JP7348776B2 - Conductive particles with an insulating part, method for producing conductive particles with an insulating part, conductive material and connected structure - Google Patents

Description

The present invention relates to conductive particles with an insulating part, in which an insulating part is arranged on the surface of the conductive particles, and a method for producing the conductive particles with an insulating part. The present invention also relates to a conductive material and a connected structure using the above-mentioned conductive particles with an insulating part.

Anisotropic conductive materials such as anisotropic conductive pastes and anisotropic conductive films are widely known. In the anisotropic conductive material, conductive particles are dispersed in a binder resin. Further, as the conductive particles, conductive particles whose surfaces of a conductive layer are subjected to insulation treatment may be used.

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

Moreover, as the above-mentioned conductive particles, conductive particles with insulating particles, in which insulating particles are arranged on the surface of the conductive particles, may be used. Furthermore, coated conductive particles with an insulating layer disposed on the surface of the conductive layer may be used.

As an example of the above-mentioned insulating particles, the following patent document 1 discloses resin particles that exist on the surface of conductive particles and insulate the above-mentioned conductive particles. The resin particles include a copolymer of polymerizable components that essentially include at least an alkyl (meth)acrylate and a polyvalent (meth)acrylate. The above polyvalent (meth)acrylate is a compound in which each (meth)acrylic group is bonded to each other via three or more carbon atoms. Patent Document 1 describes that the content of the polyvalent (meth)acrylate is 5% by mass or more based on the total amount of the polymerizable components.

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

Degree of crosslinking = number of polymerizable functional groups of crosslinkable monomer x (number of moles of crosslinkable monomer/number of moles of total monomers) x 100 Formula (1)

JP2012-72324A Japanese Patent Application Publication No. 2010-86665

In conventional conductive particles with insulating particles, when mixing the conductive particles with insulating particles and a binder resin to create an anisotropic conductive material, the insulating particles are detached from the surface of the conductive particles. Sometimes. In particular, in conventional insulating particles as described in Patent Document 1, a crosslinkable monomer (crosslinking agent) is sometimes used to improve solvent resistance. When the content of the crosslinking 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 is difficult to detach the insulating particles from the surface of the conductive particles. May be difficult to prevent. As a result, during conductive connection using an anisotropic conductive material, it may be difficult to greatly increase insulation reliability between laterally adjacent electrodes that should not be connected. In addition, if the insulating particles are hard, the insulating particles may not be easily deformed during conductive connection using an anisotropic conductive material, and the insulating particles may may not be easily excluded from As a result, it may be difficult to greatly increase the reliability of conduction between the upper and lower electrodes to be connected.

In order to solve the above problems, for example, as described in Patent Document 2, etc., there is a method in which insulating particles have a core-shell structure and the degree of crosslinking on the surface of the core and the degree of crosslinking on the surface of the shell are adjusted. is proposed. However, with conventional methods, it is difficult to make the insulating particles sufficiently soft, and when making conductive connections using anisotropic conductive materials, the insulating particles do not easily deform, etc. may not be easily removed from between the conductive particles and the conductive particles. As a result, it may be difficult to greatly increase the reliability of conduction between the upper and lower electrodes to be connected.

In addition, when an anisotropic conductive material is used to form a connection part that connects connection target members having a plurality of electrodes, and a connected structure is obtained by conductive connection, it is possible to prevent the connected structure from falling or the like. External vibrations and shocks may be applied. When a connected structure is fabricated using an anisotropic conductive material containing conventional conductive particles with insulating particles, the insulating particles are hard, making it impossible to alleviate external vibrations and shocks caused by drops, etc. It may not be possible to sufficiently increase the impact resistance of the connection part. If the impact resistance of the connection part in the connection structure is not sufficiently high, cracks, peeling, etc. may occur in the connection part due to external vibrations or shocks caused by dropping or the like. As a result, it may be difficult to considerably improve the conduction reliability between the upper and lower electrodes that should be connected and the insulation reliability between laterally adjacent electrodes that should not be connected.

An object of the present invention is to provide conductive particles with an insulating part and a method for producing the conductive particles with an insulating part, which can effectively improve continuity reliability and insulation reliability even when vibrations or shocks are applied from the outside. It is to provide. Another object of the present invention is to provide a conductive material and a connected structure using the above-mentioned conductive particles with an insulating part.

According to a broad aspect of the present invention, the present invention includes conductive particles having a conductive part on at least the surface thereof, and an insulating part disposed on the surface of the conductive particle, and the insulating part contains a plurality of types of polymerizable compounds. A polymer comprising a polymerizable component, the polymerizable component having a polymerizable compound having a first reactive functional group and a second reactive functional group different from the first reactive functional group. a polymerizable compound, the polymerizable component does not contain a crosslinking agent, and the polymerizable component has a homopolymer glass transition temperature of less than 100 ° C. in 100% by weight of the polymerizable component. Provided are electrically conductive particles with an insulating portion that contain 10% by weight or more of a polymerizable compound and in which the polymer has the first reactive functional group and the second reactive functional group.

In a particular aspect of the conductive particle with an insulating part according to the present invention, the first reactive functional group and the second reactive functional group have a property of being able to react upon stimulation.

In a particular aspect of the conductive particle with an insulating part according to the present invention, the stimulation is heating or light irradiation.

According to a broad aspect of the present invention, the present invention includes conductive particles having a conductive part on at least the surface thereof, and an insulating part disposed on the surface of the conductive particle, and the insulating part contains a plurality of types of polymerizable compounds. A polymer comprising a polymerizable component, the polymerizable component having a polymerizable compound having a first reactive functional group and a second reactive functional group different from the first reactive functional group. a polymerizable compound, the polymerizable component does not contain a crosslinking agent, and the polymerizable component has a homopolymer glass transition temperature of less than 100 ° C. in 100% by weight of the polymerizable component. Provided are conductive particles with an insulating part, which contain a polymerizable compound in an amount of 10% by weight or more, and in which the polymer includes a structure in which the first reactive functional group and the second reactive functional group react with each other. .

In a particular aspect of the conductive particle with an insulating part according to the present invention, the degree of crosslinking of the insulating part determined by the following formula (1) is 10 or more.

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

In the formula (1), A is the total number of moles of the polymerizable compound having the first reactive functional group and the polymerizable compound having the second reactive functional group, and B is the number of moles of the polymerizable compound having the first reactive functional group. is the total number of moles.

In a particular aspect of the conductive particle with an insulating part according to the present invention, the first reactive functional group is a cyclic ether group, an isocyanate group, an aldehyde group, or a nitrile group.

In a particular aspect of the electrically conductive particles with insulation parts according to the present invention, the cyclic ether group is an epoxy group or an oxetanyl group.

In a particular aspect of the conductive particle with an insulating part according to the present invention, the second reactive functional group is an amide group, a hydroxyl group, a carboxyl group, an imide group, or an amino group.

In a particular aspect of the conductive particle with an insulating part according to the present invention, the insulating part is an insulating particle.

In a particular aspect of the electrically conductive particles with insulation parts according to the present invention, a ratio of the particle diameter of the electrically conductive particles to the particle diameter of the insulating particles is 3 or more and 100 or less.

In a particular aspect of the conductive particles with an insulating part according to the present invention, the conductive particles have a particle diameter of 1 μm or more and 5 μm or less.

According to a broad aspect of the present invention, there is provided a method for producing conductive particles with an insulating part by using conductive particles having a conductive part on at least the surface thereof and an insulating material, wherein an insulating part forming step of arranging the insulating material to form an insulating part, the insulating part is a polymer of a polymerizable component containing a plurality of types of polymerizable compounds, and the polymerizable component is a first a polymerizable compound having a reactive functional group of , and the polymerizable component contains 10% by weight or more of a polymerizable compound whose homopolymer has a glass transition temperature of less than 100° C. in 100% by weight of the polymerizable component. A method is provided.

In a particular aspect of the method for producing conductive particles with an insulating part according to the present invention, the temperature in the insulating part forming step is less than 50°C, and the polymer 2. Obtain conductive particles with an insulating portion having two reactive functional groups.

In a certain aspect of the method for producing conductive particles with an insulating part according to the present invention, after the insulating part forming step, a heating step of heating the conductive particle with an insulating part is provided, and the heating temperature in the heating step is 70°C or higher, the heating time of the heating step is 1 hour or more, and the insulating part includes a structure in which the first reactive functional group and the second reactive functional group react with each other. to obtain conductive particles.

According to a broad aspect of the present invention, a conductive material is provided that includes the above-mentioned conductive particles with an insulating portion and a binder resin.

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

The conductive particle with an insulating part according to the present invention includes a conductive particle having a conductive part at least on the surface thereof, and an insulating part disposed on the surface of the conductive particle. In the conductive particle with an insulating part according to the present invention, the insulating part is a polymer of a polymerizable component containing a plurality of types of polymerizable compounds. In the conductive particle with an insulating part according to the present invention, the polymerizable component includes a polymerizable compound having a first reactive functional group and a second reactive functional group different from the first reactive functional group. and a polymerizable compound having the following. In the conductive particles with an insulating part according to the present invention, the polymerizable component does not contain a crosslinking agent, and the polymerizable component has a glass transition temperature of a homopolymer in 100% by weight of the polymerizable component. Contains 10% by weight or more of a polymerizable compound whose temperature is below 100°C. In the conductive particle with an insulating part according to the present invention, the polymer has the first reactive functional group and the second reactive functional group. Since the conductive particles with an insulating part according to the present invention have the above-described configuration, the conduction reliability and the insulation reliability can be effectively improved even when vibrations or shocks are applied from the outside.

The conductive particle with an insulating part according to the present invention includes a conductive particle having a conductive part at least on the surface thereof, and an insulating part disposed on the surface of the conductive particle. In the conductive particle with an insulating part according to the present invention, the insulating part is a polymer of a polymerizable component containing a plurality of types of polymerizable compounds. In the conductive particle with an insulating part according to the present invention, the polymerizable component includes a polymerizable compound having a first reactive functional group and a second reactive functional group different from the first reactive functional group. and a polymerizable compound having the following. In the conductive particles with an insulating part according to the present invention, the polymerizable component does not contain a crosslinking agent, and the polymerizable component has a glass transition temperature of a homopolymer in 100% by weight of the polymerizable component. Contains 10% by weight or more of a polymerizable compound whose temperature is below 100°C. In the conductive particle with an insulating portion according to the present invention, the polymer includes a structure in which the first reactive functional group and the second reactive functional group react. Since the conductive particles with an insulating part according to the present invention have the above-described configuration, the conduction reliability and the insulation reliability can be effectively improved even when vibrations or shocks are applied from the outside.

The method for producing conductive particles with insulating parts according to the present invention is a method of producing conductive particles with insulating parts using conductive particles having a conductive part on at least the surface thereof and an insulating material. and an insulating part forming step of arranging the insulating material on the surface of the magnetic particles to form an insulating part. In the method for producing conductive particles with an insulating part according to the present invention, the insulating part is a polymer of a polymerizable component containing a plurality of types of polymerizable compounds. In the method for producing conductive particles with an insulating part according to the present invention, the polymerizable component undergoes a second reaction with a polymerizable compound having a first reactive functional group and a second reaction different from the first reactive functional group. and a polymerizable compound having a functional group. In the method for producing conductive particles with insulation portions according to the present invention, the polymerizable component does not contain a crosslinking agent, and the polymerizable component is a homopolymer glass in 100% by weight of the polymerizable component. Contains 10% by weight or more of a polymerizable compound having a transition temperature of less than 100°C. Since the method for manufacturing conductive particles with an insulating part according to the present invention has the above configuration, it is possible to effectively improve continuity reliability and insulation reliability even when external vibrations or shocks are applied. I can do it.

FIG. 1 is a sectional view showing a conductive particle with an insulating part according to a first embodiment of the present invention. FIG. 2 is a sectional view showing a conductive particle with an insulating part according to a second embodiment of the present invention. FIG. 3 is a cross-sectional view showing conductive particles with an insulating part according to a third embodiment of the present invention. FIG. 4 is a cross-sectional view showing conductive particles with an insulating part according to a fourth embodiment of the present invention. FIG. 5 is a cross-sectional view schematically showing a connected structure using conductive particles with an insulating part according to the first embodiment of the present invention.

The details of the present invention will be explained below.

(Conductive particles with insulating parts and method for producing conductive particles with insulating parts)
The conductive particle with an insulating part according to the present invention includes a conductive particle having a conductive part at least on the surface thereof, and an insulating part disposed on the surface of the conductive particle. In the conductive particle with an insulating part according to the present invention, the insulating part is a polymer of a polymerizable component containing a plurality of types of polymerizable compounds. In the conductive particle with an insulating part according to the present invention, the polymerizable component includes a polymerizable compound having a first reactive functional group and a second reactive functional group different from the first reactive functional group. and a polymerizable compound having the following. In the conductive particles with an insulating part according to the present invention, the polymerizable component does not contain a crosslinking agent, and the polymerizable component has a glass transition temperature of a homopolymer in 100% by weight of the polymerizable component. Contains 10% by weight or more of a polymerizable compound whose temperature is below 100°C. In the conductive particle with an insulating part according to the present invention, the polymer has the first reactive functional group and the second reactive functional group.

Since the conductive particles with an insulating part according to the present invention have the above-described configuration, the conduction reliability and the insulation reliability can be effectively improved even when vibrations or shocks are applied from the outside.

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

In the conductive particles with an insulating part according to the present invention, the polymer has the first reactive functional group and the second reactive functional group, and the first reactive functional group and the The second reactive functional group has not reacted. This electrically conductive particle with an insulating part is a particle before the first reactive functional group and the second reactive functional group react with each other. In this electrically conductive particle with an insulating part, the first reactive functional group and the second reactive functional group do not react with each other, so the degree of crosslinking of the insulating part is low and the particle has flexibility. Adhesion between the insulating part and the surface of the conductive particles can be improved.

The conductive particle with an insulating part according to the present invention includes a conductive particle having a conductive part at least on the surface thereof, and an insulating part disposed on the surface of the conductive particle. In the conductive particle with an insulating part according to the present invention, the insulating part is a polymer of a polymerizable component containing a plurality of types of polymerizable compounds. In the conductive particle with an insulating part according to the present invention, the polymerizable component includes a polymerizable compound having a first reactive functional group and a second reactive functional group different from the first reactive functional group. and a polymerizable compound having the following. In the conductive particles with an insulating part according to the present invention, the polymerizable component does not contain a crosslinking agent, and the polymerizable component has a glass transition temperature of a homopolymer in 100% by weight of the polymerizable component. Contains 10% by weight or more of a polymerizable compound whose temperature is below 100°C. In the conductive particle with an insulating portion according to the present invention, the polymer includes a structure in which the first reactive functional group and the second reactive functional group react.

Since the conductive particles with an insulating part according to the present invention have the above-described configuration, the conduction reliability and the insulation reliability can be effectively improved even when vibrations or shocks are applied from the outside.

In the conductive particle with an insulating portion according to the present invention, the polymer includes a structure in which the first reactive functional group and the second reactive functional group react. This electrically conductive particle with an insulating part is a particle after the first reactive functional group and the second reactive functional group have reacted. It is preferable that the conductive particles with an insulating part are obtained by reacting the first reactive functional group and the second reactive functional group before being blended into the binder resin. It is preferable that the first reactive functional group and the second reactive functional group react with each other in the conductive particles with an insulating part before being blended into the binder resin. In the conductive particles with an insulating part according to the present invention, since the first reactive functional group and the second reactive functional group are reacted, the degree of crosslinking of the insulating part can be increased, and the insulating part can improve the solvent resistance of

In conventional conductive particles with insulating particles, when mixing the conductive particles with insulating particles and a binder resin to create an anisotropic conductive material, the insulating particles are detached from the surface of the conductive particles. Sometimes. In particular, in conventional insulating particles, crosslinkable monomers (crosslinking agents) are sometimes used to improve solvent resistance. Therefore, since the insulating particles are hard and lack flexibility, it is difficult to sufficiently increase the adhesion to the surface of the conductive particles, and it is difficult to prevent the insulating particles from detaching from the surface of the conductive particles. can be difficult. As a result, during conductive connection using an anisotropic conductive material, it may be difficult to greatly increase insulation reliability between laterally adjacent electrodes that should not be connected. In addition, if the insulating particles are hard, the insulating particles may not be easily deformed during conductive connection using an anisotropic conductive material, and the insulating particles may may not be easily excluded from As a result, it may be difficult to greatly increase the reliability of conduction between the upper and lower electrodes to be connected.

In addition, when an anisotropic conductive material is used to form a connection part that connects connection target members having a plurality of electrodes, and a connected structure is obtained by conductive connection, it is possible to prevent the connected structure from falling or the like. External vibrations and shocks may be applied. When a connected structure is fabricated using an anisotropic conductive material containing conventional conductive particles with insulating particles, the insulating particles are hard, making it impossible to alleviate external vibrations and shocks caused by drops, etc. It may not be possible to sufficiently increase the impact resistance of the connection part. If the impact resistance of the connection part in the connection structure is not sufficiently high, cracks, peeling, etc. may occur in the connection part due to external vibrations or shocks caused by dropping or the like. As a result, it may be difficult to considerably improve the conduction reliability between the upper and lower electrodes that should be connected and the insulation reliability between laterally adjacent electrodes that should not be connected.

The present inventors have discovered that by using a specific conductive particle with an insulating part, it is possible to achieve both adhesion to the surface of the conductive particle and solvent resistance with respect to the insulating part. In the present invention, since the above configuration is provided, it is possible to prevent the insulating portion from detaching from the surface of the conductive particles. As a result, the insulation reliability between adjacent horizontal electrodes that should not be connected can be effectively increased. Further, since the present invention has the above configuration, the insulating part is relatively flexible, and the insulating part is easily deformed during conductive connection using an anisotropic conductive material. part is easily removed from between the electrode and the conductive particles. As a result, the reliability of conduction between the upper and lower electrodes to be connected can be effectively improved.

Further, in the present invention, since the degree of crosslinking of the insulating portion can be increased, solvent resistance can be improved. On the other hand, in the present invention, a crosslinkable monomer (crosslinking agent) is not used for the insulating part, and a specific polymerizable compound is used, so that a relatively flexible insulating part is formed. be able to. For this reason, when a connected structure is manufactured using an anisotropic conductive material containing conductive particles with an insulating part according to the present invention, the insulating part is relatively flexible, so it can withstand external vibrations and shocks caused by dropping, etc. The shock resistance of the connection part can be effectively increased. As a result, even if external vibrations or shocks are applied due to a fall, etc., it is possible to effectively prevent the occurrence of cracks or peeling at the connection part, and the gap between the upper and lower electrodes to be connected can be effectively prevented. Continuity reliability and insulation reliability between horizontally adjacent electrodes that should not be connected can be effectively improved. In addition, in this specification, a "crosslinkable monomer (crosslinking agent)" is defined as a polymeric compound having two or more ethylenically unsaturated groups in one molecule.

In the present invention, the use of specific conductive particles with insulating parts greatly contributes to obtaining the above effects.

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

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

CV value (%) = (ρ/Dn) x 100
ρ: Standard deviation of particle diameter of conductive particles with insulation portion Dn: Average value of particle diameter of conductive particles with insulation portion

The shape of the conductive particles with an insulating part is not particularly limited. The shape of the conductive particles with an insulating part may be spherical, a shape other than spherical, or a flat shape.

The above-mentioned conductive particles with an insulating part are dispersed in a binder resin and suitably used to obtain a conductive material.

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

FIG. 1 is a sectional view showing a conductive particle with an insulating part according to a first embodiment of the present invention.

The conductive particles 1 with an insulating part shown in FIG. 1 include a conductive particle 2 and an insulating part 3 disposed on the surface of the conductive particle 2. The insulating portion 3 is an insulating particle. The conductive particle 1 with an insulating part includes a conductive particle 2 and a plurality of insulating particles arranged on the surface of the conductive particle 2. The insulating section 3 is formed of a material having insulation properties (insulating material).

The conductive particles 2 include base particles 11 and conductive parts 12 arranged on the surface of the base particles 11. In the conductive particles 1 with an insulating part, the conductive part 12 is a conductive layer. The conductive part 12 covers the surface of the base particle 11. The conductive particles 2 are coated particles in which the surface of a base particle 11 is coated with a conductive part 12. The conductive particles 2 have conductive parts 12 on their surfaces. In the conductive particles, the conductive part may cover the entire surface of the base particle, or the conductive part may cover a part of the surface of the base particle. In the conductive particle with an insulating part, the insulating part (the insulating particle) is preferably arranged on the surface of the conductive part.

FIG. 2 is a sectional view showing a conductive particle with an insulating part according to a second embodiment of the present invention.

The conductive particles 21 with insulating parts shown in FIG. 2 include conductive particles 22 and insulating parts 3 arranged on the surfaces of the conductive particles 22. The insulating portion 3 is an insulating particle.

The conductive particles 22 include a base particle 11 and a conductive part 31 arranged on the surface of the base particle 11. In the conductive particles 21 with an insulating part, the conductive part 31 is a conductive layer. The conductive particles 22 have a plurality of core substances 32 on the surface of the base particle 11 . The conductive part 31 covers the base particle 11 and the core substance 32. Since the conductive part 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 substance 32, and a plurality of protrusions 33 are formed. In the conductive particles, the conductive part may cover the entire surface of the base particle, or the conductive part may cover a part of the surface of the base particle. In the conductive particle with an insulating part, the insulating part (the insulating particle) is preferably arranged on the surface of the conductive part.

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

The conductive particles 41 with insulating parts shown in FIG. 3 include conductive particles 42 and insulating parts 3 arranged on the surfaces of the conductive particles 42. The insulating portion 3 is an insulating particle.

The conductive particles 42 include a base particle 11 and a conductive part 51 arranged on the surface of the base particle 11. In the conductive particles 41 with an insulating part, the conductive part 51 is a conductive layer. The conductive particles 42, unlike the conductive particles 22, do not have a core substance. The conductive portion 51 has a first portion and a second portion thicker than the first portion. The conductive particles 42 have a plurality of protrusions 52 on their surfaces. The portion excluding the plurality of protrusions 52 is the first portion of the conductive portion 51. The plurality of protrusions 52 are the second portion of the conductive portion 51 that is thick. In the conductive particles, the conductive part may cover the entire surface of the base particle, or the conductive part may cover a part of the surface of the base particle. In the conductive particle with an insulating part, the insulating part (the insulating particle) is preferably arranged on the surface of the conductive part.

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

The conductive particles 61 with insulating parts shown in FIG. 4 include the conductive particles 2 and the insulating parts 62 arranged on the surfaces of the conductive particles 2. The insulating section 62 is an insulating layer. The conductive particles 61 with insulating portions include conductive particles 2 and an insulating layer disposed on the surface of the conductive particles 2. The insulating portion 62 is formed of a material having insulation properties (insulating material).

The conductive particles 2 include base particles 11 and conductive parts 12 arranged on the surface of the base particles 11. In the conductive particles 61 with an insulating part, the conductive part 12 is a conductive layer. The conductive part 12 covers the surface of the base particle 11. The conductive particles 2 are coated particles in which the surface of a base particle 11 is coated with a conductive part 12. The conductive particles 2 have conductive parts 12 on their surfaces. In the conductive particles, the conductive part may cover the entire surface of the base particle, or the conductive part may cover a part of the surface of the base particle. In the conductive particles with an insulating part, the insulating part (the insulating layer) is preferably arranged on the surface of the conductive part.

Next, a method for manufacturing conductive particles with an insulating part according to the present invention will be explained.

The method for producing conductive particles with insulating parts according to the present invention is a method of producing conductive particles with insulating parts using conductive particles having a conductive part on at least the surface thereof and an insulating material. and an insulating part forming step of arranging the insulating material on the surface of the magnetic particles to form an insulating part. In the method for producing conductive particles with an insulating part according to the present invention, the insulating part is a polymer of a polymerizable component containing a plurality of types of polymerizable compounds. In the method for producing conductive particles with an insulating part according to the present invention, the polymerizable component undergoes a second reaction with a polymerizable compound having a first reactive functional group and a second reaction different from the first reactive functional group. and a polymerizable compound having a functional group. In the method for producing conductive particles with insulation portions according to the present invention, the polymerizable component does not contain a crosslinking agent, and the polymerizable component is a homopolymer glass in 100% by weight of the polymerizable component. Contains 10% by weight or more of a polymerizable compound having a transition temperature of less than 100°C. The obtained conductive particles with an insulating part are preferably particles before the first reactive functional group and the second reactive functional group react with each other.

Since the method for manufacturing conductive particles with an insulating part according to the present invention has the above configuration, it is possible to effectively improve continuity reliability and insulation reliability even when external vibrations or shocks are applied. I can do it.

In the method for producing conductive particles with an insulating part according to the present invention, the temperature in the insulating part forming step is preferably less than 50°C, and more preferably the temperature in the insulating part forming step is 40°C or less. In the method for producing conductive particles with insulating parts according to the present invention, in the conductive particles with insulating parts after the insulating part forming step, the polymer has the first reactive functional group and the second reactive It is preferable to have a functional group. In the method for producing conductive particles with insulation parts according to the present invention, in the conductive particles with insulation parts after the insulation part forming step, the first reactive functional group and the second reactive functional group are It is preferable that no reaction occurs. In the method for producing conductive particles with insulation parts according to the present invention, in the conductive particles with insulation parts after the insulation part forming step, the first reactive functional group and the second reactive functional group are Since it has not reacted, the degree of crosslinking of the insulating part is low and it has flexibility, and the adhesion between the insulating part and the surface of the conductive particles can be improved.

The method for producing conductive particles with insulation parts according to the present invention preferably includes a heating step of heating the conductive particles with insulation parts after the insulation part forming step. In the method for producing conductive particles with insulation parts according to the present invention, the heating temperature in the heating step is preferably 70°C or higher, and more preferably the heating temperature in the heating step is 90°C or higher. In the method for producing conductive particles with insulation parts according to the present invention, the heating time of the heating step is preferably 1 hour or more, and more preferably the heating time of the heating step is 2 hours or more. In the method for producing conductive particles with insulation parts according to the present invention, in the conductive particles with insulation parts after the heating step, the polymer has the first reactive functional group and the second reactive functional group. It is preferable to include a structure in which the group is reacted with a group. In the method for producing conductive particles with insulation parts according to the present invention, in the conductive particles with insulation parts after the heating step, the first reactive functional group and the second reactive functional group react with each other. It is preferable that The resulting conductive particles with an insulating part are preferably particles after the first reactive functional group and the second reactive functional group have reacted. In the method for producing conductive particles with insulation parts according to the present invention, in the conductive particles with insulation parts after the heating step, the first reactive functional group and the second reactive functional group react with each other. Therefore, the degree of crosslinking of the insulating part can be increased, and the solvent resistance of the insulating part can be improved.

In the method for producing conductive particles with an insulating part according to the present invention, the heating step is provided after the insulating part forming step, so that the insulating part has good adhesion to the surface of the conductive particles and solvent resistance. It is possible to balance both sex and gender. As a result, when electrically connecting electrodes using conductive particles with insulating parts, insulation reliability between adjacent horizontal electrodes that should not be connected can be further effectively increased.

Further, in the method for producing conductive particles with an insulating part according to the present invention, since the degree of crosslinking of the insulating part can be increased, solvent resistance can be increased. Since no crosslinking agent (crosslinking agent) is used and a specific polymerizable compound is used, a relatively flexible insulating part can be formed. For this reason, when a connected structure is manufactured using an anisotropic conductive material containing conductive particles with an insulating part according to the present invention, the insulating part is relatively flexible, so it can withstand external vibrations and shocks caused by dropping, etc. The shock resistance of the connection part can be effectively increased. As a result, even if external vibrations or shocks are applied due to a fall, etc., it is possible to effectively prevent the occurrence of cracks or peeling at the connection part, and the gap between the upper and lower electrodes to be connected can be effectively prevented. Continuity reliability and insulation reliability between horizontally adjacent electrodes that should not be connected can be effectively improved.

Other details of the conductive particles with insulating parts will be explained below.

Conductive particles:
The conductive particles preferably include a base particle and a conductive part disposed on the surface of the base particle. The conductive portion may have a single layer structure or a multilayer structure of two or more layers.

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 10 μm or less, and particularly preferably is 5 μm or less. When the particle diameter of the conductive particles is not less than the lower limit and not more than the upper limit, when the conductive particles are used to connect the electrodes, the contact area between the conductive particles and the electrodes is sufficiently large; In addition, agglomerated conductive particles are less likely to be formed when forming a conductive part. Moreover, the distance between the electrodes connected via the conductive particles does not become too large, and the conductive part becomes difficult to peel off from the surface of the base particle.

The particle diameter of the conductive particles is preferably an average particle diameter, more preferably a number average particle diameter. The particle diameter of the conductive particles can be determined, for example, by observing 50 arbitrary conductive particles with an electron microscope or optical microscope and calculating the average value of the particle diameter of each conductive particle, or by laser diffraction particle size distribution measurement. It can be obtained by doing the following. In observation using an electron microscope or an optical microscope, the particle diameter of each conductive particle is determined as the particle diameter in equivalent circle diameter. In observation using an electron microscope or an optical microscope, the average particle diameter of any 50 conductive particles in equivalent circle diameter is approximately equal to the average particle diameter in equivalent sphere diameter. In the laser diffraction particle size distribution measurement, the particle diameter of each conductive particle is determined as the particle diameter in equivalent sphere diameter. The average particle diameter 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. When the coefficient of variation of the particle diameter of the conductive particles is equal to or less than the above upper limit, the conduction reliability and insulation reliability between the electrodes can be further effectively improved.

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

CV value (%) = (ρ/Dn) x 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 conductive particles may have a spherical shape, a shape other than a spherical shape, a flat shape, or the like.

Base material particles:
Examples of the base particles include resin particles, inorganic particles other than metal particles, organic-inorganic hybrid particles, and metal particles. The base particles are preferably base particles excluding metal particles, and more preferably resin particles, inorganic particles excluding metal particles, or organic-inorganic hybrid particles. The base particle may 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.

Various organic substances are suitably used as materials for the resin particles. 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, and 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, Examples include polyamideimide, polyetheretherketone, polyethersulfone, divinylbenzene polymer, and divinylbenzene copolymer. Examples of the divinylbenzene copolymers include divinylbenzene-styrene copolymers and divinylbenzene-(meth)acrylic acid ester copolymers. Since the hardness of the resin particles can be easily controlled within a suitable range, the material of the resin particles is a polymer obtained by polymerizing one or more polymerizable monomers having ethylenically unsaturated groups. is preferred.

When the above-mentioned resin particles are obtained by polymerizing a polymerizable monomer having an ethylenically unsaturated group, the polymerizable monomer having an ethylenically unsaturated group may be a non-crosslinkable monomer. Examples include crosslinkable monomers.

Examples of the non-crosslinkable monomer include styrene monomers such as styrene and α-methylstyrene; carboxyl group-containing monomers such as (meth)acrylic acid, maleic acid, and maleic anhydride; methyl ( meth)acrylate, ethyl(meth)acrylate, propyl(meth)acrylate, butyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, lauryl(meth)acrylate, cetyl(meth)acrylate, stearyl(meth)acrylate, cyclohexyl( Alkyl (meth)acrylate compounds such as meth)acrylate and isobornyl (meth)acrylate; such as 2-hydroxyethyl (meth)acrylate, glycerol (meth)acrylate, polyoxyethylene (meth)acrylate, and glycidyl (meth)acrylate; Oxygen atom-containing (meth)acrylate compounds; nitrile-containing monomers such as (meth)acrylonitrile; vinyl ether compounds such as methyl vinyl ether, ethyl vinyl ether, and propyl vinyl ether; vinyl acetate, vinyl butyrate, vinyl laurate, vinyl stearate, etc. acid vinyl ester compounds; unsaturated hydrocarbons such as ethylene, propylene, isoprene, and butadiene; halogens such as trifluoromethyl (meth)acrylate, pentafluoroethyl (meth)acrylate, vinyl chloride, vinyl fluoride, and chlorostyrene. Containing monomers, etc. may be mentioned.

Examples of the crosslinkable monomers include tetramethylolmethanetetra(meth)acrylate, tetramethylolmethanetri(meth)acrylate, tetramethylolmethanedi(meth)acrylate, trimethylolpropanetri(meth)acrylate, and dipentaerythritol hexaacrylate. (meth)acrylate, dipentaerythritol penta(meth)acrylate, glycerol tri(meth)acrylate, glycerol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, Polyfunctional (meth)acrylate compounds such as (poly)tetramethylene glycol di(meth)acrylate and 1,4-butanediol di(meth)acrylate; triallyl(iso)cyanurate, triallyl trimellitate, divinylbenzene, diallyl Examples include phthalate, diallylacrylamide, diallyl ether, and silane-containing monomers such as γ-(meth)acryloxypropyltrimethoxysilane, trimethoxysilylstyrene, and vinyltrimethoxysilane.

The term "(meth)acrylate" refers to acrylates and methacrylates. The term "(meth)acrylic" refers to acrylic and methacrylic. 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 in which suspension polymerization is carried out in the presence of a radical polymerization initiator, and a method in which non-crosslinked seed particles are used to swell and polymerize monomers together with a radical polymerization initiator.

When the base particles are inorganic particles excluding metals or organic-inorganic hybrid particles, examples of the inorganic substance for forming the base particles include silica, alumina, barium titanate, zirconia, and carbon black. Preferably, the inorganic substance is not a metal. The particles formed from the silica are not particularly limited, but for example, after hydrolyzing a silicon compound having two or more hydrolyzable alkoxysilyl groups to form crosslinked polymer particles, baking may be performed as necessary. Examples include particles obtained by Examples of the organic-inorganic hybrid particles include organic-inorganic hybrid particles formed from 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. Preferably, the core is an organic core. Preferably, the shell is an inorganic shell. From the viewpoint of further effectively lowering the connection resistance between electrodes, the base particles are preferably organic-inorganic hybrid particles having an organic core and an inorganic shell arranged on the surface of the organic core. .

Examples of the material for the organic core include the materials for the resin particles described above.

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

When the base particles are metal particles, examples of the metal that is the material of the metal particles include silver, copper, nickel, silicon, gold, and titanium.

The particle size of the base particles is preferably 0.5 μm or more, more preferably 1 μm or more, even more preferably 2 μm or more, and preferably 100 μm or less, more preferably 60 μm or less, and still more preferably 50 μm or less. When the particle diameter of the base particles is at least the above lower limit and below the above upper limit, the distance between the electrodes becomes small, and even if the thickness of the conductive layer is increased, small conductive particles can be obtained. Furthermore, when forming a conductive part on the surface of the base material particles, it becomes difficult to aggregate, and it becomes difficult to form aggregated conductive particles.

The particle diameter of the base particles is particularly preferably 2 μm or more and 50 μm or less. When the particle size of the base particles is within the range of 2 μm or more and 50 μm or less, it becomes difficult to aggregate when forming a conductive part on the surface of the base particles, and it becomes difficult to form aggregated conductive particles.

The particle size of the base particles is preferably an average particle size, more preferably a number average particle size.

The particle diameter of the base material particles is determined using a particle size distribution measuring device or the like. The particle diameter of the base particles is preferably determined by observing 50 base particles using 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 base particle is determined as the particle diameter in equivalent circle diameter. In observation using an electron microscope or an optical microscope, the average particle diameter of any 50 base particles in equivalent circle diameter is approximately equal to the average particle diameter in equivalent sphere diameter. In the laser diffraction particle size distribution measurement, the particle diameter of each base particle is determined as the particle diameter in equivalent sphere diameter. When measuring the particle diameter of the base particle in the conductive particles, it can be measured, for example, as follows.

The conductive particles are added to "Technovit 4000" manufactured by Kulzer Co., Ltd. so that the content thereof is 30% by weight, and dispersed to prepare an embedded resin for conductive particle inspection. Using an ion milling device ("IM4000" manufactured by Hitachi High Technologies), a cross section of the conductive particles is cut out so as to pass through 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 was set to 25,000 times, 50 conductive particles were randomly selected, and the base material particles of each conductive particle were observed. do. The particle diameter of the base material particle in each conductive particle is measured, and the arithmetic average of the measurements is taken as the particle diameter of the base material particle.

Conductive part:
In the present invention, the conductive particles have a conductive portion at least on the surface. Preferably, the conductive part includes metal. The metal constituting the conductive part is not particularly limited. Examples of the metals include gold, silver, copper, platinum, palladium, zinc, lead, aluminum, cobalt, indium, nickel, chromium, titanium, antimony, bismuth, germanium, cadmium, and alloys thereof. Furthermore, tin-doped indium oxide (ITO) may be used as the metal. The above metals may be used alone or in combination of two or more. From the viewpoint of further lowering the connection resistance between electrodes, alloys containing tin, nickel, palladium, copper, or gold are preferable, and nickel or palladium is more preferable.

Further, from the viewpoint of further effectively increasing conduction reliability, it is preferable that the conductive portion and the outer surface portion of the conductive portion contain nickel. The content of nickel 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, still more preferably 70% by weight or more, particularly preferably is 90% by weight or more. The content of nickel in 100% by weight of the conductive portion containing nickel may be 97% by weight or more, 97.5% by weight or more, or 98% by weight or more.

Note that hydroxyl groups often exist on the surface of the conductive part due to oxidation. Generally, hydroxyl groups are present on the surface of a conductive part made of nickel due to oxidation. An insulating part can be disposed on the surface of the conductive part (the surface of the conductive particles) having such a hydroxyl group via a chemical bond.

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

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

The thickness of the conductive part is preferably 0.005 μm or more, more preferably 0.01 μm or more, and preferably 10 μm or less, more preferably 1 μm or less, and still more preferably 0.3 μm or less. When the thickness of the conductive part is not less than the lower limit and not more than the upper limit, sufficient conductivity can be obtained, the conductive particles do not become too hard, and the conductive particles can be sufficiently bonded during connection between the electrodes. It can be transformed.

When the conductive part is formed of a plurality of layers, the thickness of the outermost conductive part is preferably 0.001 μm or more, more preferably 0.01 μm or more, and preferably 0.5 μm or less, more preferably is 0.1 μm or less. When the thickness of the conductive part of the outermost layer is greater than or equal to the lower limit and less than the upper limit, the conductive part of the outermost layer will be uniform, the corrosion resistance will be sufficiently high, and the connection resistance between the electrodes will be sufficiently low. can do.

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

Core material:
It is preferable that the conductive particles have a plurality of protrusions on the outer surface of the conductive part. An oxide film is often formed on the surface of the electrode connected by the conductive particles with an insulating part. When using conductive particles with an insulating part that have protrusions on the surface of the conductive part, by placing the conductive particles with an insulating part between the electrodes and crimping them, the protrusions can effectively eliminate the oxide film. . For this reason, the electrode and the conductive part come into contact with each other more reliably, and the connection resistance between the electrodes becomes even lower. Furthermore, when connecting the electrodes, the protrusions of the conductive particles can effectively eliminate insulating particles between the conductive particles and the electrodes. Therefore, the reliability of conduction between the electrodes is further increased.

The above protrusions can be formed by attaching a core substance to the surface of the base particle and then forming a conductive part by electroless plating, or by forming a conductive part by electroless plating on the surface of the base particle. After that, a method of attaching a core material and further forming a conductive part by electroless plating is mentioned. Other methods for forming the protrusions include a method of adding a core substance during the formation of the conductive portion on the surface of the base particle. In addition, in order to form protrusions, a conductive part is formed on the base material particle by electroless plating without using the above-mentioned core material, and then plating is deposited in the shape of a protrusion on the surface of the conductive part, and then electroless plating is performed. Alternatively, a method of forming a conductive portion using the above method may be used.

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

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

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

The shape of the core material is not particularly limited. The shape of the core material is preferably a block. Examples of the core substance include particulate lumps, aggregates of a plurality of microparticles, and irregularly shaped lumps.

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. When the average diameter of the core material is not less than the lower limit and not more than the upper limit, the connection resistance between the electrodes can be effectively reduced.

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

Insulation part:
The conductive particle with an insulating part according to the present invention includes an insulating part disposed on the surface of the conductive particle. The form of the insulating section is not particularly limited. The form of the insulating portion may be insulating particles, an insulating sea-island structure, or an insulating layer. When the above-mentioned insulating part is an insulating particle, it is preferable that the above-mentioned conductive particle with an insulating part (insulating particle) has a plurality of insulating particles arranged on the surface of the above-mentioned conductive particle. When the above-mentioned insulating part is an insulating layer, it is preferable that the above-mentioned conductive particles with an insulating part (insulating layer) have an insulating layer arranged on the surface of the above-mentioned conductive particles, and Preferably, the surface is covered with an insulating layer. From the viewpoint of more easily eliminating the insulating part between the conductive part of the conductive particle and the electrode, the insulating part is preferably an insulating particle.

When the conductive particles with an insulating part are used for connecting electrodes, short circuits between adjacent electrodes can be prevented. Specifically, when a plurality of conductive particles with insulating parts come into contact, since the insulating part exists between the plurality of electrodes, a short circuit can be prevented not between upper and lower electrodes but between laterally adjacent electrodes. Note that when connecting the electrodes, by pressurizing the conductive particles with an insulating part between two electrodes, the insulating part between the conductive part of the conductive particle and the electrode can be easily removed. Furthermore, in the case of conductive particles having a plurality of protrusions on the outer surface of the conductive part, the insulating part between the conductive part of the conductive particle and the electrode can be more easily removed.

In the conductive particle with an insulating part according to the present invention, the insulating part is a polymer of a polymerizable component containing a plurality of types of polymerizable compounds. The above polymerizable component is not particularly limited. Examples of the polymerizable component include the materials for the resin particles described above. When the insulating part is an insulating particle, it may be the resin particle mentioned above.

In the conductive particles with an insulating part according to the present invention, the polymerizable component includes a polymerizable compound having a first reactive functional group and a second reactive functional group different from the first reactive functional group. and a polymerizable compound having the following.

The first reactive 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 a cyclic ether group or a nitrile group. It is more preferable that The cyclic ether group is preferably an epoxy group or an oxetanyl group, more preferably an epoxy group. When the first reactive functional group is the preferred functional group described above, insulation reliability can be further effectively improved when electrically connecting electrodes using conductive particles with an insulating part. can be increased.

Examples of the polymerizable compound having an epoxy group include glycidyl (meth)acrylate, allyl glycidyl ether, 4-hydroxybutyl (meth)acrylate glycidyl ether, and 3,4-epoxycyclohexylmethyl (meth)acrylate. Only one kind of the above polymerizable compound having an epoxy group may be used, or two or more kinds thereof may be used in combination.

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

Examples of the polymerizable compounds having the above-mentioned cyclic ether group (excluding the above-mentioned epoxy group) include (3-ethyloxetan-3-yl)methyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, and cyclic trimethylolpropane formal ( Examples include meth)acrylate. Only one kind of the polymerizable compound having the above-mentioned cyclic ether group (excluding the above-mentioned epoxy group) may be used, or two or more kinds thereof may be used in combination.

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

Examples of the polymerizable compound having an isocyanate group include 2-(meth)acryloyloxyethyl isocyanate, 2-(0-[1'-methylpropylideneamino]carboxyamino)ethyl (meth)acrylate, 2-[(3 ,5-dimethylpyrazolyl)carbonylamino]ethyl (meth)acrylate, 2-(2-(meth)acryloyloxyethyloxy)ethyl isocyanate, 2-propylene isocyanate, 1-phenyl-2-propylene isocyanate, 4,4-dimethyl Pentene-5-isocyanate, 2,4,4-trimethylpentene-5-isocyanate, 3,3-dimethylpentene-5-isocyanate, 2-allyl-2-isocyanate methyl-malonic acid diethyl ester, 1-phenyl-3- Examples include methyl-3-butene isocyanate, 4-vinylbenzene isocyanate, 1-isocyanatemethyl-4-vinyl-benzene, and 1,1-(bisacryloyloxymethyl)ethyl isocyanate. Only one kind of the above-mentioned polymerizable compound having an isocyanate group may be used, or two or more kinds thereof may be used in combination.

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

Examples of the polymerizable compound having an aldehyde group include acrolein and the like.

Examples of the polymerizable compound having a nitrile group include (meth)acrylonitrile and the like.

The second reactive functional group is different from the first reactive functional group. The second reactive 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; It is even more preferable that there be. When the second reactive functional group is the preferred functional group described above, insulation reliability can be further effectively improved when electrically connecting electrodes using conductive particles with an insulating part. can be increased.

Examples of the polymerizable compound having an amide group include (meth)acrylamide, N-substituted (meth)acrylamide, and N,N-substituted (meth)acrylamide. The above 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, ) acrylamide, N,N-dimethylaminopropyl (meth)acrylamide, and the like. The above 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. The above polymerizable compounds having an amide group may be used alone or in combination of two or more.

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

Examples of the polymerizable compounds having a hydroxyl group include 2-hydroxyethyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, (4-hydroxymethylcyclohexyl) Methyl acrylate, vinyl alcohol, allyl alcohol, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, diethylene glycol monovinyl ether, pentaerythritol tri(meth)acrylate, pentaerythritol di(meth)acrylate monostearate, isocyanuric acid ethylene oxide modified Examples include (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, glycerin (meth)acrylate, and 2-hydroxy-3-(meth)acryloyloxypropyl (meth)acrylate. Only one kind of the above polymerizable compound having a hydroxyl group may be used, or two or more kinds thereof may be used in combination.

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

Examples of the above-mentioned polymerizable compounds having a carboxyl group include unsaturated monocarboxylic acids such as (meth)acrylic acid, crotonic acid, and cinnamic acid, and unsaturated dicarboxylic acids such as maleic acid, itaconic acid, succinic acid, fumaric acid, and citraconic acid. Examples include acids, their salts, anhydrides, and the like. Only one kind of the above-mentioned polymerizable compound having a carboxyl group may be used, or two or more kinds thereof may be used in combination.

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

Examples of the polymerizable compound having an imide group include imide (meth)acrylate, maleimide, and the like. Only one kind of the polymerizable compound having an imide group may be used, or two or more kinds thereof may be used in combination.

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

Examples of the polymerizable compound having an amino group include N,N-dimethylaminoethyl (meth)acrylate and N,N-dimethylaminopropyl methacrylate. Only one kind of the above polymerizable compound having an amino group may be used, or two or more kinds thereof may be used in combination.

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

In the conductive particles with an insulating part according to the present invention, the polymerizable component does not contain a crosslinking agent, and the polymerizable component has a glass transition temperature of a homopolymer in 100% by weight of the polymerizable component. Contains 10% by weight or more of a polymerizable compound whose temperature is below 100°C. Here, the homopolymer in a polymerizable compound having a glass transition temperature of less than 100°C means a homopolymer obtained by homopolymerizing a polymerizable compound.

From the viewpoint of further effectively increasing conduction reliability and insulation reliability even when external vibrations or shocks are applied, the glass transition temperature (Tg(H)) of the above homopolymer is lower than 100°C. The temperature is preferably 90°C or lower, more preferably 70°C or lower. In addition, from the viewpoint of fusion of adjacent insulating parts and more effectively suppressing aggregation of conductive particles with insulating parts, the glass transition temperature of the above homopolymer should be 0°C or higher. The temperature is preferably 20°C or higher, and more preferably 20°C or higher.

In the polymerization to obtain the above-mentioned homopolymer, the polymerization method is not particularly limited. The above homopolymer can be obtained by homopolymerizing the above polymerizable compound by a known method. As this method, for example, all of the above polymerizable compounds may be polymerized at once, or the above polymerizable compounds may be added sequentially and polymerized.

The glass transition temperature (Tg(H)) can be measured in accordance with JIS-K7121 using a differential scanning calorimeter at a heating rate of 10° C./min. Examples of the differential scanning calorimeter include "DSC7020" manufactured by Hitachi High-Tech Science.

Examples of the above polymerizable compounds include isobornyl acrylate (Tg(H): 92°C), t-butyl acrylate (Tg(H): 14°C), stearyl acrylate (Tg(H): 30°C), and cyclohexyl acrylate ( Tg(H): 15°C), 2-hydroxy-3-phenoxypropyl acrylate (Tg(H): 17°C), dicyclopentenyloxyethyl acrylate (Tg(H): 15°C), and cyclic trimethylolpropane formal Acrylate compounds such as acrylate (Tg(H): 27°C); ethyl methacrylate (Tg(H): 65°C), n-butyl methacrylate (Tg(H): 20°C), isobutyl methacrylate (Tg(H): 48 °C), n-stearyl methacrylate (Tg (H): 38 °C), cyclohexyl methacrylate (Tg (H): 66 °C), tetrahydrofurfuryl methacrylate (Tg (H): 60 °C), benzyl methacrylate (Tg (H) : 54°C), 2-hydroxyethyl methacrylate (Tg(H): 55°C), 2-hydroxypropyl methacrylate (Tg(H): 26°C), dimethylaminoethyl methacrylate (Tg(H): 18°C), diethylamino Ethyl methacrylate (Tg(H): 20°C), glycidyl methacrylate (Tg(H): 46°C), dicyclopentenyloxyethyl methacrylate (Tg(H): 50°C), phenoxyethyl methacrylate (Tg(H): 36 ℃), methacrylate compounds such as 2-methacryloyloxyethyl phthalate (Tg(H): 75℃), and 2-methacryloyloxyethyl hexahydrophthalate (Tg(H): 70℃); vinyl acetate (Tg(H): 70℃); ): 28°C), acid vinyl ester compounds such as vinyl pivalate (Tg(H): 86°C), and vinyl monochloroacetate (Tg(H): 35°C); vinyl chloride (Tg(H): 87°C) and halogen-containing monomers such as vinyl fluoride (Tg(H): 35°C).

The polymerizable compound is preferably the following compound A, and more preferably the following compound B. The above compound A includes stearyl acrylate (Tg(H): 30°C), cyclic trimethylolpropane formal acrylate (Tg(H): 27°C), ethyl methacrylate (Tg(H): 65°C), n-butyl methacrylate (Tg(H): 20°C), isobutyl methacrylate (Tg(H): 48°C), n-stearyl methacrylate (Tg(H): 38°C), cyclohexyl methacrylate (Tg(H): 66°C), tetrahydrofur Furyl methacrylate (Tg(H): 60°C), benzyl methacrylate (Tg(H): 54°C), 2-hydroxyethyl methacrylate (Tg(H): 55°C), 2-hydroxypropyl methacrylate (Tg(H): 26°C), diethylaminoethyl methacrylate (Tg(H): 20°C), glycidyl methacrylate (Tg(H): 46°C), dicyclopentenyloxyethyl methacrylate (Tg(H): 50°C), phenoxyethyl methacrylate (Tg (H): 36°C), 2-methacryloyloxyethyl hexahydrophthalate (Tg(H): 70°C), vinyl acetate (Tg(H): 28°C), monochlorovinyl acetate (Tg(H): 35°C) ), and vinyl fluoride (Tg(H): 35°C). The above compound B includes ethyl methacrylate (Tg(H): 65°C), isobutyl methacrylate (Tg(H): 48°C), cyclohexyl methacrylate (Tg(H): 66°C), tetrahydrofurfuryl methacrylate (Tg(H): 66°C), ): 60°C), benzyl methacrylate (Tg(H): 54°C), 2-hydroxyethyl methacrylate (Tg(H): 55°C), glycidyl methacrylate (Tg(H): 46°C), and dicyclopentenyloxy Ethyl methacrylate (Tg(H): 50°C) is mentioned. Only one type of the above compound A may be used, or two or more types may be used in combination. Only one type of the above compound B may be used, or two or more types may be used in combination.

In the conductive particles with an insulating part according to the present invention, the polymerizable component does not contain a crosslinking agent, and the polymerizable component has a glass transition temperature of a homopolymer in 100% by weight of the polymerizable component. Contains 10% by weight or more of a polymerizable compound whose temperature is below 100°C. The polymerizable component preferably contains 20% by weight or more, and more preferably 30% by weight or more of a polymerizable compound whose homopolymer has a glass transition temperature of less than 100°C in 100% by weight of the polymerizable component. preferable. If the content of the polymerizable compound having a glass transition temperature of less than 100°C in the above homopolymer is at least the above lower limit, the continuity reliability and insulation reliability will be improved even when external vibrations or shocks are applied. It can be improved even more effectively. The upper limit of the content of the polymerizable compound whose glass transition temperature of the homopolymer is less than 100° C. is not particularly limited. The content of the polymerizable compound having a glass transition temperature of less than 100°C in the homopolymer may be 90% by weight or less. When the content of the polymerizable compound having a glass transition temperature of less than 100°C in the homopolymer is below the above upper limit, the degree of crosslinking of the insulation part can be increased, and the solvent resistance can be further improved. . In the present invention, a crosslinking monomer (crosslinking agent) is not used for the insulating part, and a specific polymerizable compound is used, so a relatively flexible insulating part can be formed. . For this reason, when a connected structure is manufactured using an anisotropic conductive material containing conductive particles with an insulating part according to the present invention, the insulating part is relatively flexible, so it can withstand external vibrations and shocks caused by dropping, etc. The shock resistance of the connection part can be effectively increased. As a result, even if external vibrations or shocks are applied due to a fall, etc., it is possible to effectively prevent the occurrence of cracks or peeling at the connection part, and the gap between the upper and lower electrodes to be connected can be effectively prevented. Continuity reliability and insulation reliability between horizontally adjacent electrodes that should not be connected can be effectively improved.

In addition, in the conductive particles with an insulating part, the type of polymerizable compound, etc. contained in the polymerizable component that is the material of the insulating part can be specified according to the following procedure. After dispersing the conductive particles with an insulating part in methanol, vibration is applied for 30 minutes using an ultrasonic homogenizer ("UX-050" manufactured by Mitsui Electric Seiki Co., Ltd.). After that, centrifugation is performed to separate the insulating part and the conductive particles. A sample is obtained by concentrating the solution containing the separated insulating part. By analyzing the constituent components of the insulating portion of the obtained sample using GC-MS and NMR, it is possible to identify the type of polymerizable compound contained in the polymerizable component. Moreover, by producing a homopolymer of the monomer of the specified polymerizable compound, the glass transition temperature of the homopolymer can be measured.

In the electrically conductive particles with insulation parts according to the present invention, the polymerizable component may include a third polymerizable compound. The third polymerizable compound does not correspond to the polymerizable compound having the first reactive functional group (first polymerizable compound) and is a second polymerizable compound different from the first reactive functional group. This is a polymerizable compound that does not correspond to a polymerizable compound (second polymerizable compound) having a reactive functional group. When the polymerizable component contains the third polymerizable compound, for example, the glass transition temperature of the homopolymer of the first polymerizable compound is less than 100°C, or The homopolymer has a glass transition temperature of less than 100°C, or the homopolymer of the third polymerizable compound has a glass transition temperature of less than 100°C. The homopolymer of the third polymerizable compound preferably has a glass transition temperature of less than 100°C.

In the conductive particles with an insulating part according to the present invention, the degree of crosslinking of the insulating part determined by the following formula (1) is preferably 10 or more, more preferably 20 or more. When the degree of crosslinking of the insulating part is equal to or higher than the lower limit, insulation reliability can be further effectively improved when electrically connecting electrodes using conductive particles with an insulating part.

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

In the above formula (1), A is the total number of moles of the polymerizable compound having the first reactive functional group and the polymerizable compound having the second reactive functional group, and B is the total number of moles of the polymerizable compound having the first reactive functional group and the second reactive functional group. is the total number of moles.

The conductive particle with an insulating part according to the present invention has a configuration (first configuration) in which the polymer has the first reactive functional group and the second reactive functional group, or The polymer has a structure (second structure) in which the polymer includes a structure in which the first reactive functional group and the second reactive functional group react.

When the conductive particles with an insulating part according to the present invention have the first configuration, the polymer has the first reactive functional group and the second reactive functional group. , the first reactive functional group and the second reactive functional group do not react. When the conductive particles with an insulating part according to the present invention have the above first configuration, the first reactive functional group and the second reactive functional group do not react with each other, so that the insulating part is It has a low degree of crosslinking and flexibility, and can improve the adhesion between the insulating part and the surface of the conductive particles.

When the conductive particle with an insulating part according to the present invention has the above first configuration, the first reactive functional group and the second reactive functional group have the property of being able to react upon stimulation. It is preferable. The stimulus is preferably heating or light irradiation, and more preferably heating.

When the conductive particles with an insulating part according to the present invention have the second configuration, the polymer has a structure in which the first reactive functional group and the second reactive functional group react with each other. The first reactive functional group and the second reactive functional group are reacted. When the conductive particles with an insulating part according to the present invention have the above second configuration, the first reactive functional group and the second reactive functional group are reacted, so that the insulating part is The degree of crosslinking can be increased, and the solvent resistance of the insulating part can be improved.

In the conductive particles with insulating parts according to the present invention, conductive particles with insulating parts having the above-mentioned second configuration can be obtained by heating or irradiating the conductive particles with insulating parts having the above-mentioned first configuration. is preferred. It is more preferable that the insulating part-equipped conductive particles having the second configuration are obtained by heating the insulating part-attached conductive particles having the first configuration. When the conductive particles with an insulating part satisfy the above preferable aspects, it is possible to achieve both adhesion to the surface of the conductive particle and solvent resistance with respect to the insulating part. As a result, when electrically connecting electrodes using conductive particles with insulating parts, insulation reliability can be improved even more effectively.

Examples of methods for arranging the insulating section on the surface of the conductive section include chemical methods, physical or mechanical methods, and the like. Examples of the chemical methods 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 adhesion, spraying, dipping, and vacuum deposition. Since the insulating part is difficult to detach, it is preferable to arrange the insulating part on the surface of the conductive part via a chemical bond. In the conductive particles with an insulating part according to the present invention, it is preferable that the hydroxyl group or the like present on the surface of the conductive part and the polymerizable compound having the first reactive functional group are chemically bonded to each other, and It is preferable that the hydroxyl group or the like present on the surface of the part and the polymerizable compound having the second reactive functional group are chemically bonded. In the conductive particles with an insulating part according to the present invention, a hydroxyl group or the like present on the surface of the conductive part and the first reactive functional group may be chemically bonded, and The hydroxyl group and the like and the first reactive functional group do not need to be chemically bonded. In the conductive particles with an insulating part according to the present invention, the hydroxyl group, etc. present on the surface of the conductive part and the second reactive functional group may be chemically bonded, and the hydroxyl group etc. present on the surface of the conductive part may be chemically bonded. The hydroxyl group and the like and the second reactive functional group do not need to be chemically bonded.

The outer surface of the conductive part and the outer surface of the insulating part may each be coated with a compound having a reactive functional group. The outer surface of the conductive part and the outer surface of the insulating part may not be directly chemically bonded to each other, but may be indirectly chemically bonded to each other 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 via a polymer electrolyte such as polyethyleneimine.

When the insulating part is an insulating particle, the particle size of the insulating particle can be appropriately selected depending on the particle size of the insulating part-attached conductive particle, the use of the insulating part-attached conductive particle, and the like. The particle size of the insulating particles is preferably 10 nm or more, more preferably 100 nm or more, even more preferably 200 nm or more, particularly preferably 300 nm or more, and preferably 4000 nm or less, more preferably 2000 nm or less, and even more preferably 1500 nm or less. , particularly preferably 1000 nm or less. When the particle size of the insulating particles is equal to or larger than the lower limit, when the conductive particles with an insulating part are dispersed in a binder resin, the conductive parts of the plurality of conductive particles with an insulating part come into contact with each other. It becomes difficult. When the particle size of the insulating particles is below the above upper limit, there is no need to increase the pressure too high in order to eliminate the insulating particles between the electrodes and the conductive particles when connecting the electrodes. , there is no need to heat it to high temperatures.

The particle size of the insulating particles is preferably an average particle size, more preferably a number average particle size. The particle size 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 the case of measuring the particle size of the insulating particles in the insulating part-attached conductive particles, the measurement can be performed, for example, as follows.

Conductive particles with an insulating part are added to "Technovit 4000" manufactured by Kulzer Co., Ltd. to a content of 30% by weight, and dispersed to prepare an embedded resin for conductive particle inspection. Using an ion milling device ("IM4000" manufactured by Hitachi High-Technologies), a cross section of the conductive particles with insulation parts is cut out so as to pass through the center of the conductive particles with insulation parts 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, 50 conductive particles with an insulating part were randomly selected, and each conductive particle with an insulating part was Observe the insulating particles. The particle size of the insulating particle in each conductive particle with an insulating part is measured, and the arithmetic mean of the measured values is determined as the particle size of the insulating particle.

When the insulating part is an insulating particle, the ratio of the particle diameter of the conductive particle to the particle diameter of the insulating particle (particle diameter of the conductive particle/particle diameter of the insulating particle) is preferably 3. Above, it is more preferably 5 or more, preferably 100 or less, and more preferably 50 or less. If the above ratio (particle size of conductive particles/particle size of insulating particles) is above the above lower limit and below the above upper limit, the continuity reliability and insulation reliability will be maintained even when external vibrations or shocks are applied. It can be improved even more effectively. When the above ratio (particle size of conductive particles/particle size of insulating particles) is greater than or equal to the above lower limit and less than or equal to the above upper limit, when the above-mentioned conductive particles with insulating parts are dispersed in the binder resin, a plurality of The conductive parts in the above-mentioned conductive particles with an insulating part become difficult to come into contact with each other. Further, when connecting the electrodes, there is no need to apply too high a pressure to eliminate insulating particles between the electrodes and the conductive particles, and there is no need to heat the electrodes to high temperatures.

When the above-mentioned insulating part is an insulating particle, the above-mentioned conductive particle with an insulating part may be a combination of two or more kinds of insulating particles having different particle diameters. By using two or more types of insulating particles with different particle sizes, the insulating particles with a small particle size can enter the gaps covered by the insulating particles with a large particle size, making the above coverage even more effective. can be increased. When the insulating particles are used as the insulating part, the insulating particles include first insulating particles having a particle size of 0.1 μm or more and less than 0.25 μm, and first insulating particles having a particle size of 0.25 μm or more and less than 0.8 μm. It is preferable to include the following second insulating particles. It is preferable that the particle size distribution of the first insulating particles has no overlap with the particle size distribution of the second insulating particles. The average particle diameter of the first insulating particles and the average particle diameter of the second insulating particles are preferably different.

When the insulating portion is an insulating particle, the coefficient of variation (CV value) of the particle diameter of the insulating particle is preferably 20% or less. When the coefficient of variation of the particle diameter of the insulating particles is less than or equal to the above upper limit, the thickness of the insulating particles of the obtained conductive particles with an insulating part becomes even more uniform, and the pressure can be applied more uniformly during conductive connection. It can be easily applied, and the connection resistance between electrodes can be further lowered.

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

CV value (%) = (ρ/Dn) x 100
ρ: Standard deviation of particle diameter of insulating particles Dn: Average value of particle diameter of insulating particles

When the insulating portion is an insulating particle, the shape of the insulating particle is not particularly limited. The shape of the insulating particles may be spherical, a shape other than spherical, or a flat shape.

When the insulating part is an insulating layer, the thickness of the insulating layer can be appropriately selected depending on the particle diameter of the conductive particles with an insulating part, the use of the conductive particles with an insulating part, and the like. The thickness of the insulating layer is preferably 10 nm or more, more preferably 100 nm or more, even more preferably 200 nm or more, particularly preferably 300 nm or more, preferably 4000 nm or less, more preferably 2000 nm or less, still more preferably 1500 nm or less, especially Preferably it is 1000 nm or less. When the thickness of the insulating layer is equal to or greater than the lower limit, when the conductive particles with an insulating part are dispersed in a binder resin, the conductive parts of the plurality of conductive particles with an insulating part become difficult to come into contact with each other. . When the thickness of the insulating layer is less than the upper limit above, there is no need to apply too high a pressure to eliminate the insulating layer between the electrode and the conductive particles when connecting the electrodes, and it is possible to avoid high temperatures. There is no need to heat it.

The thickness of the insulating layer is preferably determined by observing the cross section of the conductive particle with an insulating part using an electron microscope or an optical microscope, and calculating the average thickness of the insulating layer at 50 arbitrary locations. When measuring the thickness of the insulating layer in the conductive particles with an insulating part, for example, the thickness can be measured as follows.

Conductive particles with an insulating part are added to "Technovit 4000" manufactured by Kulzer Co., Ltd. to a content of 30% by weight, and dispersed to prepare an embedded resin for conductive particle inspection. Using an ion milling device ("IM4000" manufactured by Hitachi High-Technologies), a cross section of the conductive particles with insulation parts is cut out so as to pass through the center of the conductive particles with insulation parts 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 with insulating parts were randomly selected, and an insulating layer of the conductive particles with insulating parts was formed. Observe. The thickness of the insulating layer is measured at 50 arbitrary locations, and the thickness of the insulating layer is determined by taking the arithmetic average of the thicknesses.

(conductive material)
The electrically conductive material according to the present invention includes the above-mentioned electrically conductive particles with an insulating portion and a binder resin. The conductive particles with an insulating part are preferably used by being dispersed in a binder resin, and preferably used as a conductive material by being dispersed in a binder resin. Preferably, the conductive material is an anisotropic conductive material. The conductive material is preferably used for electrical connection between electrodes. Preferably, the conductive material is a conductive material for circuit connection. Since the above-described conductive particles with an insulating part are used in the above-mentioned conductive material, the conductive particles with an insulating part are insulated from the surface of the conductive particles with an insulating part before conductive connection, such as by dispersing the conductive particles with an insulating part in a binder resin. It is possible to prevent the parts from unintentionally detaching, and it is possible to further improve the insulation reliability between the electrodes.

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

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

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

In addition to the conductive particles with insulating parts and the binder resin, the conductive material includes, for example, fillers, extenders, softeners, plasticizers, polymerization catalysts, curing catalysts, colorants, antioxidants, and heat stabilizers. , a light stabilizer, an ultraviolet absorber, a lubricant, an antistatic agent, and a flame retardant.

A conventionally known dispersion method can be used as a method for dispersing the conductive particles with insulating parts in the binder resin, and is not particularly limited. Examples of methods for dispersing the conductive particles with insulating parts in the binder resin include the following methods. A method in which the conductive particles with an insulating part are added to the binder resin and then kneaded and dispersed using a planetary mixer or the like. A method of uniformly dispersing the conductive particles with an insulating part in water or an organic solvent using a homogenizer or the like, adding them to the binder resin, and kneading and dispersing them with a planetary mixer or the like. A method in which the binder resin is diluted with water or an organic solvent, the conductive particles with an insulating part are added thereto, and the conductive particles are kneaded and dispersed using 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, and preferably 400 Pa·s or less, more preferably 300 Pa·s or less. When the viscosity at 25°C of the conductive material is not less than the lower limit and not more than the upper limit, the insulation reliability between the electrodes can be further effectively increased, and the continuity reliability between the electrodes can be further effectively increased. can be increased to The above viscosity (η25) can be adjusted as appropriate depending on the types and amounts of the ingredients.

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

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

The content of the binder resin in 100% by weight of the conductive material is preferably 10% by weight or more, more preferably 30% by weight or more, further preferably 50% by weight or more, particularly preferably 70% by weight or more, and preferably is 99.99% by weight or less, more preferably 99.9% by weight or less. When the content of the binder resin is at least the above lower limit and below the above upper limit, conductive particles are efficiently arranged between the electrodes, further increasing the connection reliability of the connection target members connected by the conductive material. I can do it.

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

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

The above-mentioned connected structure can be made conductive by arranging the above-mentioned conductive particles with an insulating part or the above-mentioned conductive material between the above-mentioned first connection target member and the above-mentioned second connection target member, and thermocompression bonding. It can be obtained through the process of connecting. It is preferable that the insulating part is detached from the insulating part-attached conductive particles during the thermocompression bonding.

FIG. 5 is a cross-sectional view schematically showing a connected structure using conductive particles with an insulating part according to the first embodiment of the present invention.

The connection structure 81 shown in FIG. 5 includes a first connection target member 82, a second connection target member 83, and a connection portion connecting the first connection target member 82 and the second connection target member 83. 84. The connecting portion 84 is formed of a conductive material containing the conductive particles 1 with an insulating portion. The connecting portion 84 is preferably formed by curing a conductive material containing a plurality of insulating portion-attached conductive particles 1. In addition, in FIG. 5, the electrically conductive particles 1 with an insulating part are shown schematically for convenience of illustration. In place of the conductive particles 1 with insulation parts, conductive particles 21, 41, or 61 with insulation parts 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 the front surface (lower surface). The first electrode 82a and the second electrode 83a are electrically connected by the conductive particles 2 of one or more conductive particles 1 with insulating parts. Therefore, the first connection target member 82 and the second connection target member 83 are electrically connected by the conductive part in the conductive particle 1 with an insulating part.

The method for manufacturing the above-mentioned connected structure is not particularly limited. As an example of a method for manufacturing a connected structure, the conductive material is placed between a first member to be connected and a second member to be connected, a laminate is obtained, and then the laminate is heated and pressurized. Examples include methods. The pressure of the thermocompression bonding is preferably 40 MPa or more, more preferably 60 MPa or more, and preferably 90 MPa or less, more preferably 70 MPa or less. The heating temperature for the thermocompression bonding is preferably 80°C or higher, more preferably 100°C or higher, and preferably 140°C or lower, more preferably 120°C or lower. When the pressure and temperature of the thermocompression bonding are above the above lower limit and below the above upper limit, the insulating part can be easily detached from the surface of the conductive particles with an insulating part during conductive connection, further improving the continuity reliability between the electrodes. can be increased.

When heating and pressurizing the laminate, the insulating portion existing between the conductive particles and the first and second electrodes can be removed. For example, during the heating and pressurization, the insulating part existing between the conductive particles and the first electrode and the second electrode is removed from the conductive particles with an insulating part. Easily detached from surfaces. Note that during the heating and pressurization, some of the insulating parts may detach from the surface of the conductive particles with insulating parts, and the surface of the conductive part may be partially exposed. The exposed surface of the conductive part contacts the first electrode and the second electrode, thereby electrically connecting the first electrode and the second electrode via the conductive particles. can do.

The first connection target member and the second connection target member are not particularly limited. Specifically, the first connection target member and the second connection target member include semiconductor chips, semiconductor packages, LED chips, LED packages, electronic components such as capacitors and diodes, resin films, printed circuit boards, flexible Examples include electronic components such as printed circuit boards, flexible flat cables, rigid flexible boards, circuit boards such as 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 the 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 member to be connected is a flexible printed circuit board, the electrode is preferably a gold electrode, a nickel electrode, a tin electrode, a silver electrode, or a copper electrode. When the member to be connected is a glass substrate, the electrode is preferably an aluminum electrode, a copper electrode, a molybdenum electrode, a silver electrode, or a tungsten electrode. In addition, when the said electrode is an aluminum electrode, it may be an electrode formed only with aluminum, and the electrode may be an electrode in which an aluminum layer is laminated|stacked on the surface of a metal oxide layer. Examples of the material for the metal oxide layer include indium oxide doped with a trivalent metal element and zinc oxide doped with a trivalent metal element. Examples of the trivalent metal elements include Sn, Al, and Ga.

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

(Example 1)
(1) Preparation of conductive particles Resin particles (particle size 3 μm) formed from a copolymer resin of tetramethylolmethanetetraacrylate and divinylbenzene were prepared. After 10 parts by weight of the base particles were dispersed in 100 parts by weight of an alkaline solution containing 5% by weight of the palladium catalyst liquid using an ultrasonic disperser, the base particles were taken out by filtering the solution. Next, the base particles were added to 100 parts by weight of a 1% by weight dimethylamine borane solution to activate the surface of the base particles. After thoroughly washing the surface-activated base material particles with water, they were added to 500 parts by weight of distilled water and dispersed to obtain a dispersion. 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 substance was attached.

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

While stirring the resulting suspension at 60° C., the above nickel plating solution was gradually dropped into the suspension to perform electroless nickel plating. Thereafter, by filtering the suspension, the particles are taken out, washed with water, and dried to form a nickel-boron conductive layer (thickness 0.15 μm) on the surface of the base material particles, which has a conductive part on the surface. Conductive particles were obtained.

(2) Preparation of insulating part (insulating particles) A composition containing the following polymerizable compound was placed in a 1000 mL separable flask equipped with a four-necked separable cover, a stirring blade, a three-way cock, a cooling tube, and a temperature probe. After that, the mixture was stirred at 200 rpm and polymerized at 50° C. for 5 hours in a nitrogen atmosphere. The above composition contains 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}. 0.2 parts by weight (0.5 mmol) and a polymerizable component containing multiple types of polymerizable compounds. The polymerizable component includes 85 parts by weight (0.85 mol) of methyl methacrylate, a polymerizable compound having a first reactive functional group, and a polymerizable compound having a second reactive functional group. The polymerizable compounds include 7 parts by weight (0.05 mol) of glycidyl methacrylate, 4 parts by weight (0.05 mol) of methacrylamide, and 9 parts by weight (0.05 mol) of benzyl methacrylate. After the reaction was completed, the mixture was freeze-dried to obtain insulating particles (particle size: 300 nm) having on their surfaces an amide group derived from methacrylamide and an epoxy group derived from glycidyl methacrylate.

(3) Preparation of conductive particles with insulating parts (insulating particles) The insulating particles obtained above were dispersed in distilled water under ultrasonic irradiation to obtain a 10% by weight aqueous dispersion of 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 insulating particles was added, and the mixture was stirred at room temperature for 8 hours. After filtering through a 3 μm mesh filter, the particles were further washed with methanol and dried to obtain conductive particles (A) with an insulating portion (insulating particles). In this conductive particle with an insulating part (A), the insulating part has an amide group and an epoxy group.

(4) Preparation of conductive material (anisotropic conductive paste) 7 parts by weight of the obtained conductive particles with insulating parts (A), 25 parts by weight of bisphenol A type phenoxy resin, 4 parts by weight of fluorene type epoxy resin, A conductive material (anisotropic conductive paste) was obtained by blending 30 parts by weight of a phenol novolac type epoxy resin and SI-60L (manufactured by Sanshin Kagaku Kogyo Co., Ltd.), defoaming and stirring for 3 minutes.

(5) Preparation of connected structure A glass-epoxy substrate on which a Cu electrode pattern (first electrode) with L/S of 7 μm/13 μm was formed was prepared. In addition, a polyimide substrate on which an Au electrode pattern (second electrode) with L/S of 7 μm/13 μm was formed on the lower surface was prepared.

The obtained anisotropic conductive paste was applied to a thickness of 30 μm on the glass-epoxy substrate to form an anisotropic conductive paste layer. Next, the polyimide substrate was laminated on the anisotropic conductive paste layer so that the electrodes faced each other. After that, while adjusting the temperature of the head so that the temperature of the anisotropic conductive paste layer becomes 120°C, a pressure heating head is placed on the top surface of the polyimide substrate, and a pressure of 50 MPa is applied to the anisotropic conductive paste layer. It was cured at 120°C to obtain a connected structure.

(Example 2)
After obtaining the conductive particles (A) with an insulating part (insulating particles), they were further heated at 90°C for 2 hours to react the amide group and epoxy group on the surface of the insulating part (insulating particle). Conductive particles (B) with an insulating part (insulating particles) were obtained. The electrically conductive particles (B) with an insulating part include a structure in which the insulating part is a reaction between an amide group and an epoxy group. A conductive material and a connected structure were obtained in the same manner as in Example 1, except that the obtained conductive particles with insulating parts (B) were used.

(Example 3)
When producing the insulating part (insulating particles), the amount of methyl methacrylate added to the above polymerizable compound was changed to 75 parts by weight (0.75 mol). In addition, the amount of glycidyl methacrylate was changed to 14 parts by weight (0.1 mol), and the amount of methacrylamide was changed to 9 parts by weight (0.1 mol). Conductive particles (A) with insulating portions (insulating particles) were obtained in the same manner as in Example 1 except for the above changes. In this conductive particle with an insulating part (A), the insulating part has an amide group and an epoxy group. In addition, the conductive particles with an insulating part (A) were heated at 90°C for 2 hours to react with the amide groups and epoxy groups on the surface of the insulating part (insulating particles). )-attached conductive particles (B) were obtained. The electrically conductive particles (B) with an insulating part include a structure in which the insulating part is a reaction between an amide group and an epoxy group. A conductive material and a connected structure were obtained in the same manner as in Example 1, except that the obtained conductive particles (A) and (B) with insulating parts were used.

(Example 4)
When producing the insulating part (insulating particles), the amount of methyl methacrylate added to the above polymerizable compound was changed to 60 parts by weight (0.6 mol). Furthermore, the amount of glycidyl methacrylate was changed to 14 parts by weight (0.1 mol), the amount of methacrylamide was changed to 9 parts by weight (0.1 mol), and the amount of benzyl methacrylate was changed to 36 parts by weight (0.1 mol). 0.2 mol). Conductive particles (A) with insulating portions (insulating particles) were obtained in the same manner as in Example 1 except for the above changes. Further, the conductive particles (A) with an insulating part were heated at 90° C. for 2 hours to obtain conductive particles (B) with an insulating part (insulating particles). A conductive material and a connected structure were respectively produced in the same manner as in Example 1, except that the obtained conductive particles with insulating parts (A) and (B) were used.

(Example 5)
When preparing the insulating part (insulating particles), 36 parts by weight (0.2 mol) of benzyl methacrylate was changed to 23 parts by weight (0.2 mol) of ethyl methacrylate regarding the above polymerizable compound. Except for the above changes, conductive particles (A) and (B) with insulating parts (insulating particles), a conductive material, and a connected structure were obtained in the same manner as in Example 4.

(Example 6)
When producing the insulating part (insulating particles), the amount of methyl methacrylate added to the above polymerizable compound was changed to 50 parts by weight (0.5 mol). Furthermore, the amount of glycidyl methacrylate was changed to 14 parts by weight (0.1 mol), the amount of methacrylamide was changed to 9 parts by weight (0.1 mol), and the amount of benzyl methacrylate was changed to 54 parts by weight (0.1 mol). 0.3 mol). Conductive particles (A) with insulating portions (insulating particles) were obtained in the same manner as in Example 1 except for the above changes. Further, the conductive particles (A) with an insulating part were heated at 90° C. for 2 hours to obtain conductive particles (B) with an insulating part (insulating particles). A conductive material and a connected structure were respectively produced in the same manner as in Example 1, except that the obtained conductive particles with insulating parts (A) and (B) were used.

(Example 7)
When producing the insulating part (insulating particles), the amount of methyl methacrylate added to the above polymerizable compound was changed to 10 parts by weight (0.1 mol). Furthermore, the amount of glycidyl methacrylate was changed to 14 parts by weight (0.1 mol), the amount of methacrylamide was changed to 9 parts by weight (0.1 mol), and the amount of benzyl methacrylate was changed to 126 parts by weight (0.1 mol). 0.7 mol). Conductive particles (A) with insulating portions (insulating particles) were obtained in the same manner as in Example 1 except for the above changes. Further, the conductive particles (A) with an insulating part were heated at 90° C. for 2 hours to obtain conductive particles (B) with an insulating part (insulating particles). A conductive material and a connected structure were respectively produced in the same manner as in Example 1, except that the obtained conductive particles with insulating parts (A) and (B) were used.

(Example 8)
Preparation of conductive particles with insulating part (insulating layer):
After putting a composition containing the following polymerizable compound into a 1000 mL separable flask equipped with a four-necked separable cover, a stirring blade, a three-way cock, a cooling tube, and a temperature probe, it was thoroughly heated using an ultrasonic irradiator. Emulsified. Thereafter, the mixture was stirred at 200 rpm and polymerized at 48° C. for 5 hours under a nitrogen atmosphere. The above composition contains 200 mL of distilled water, 20 parts of conductive particles, 0.02 part (0.05 mmol) of 2,2'-azobis{2-[N-(2-carboxyethyl)amidino]propane}, and an emulsifier. Contains 0.1 part by weight of a certain polyoxyethylene lauryl ether ("Emulgen 106" manufactured by Kao Corporation) and a polymerizable component containing multiple types of polymerizable compounds. The polymerizable component includes 0.6 parts by weight (6 mmol) of methyl methacrylate, a polymerizable compound having a first reactive functional group, and a polymerizable compound having a second reactive functional group. The polymerizable compounds include 0.14 parts by weight (1 mmol) of glycidyl methacrylate, 0.09 parts by weight (1 mmol) of methacrylamide, and 0.36 parts by weight (2 mmol) of benzyl methacrylate. After the reaction is completed, it is cooled, solid-liquid separation is performed twice using a centrifuge, and excess polymerizable compound is removed by washing. Conductive particles (A) with a covered insulating portion (insulating layer) (insulating layer thickness: 200 nm) were obtained. Further, the conductive particles (A) with an insulating part were heated at 90° C. for 2 hours to obtain conductive particles (B) with an insulating part (insulating layer). A conductive material and a connected structure were respectively produced in the same manner as in Example 1, except that the obtained conductive particles with insulating parts (A) and (B) were used.

(Example 9)
When preparing the insulating part (insulating particles), 36 parts by weight (0.2 mol) of benzyl methacrylate was changed to 28 parts by weight (0.2 mol) of isobutyl methacrylate regarding the polymerizable compound. Except for the above changes, conductive particles (A) and (B) with insulating parts (insulating particles), a conductive material, and a connected structure were obtained in the same manner as in Example 4.

(Example 10)
When producing the insulating part (insulating particles), 7 parts by weight (0.1 mol) of methacrylonitrile was used instead of 14 parts by weight (0.1 mol) of glycidyl methacrylate with respect to the polymerizable compound. Furthermore, 9 parts by weight (0.1 mol) of methacrylic acid was used instead of 9 parts by weight (0.1 mol) of methacrylamide. Except for the above changes, conductive particles (A) and (B) with insulating parts (insulating particles), a conductive material, and a connected structure were obtained in the same manner as in Example 4.

(Comparative example 1)
When producing the insulating part (insulating particles), the amount of methyl methacrylate added to the above polymerizable compound was changed to 95 parts by weight (0.95 mol). Furthermore, glycidyl methacrylate, methacrylamide, and benzyl methacrylate were not added. Furthermore, 10 parts by weight (0.05 mol) of ethylene glycol dimethacrylate as a crosslinking agent was added. Except for the above changes, conductive particles (A) with insulating parts (insulating particles), a conductive material, and a connected structure were obtained in the same manner as in Example 1.

(Comparative example 2)
When producing the insulating part (insulating particles), the amount of methyl methacrylate added to the above polymerizable compound was changed to 90 parts by weight (0.9 mol). Also, benzyl methacrylate was not added. Conductive particles (A) with insulating portions (insulating particles) were obtained in the same manner as in Example 1 except for the above changes. Further, the conductive particles (A) with an insulating part were heated at 90° C. for 2 hours to obtain conductive particles (B) with an insulating part (insulating particles). A conductive material and a connected structure were respectively produced in the same manner as in Example 1, except that the obtained conductive particles with insulating parts (A) and (B) were used.

(Comparative example 3)
When producing the insulating part (insulating particles), the amount of methyl methacrylate added to the above polymerizable compound was changed to 57 parts by weight (0.57 mol). Furthermore, the amount of glycidyl methacrylate was changed to 14 parts by weight (0.1 mol), the amount of methacrylamide was changed to 9 parts by weight (0.1 mol), and the amount of benzyl methacrylate was changed to 36 parts by weight (0.1 mol). 0.2 mol). Furthermore, 6 parts by weight (0.03 mol) of ethylene glycol dimethacrylate as a crosslinking agent was added. Conductive particles (A) with insulating portions (insulating particles) were obtained in the same manner as in Example 1 except for the above changes. Further, the conductive particles (A) with an insulating part were heated at 90° C. for 2 hours to obtain conductive particles (B) with an insulating part (insulating particles). A conductive material and a connected structure were respectively produced in the same manner as in Example 1, except that the obtained conductive particles with insulating parts (A) and (B) were used.

(Calculation of degree of crosslinking)
Regarding the obtained insulating part (insulating particles or insulating layer), the degree of crosslinking was calculated using the following formula (1).

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

In the above formula (1), A is the total number of moles of the polymerizable compound having the first reactive functional group and the polymerizable compound having the second reactive functional group, and B is the total number of moles of the polymerizable compound having the first reactive functional group. It is the number of moles.

In addition, when the insulating part (insulating particles or insulating layer) contained a crosslinking agent, the degree of crosslinking was calculated using the following formula (2) regarding the obtained insulating part (insulating particles or insulating layer).

Degree of crosslinking=C×[(D/B)×100]+[(A/B)×100] Formula (2)

In the above formula (2), C is the number of polymerizable functional groups of the crosslinking agent, D is the number of moles of the crosslinking agent, and A is the number of polymerizable functional groups having the first reactive functional group and the second reactive functional group. It is the total number of moles of the polymerizable compounds having groups, and B is the total number of moles of the polymerizable compounds.

(evaluation)
(1) Adhesion of the insulation part The adhesion of the insulation part was evaluated as follows. The adhesion of the insulation part was judged according to the following criteria.

Evaluation method for adhesion of insulation parts:
Immediately after fabrication, 50 arbitrary conductive particles with insulating parts were observed using a scanning electron microscope (SEM). Moreover, after preparing a dispersion of conductive particles with insulation parts using the obtained conductive material, arbitrary 50 conductive particles with insulation parts were observed using SEM. Based on the results of these SEM observations, the insulating parts in the conductive particles with insulating parts immediately after production were compared with the insulating parts in the conductive particles with insulating parts after the dispersion was prepared.

In addition, when the insulating part is insulating particles, the number of coatings of insulating particles in the conductive particles with insulating particles immediately after preparation and the number of insulating particles covered in the conductive particles with insulating particles after dispersion preparation The number of coatings was compared. In addition, in the SEM observation, the total number of observed insulating particles was defined as the number of coatings.

In addition, when the insulating part is an insulating layer, compare the area covered by the insulating layer in the conductive particles with an insulating layer immediately after preparation and the area covered by the insulating layer in the conductive particles with an insulating layer after adjusting the dispersion liquid. did. In addition, in the SEM observation, the total area covered by the observed insulating layer was defined as the covered area.

[Criteria for adhesion of insulating parts (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 preparation is 90% or more ○○: The ratio of the number of coatings of insulating particles in conductive particles with insulating particles after dispersion adjustment to the number of coatings of insulating particles in conductive particles with insulating particles immediately after preparation is 70% or more and less than 90% ○: Immediately after preparation 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 is 50% or more and less than 70% ×: Insulation immediately after fabrication The ratio of the number of coated insulating particles in the conductive particles with insulating particles after dispersion adjustment to the number of coated insulating particles in the conductive particles with insulating particles is less than 50%.

[Criteria for adhesion of insulation part (insulation layer)]
○○○: The ratio of the area covered by the insulating layer in the conductive particles with an insulating layer after dispersion adjustment to the area covered by the insulating layer in the conductive particles with an insulating layer immediately after preparation is 90% or more. ○○: Insulation immediately after preparation The ratio of the area covered by the insulating layer in the conductive particles with an insulating layer after dispersion adjustment to the area covered by the insulating layer in the conductive particles with a layer is 70% or more and less than 90% ○: In the conductive particle with an insulating layer immediately after preparation The ratio of the area covered by the insulating layer in the conductive particles with an insulating layer after adjusting the dispersion to the area covered by the insulating layer is 50% or more and less than 70%. The ratio of the area covered by the insulating layer in the conductive particles with an insulating layer after preparing the dispersion is less than 50%.

(2) Continuity reliability after impact (between upper and lower electrodes)
The resulting 20 connected structures were dropped from a height of 70 cm to apply impact (and vibration) to the connected structures. After the impact was applied, the connection resistance between the upper and lower electrodes of the connected structure was measured by a four-terminal method. Note that from the relationship of voltage=current×resistance, the connection resistance can be determined by measuring the voltage when a constant current is passed. Continuity reliability after impact was evaluated using the following criteria.

[Criteria for determining continuity reliability after impact]
○○○: Connection resistance is 1.5Ω or less ○○: Connection resistance is more than 1.5Ω and 2.0Ω or less ○: Connection resistance is more than 2.0Ω and 5.0Ω or less △: Connection resistance is more than 5.0Ω 10Ω or less ×: Connection resistance exceeds 10Ω

(3) Insulation reliability after impact (between horizontally adjacent electrodes)
The resulting 20 connected structures were dropped from a height of 70 cm to apply impact (and vibration) to the connected structures. In the connected structure after impact was applied, the presence or absence of leakage between adjacent electrodes was evaluated by measuring the resistance value with a tester. Insulation reliability after impact was evaluated using the following criteria.

[Criteria for determining insulation reliability after impact]
○○○: The number of connected structures with a resistance value of 10 ⁸ Ω or more is 20 pieces. ○○: The number of connected structures with a resistance value of 10 ⁸ Ω or more is 18 or more but less than 20. ○: The resistance value is 18 or more but less than 20 pieces. The number of connected structures with a resistance value of 10 ⁸ Ω or more is 15 or more and less than 18 △: The number of connected structures with a resistance value of 10 ⁸ Ω or more is 10 or more and less than 15 ×: The resistance value is 10 ⁸ Ω or more The number of connected structures is 5 or more and less than 10 ××: The number of connected structures with a resistance value of 10 ⁸ Ω or more is less than 5

(4) Change in conduction reliability before and after impact application In the above (2) evaluation of continuity reliability after impact application, a connected structure before impact application was prepared. The connection resistance between the upper and lower electrodes of the connected structure before impact was each measured by a four-terminal method.

The change in conduction reliability before and after impact was determined based on the rate of increase in the connection resistance of the connected structure after impact from the connection resistance of the connected structure before impact was applied using the following criteria.

[Criteria for determining continuity reliability after impact]
○○: The rate of increase in resistance value from the average value of connection resistance is 20% or less ○: The rate of increase in resistance value from the average value of connection resistance is more than 20% and 35% or less △: The rate of increase from the average value of connection resistance The rate of increase in resistance value is more than 35% and less than 50% ×: The rate of increase in resistance value from the average value of connection resistance is more than 50%

(5) Solvent resistance A particle dispersion obtained by mixing 0.05 g of conductive particles with insulating parts and 10 g of ethyl acetate was shaken using a shaker (“VORTEX-GENIE 2” manufactured by Scientific Industries). A shaking treatment was performed for 60 seconds at an intensity of 9 on the scale. The particles after the shaking treatment were observed with a scanning electron microscope (SEM), and the solvent resistance was determined based on the following criteria.

[Judgment criteria for solvent resistance]
A: Insulating part is not deformed B: Insulating part is deformed but does not melt and retains its original shape C: Insulating part completely melts

The results are shown in Tables 1 and 2 below. In addition, in the table, Tg indicates the glass transition temperature.

DESCRIPTION OF SYMBOLS 1... Conductive particle with an insulating part 2... Conductive particle 3... Insulating part 11... Base particle 12... Conductive part 21... Conductive particle with an insulating part 22... Conductive particle 31... Conductive part 32... Core material 33... Protrusion 41... Conductive particle with insulating part 42... Conductive particle 51... Conductive part 52... Protrusion 61... Conductive particle with insulating part 62... Insulating part 81... Connection structure 82... First connection target member 82a... First Electrode 83...Second connection target member 83a...Second electrode 84...Connection part

Claims (13)

conductive particles having a conductive part at least on the surface;
an insulating part disposed on the surface of the conductive particle,
The insulating part is a polymer of a polymerizable component containing multiple types of polymerizable compounds,
The polymerizable component 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 does not contain a crosslinking agent, and the polymerizable component contains 10% by weight of a polymerizable compound whose homopolymer has a glass transition temperature of less than 100° C. in 100% by weight of the polymerizable component. Including the above,
The polymer includes a structure in which the first reactive functional group and the second reactive functional group have reacted,
Conductive particles with an insulating portion, wherein the first reactive functional group is a cyclic ether group, an isocyanate group, an aldehyde group, or a nitrile group . conductive particles having a conductive part at least on the surface;
an insulating part disposed on the surface of the conductive particle,
The insulating part is a polymer of a polymerizable component containing multiple types of polymerizable compounds,
The polymerizable component 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 does not contain a crosslinking agent, and the polymerizable component contains 10% by weight of a polymerizable compound whose homopolymer has a glass transition temperature of less than 100° C. in 100% by weight of the polymerizable component. Including the above,
The polymer includes a structure in which the first reactive functional group and the second reactive functional group have reacted,
A conductive particle with an insulating part, wherein the insulating part is an insulating particle. The conductive particle with an insulating part according to claim 2, wherein the ratio of the particle diameter of the conductive particle to the particle diameter of the insulating particle is 3 or more and 100 or less. The conductive particle with an insulating part according to claim 2 or 3, wherein the first reactive functional group is a cyclic ether group, an isocyanate group, an aldehyde group, or a nitrile group. The conductive particle with an insulating part according to claim 1 or 4, wherein the cyclic ether group is an epoxy group or an oxetanyl group. The conductive particles with an insulating part according to any one of claims 1 to 5 , wherein the degree of crosslinking of the insulating part determined by the following formula (1) is 10 or more.
Degree of crosslinking=[(A/B)×100] Formula (1)
In the formula (1), A is the total number of moles of the polymerizable compound having the first reactive functional group and the polymerizable compound having the second reactive functional group, and B is the number of moles of the polymerizable compound having the first reactive functional group. is the total number of moles. The conductive particle with an insulating part according to any one of claims 1 to 6 , wherein the second reactive functional group is an amide group, a hydroxyl group, a carboxyl group, an imide group, or an amino group. The conductive particles with an insulating part according to any one of claims 1 to 7 , wherein the conductive particles have a particle diameter of 1 μm or more and 5 μm or less. A method for producing conductive particles with an insulating part according to any one of claims 1 to 8 , using conductive particles having a conductive part at least on the surface and an insulating material,
an insulating part forming step of arranging the insulating material on the surface of the conductive particles to form an insulating part,
The insulating part is a polymer of a polymerizable component containing multiple types of polymerizable compounds,
The polymerizable component 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 does not contain a crosslinking agent, and the polymerizable component contains 10% by weight of a polymerizable compound whose homopolymer has a glass transition temperature of less than 100° C. in 100% by weight of the polymerizable component. A method for producing conductive particles with an insulating part, including the above. The temperature of the insulating part forming step is less than 50°C,
The method for producing conductive particles with insulation parts according to claim 9 , wherein the polymer obtains conductive particles with insulation parts in which the polymer has the first reactive functional group and the second reactive functional group. After the insulating part forming step, a heating step of heating the conductive particles with an insulating part is provided,
The heating temperature in the heating step is 70°C or more, and the heating time in the heating step is 1 hour or more,
The conductive particles with an insulating part according to claim 9 or 10 , wherein the polymer obtains conductive particles with an insulating part including a structure in which the first reactive functional group and the second reactive functional group are reacted. Method for producing sexual particles. A conductive material comprising the conductive particles with an insulating part according to any one of claims 1 to 8 and a binder resin. a first connection target member having a first electrode on its surface;
a second connection target member having a second electrode on its surface;
comprising a connection part connecting the first connection target member and the second connection target member,
The material of the connecting portion is the conductive particle with an insulating part according to any one of claims 1 to 8 , or a conductive material containing the conductive particle with an insulating part and a binder resin,
A connected structure in which the first electrode and the second electrode are electrically connected by the conductive part of the conductive particle with an insulating part.

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