for forming the protrusions include a method of attaching a core material to the surface of a substrate particle and then forming a conductive portion by electroless plating, and a method of forming a conductive portion by electroless plating on the surface of the substrate particle and then forming the core material. and a method of forming a conductive portion by electroless plating. Another method of forming the protrusion is a method of forming a first conductive portion on the surface of a substrate particle, then arranging a core material on the first conductive portion, and then forming a second conductive portion, and forming the second conductive portion on the surface of the substrate particle. A method of adding a core material during the formation of a conductive portion (such as a first conductive portion or a second conductive portion) on the surface may be included. In addition, in order to form the protrusions, the conductive portion is formed on the base particle by electroless plating without using the core material, and then the plating is deposited in the form of a protrusion on the surface of the conductive portion, and the conductive portion is further formed by electroless plating. You can also use methods to create wealth.

As a method of attaching the core material to the surface of the substrate particles, for example, a method of adding the core material to the dispersion of the substrate particles, accumulating the core material on the surface of the substrate particles by van der Waals forces, and attaching the core material to the surface of the substrate particles. , and a method of adding a core substance to a container containing base particles and attaching the core substance to the surface of the base particles by mechanical action such as rotation of the container. From the viewpoint of controlling the amount of the core substance to be deposited, it is preferable that the method of attaching the core substance to the surface of the substrate particles is a method of accumulating the core substance to the surface of the substrate particles in the dispersion liquid and causing it to adhere.

Materials constituting the core material include conductive materials and non-conductive materials. Examples of the conductive material include conductive non-metals such as metals, metal oxides, and graphite, and conductive polymers. Examples of the conductive polymer include polyacetylene. Examples of the non-conductive materials include silica, alumina, and zirconia. From the viewpoint of further improving the reliability of conduction between electrodes, it is preferable that the core material is a metal.

The metal is not particularly limited. Examples of the metal 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, tin-copper alloys, tin-silver alloys, tin-lead-silver alloys, and alloys composed of two or more types of metals such as tungsten carbide. From the viewpoint of further improving the reliability of conduction between 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 material is not particularly limited. The shape of the core material is preferably blocky. Examples of the core material include a particulate mass, an agglomerated mass of a plurality of fine particles, and an irregular mass.

The average diameter (average particle diameter) of the core material 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. If the average diameter of the core material is equal to or greater than the lower limit and equal to or smaller than the upper limit, the connection resistance between electrodes can be effectively lowered.

The average particle diameter of the core material is preferably a number average particle diameter. The average particle diameter of the core material is obtained, for example, by observing 50 arbitrary core materials with an electron microscope or an optical microscope and calculating the average value of the particle diameter of each core material, or by performing laser diffraction particle size distribution measurement. In observation using an electron microscope or an optical microscope, the particle size of each core material is determined as the particle size in the equivalent circle diameter. In observation using an electron microscope or an optical microscope, the average particle diameter in the equivalent circle diameter of any 50 core materials becomes almost equal to the average particle diameter in the equivalent sphere diameter. In laser diffraction particle size distribution measurement, the particle size of each core material is determined as the particle size in the equivalent sphere diameter. The average particle diameter of the core material is preferably calculated by laser diffraction particle size distribution measurement.

Insulating particles:

The electrically conductive particle having insulating particles according to the present invention includes a plurality of insulating particles arranged on the surface of the electrically conductive particle. In this case, if conductive particles having the above insulating particles are used for connection between electrodes, short circuit between adjacent electrodes can be prevented. Specifically, when conductive particles having a plurality of insulating particles come into contact, the insulating particles exist between the plurality of electrodes, so short circuiting can be prevented not between the upper and lower electrodes but between horizontally adjacent electrodes. Additionally, when connecting electrodes, by pressing the conductive particles having insulating particles on the two electrodes, the insulating particles between the conductive portion of the conductive particles and the electrodes can be easily removed. Additionally, in the case of conductive particles having a plurality of protrusions on the outer surface of the conductive portion, insulating particles between the conductive portion of the conductive particle and the electrode can be more easily excluded.

In the conductive particles having insulating particles according to the present invention, the insulating particles are polymers of a polymerizable compound. The insulating particles are preferably a polymer of a polymerizable component containing multiple types of polymerizable compounds. The polymerizable compound is not particularly limited. Examples of the polymerizable compound include the above-mentioned resin particle materials. The above-mentioned resin particles may be used as the insulating particles.

Additionally, the polymerizable compound may contain a polymerizable compound whose homopolymer has a glass transition temperature of less than 100°C. The polymerizable component may contain a polymerizable compound whose homopolymer has a glass transition temperature of less than 100°C. The polymerizable compound may contain 10% by weight or more of a polymerizable compound whose homopolymer has a glass transition temperature of less than 100°C, based on 100% by weight of the polymerizable compound. The polymerizable component may contain 10% by weight or more of a polymerizable compound whose homopolymer has a glass transition temperature of less than 100°C, based on 100% by weight of the polymerizable component. Here, the homopolymer in the polymerizable compound whose glass transition temperature of the homopolymer is less than 100°C means a homopolymer obtained by homopolymerizing the polymerizable compound. When the polymerizable compound (the polymerizable component) contains a polymerizable compound whose glass transition temperature of the homopolymer is less than 100°C, the insulating particles can be made more flexible and the adhesion between the surfaces of the insulating particles and the conductive particles can be improved. It can be raised even further.

In the conductive particle having the insulating particle according to the present invention, the polymerizable compound includes a compound having a first functional group and a compound having a second functional group different from the first functional group. It is preferable that the first functional group and the second functional group are reactive functional groups. It is preferable that the compound having the first functional group and the compound having the second functional group are polymerizable compounds. The polymerizable compound preferably includes a polymerizable compound having a first reactive functional group and a polymerizable compound having a second reactive functional group different from the first reactive functional group. The polymerizable component preferably contains a polymerizable compound having a first reactive functional group and a polymerizable compound having a second reactive functional group different from the first reactive functional group.

The first functional group is preferably a cyclic ether group, an isocyanate group, an aldehyde group, or a nitrile group, more preferably a cyclic ether group, an isocyanate group, or a nitrile group, and even more preferably a cyclic ether group or a nitrile group. The cyclic ether group is preferably an epoxy group or oxetanyl group, and more preferably an epoxy group. When the first functional group is the preferred functional group described above, the insulation reliability can be improved more effectively when the electrodes are electrically connected using conductive particles having insulating particles.

Examples of the compounds having the epoxy group include glycidyl (meth)acrylate, allyl glycidyl ether, 4-hydroxybutyl (meth)acrylate glycidyl ether, and 3,4-epoxycyclohexylmethyl (meth)acrylate. can be mentioned. As for the compound which has the said epoxy group, only 1 type may be used, and 2 or more types may be used together.

The compound having the epoxy group is preferably glycidyl (meth)acrylate or 4-hydroxybutyl (meth)acrylate glycidyl ether.

Examples of compounds having the cyclic ether group (excluding the epoxy group) include (3-ethyloxetan-3-yl)methyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, and cyclic trimethylolpropane formal (meth)acrylate, etc. can be mentioned. As for the compound having the cyclic ether group (excluding the epoxy group), only one type may be used, or two or more types may be used in combination.

The compound having the cyclic ether group (excluding the epoxy group) is preferably (3-ethyloxetan-3-yl)methyl (meth)acrylate.

Examples of the compound having the isocyanate group include 2-(meth)acryloyloxyethyl isocyanate, 2-(meth)acrylic acid 2-(0-[1'-methylpropylideneamino]carboxyamino)ethyl, 2-[(3,5- Dimethylpyrazolyl)carbonylamino]ethyl (meth)acrylate, 2-(2-(meth)acryloyloxyethyloxy)ethyl isocyanate, 2-propylene isocyanate, 1-phenyl-2-propylene isocyanate, 4,4 -Dimethylpentene-5-isocyanate, 2,4,4-trimethylpentene-5-isocyanate, 3,3-dimethylpentene-5-isocyanate, 2-allyl-2-isocyanatomethyl-malonic acid diethyl ester, 1 -Phenyl-3-methyl-3-butene isocyanate, 4-vinylbenzene isocyanate, 1-isocyanatomethyl-4-vinyl-benzene, and 1,1-(bisacryloyloxymethyl)ethyl isocyanate, etc. there is. As for the compound which has the said isocyanate group, only 1 type may be used, and 2 or more types may be used together.

The compound having the isocyanate group is preferably 2-(meth)acryloyloxyethyl isocyanate or 2-(2-(meth)acryloyloxyethyloxy)ethyl isocyanate.

Examples of the compound having the aldehyde group include acrolein.

Examples of the compound having the nitrile group include (meth)acrylonitrile.

The second functional group is different from the first functional group. The second functional group is preferably an amide group, a hydroxyl group, a carboxyl group, an imide group, or an amino group, more preferably an amide group, a carboxyl group, or an amino group, and even more preferably an amide group or a carboxyl group. When the second functional group is the preferred functional group described above, the insulation reliability can be improved more effectively when the electrodes are electrically connected using conductive particles having insulating particles.

Examples of the compound having the amide group include (meth)acrylamide, N-substituted (meth)acrylamide, and N,N-substituted (meth)acrylamide. The N-substituted (meth)acrylamide is not particularly limited. Examples of the N-substituted (meth)acrylamide include N-isopropyl (meth)acrylamide, N-methylol (meth)acrylamide, N-(2-hydroxyethyl)(meth)acrylamide, N -Methoxymethyl (meth)acrylamide, N-ethoxymethyl (meth)acrylamide, N-propoxymethyl (meth)acrylamide, N-isopropoxymethyl (meth)acrylamide, N-butoxymethyl ( Meth)acrylamide, N-isobutoxymethyl (meth)acrylamide, diacetone (meth)acrylamide, and N,N-dimethylaminopropyl (meth)acrylamide. The N,N-substituted (meth)acrylamide is not particularly limited. Examples of the N,N-substituted (meth)acrylamide include N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, and (meth)acryloylmorpholine. You can. As for the compound which has the said amide group, only 1 type may be used, and 2 or more types may be used together.

The compound having the amide group is preferably (meth)acrylamide, N-methoxymethyl(meth)acrylamide, or N,N-dimethyl(meth)acrylamide, and more preferably (meth)acrylamide. .

Examples of compounds having the hydroxyl group include 2-hydroxyethyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 3-hydroxypropyl (meth)acrylate. , 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxyl. Uryl (meth)acrylate, (4-hydroxymethylcyclohexyl)methyl acrylate, vinyl alcohol, allyl alcohol, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, diethylene glycol monovinyl ether, penta Erythritol tri(meth)acrylate, pentaerythritol di(meth)acrylate monostearate, isocyanuric acid ethylene oxide modified di(meth)acrylate, 2-hydroxy-3-phenoxypropyl(meth)acrylate salt, glycerin (meth)acrylate, and 2-hydroxy-3-(meth)acryloyloxypropyl (meth)acrylate. As for the compound which has the said hydroxyl group, only 1 type may be used, and 2 or more types may be used together.

The compound having the hydroxyl group is preferably 2-hydroxyethyl (meth)acrylate or 2-hydroxybutyl (meth)acrylate.

Examples of the compounds having the carboxyl group include unsaturated monocarboxylic acids such as (meth)acrylic acid, crotonic acid, and cinnamic acid, unsaturated dicarboxylic acids such as maleic acid, itaconic acid, succinic acid, fumaric acid, and citraconic acid, and salts thereof. Anhydrides, etc. can be mentioned. As for the compound which has the said carboxyl group, only 1 type may be used, and 2 or more types may be used together.

The compound having the carboxyl group is preferably (meth)acrylic acid.

Examples of compounds having the imide group include imide (meth)acrylate and maleimide. As for the compound which has the said imide group, only 1 type may be used, and 2 or more types may be used together.

The compound having the imide group is preferably imide (meth)acrylate.

Examples of compounds having the amino group include N,N-dimethylaminoethyl (meth)acrylate and N,N-dimethylaminopropyl methacrylate. As for the compound which has the said amino group, only 1 type may be used, and 2 or more types may be used together.

The compound having the amino group is preferably N,N-dimethylaminoethyl (meth)acrylate.

In the conductive particles having the insulating particles according to the present invention, it is preferable that the polymerizable compound does not contain a crosslinking agent, or that the crosslinking agent is contained in an amount of 10% by weight or less out of 100% by weight of the polymerizable compound. In the conductive particles having the above insulating particles, it is preferable that the polymerizable component does not contain a crosslinking agent, or that the crosslinking agent is contained in an amount of 10% by weight or less in 100% by weight of the polymerizable component. When electrically connecting electrodes using conductive particles having insulating particles, from the viewpoint of more effectively increasing insulation reliability, the polymerizable compound contains 7% by weight or less of the crosslinking agent in 100% by weight of the polymerizable compound. It is preferable to include 6% by weight or less of the crosslinking agent in 100% by weight of the polymerizable compound. When electrically connecting electrodes using conductive particles having insulating particles, from the viewpoint of more effectively increasing insulation reliability, the polymerizable component contains 7% by weight or less of the crosslinking agent in 100% by weight of the polymerizable component. It is preferable to include the crosslinking agent in an amount of 6% by weight or less based on 100% by weight of the polymerizable component. When electrically connecting electrodes using conductive particles having insulating particles, from the viewpoint of more effectively increasing insulation reliability, the polymerizable compound contains 5% by weight or less of the crosslinking agent in 100% by weight of the polymerizable compound. It is more preferable to include the crosslinking agent in an amount of less than 5% by weight based on 100% by weight of the polymerizable compound. When electrically connecting electrodes using conductive particles having insulating particles, from the viewpoint of more effectively increasing insulation reliability, the polymerizable component contains 5% by weight or less of the crosslinking agent in 100% by weight of the polymerizable component. It is more preferable to include the crosslinking agent in an amount of less than 5% by weight in 100% by weight of the polymerizable component. When electrically connecting electrodes using conductive particles having insulating particles, it is particularly preferable that the polymerizable compound does not contain a crosslinking agent from the viewpoint of more effectively improving insulation reliability. When electrically connecting electrodes using conductive particles having insulating particles, it is particularly preferable that the polymerizable component does not contain a crosslinking agent from the viewpoint of improving insulation reliability more effectively.

In the conductive particles having the insulating particles according to the present invention, the degree of crosslinking of the insulating particles determined by the following formula (1) is preferably 10 or more, and more preferably 14 or more. If the degree of crosslinking of the insulating particles is more than the above lower limit, the insulation reliability can be improved more effectively when electrical connection between electrodes is made using conductive particles having insulating particles.

Degree of crosslinking = A × [(B/D) × 100] + [(C/D) × 100] Formula (1)

In the formula (1), A is the number of polymerizable functional groups of the crosslinking agent, B is the number of moles of the crosslinking agent, C is the total number of moles of the compound having the first functional group and the compound having the second functional group, and D is the number of moles of the above It is the total number of moles of polymerizable compounds.

The crosslinking agent is not particularly limited. The crosslinking agent is preferably a polymerizable compound having two or more ethylenically unsaturated groups in one molecule. Examples of the crosslinking agent include crosslinkable monomers that are materials for the resin particles described above. From the viewpoint of easily controlling the reaction of the polymerizable compound, the crosslinking agent is preferably ethylene glycol di(meth)acrylate or tetramethylolmethane tetra(meth)acrylate.

In the conductive particles having the insulating particles according to the present invention, the polymer has a configuration (first configuration) in which the polymer has the first functional group and the second functional group, or the polymer has the first functional group and the second functional group. It has a configuration (second configuration) that includes a structure reacted with .

When the conductive particle having the insulating particle according to the present invention has the first configuration, the polymer has the first functional group and the second functional group, and the first functional group and the second functional group do not react. No. When the conductive particle having the insulating particle according to the present invention has the first configuration, the first functional group and the second functional group do not react, so the degree of crosslinking of the insulating particle is low, it has flexibility, and the insulating particle The adhesion of the surface of the conductive particles can be improved.

When the conductive particles having the insulating particles according to the present invention have the above-mentioned first structure, it is preferable that the first functional group and the second functional group have a property capable of reacting to stimulation. The stimulation is preferably heating or irradiation of light, and more preferably heating. Additionally, reactive properties mean properties that can form chemical bonds. In the conductive particles having the insulating particles according to the present invention, it is preferable that the first functional group and the second functional group form a chemical bond by stimulation (heating or irradiation of light).

When the conductive particles having the insulating particles according to the present invention have the second structure, the polymer contains a structure in which the first functional group reacts with the second functional group, and the first functional group and the second functional group react with each other. 2 The functional group is reacting. When the conductive particles having the insulating particles according to the present invention have the second structure, the first functional group and the second functional group react, so the degree of crosslinking of the insulating particles can be increased, and the solvent resistance of the insulating particles can be increased. It can be raised.

In the conductive particles having the insulating particles according to the present invention, it is preferable to obtain the conductive particles having the insulating particles having the second structure by heating or irradiating the conductive particles with light. do. It is more preferable that the electroconductive particles having the insulating particles having the second structure are obtained by heating the electroconductive particles having the insulating particles having the first structure. When the conductive particles having the above-mentioned insulating particles satisfy the above-described preferred form, the insulating particles can achieve both adhesion to the surface of the conductive particles, insulation properties, and solvent resistance. As a result, when electrically connecting electrodes using conductive particles having insulating particles, insulation reliability can be improved more effectively.

Methods for disposing the insulating particles on the surface of the conductive part include chemical methods and physical or mechanical methods. Examples of the chemical method include interfacial polymerization, suspension polymerization in the presence of particles, and emulsion polymerization. Examples of the physical or mechanical methods include spray drying, hybridization, electrostatic attachment, spraying, dipping, and vacuum deposition. Since the insulating particles are difficult to detach from, a method of arranging the insulating particles on the surface of the conductive part through chemical bonding is preferable. In the conductive particle having the insulating particle according to the present invention, it is preferable that a compound having the first functional group is chemically bonded to a hydroxyl group present on the surface of the conductive part, etc., and the hydroxyl group etc. present on the surface of the conductive part and the first functional group are preferably chemically bonded to each other. It is preferable that the compound having a bifunctional group is chemically bonded. In the conductive particle having the insulating particle according to the present invention, the first functional group may be chemically bonded to a hydroxyl group, etc., present on the surface of the conductive portion, or the first functional group may be chemically bonded to a hydroxyl group, etc., present on the surface of the conductive portion. It does not have to be done. In the conductive particle having the insulating particle according to the present invention, the second functional group may be chemically bonded to a hydroxyl group, etc., present on the surface of the conductive portion, or the second functional group may be chemically bonded to a hydroxyl group, etc., present on the surface of the conductive portion. It does not have to be done.

The outer surface of the conductive portion and the outer surface of the insulating particles 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 particles do not have to be directly chemically bonded, but may be indirectly chemically bonded through a compound having a reactive functional group. After introducing a carboxyl group to the outer surface of the conductive part, the carboxyl group may be chemically bonded to a functional group on the outer surface of the insulating particle through a polymer electrolyte such as polyethyleneimine.

The particle size of the insulating particles can be appropriately selected depending on the particle size of the conductive particles containing the insulating particles and the purpose of the conductive particles containing the insulating particles. The particle diameter of the insulating particles is preferably 10 nm or more, more preferably 100 nm or more, further preferably 200 nm or more, particularly preferably 300 nm or more, preferably 4000 nm or less, more preferably It is 2000 nm or less, more preferably 1500 nm or less, particularly preferably 1000 nm or less. If the particle size of the insulating particles is more than the above lower limit, when the conductive particles containing the insulating particles are dispersed in the binder resin, it becomes difficult for the conductive parts in the plurality of conductive particles containing the insulating particles to contact each other. If the particle size of the insulating particles is below the upper limit, there is no need to apply too high a pressure to exclude the insulating particles between the electrodes and the conductive particles when connecting the electrodes, and there is no need to heat it to a high temperature.

The particle diameter of the insulating particles represents the number average particle diameter. The particle diameter of the insulating particles is determined using a particle size distribution measuring device or the like. The particle diameter of the insulating particles is preferably determined by observing 50 arbitrary insulating particles with an electron microscope or an optical microscope and calculating the average value. In observation using an electron microscope or an optical microscope, the particle size of each insulating particle is determined as the particle size in the equivalent circle diameter. In observation using an electron microscope or an optical microscope, the average particle diameter in the equivalent circle diameter of any 50 insulating particles becomes almost equal to the average particle diameter in the equivalent sphere diameter. In a particle size distribution measuring device, the particle diameter of each insulating particle is determined as the particle diameter in the equivalent sphere diameter. It is preferable to calculate the particle size of the insulating particles using a particle size distribution measuring device. In the case of measuring the particle diameter of the insulating particles in the conductive particles having the insulating particles, for example, it can be measured as follows.

Conductive particles having insulating particles are added to “Techno Bit 4000” manufactured by Kulzer so that the content is 30% by weight, dispersed, and an embedding resin for conductive particle inspection is produced. Using an ion milling device (“IM4000” manufactured by Hitachi High-Technologies), a cross section of the conductive particle having the insulating particle is cut so as to pass near the center of the conductive particle having the insulating particle dispersed in the embedding resin for inspection. Then, using a field emission scanning electron microscope (FE-SEM), the image magnification was set to 50,000 times, conductive particles having 50 insulating particles were randomly selected, and the insulating particles of the conductive particles having each insulating particle were Observe. The particle diameter of the insulating particles in the conductive particles having each insulating particle is measured, and the arithmetic average of them is taken to determine the particle size of the insulating particle.

As for the conductive particles having insulating particles according to the present invention, two or more types of insulating particles having different particle sizes may be used in combination. By using two or more types of insulating particles with different particle sizes in combination, insulating particles with a small particle size enter the gaps covered by insulating particles with a large particle size, and the coverage can be increased more effectively. When two or more types of insulating particles having different particle sizes are used together, the insulating particles preferably include first insulating particles having a particle size of 0.1 μm or more and less than 0.25 μm, and second insulating particles having a particle size of 0.25 μm or more and 0.8 μm or less. do. It is preferable that the particle size distribution of the first insulating particles does not overlap with the particle size distribution of the second insulating particles. It is preferable that the average particle diameter of the first insulating particles and the average particle diameter of the second insulating particles are different.

The coefficient of variation (CV value) of the particle diameter of the insulating particles is preferably 20% or less. If the coefficient of variation of the particle diameter of the insulating particles is less than or equal to the upper limit, the thickness of the insulating particles of the resulting conductive particles having the insulating particles becomes more uniform, and pressure can be more easily applied uniformly during conductive connection, The connection resistance between electrodes can be further lowered.

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

CV value (%) = (ρ/Dn) × 100

ρ: Standard deviation of particle size of insulating particles

Dn: Average value of particle diameter of insulating particles

The shape of the insulating particles is not particularly limited. The shape of the insulating particles may be spherical, may be of a shape other than spherical, may be flat, etc.

(Challenge Material)

The electrically conductive material according to the present invention contains electrically conductive particles having the above-mentioned insulating particles and binder resin. The conductive particles having the above insulating particles are preferably dispersed in a binder resin and used, and are preferably dispersed in a binder resin and used as a conductive material. It is preferable that the said electrically-conductive material is an anisotropic electrically-conductive material. The above-mentioned conductive material is preferably used for electrical connection between electrodes. It is preferable that the said electrically-conductive material is a electrically-conductive material for circuit connection. In the above-mentioned electrically conductive material, since conductive particles having the above-mentioned insulating particles are used, insulating particles are not intended to be removed from the surface of the conductive particles having the insulating particles before conductive connection, such as by dispersing the conductive particles having the insulating particles in a binder resin. It is possible to prevent the electrodes from detaching without causing damage, and the insulation reliability between the electrodes can be further improved.

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 photocurable components and thermosetting components. 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 resin, thermoplastic resin, curable resin, thermoplastic block copolymer, and elastomer. Only one type of the binder resin may be used, and two or more types may be used together.

Examples of the vinyl resin include vinyl acetate resin, acrylic resin, and styrene resin. Examples of the thermoplastic resin include polyolefin resin, ethylene-vinyl acetate copolymer, and polyamide resin. Examples of the curable resin include epoxy resin, urethane resin, polyimide resin, and unsaturated polyester resin. In addition, the curable resin may be a room temperature curable resin, a thermosetting resin, a photocurable resin, or a moisture curable resin. The curable resin may be used in combination with a curing agent. Examples of the thermoplastic block copolymer include styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, hydrogenated product of styrene-butadiene-styrene block copolymer, and hydrogenated product of styrene-isoprene-styrene block copolymer. Additives, etc. can be mentioned. Examples of the elastomer include styrene-butadiene copolymer rubber and acrylonitrile-styrene block copolymer rubber.

In addition to the conductive particles having the insulating particles and the binder resin, the electrically conductive material includes, for example, fillers, extenders, softeners, plasticizers, polymerization catalysts, curing catalysts, colorants, antioxidants, heat stabilizers, light stabilizers, ultraviolet absorbers, and lubricants. , may contain various additives such as antistatic agents and flame retardants.

The method of dispersing the conductive particles having the insulating particles in the binder resin can be a conventionally known dispersion method and is not particularly limited. Examples of a method for dispersing the conductive particles having the insulating particles in the binder resin include the following methods. A method of adding conductive particles having the insulating particles to the binder resin and then kneading them with a planetary mixer or the like to disperse them. A method of dispersing the conductive particles having the insulating particles uniformly in water or an organic solvent using a homogenizer or the like, then adding them to the binder resin and kneading them with a planetary mixer or the like. A method of diluting the binder resin with water or an organic solvent, adding conductive particles having the insulating particles, and dispersing them by kneading them 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, more preferably 300 Pa·s. It is as follows. If the viscosity of the conductive material at 25°C is higher than the lower limit and lower than the upper limit, the insulation reliability between electrodes can be improved more effectively, and the conduction reliability between electrodes can be improved more effectively. The viscosity (η25) can be appropriately adjusted depending on the types and amounts of the ingredients.

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

The electrically conductive material according to the present invention can be used as a conductive paste, a conductive film, etc. When the conductive material according to the present invention is a conductive film, a film not containing conductive particles may be laminated on the conductive film containing conductive particles. It is preferable that the said electrically conductive paste is an anisotropic electrically conductive paste. It is preferable that the said conductive film is an anisotropic conductive film.

The content of the binder resin in 100% by weight of the electrically conductive material is preferably 10% by weight or more, more preferably 30% by weight or more, further preferably 50% by weight or more, particularly preferably 70% by weight or more. , Preferably it is 99.99% by weight or less, more preferably 99.9% by weight or less. If the content of the binder resin is equal to or greater than the lower limit and equal to or lower than the upper limit, the conductive particles are efficiently disposed between the electrodes, and the connection reliability of the connection target members connected by the electrically conductive material can be further improved.

In 100% by weight of the electrically conductive material, the content of the electrically conductive particles having the insulating particles is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, preferably 80% by weight or less, more preferably 60% by weight. It is % by weight or less, more preferably 40% by weight or less, especially preferably 20% by weight or less, and most preferably 10% by weight or less. If the content of the electrically conductive particles having the insulating particles is more than the above lower limit and less than the above upper limit, the conduction reliability and insulation reliability between 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 its surface, a second connection target member having a second electrode on its surface, the first connection target member, and the second connection target member. It is provided with a connection part that connects. In the bonded structure according to the present invention, the material of the connection portion is conductive particles having the above-described insulating particles, or is a conductive material containing conductive particles having the above-described insulating particles and a binder resin. In the bonded structure according to the present invention, the first electrode and the second electrode are electrically connected by the conductive portion in the conductive particles having the insulating particles.

The connection structure can be obtained through a step of disposing the conductive particles having the insulating particles or the conductive material between the first connection target member and the second connection target member, and a step of conducting conductive connection by thermal compression. there is. During the thermocompression bonding, it is preferable that the insulating particles detach from the conductive particles having the insulating particles.

Fig. 4 is a cross-sectional view schematically showing a bonded structure using conductive particles having insulating particles according to the first embodiment of the present invention.

The connection structure 81 shown in FIG. 4 includes a first connection target member 82, a second connection target member 83, and a first connection target member 82 and a second connection target member 83. It is provided with a connecting portion 84 that is connected. The connection portion 84 is formed of a conductive material containing conductive particles 1 having insulating particles. The connection portion 84 is preferably formed by curing a conductive material containing a plurality of conductive particles 1 having insulating particles. In addition, in FIG. 4, the conductive particles 1 having insulating particles are schematically shown for convenience of illustration. In addition to the conductive particles 1 having insulating particles, conductive particles 21 or 41 having insulating particles may be used.

The first connection target member 82 has a plurality of first electrodes 82a on its surface (upper surface). The second connection target member 83 has a plurality of second electrodes 83a on its surface (lower surface). The first electrode 82a and the second electrode 83a are electrically connected by conductive particles 2 in the conductive particles 1 having one or more insulating particles. Therefore, the first connection target member 82 and the second connection target member 83 are electrically connected by the conductive portion in the conductive particles 1 having insulating particles.

The manufacturing method of the connection structure is not particularly limited. An example of a method of manufacturing a connected structure includes arranging the above-mentioned conductive material between a first connection target member and a second connection target member, obtaining a laminate, and then heating and pressurizing the laminate. The pressure of the thermocompression 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 for the thermocompression is preferably 80°C or higher, more preferably 100°C or higher, preferably 140°C or lower, and more preferably 120°C or lower. If the pressure and temperature of the thermocompression are above the above lower limit and below the above upper limit, insulating particles can be easily detached from the surface of the conductive particles having insulating particles during conductive connection, thereby further improving the reliability of conduction between electrodes. You can.

When heating and pressurizing the laminate, the conductive particles and the insulating particles present between the first electrode and the second electrode can be excluded. For example, during the heating and pressurization, the conductive particles and the insulating particles present between the first electrode and the second electrode are easily detached from the surface of the conductive particles having the insulating particles. Additionally, during the heating and pressurization, some of the insulating particles may detach from the surface of the conductive particles containing the insulating particles, and the surface of the conductive portion may be partially exposed. The exposed portion of the surface of the conductive part contacts the first electrode and the second electrode, so that the first electrode and the second electrode can be electrically connected through the conductive particles.

The first connection target member and the second connection target member are not particularly limited. The first connection target member and the second connection target member specifically include electronic components such as semiconductor chips, semiconductor packages, LED chips, LED packages, condensers and diodes, and resin films, printed boards, flexible printed boards, and flexible devices. Examples include electronic components such as circuit boards such as flat cables, rigid flexible boards, glass epoxy boards, and glass boards. It is preferable that the first connection target member and the second connection target member are electronic components.

Examples of electrodes provided on the connection target member include metal electrodes such as gold electrodes, nickel electrodes, tin electrodes, aluminum electrodes, copper electrodes, molybdenum electrodes, silver electrodes, SUS electrodes, and tungsten electrodes. When the connection target member is a flexible printed circuit board, the electrode is preferably a gold electrode, nickel electrode, tin electrode, silver electrode, or copper electrode. When the connection target member is a glass substrate, the electrode is preferably an aluminum electrode, a copper electrode, a molybdenum electrode, a silver electrode, or a tungsten electrode. In addition, 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 materials for the metal oxide layer include indium oxide doped with a trivalent metal element and zinc oxide doped with a trivalent metal element. Examples of the trivalent metal elements include Sn, Al, and Ga.

Hereinafter, the present invention will be described in detail through examples and comparative examples. The present invention is not limited to the following examples.

(Example 1)

(1) Production of conductive particles

Resin particles formed by a copolymer resin of tetramethylolmethane tetraacrylate and divinylbenzene with a particle diameter of 3 μm were prepared. After dispersing 10 parts by weight of the substrate particles in 100 parts by weight of the alkaline solution containing 5% by weight of the palladium catalyst liquid using an ultrasonic disperser, the substrate particles were taken out by filtering the solution. Next, the substrate particles were added to 100 parts by weight of a 1% by weight solution of dimethylamine borane, and the surface of the substrate particles was activated. After sufficiently washing the surface-activated substrate particles with water, they were added to 500 parts by weight of distilled water and dispersed to obtain a dispersion liquid. Next, 1 g of nickel particle slurry (average particle diameter 100 nm) was added to the above dispersion over 3 minutes to obtain a suspension containing base particles to which the core material was attached.

Additionally, a nickel plating solution (pH 8.5) containing 0.35 mol/L nickel sulfate, 1.38 mol/L dimethylamine borane, and 0.5 mol/L sodium citrate was prepared.

While stirring the obtained suspension at 60°C, the nickel plating solution was gradually added dropwise to the suspension to perform electroless nickel plating. After that, the suspension was filtered to take out the particles, washed with water, and dried to form a nickel-boron conductive layer (thickness of 0.15 μm) on the surface of the substrate particles, and conductive particles having a conductive portion on the surface were obtained.

(2) Production of insulating particles

A composition containing the following polymerizable compounds was added to a 1000 mL separable flask equipped with a 4-neck separable cover, stirring blade, three-way cock, cooling pipe, and temperature probe, stirred at 200 rpm, and stirred at 50°C under a nitrogen atmosphere. Polymerization was performed for 5 hours. The composition includes 500 mL of distilled water, 0.2 parts by weight (0.5 mmol) of acid phosphooxypolyoxyethylene glycol methacrylate, and 2,2'-azobis{2-[N-(2-carboxyethyl)amidino]propane} It contains 0.2 parts by weight (0.5 mmol) and a polymerizable compound. The polymerizable compound is 90 parts by weight (0.9 mol) of methyl methacrylate, 7 parts by weight (0.05 mol) of glycidyl methacrylate, which is a compound having a first functional group, and methacrylamide 4, which is a compound having a second functional group. Contains parts by weight (0.05 mol). After completion of the reaction, it was freeze-dried to obtain insulating particles (particle diameter of 300 nm) having an amide group derived from methacrylamide and an epoxy group derived from glycidyl methacrylate on the surface.

(3) Production of conductive particles having insulating particles

The insulating particles obtained above were dispersed in distilled water under ultrasonic irradiation to obtain a 10% by weight aqueous dispersion of the insulating particles. 10 g of the obtained conductive particles were dispersed in 500 mL of distilled water, 1 g of a 10% by weight aqueous dispersion of the insulating particles was added, and the mixture was stirred at room temperature for 8 hours. After filtration with a 3 µm mesh filter, it was further washed with methanol and dried to obtain conductive particles having insulating particles.

(4) Production of conductive material (anisotropic conductive paste)

7 parts by weight of conductive particles having the obtained insulating particles, 25 parts by weight of bisphenol A type phenoxy resin, 4 parts by weight of fluorene type epoxy resin, 30 parts by weight of phenol novolac type epoxy resin, and SI-60L (Sanshin Kagawa) (manufactured by Ku Kogyo Co., Ltd.) was mixed, defoamed and stirred for 3 minutes to obtain a conductive material (anisotropic conductive paste).

(5) Fabrication of connection structure

A transparent glass substrate with an IZO electrode pattern (first electrode, Vickers hardness of the metal on the electrode surface, 100 Hv) with L/S of 10 μm/10 μm formed on the upper surface was prepared. Additionally, a semiconductor chip was prepared with an Au electrode pattern (second electrode, Vickers hardness of the metal on the electrode surface 50 Hv) with L/S of 10 μm/10 μm formed on the lower surface.

The obtained anisotropic conductive paste was applied to the transparent glass substrate to a thickness of 30 μm to form an anisotropic conductive paste layer. Next, the semiconductor chip was laminated on the anisotropic conductive paste layer so that the electrodes faced each other. Thereafter, while adjusting the temperature of the head so that the temperature of the anisotropic conductive paste layer is 100°C, a pressure heating head is placed on the upper surface of the semiconductor chip, and a pressure of 60 MPa is applied to cure the anisotropic conductive paste layer to 100°C. A connection structure was obtained.

(Example 2)

When producing conductive particles having insulating particles, after obtaining conductive particles having insulating particles, they are further heated under conditions of 90°C and 2 hours to react the amide group on the surface of the insulating particle with an epoxy group. (Insulating particles contain a structure in which amide groups and epoxy groups react) were obtained. An electrically-conductive material and a bonded structure were obtained in the same manner as in Example 1, except that the conductive particles having the obtained insulating particles were used.

(Example 3)

When producing insulating particles, with respect to the polymerizable compound, the amount of methyl methacrylate was changed to 80 parts by weight (0.8 mol), and the amount of glycidyl methacrylate, which is a compound having a first functional group, was changed to 14 parts by weight. parts (0.1 mol), and the amount of methacrylamide, which is a compound having a second functional group, was changed to 9 parts by weight (0.1 mol). Except for the above-mentioned changes, the same procedure as in Example 2 was performed to obtain conductive particles having insulating particles, an electrically-conductive material, and a bonded structure.

(Example 4)

When producing the insulating particles, the amount of methyl methacrylate mixed with the polymerizable compound was changed to 80 parts by weight (0.8 mol). Additionally, instead of 7 parts by weight (0.05 mol) of glycidyl methacrylate, which is a compound having a first functional group, 7 parts by weight (0.1 mol) of methacrylonitrile, which is a compound having a first functional group, was used. Additionally, instead of 4 parts by weight (0.05 mol) of methacrylamide, which is a compound having a second functional group, 9 parts by weight (0.1 mol) of methacrylic acid, which is a compound having a second functional group, was used. Except for the above-mentioned changes, the same procedure as in Example 2 was performed to obtain conductive particles having insulating particles, an electrically-conductive material, and a bonded structure.

(Example 5)

When producing insulating particles, with respect to the polymerizable compound, the amount of methyl methacrylate was changed to 92 parts by weight (0.92 mol), and the amount of glycidyl methacrylate, which is a compound having a first functional group, was changed to 4 parts by weight. parts (0.03 mol), and the amount of methacrylamide, which is a compound having a second functional group, was changed to 3 parts by weight (0.03 mol). Additionally, 4 parts by weight (0.02 mol) of ethylene glycol dimethacrylate, a cross-linking agent, was added. Except for the above-mentioned changes, the same procedure as in Example 2 was performed to obtain conductive particles having insulating particles, an electrically-conductive material, and a bonded structure.

(Example 6)

When producing insulating particles, with respect to the polymerizable compound, the amount of methyl methacrylate was changed to 58 parts by weight (0.58 mol), and the amount of glycidyl methacrylate, which is a compound having a first functional group, was changed to 14 parts by weight. parts (0.1 mol), and the amount of methacrylamide, which is a compound having a second functional group, was changed to 9 parts by weight (0.1 mol). Additionally, 35 parts by weight (0.2 mol) of benzyl methacrylate was added, and 6 parts by weight (0.02 mol) of trimethylolpropane triacrylate, a crosslinking agent, was added. Except for the above-mentioned changes, the same procedure as in Example 2 was performed to obtain conductive particles having insulating particles, an electrically-conductive material, and a bonded structure.

(Example 7)

When producing insulating particles, with respect to the polymerizable compound, the amount of methyl methacrylate was changed to 56 parts by weight (0.56 mol), and the amount of glycidyl methacrylate, which is a compound having a first functional group, was changed to 14 parts by weight. parts (0.1 mol), and the amount of methacrylamide, which is a compound having a second functional group, was changed to 9 parts by weight (0.1 mol). Additionally, 35 parts by weight (0.2 mol) of benzyl methacrylate was added, and 8 parts by weight (0.04 mol) of ethylene glycol dimethacrylate, a crosslinking agent, was added. Except for the above-mentioned changes, the same procedure as in Example 2 was performed to obtain conductive particles having insulating particles, an electrically-conductive material, and a bonded structure.

(Comparative Example 1)

When producing insulating particles, with respect to the polymerizable compound, the amount of methyl methacrylate was changed to 88 parts by weight (0.88 mol), and the amount of glycidyl methacrylate, which is a compound having a first functional group, was changed to 14 parts by weight. It was changed to parts (0.1 mol), and 4 parts by weight (0.05 mol) of methacrylamide, a compound having a second functional group, was not added. Additionally, 4 parts by weight (0.02 mol) of ethylene glycol dimethacrylate, a cross-linking agent, was added. Except for the above-mentioned changes, the same procedure as in Example 1 was performed to obtain conductive particles having insulating particles, an electrically-conductive material, and a bonded structure.

(Comparative Example 2)

When producing insulating particles, the amount of methyl methacrylate mixed with respect to the polymerizable compound was changed to 85 parts by weight (0.85 mol), and 7 parts by weight (0.05 mol) of glycidyl methacrylate, which is a compound having a first functional group, was added. mol) was not added. Additionally, the compounding amount of methacrylamide, which is a compound having a second functional group, was changed to 9 parts by weight (0.1 mol). Additionally, 15 parts by weight (0.05 mol) of trimethylolpropane triacrylate, a crosslinking agent, was added. Except for the above-mentioned changes, the same procedure as in Example 1 was performed to obtain conductive particles having insulating particles, an electrically-conductive material, and a bonded structure.

(evaluation)

(1) Adhesion of insulating particles

The adhesion of the insulating particles was evaluated as follows. The adhesion of the insulating particles was determined based on the following standards.

Method for evaluating the adhesion of insulating particles:

Conductive particles having an arbitrary number of 50 insulating particles were observed using a scanning electron microscope (SEM) immediately after production. In addition, even after preparing a conductive particle dispersion liquid containing insulating particles using the obtained electrically-conductive material, conductive particles containing an arbitrary 50 insulating particles were observed using an SEM. From the results of these SEM observations, the number of coatings of insulating particles in the conductive particles with insulating particles immediately after production was compared with the number of coatings of insulating particles in the conductive particles with insulating particles after dispersion adjustment. In addition, in SEM observation, the total number of observed insulating particles was taken as the coverage number.

[Judgment criteria for adhesion of insulating particles]

○○○: The ratio of the number of coatings of insulating particles in the conductive particles with insulating particles after dispersion adjustment to the number of coatings of insulating particles in the conductive particles with insulating particles immediately after production is 90% or more.

○○: The ratio of the number of coatings of insulating particles in the conductive particles with insulating particles after dispersion adjustment to the number of coatings of insulating particles in the conductive particles with insulating particles immediately after production is 70% or more and less than 90%.

○: The ratio of the number of coatings of insulating particles in the conductive particles with insulating particles after dispersion adjustment to the number of coatings of insulating particles in the conductive particles with insulating particles immediately after production is 50% or more and less than 70%.

×: The ratio of the number of coatings of insulating particles in the conductive particles with insulating particles after dispersion adjustment to the number of coatings of insulating particles in the conductive particles with insulating particles immediately after production is less than 50%.

(2) Continuity reliability (between upper and lower electrodes)

The connection resistance between the upper and lower electrodes of the obtained 20 connected structures was each measured by the four-terminal method. Additionally, from the relationship of voltage = current × resistance, the connection resistance can be obtained by measuring the voltage when a constant current flows. Continuity reliability was judged based on the following criteria.

[Judgement criteria for continuity reliability]

○○○: Connection resistance is 1.5Ω or less

○○: Connection resistance exceeds 1.5Ω and is less than 2.0Ω

○: Connection resistance exceeds 2.0Ω and is 5.0Ω or less.

△: Connection resistance exceeds 5.0Ω and is less than 10Ω

×: Connection resistance exceeds 10Ω

(3) Insulation reliability (between horizontally adjacent electrodes)

In the 20 connection structures obtained in the above (2) evaluation of conduction reliability, the presence or absence of leakage between adjacent electrodes was evaluated by measuring the resistance value with a tester. Insulation reliability was evaluated based on the following criteria.

[Judgment criteria for insulation reliability]

○○○: The number of connection structures with a resistance value of 10 ⁸ Ω or more is 20.

○○: The number of connection structures with a resistance value of 10 ⁸ Ω or more is 18 or more and less than 20.

○: The number of connection structures with a resistance value of 10 ⁸ Ω or more is 15 or more and less than 18.

△: The number of connection structures with a resistance value of 10 ⁸ Ω or more is 10 or more and less than 15.

×: The number of connection structures with a resistance value of 10 ⁸ Ω or more is 5 or more and less than 10.

××: The number of connection structures with a resistance value of 10 ⁸ Ω or more is less than 5

The results are shown in Table 1 below.

1: Conductive particles having insulating particles
2: Conductive particles
3: Insulating particles
11: Base particle
12: Challenge section
21: Conductive particles having insulating particles
22: Conductive particles
31: Challenge section
32: Core material
33: protrusion
41: Conductive particles with insulating particles
42: Conductive particles
51: Challenge section
52: protrusion
81: Connection structure
82: Absence of first connection target
82a: first electrode
83: Absence of second connection target
83a: second electrode
84: connection part

Claims (17)

Conductive particles having a conductive portion at least on the surface,
Provided with a plurality of insulating particles disposed on the surface of the conductive particles,
The insulating particles are polymers of polymerizable compounds,
The polymerizable compound includes a compound having a first functional group and a compound having a second functional group different from the first functional group,
The polymer has the first functional group and the second functional group,
The first functional group is a cyclic ether group, an isocyanate group, an aldehyde group, or a nitrile group,
Conductive particles having insulating particles in which the second functional group is an amide group, a hydroxyl group, a carboxyl group, an imide group, or an amino group. The conductive particle having insulating particles according to claim 1, wherein the polymerizable compound does not contain a crosslinking agent or contains 10% by weight or less of a crosslinking agent in 100% by weight of the polymerizable compound. The conductive particle having an insulating particle according to claim 1 or 2, wherein the first functional group and the second functional group have a property capable of reacting with stimulation. The conductive particle having insulating particles according to claim 3, wherein the stimulus is heating or irradiation of light. Conductive particles having a conductive portion at least on the surface,
Provided with a plurality of insulating particles disposed on the surface of the conductive particles,
The insulating particles are polymers of polymerizable compounds,
The polymerizable compound includes a compound having a first functional group and a compound having a second functional group different from the first functional group,
The polymer includes a structure in which the first functional group and the second functional group react,
The first functional group is a cyclic ether group, an isocyanate group, an aldehyde group, or a nitrile group,
Conductive particles having insulating particles in which the second functional group is an amide group, a hydroxyl group, a carboxyl group, an imide group, or an amino group. The conductive particle having insulating particles according to claim 5, wherein the polymerizable compound does not contain a crosslinking agent or contains 10% by weight or less of a crosslinking agent in 100% by weight of the polymerizable compound. The electroconductive particle according to claim 2 or 6, wherein the insulating particle has a crosslinking degree of 10 or more, as determined by the following formula (1).
Degree of crosslinking = A × [(B/D) × 100] + [(C/D) × 100] Formula (1)
In the formula (1), A is the number of polymerizable functional groups of the crosslinking agent, B is the number of moles of the crosslinking agent, C is the total number of moles of the compound having the first functional group and the compound having the second functional group, and D is the number of moles of the above It is the total number of moles of polymerizable compounds. The conductive particle having an insulating particle according to claim 1, 2, 5 or 6, wherein the cyclic ether group is an epoxy group or an oxetanyl group. The electroconductive particle according to claim 1, 2, 5, or 6, wherein the electroconductive particle has a particle size of 1 μm or more and 5 μm or less. Using conductive particles having a conductive portion at least on the surface and a plurality of insulating particles,
Provided with a placement process of disposing the insulating particles on the surface of the conductive particles,
The insulating particles are polymers of polymerizable compounds,
The polymerizable compound includes a compound having a first functional group and a compound having a second functional group different from the first functional group,
The first functional group is a cyclic ether group, an isocyanate group, an aldehyde group, or a nitrile group,
A method for producing conductive particles having insulating particles, wherein the second functional group is an amide group, a hydroxyl group, a carboxyl group, an imide group, or an amino group. The method for producing conductive particles having insulating particles according to claim 10, wherein the polymerizable compound does not contain a crosslinking agent or contains 10% by weight or less of a crosslinking agent in 100% by weight of the polymerizable compound. 12. The method of claim 10 or 11, wherein the temperature of the batch process is less than 50°C,
A method for producing conductive particles having insulating particles, wherein the polymer obtains conductive particles having insulating particles having the first functional group and the second functional group. The method according to claim 10 or 11, wherein after the arrangement step, a heating step of heating the conductive particles having the insulating particles is provided,
The heating temperature of the heating process is 70°C or more, and the heating time of the heating process is 1 hour or more,
A method for producing conductive particles having insulating particles, wherein the polymer obtains conductive particles having insulating particles containing a structure in which the first functional group and the second functional group react. An electrically conductive material containing electrically conductive particles having the insulating particles according to any one of claims 1, 2, 5, or 6, and binder resin. A first connection target member having a first electrode on its surface,
A second connection target member having a second electrode on its surface,
A connection part connecting the first connection target member and the second connection target member is provided,
The material of the connection part is a conductive particle having the insulating particles according to any one of claims 1, 2, 5, or 6, or a conductive material containing the conductive particles having the insulating particles and a binder resin. It's a material,
A bonded structure in which the first electrode and the second electrode are electrically connected by the conductive portion in the conductive particles having the insulating particles. delete delete

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