JP2020098764A - Conductive particle with insulating part, method for producing conductive particle with insulating part, conductive material and connection structure - Google Patents

Abstract

To provide conductive particles with insulating part which can effectively enhance conductive reliability and insulating reliability even when vibration and impact are applied thereto from the outside.SOLUTION: Conductive particles with insulating part include conductive particles having a conductive part on at least its surface, and an insulating part arranged on the surface of the conductive particles, in which the insulating part is a polymer of a polymerizable component containing a plurality of kinds of polymerizable compounds, the polymerizable component contains a polymerizable compound having a first reactive functional group and a polymerizable compound having a second reactive functional group different from the first reactive functional group, the polymerizable component contains no crosslinking agent, the polymerizable component contains 10 wt.% or more of a polymerizable compound having a glass transition temperature of a homopolymer of lower than 100°C in 100 wt.% of the polymerizable component, and the polymer has the first reactive functional group and the second reactive functional group.SELECTED DRAWING: Figure 1

Description

The present invention relates to a conductive particle with an insulating portion in which an insulating portion is arranged on the surface of the conductive particle, and a method for producing the conductive particle with an insulating portion. The present invention also relates to a conductive material and a connection structure using the conductive particles with an insulating portion.

Anisotropic conductive materials such as anisotropic conductive paste and anisotropic conductive film are widely known. In the anisotropic conductive material, conductive particles are dispersed in a binder resin. In addition, as the conductive particles, conductive particles whose surface is subjected to an insulation treatment may be used.

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

In addition, as the 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 in which an insulating layer is arranged on the surface of the conductive layer may be used.

As an example of the insulating particles, Patent Document 1 below discloses resin particles that are present on the surface of the conductive particles and insulate the conductive particles. The resin particles include a copolymer of a polymerizable component containing at least an alkyl (meth)acrylate and a polyvalent (meth)acrylate as essential components. The polyvalent (meth)acrylate is a compound in which each (meth)acrylic group is bonded to each other through three or more carbon atoms. Patent Document 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.

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

Crosslinking degree=number of polymerizable functional groups of crosslinkable monomer×(mol number of crosslinkable monomer/mol number of all monomers)×100 Formula (1)

JP2012-72324A JP, 2010-86665, A

In the conventional conductive particles with insulating particles, when the conductive particles with insulating particles and the binder resin are mixed to produce an anisotropic conductive material, the insulating particles are detached from the surface of the conductive particles. Sometimes. In particular, in the conventional insulating particles described in Patent Document 1, a crosslinkable monomer (crosslinking agent) may be used in order to improve solvent resistance. When the content of the crosslinkable monomer (crosslinking agent) increases, the solvent resistance of the obtained insulating particles can be improved. On the other hand, since the obtained insulating particles are hard and lack flexibility, it is difficult to sufficiently enhance the adhesion to the surface of the conductive particles, and the insulating particles are prevented from being detached from the surface of the conductive particles. It can be difficult to prevent. As a result, when conducting conductive connection using an anisotropic conductive material, it may be difficult to significantly increase the insulation reliability between electrodes that are laterally adjacent and that should not be connected. Further, when the insulating particles are hard, the insulating particles may not be easily deformed during conductive connection using the anisotropic conductive material, and the insulating particles may not be easily deformed between the electrode and the conductive particles. May not be easily excluded from As a result, it may be difficult to significantly improve the conduction reliability between the upper and lower electrodes to be connected.

In order to solve the above-mentioned problems, for example, as described in Patent Document 2 or the like, a method of adjusting the degree of crosslinking of the surface of the core and the degree of crosslinking of the surface of the core, insulating particles have a core-shell structure Is proposed. However, in the conventional method, it is difficult to sufficiently soften the insulating particles, the insulating particles are not easily deformed during the conductive connection using the anisotropic conductive material, or the insulating particles are In some cases, it may not be easily removed from between the conductive particles and the conductive particles. As a result, it may be difficult to significantly improve the conduction reliability 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 the connection target members having a plurality of electrodes, and conductive connection is obtained to obtain a connection structure, the connection structure may be dropped into the connection structure. External vibration or shock may be applied. When a connection structure is manufactured using an anisotropic conductive material containing conductive particles with conventional insulating particles, since the insulating particles are hard, it is not possible to mitigate external vibration or shock due to falling or the like, The impact resistance of the connection portion may not be sufficiently enhanced. If the impact resistance of the connection portion of the connection structure is not sufficiently high, the connection portion may be cracked or peeled off due to external vibration or impact caused by dropping or the like. As a result, it may be difficult to significantly increase the conduction reliability between the upper and lower electrodes to be connected and the insulation reliability between the laterally adjacent electrodes that should not be connected.

An object of the present invention is to provide a conductive particle with an insulating part and a method for producing a conductive particle with an insulating part, which can effectively enhance conduction reliability and insulation reliability even when external vibration or shock is applied. Is to provide. Another object of the present invention is to provide a conductive material and a connection structure using the above-mentioned conductive particles with an insulating portion.

According to a wide aspect of the present invention, a conductive particle having a conductive portion on at least the surface, and an insulating portion arranged on the surface of the conductive particles, the insulating portion, a plurality of polymerizable compounds. A polymer of a polymerizable component containing, wherein the polymerizable component has 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 glass transition temperature of less than 100° C. of a homopolymer in 100% by weight of the polymerizable component. Provided is an electrically conductive particle with an insulating part, which contains a polymerizable compound in an amount of 10% by weight or more and in which the polymer has the first reactive functional group and the second reactive functional group.

In a specific aspect of the conductive particle with an insulating portion according to the present invention, the first reactive functional group and the second reactive functional group have a property capable of reacting by stimulation.

In a specific aspect of the electrically conductive particles with an insulating portion according to the present invention, the stimulus is heating or light irradiation.

According to a wide aspect of the present invention, a conductive particle having a conductive portion on at least the surface, and an insulating portion arranged on the surface of the conductive particles, the insulating portion, a plurality of polymerizable compounds. A polymer of a polymerizable component containing, wherein the polymerizable component has 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 glass transition temperature of less than 100° C. of a homopolymer in 100% by weight of the polymerizable component. Provided is an electrically conductive particle with an insulating part, which comprises 10% by weight or more of a polymerizable compound and the polymer has a structure in which the first reactive functional group and the second reactive functional group are reacted. ..

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

Crosslinking degree=[(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 polymerizable compound. Is the total number of moles of.

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

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

In a specific aspect of the conductive particle with an insulating portion according to the present invention, 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.

In a specific aspect of the conductive particle with an insulating portion according to the present invention, the particle diameter of the conductive particle is 1 μm or more and 5 μm or less.

According to a wide aspect of the present invention, a conductive particle having a conductive portion on at least the surface, and an insulating material, is a method of producing a conductive particle with an insulating portion, on the surface of the conductive particle. An insulating part forming step of arranging the insulating material to form an insulating part, wherein 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 Of a polymerizable compound having a reactive functional group and a polymerizable compound having a second reactive functional group different from the first reactive functional group, wherein the polymerizable component does not include a crosslinking agent. And the production of electrically conductive particles with an insulating part, wherein the polymerizable component contains 10% by weight or more of a polymerizable compound having a glass transition temperature of a homopolymer 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 a conductive particle with an insulating portion according to the present invention, the temperature of the insulating portion forming step is lower than 50°C, and the polymer has the first reactive functional group and the first reactive functional group. Conductive particles with an insulating part having the reactive functional group of 2 are obtained.

In a particular aspect of the method for producing an electrically conductive particle with an insulating portion according to the present invention, after the insulating portion forming step, a heating step of heating the electrically conductive particle with an insulating portion is provided, and the heating temperature of the heating step is An insulating part containing a structure in which the temperature is 70° C. or higher, the heating time in the heating step is 1 hour or longer, and the polymer reacts with the first reactive functional group and the second reactive functional group. To obtain conductive particles.

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

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

The conductive particle with an insulating portion according to the present invention includes a conductive particle having a conductive portion on at least the surface thereof, and an insulating portion 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 kinds of polymerizable compounds. In the conductive particle with an insulating portion according to the present invention, the polymerizable component has 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 In the electrically conductive particles with an insulating portion according to the present invention, the polymerizable component does not contain a crosslinking agent, and the polymerizable component is 100% by weight of the polymerizable component, the glass transition temperature of the homopolymer is It contains 10% by weight or more of a polymerizable compound having a temperature of less than 100°C. In the conductive particle with an insulating portion according to the present invention, the polymer has the first reactive functional group and the second reactive functional group. Since the electrically conductive particles with an insulating portion according to the present invention are provided with the above configuration, it is possible to effectively improve the conduction reliability and the insulation reliability even when vibration or impact is applied from the outside.

The conductive particle with an insulating portion according to the present invention includes a conductive particle having a conductive portion on at least the surface thereof, and an insulating portion 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 kinds of polymerizable compounds. In the conductive particle with an insulating portion according to the present invention, the polymerizable component has 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 In the electrically conductive particles with an insulating portion according to the present invention, the polymerizable component does not contain a crosslinking agent, and the polymerizable component is 100% by weight of the polymerizable component, the glass transition temperature of the homopolymer is It contains 10% by weight or more of a polymerizable compound having a temperature of less than 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 with each other. Since the electrically conductive particles with an insulating portion according to the present invention are provided with the above configuration, it is possible to effectively improve the conduction reliability and the insulation reliability even when vibration or impact is applied from the outside.

The method for producing a conductive particle with an insulating portion according to the present invention is a method for producing a conductive particle with an insulating portion using a conductive particle having a conductive portion on at least the surface and an insulating material, An insulating part forming step of forming the insulating part by disposing the insulating material on the surface of the conductive particles. In the method for producing conductive particles with an insulating portion according to the present invention, the insulating portion 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 portion according to the present invention, the polymerizable component has 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 electrically conductive particles with an insulating portion according to the present invention, the polymerizable component does not include a crosslinking agent, and the polymerizable component is a homopolymer glass in 100% by weight of the polymerizable component. It contains 10% by weight or more of a polymerizable compound having a transition temperature of less than 100°C. In the method for producing electrically conductive particles with an insulating portion according to the present invention, since the above configuration is provided, it is possible to effectively enhance conduction reliability and insulation reliability even when external vibration or shock is applied. You can

FIG. 1 is a sectional view showing a conductive particle with an insulating portion according to the first embodiment of the present invention. FIG. 2 is a sectional view showing a conductive particle with an insulating portion according to the second embodiment of the present invention. FIG. 3 is a sectional view showing a conductive particle with an insulating portion according to a third embodiment of the present invention. FIG. 4 is a cross-sectional view showing a conductive particle with an insulating portion according to the fourth embodiment of the present invention. FIG. 5: is sectional drawing which shows typically the connection structure using the electrically conductive particle with an insulation part which concerns on the 1st Embodiment of this invention.

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

(Conductive particle with insulating part and method for producing conductive particle with insulating part)
The conductive particle with an insulating portion according to the present invention includes a conductive particle having a conductive portion on at least the surface thereof, and an insulating portion 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 kinds of polymerizable compounds. In the conductive particle with an insulating portion according to the present invention, the polymerizable component has 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 In the electrically conductive particles with an insulating portion according to the present invention, the polymerizable component does not contain a crosslinking agent, and the polymerizable component is 100% by weight of the polymerizable component, the glass transition temperature of the homopolymer is It contains 10% by weight or more of a polymerizable compound having a temperature of less than 100°C. In the conductive particle with an insulating portion according to the present invention, the polymer has the first reactive functional group and the second reactive functional group.

Since the electrically conductive particles with an insulating portion according to the present invention are provided with the above configuration, it is possible to effectively improve the conduction reliability and the insulation reliability even when vibration or impact is applied from the outside.

In the present specification, the particles before 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 Both the particles after reacting are disclosed.

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, and the first reactive functional group and the The second reactive functional group has not reacted. The electrically conductive particles with an insulating portion are particles 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, since the first reactive functional group and the second reactive functional group do not react with each other, the insulating part has a low degree of crosslinking and has flexibility, The adhesion between the insulating portion and the surface of the conductive particles can be improved.

The conductive particle with an insulating portion according to the present invention includes a conductive particle having a conductive portion on at least the surface thereof, and an insulating portion 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 kinds of polymerizable compounds. In the conductive particle with an insulating portion according to the present invention, the polymerizable component has 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 In the electrically conductive particles with an insulating portion according to the present invention, the polymerizable component does not contain a crosslinking agent, and the polymerizable component is 100% by weight of the polymerizable component, the glass transition temperature of the homopolymer is It contains 10% by weight or more of a polymerizable compound having a temperature of less than 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 with each other.

Since the electrically conductive particles with an insulating portion according to the present invention are provided with the above configuration, it is possible to effectively improve the conduction reliability and the insulation reliability even when vibration or impact is 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 with each other. The electrically conductive particles with an insulating portion are particles after the first reactive functional group and the second reactive functional group have reacted with each other. It is preferable that the conductive particles with an insulating portion are obtained by reacting the first reactive functional group with the second reactive functional group before being mixed in the binder resin. In the electrically conductive particles with insulating portion before being mixed in the binder resin, it is preferable that the first reactive functional group and the second reactive functional group react with each other. In the electrically conductive particles with an insulating part according to the present invention, since the first reactive functional group and the second reactive functional group react with each other, the degree of crosslinking of the insulating part can be increased, and the insulating part can be increased. The solvent resistance of can be improved.

In the conventional conductive particles with insulating particles, when the conductive particles with insulating particles and the binder resin are mixed to produce an anisotropic conductive material, the insulating particles are detached from the surface of the conductive particles. Sometimes. In particular, in conventional insulating particles, a crosslinkable monomer (crosslinking agent) may be used in order to improve solvent resistance. Therefore, since the insulating particles are hard and lack flexibility, it is difficult to sufficiently enhance the adhesion to the surface of the conductive particles, and prevent the insulating particles from being detached from the surface of the conductive particles. Can be difficult. As a result, when conducting conductive connection using an anisotropic conductive material, it may be difficult to significantly increase the insulation reliability between electrodes that are laterally adjacent and that should not be connected. Further, when the insulating particles are hard, the insulating particles may not be easily deformed during conductive connection using the anisotropic conductive material, and the insulating particles may not be easily deformed between the electrode and the conductive particles. May not be easily excluded from As a result, it may be difficult to significantly improve the conduction reliability 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 the connection target members having a plurality of electrodes, and conductive connection is obtained to obtain a connection structure, the connection structure may be dropped into the connection structure. External vibration or shock may be applied. When a connection structure is manufactured using an anisotropic conductive material containing conductive particles with conventional insulating particles, since the insulating particles are hard, it is not possible to mitigate external vibration or shock due to falling or the like, The impact resistance of the connection portion may not be sufficiently enhanced. If the impact resistance of the connection portion of the connection structure is not sufficiently high, the connection portion may be cracked or peeled off due to external vibration or impact caused by dropping or the like. As a result, it may be difficult to significantly increase the conduction reliability between the upper and lower electrodes to be connected and the insulation reliability between the laterally adjacent electrodes that should not be connected.

The present inventors have found that by using specific conductive particles with an insulating portion, it is possible to achieve both the adhesiveness to the surface of the conductive particles and the solvent resistance of the insulating portion. Since the present invention is provided with the above configuration, it is possible to prevent the insulating portion from being detached from the surface of the conductive particles. As a result, the insulation reliability between adjacent lateral electrodes that should not be connected can be effectively increased. Further, in the present invention, since the above-described configuration is provided, the insulating portion is relatively flexible, and the insulating portion is easily deformed or the like during conductive connection using the anisotropic conductive material, or The part is easily removed from between the electrode and the conductive particles. As a result, the conduction reliability between the upper and lower electrodes to be connected can be effectively enhanced.

Further, in the present invention, since the degree of crosslinking of the insulating portion can be increased, the solvent resistance can be increased. On the other hand, in the present invention, the insulating portion does not use a crosslinkable monomer (crosslinking agent) and a specific polymerizable compound is used, so that a relatively flexible insulating portion is formed. be able to. Therefore, when a connection structure is manufactured using an anisotropic conductive material containing the conductive particles with an insulating portion according to the present invention, since the insulating portion is relatively flexible, it is not subject to external vibration or impact due to falling or the like. The impact resistance of the connecting portion can be effectively increased. As a result, it is possible to effectively prevent the occurrence of cracks or peeling at the connection portion even when external vibration or impact is applied due to a drop or the like, and between the upper and lower electrodes to be connected. Conduction reliability and insulation reliability between laterally adjacent electrodes that must not be connected can be effectively improved. In addition, in this specification, a "crosslinkable monomer (crosslinking agent)" is defined as a polymerizable compound having two or more ethylenically unsaturated groups in one molecule.

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

From the viewpoint of more effectively improving the conduction reliability and the insulation reliability between the 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 coefficient of variation (CV value) can be measured as follows.

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

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

The above-mentioned conductive particles with an insulating portion are dispersed in a binder resin and are suitably used for obtaining 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 portion according to the first embodiment of the present invention.

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

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

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

The conductive particle 21 with an insulating part shown in FIG. 2 includes a conductive particle 22 and an insulating part 3 arranged on the surface of the conductive particle 22. The insulating part 3 is an insulating particle.

The conductive particles 22 have the base particles 11 and the conductive portions 31 arranged on the surfaces of the base particles 11. In the conductive particle 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 material particles 11. The conductive portion 31 covers the base material particles 11 and the core substance 32. Since the core material 32 is covered with the conductive portion 31, the conductive particles 22 have a plurality of protrusions 33 on the surface. In the conductive particle 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 portion may cover the entire surface of the base material particle, or the conductive portion may cover a part of the surface of the base material particle. In the conductive particle with an insulating portion, the insulating portion (the insulating particle) is preferably arranged on the surface of the conductive portion.

FIG. 3 is a sectional view showing a conductive particle with an insulating portion according to a third embodiment of the present invention.

The electrically conductive particles 41 with an insulating part shown in FIG. 3 are provided with the electrically conductive particles 42 and the insulating parts 3 arranged on the surfaces of the electrically conductive particles 42. The insulating part 3 is an insulating particle.

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

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

The conductive particle 61 with an insulating part shown in FIG. 4 includes the conductive particle 2 and the insulating part 62 arranged on the surface of the conductive particle 2. The insulating portion 62 is an insulating layer. The electrically conductive particles 61 with an insulating part include the electrically conductive particles 2 and an insulating layer arranged on the surfaces of the electrically conductive particles 2. The insulating portion 62 is formed of an insulating material (insulating material).

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

Next, a method of manufacturing the conductive particles with an insulating portion according to the present invention will be described.

The method for producing a conductive particle with an insulating portion according to the present invention is a method for producing a conductive particle with an insulating portion using a conductive particle having a conductive portion on at least the surface and an insulating material, An insulating part forming step of forming the insulating part by disposing the insulating material on the surface of the conductive particles. In the method for producing conductive particles with an insulating portion according to the present invention, the insulating portion 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 portion according to the present invention, the polymerizable component has 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 electrically conductive particles with an insulating portion according to the present invention, the polymerizable component does not include a crosslinking agent, and the polymerizable component is a homopolymer glass in 100% by weight of the polymerizable component. It contains 10% by weight or more of a polymerizable compound having a transition temperature of less than 100°C. It is preferable that the obtained conductive particles with an insulating portion are particles before the first reactive functional group and the second reactive functional group react with each other.

In the method for producing electrically conductive particles with an insulating portion according to the present invention, since the above configuration is provided, it is possible to effectively enhance conduction reliability and insulation reliability even when external vibration or shock is applied. You can

In the method for producing conductive particles with an insulating portion according to the present invention, the temperature in the insulating portion forming step is preferably lower than 50°C, more preferably 40°C or lower. In the method for producing a conductive particle with an insulating portion according to the present invention, in the conductive particle with an insulating portion after the insulating portion forming step, the polymer has the first reactive functional group and the second reactivity. It preferably has a functional group. In the method for producing a conductive particle with an insulating portion according to the present invention, in the conductive particle with an insulating portion after the insulating portion forming step, the first reactive functional group and the second reactive functional group are It has preferably not reacted. In the method for producing a conductive particle with an insulating portion according to the present invention, in the conductive particle with an insulating portion after the insulating portion forming step, the first reactive functional group and the second reactive functional group are Since it has not reacted, the degree of cross-linking of the insulating portion is low and it has flexibility, and the adhesion between the insulating portion and the surface of the conductive particles can be enhanced.

In the method for producing conductive particles with an insulating portion according to the present invention, it is preferable to include a heating step of heating the conductive particles with an insulating portion after the insulating portion forming step. In the method for producing conductive particles with an insulating portion according to the present invention, the heating temperature in the heating step is preferably 70°C or higher, and more preferably 90°C or higher. In the method for producing conductive particles with an insulating portion according to the present invention, the heating time in the heating step is preferably 1 hour or longer, and more preferably 2 hours or more. In the method for producing a conductive particle with an insulating portion according to the present invention, in the conductive particle with an insulating portion 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 a group is reacted. In the method for producing a conductive particle with an insulating portion according to the present invention, in the conductive particle with an insulating portion after the heating step, the first reactive functional group and the second reactive functional group react with each other. Preferably. The obtained conductive particles with an insulating portion are preferably particles after the first reactive functional group and the second reactive functional group have reacted with each other. In the method for producing a conductive particle with an insulating portion according to the present invention, in the conductive particle with an insulating portion 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 portion can be increased, and the solvent resistance of the insulating portion can be increased.

In the method for producing electrically conductive particles with an insulating portion according to the present invention, since the heating step is provided after the insulating portion forming step, the insulating portion, the adhesion to the surface of the conductive particles and solvent resistance. It is possible to achieve both the sex and the compatibility. As a result, when the electrodes are electrically connected using the electrically conductive particles with the insulating portion, the insulation reliability between the adjacent lateral electrodes that should not be connected can be more effectively enhanced.

Further, in the method for producing an electrically conductive particle with an insulating portion according to the present invention, since the degree of crosslinking of the insulating portion can be increased, solvent resistance can be increased, while the insulating portion can have a crosslinkable monomer ( Since a cross-linking agent) is not used and a specific polymerizable compound is used, a relatively flexible insulating part can be formed. Therefore, when a connection structure is manufactured using an anisotropic conductive material containing the conductive particles with an insulating portion according to the present invention, since the insulating portion is relatively flexible, it is not subject to external vibration or impact due to falling or the like. The impact resistance of the connecting portion can be effectively increased. As a result, it is possible to effectively prevent the occurrence of cracks or peeling at the connection portion even when external vibration or impact is applied due to a drop or the like, and between the upper and lower electrodes to be connected. Conduction reliability and insulation reliability between laterally adjacent electrodes that must not be connected can be effectively improved.

Hereinafter, other details of the conductive particles with an insulating portion will be described.

Conductive particles:
The conductive particles preferably have base particles and conductive portions arranged on the surfaces of the base particles. The conductive part may have a single-layer structure or a multi-layer structure having 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, further preferably 10 μm or less, 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 electrodes are connected using the conductive particles, the contact area between the conductive particles and the electrode becomes sufficiently large, In addition, it is difficult for the conductive particles that are aggregated to form when forming the conductive portion. In addition, the distance between the electrodes connected via the conductive particles does not become too large, and the conductive portion is less likely to peel off from the surface of the base material particles.

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

The variation coefficient (CV value) of the particle diameter of the conductive particles is preferably 10% or less, more preferably 5% or less. When the variation coefficient of the particle diameter of the conductive particles is equal to or less than the upper limit, it is possible to more effectively enhance the conduction reliability and the insulation reliability between the electrodes.

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

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

The shape of the conductive particles is not particularly limited. The conductive particles may have a spherical shape, a shape other than a spherical shape, or a flat shape.

Base particle:
Examples of the base particles include resin particles, inorganic particles excluding 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 arranged 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 preferably used as the material of the resin particles. Examples of the material of the resin particles include polyolefin resins such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyisobutylene, and polybutadiene; acrylic resins such as polymethyl methacrylate and polymethyl acrylate; polycarbonate, polyamide, phenol formaldehyde. Resin, melamine formaldehyde resin, benzoguanamine formaldehyde resin, urea formaldehyde resin, phenol resin, melamine resin, benzoguanamine resin, urea resin, epoxy resin, unsaturated polyester resin, saturated polyester resin, polyethylene terephthalate, polysulfone, polyphenylene oxide, polyacetal, polyimide, Examples thereof include polyamide imide, polyether ether ketone, polyether sulfone, divinylbenzene polymer, and divinylbenzene copolymer. Examples of the divinylbenzene-based copolymer and the like include divinylbenzene-styrene copolymer and divinylbenzene-(meth)acrylic acid ester copolymer. Since the hardness of the resin particles can be easily controlled in a suitable range, the material of the resin particles is a polymer obtained by polymerizing one or more polymerizable monomers having an ethylenically unsaturated group. Is preferred.

When the resin particles are obtained by polymerizing a polymerizable monomer having an ethylenically unsaturated group, the polymerizable monomer having the ethylenically unsaturated group is a non-crosslinkable monomer. And a crosslinkable monomer.

Examples of the non-crosslinkable monomer include styrene-based monomers such as styrene and α-methylstyrene; carboxyl group-containing monomers such as (meth)acrylic acid, maleic acid, and maleic anhydride; methyl ( (Meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, cetyl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl ( Alkyl (meth)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 ester compounds of unsaturated hydrocarbons such as ethylene, propylene, isoprene, and butadiene; trifluoromethyl (meth)acrylate, pentafluoroethyl (meth)acrylate, vinyl chloride, vinyl fluoride, and halogens such as chlorostyrene Examples include contained monomers.

Examples of the crosslinkable monomer include tetramethylolmethane tetra(meth)acrylate, tetramethylolmethane tri(meth)acrylate, tetramethylolmethane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, dipentaerythritol hexa. (Meth)acrylate, dipentaerythritol penta(meth)acrylate, glycerol tri(meth)acrylate, glycerol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)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 thereof include phthalate, diallyl acrylamide, diallyl ether, and silane-containing monomers such as γ-(meth)acryloxypropyltrimethoxysilane, trimethoxysilylstyrene, and vinyltrimethoxysilane.

The term "(meth)acrylate" refers to acrylate and methacrylate. 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 of suspension polymerization in the presence of a radical polymerization initiator, and a method of swelling a monomer together with a radical polymerization initiator using non-crosslinked seed particles to perform polymerization.

When the base particles are inorganic particles excluding metal or organic-inorganic hybrid particles, examples of the inorganic material for forming the base particles include silica, alumina, barium titanate, zirconia and carbon black. The inorganic substance is preferably not a metal. The particles formed of the above silica are not particularly limited, but for example, after hydrolyzing a silicon compound having two or more hydrolyzable alkoxysilyl groups to form crosslinked polymer particles, firing is optionally performed. Particles obtained by carrying out are included. Examples of the organic-inorganic hybrid particles include organic-inorganic hybrid particles formed of a crosslinked alkoxysilyl polymer and an acrylic resin.

The organic-inorganic hybrid particles are preferably core-shell type organic-inorganic hybrid particles having a core and a shell arranged on the surface of the core. The core is preferably an organic core. The shell is preferably an inorganic shell. From the viewpoint of further effectively lowering the connection resistance between the electrodes, the base particle is preferably an organic-inorganic hybrid particle having an organic core and an inorganic shell arranged on the surface of the organic core. ..

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

Examples of the material of the inorganic shell include the inorganic materials mentioned as the material of the base particle. The material of the inorganic shell is preferably silica. The inorganic shell is preferably formed on the surface of the core by forming a metal alkoxide into a shell-like material by a sol-gel method and then firing the shell-like material. The metal alkoxide is preferably silane alkoxide. The inorganic shell is preferably made 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 diameter of the base particles is preferably 0.5 μm or more, more preferably 1 μm or more, still more preferably 2 μm or more, preferably 100 μm or less, more preferably 60 μm or less, still more preferably 50 μm or less. When the particle size of the base material particles is equal to or more than the above lower limit and equal to or less than the above upper limit, small conductive particles can be obtained even when the distance between the electrodes is small and the thickness of the conductive layer is increased. Further, it becomes difficult for the conductive particles to aggregate when forming the conductive portion on the surface of the base material particles, and it becomes difficult for the aggregated conductive particles to be formed.

It is particularly preferable that the base particles have a particle size of 2 μm or more and 50 μm or less. When the particle size of the base material particles is in the range of 2 μm or more and 50 μm or less, it becomes difficult to aggregate when forming the conductive portion on the surface of the base material particles, and it is difficult to form the aggregated conductive particles.

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

The particle diameter of the above-mentioned base particles is determined by using a particle size distribution measuring device or the like. The particle diameter of the base material particles is preferably obtained by observing 50 arbitrary base material particles with an electron microscope or an optical microscope and calculating an average value. In observation with an electron microscope or an optical microscope, the particle size of each base particle is determined as the particle size in terms of a circle equivalent diameter. In observation with an electron microscope or an optical microscope, the average particle diameter of any 50 base particles in terms of equivalent circle diameter is almost equal to the average particle diameter in equivalent sphere diameter. In the laser diffraction type particle size distribution measurement, the particle size of each base particle is obtained as the particle size in terms of sphere equivalent diameter. In the case of measuring the particle size of the above-mentioned base particles in the conductive particles, for example, it can be measured as follows.

The conductive particles are added to "Technobit 4000" manufactured by Kulzer so that the content of the conductive particles is 30% by weight, and dispersed to prepare a conductive particle inspection embedded resin. A cross section of the conductive particles is cut out using an ion milling device (“IM4000” manufactured by Hitachi High-Technologies Corporation) so as to pass near the center of the conductive particles dispersed in the inspection embedded resin. 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 particles of each conductive particle were observed. To do. The particle diameter of the base material particle in each conductive particle is measured, and they are arithmetically averaged to obtain the particle diameter of the base material particle.

Conductive part:
In the present invention, the conductive particles have a conductive portion on at least the surface. The conductive part preferably contains a metal. The metal forming the conductive part is not particularly limited. Examples of the metal include gold, silver, copper, platinum, palladium, zinc, lead, aluminum, cobalt, indium, nickel, chromium, titanium, antimony, bismuth, germanium and cadmium, and alloys thereof. In addition, tin-doped indium oxide (ITO) may be used as the metal. Only 1 type may be used for the said metal and 2 or more types may be used together. From the viewpoint of further lowering the connection resistance between the electrodes, an alloy containing tin, nickel, palladium, copper or gold is preferable, and nickel or palladium is more preferable.

Further, from the viewpoint of further effectively increasing the 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 portion containing nickel is preferably 10% by weight or more, more preferably 50% by weight or more, even more preferably 60% by weight or more, further 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.

Incidentally, hydroxyl groups often exist on the surface of the conductive portion due to oxidation. Generally, hydroxyl groups are present on the surface of the conductive portion formed of nickel due to oxidation. The insulating portion can be arranged on the surface of the conductive portion having such a hydroxyl group (the surface of the conductive particles) through 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 part may have a laminated structure of two or more layers. When the conductive portion is formed by a plurality of layers, the metal forming the outermost layer is preferably gold, nickel, palladium, copper or an alloy containing tin and silver, and is preferably gold. More preferable. When the metal forming the outermost layer is one of these preferable metals, the connection resistance between the electrodes becomes even lower. Further, when the metal forming the outermost layer is gold, the corrosion resistance is further enhanced.

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

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

When the conductive portion is formed of a plurality of layers, the thickness of the conductive portion of the outermost layer is preferably 0.001 μm or more, more preferably 0.01 μm or more, preferably 0.5 μm or less, more preferably Is 0.1 μm or less. When the thickness of the conductive portion of the outermost layer is not less than the lower limit and not more than the upper limit, the conductive portion of the outermost layer is uniform, corrosion resistance is sufficiently high, and the connection resistance between the electrodes is sufficiently low. can do.

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

Core substance:
The conductive particles preferably have a plurality of protrusions on the outer surface of the conductive portion. An oxide film is often formed on the surface of the electrode connected by the conductive particles with an insulating portion. When the insulating part-containing conductive particles having protrusions on the surface of the conductive part are used, the oxide film can be effectively eliminated by the protrusions by disposing the insulating part-containing conductive particles between the electrodes and pressing them. .. For this reason, the electrodes and the conductive portions contact each other more reliably, and the connection resistance between the electrodes becomes even lower. Further, when connecting the electrodes, the protrusions of the conductive particles can effectively eliminate the insulating particles between the conductive particles and the electrodes. Therefore, the conduction reliability between the electrodes is further enhanced.

As the method of forming the protrusions, after attaching the core substance to the surface of the base material particles, a method of forming a conductive portion by electroless plating, and forming a conductive portion by electroless plating on the surface of the base material particles Then, a method of attaching a core substance and then forming a conductive portion by electroless plating, etc. may be mentioned. As another method of forming the protrusions, a method of adding a core substance in the middle of forming the conductive portion on the surface of the base material particles may be mentioned. Further, in order to form the protrusions, the conductive material is formed by electroless plating on the base material particles without using the core substance, and then the plating is deposited in the shape of protrusions on the surface of the conductive portion, and the electroless plating is further performed. You may use the method of forming a conductive part by.

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

Examples of the substance forming the core substance include a conductive substance and a non-conductive substance. 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 enhancing the conduction reliability between the electrodes, the core substance is preferably a metal.

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

The shape of the core substance is not particularly limited. The shape of the core substance is preferably massive. Examples of the core substance include a particulate mass, an agglomerate of a plurality of fine particles, and an amorphous mass.

The average diameter (average particle diameter) of the core substance is preferably 0.001 μm or more, more preferably 0.05 μm or more, preferably 0.9 μm or less, more preferably 0.2 μm or less. When the average diameter of the core substance 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, and more preferably a number average particle size. The particle size of the core substance is, for example, observing 50 arbitrary core substances with an electron microscope or an optical microscope, calculating the average value of the particle size of each core substance, and performing a laser diffraction type particle size distribution measurement. Required by. In observation with an electron microscope or an optical microscope, the particle size of each core substance is determined as the particle size in terms of a circle equivalent diameter. In observation with an electron microscope or an optical microscope, the average particle diameter of any 50 core substances in the circle-equivalent diameter is substantially equal to the average particle diameter in the sphere-equivalent diameter. In the laser diffraction particle size distribution measurement, the particle size of each core substance is determined as the particle size in terms of sphere equivalent diameter. The average particle size of the core substance is preferably calculated by laser diffraction type particle size distribution measurement.

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

When the above-mentioned conductive particles with an insulating portion are used for connecting electrodes, a short circuit between adjacent electrodes can be prevented. Specifically, when a plurality of conductive particles with an insulating part are in contact with each other, the insulating part is present between the plurality of electrodes, so that it is possible to prevent a short circuit between laterally adjacent electrodes instead of between the upper and lower electrodes. When connecting the electrodes, the insulating particles between the conductive parts of the conductive particles and the electrodes can be easily eliminated by pressing the conductive particles with the insulating parts by the two electrodes. Further, in the case of conductive particles having a plurality of protrusions on the outer surface of the conductive portion, the insulating portion between the conductive portion of the conductive particles and the electrode can be eliminated more easily.

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

In the conductive particle with an insulating portion according to the present invention, the polymerizable component is 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 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, a cyclic ether group or a nitrile group Is more preferable. The cyclic ether group is preferably an epoxy group or an oxetanyl group, and more preferably an epoxy group. In the case where the first reactive functional group is the above-mentioned preferable functional group, the insulation reliability is further effectively improved when the electrodes are electrically connected using the electrically conductive particles with an insulating portion. 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. As the polymerizable compound having an epoxy group, only one type may be used, or two or more types 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 compound having the cyclic ether group (excluding the epoxy group) include (3-ethyloxetan-3-yl)methyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, and cyclic trimethylolpropane formal ( Examples thereof include (meth)acrylate. As the polymerizable compound having a cyclic ether group (excluding the epoxy group), only one type may be used, or two or more types 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, and 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- Methyl-3-butene isocyanate, 4-vinylbenzene isocyanate, 1-isocyanate methyl-4-vinyl-benzene, 1,1-(bisacryloyloxymethyl)ethyl isocyanate and the like can be mentioned. As the polymerizable compound having an isocyanate group, only one type may be used, or two or more types 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.

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

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, and an amide group or a carboxyl group. It is more preferable that there is. In the case where the second reactive functional group is the above-mentioned preferable functional group, insulation reliability is further effectively improved when electrically connecting the electrodes using the conductive particles with an insulating portion. 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 N-substituted (meth)acrylamide is not particularly limited. As the N-substituted (meth)acrylamide, 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, N,N-dimethylaminopropyl (meth)acrylamide and the like. The N,N-substituted (meth)acrylamide is not particularly limited. Examples of the N,N-substituted (meth)acrylamide include N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, and (meth)acryloylmorpholine. As the polymerizable compound having an amide group, only one kind may be used, or two or more kinds may be used in combination.

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

Examples of the polymerizable compound 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 diester Examples thereof include (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, glycerin (meth)acrylate, and 2-hydroxy-3-(meth)acryloyloxypropyl (meth)acrylate. As the polymerizable compound having a hydroxyl group, only one type may be used, or two or more types 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 polymerizable compound having a carboxyl group include unsaturated monocarboxylic acids such as (meth)acrylic acid, crotonic acid and cinnamic acid, unsaturated dicarboxylic acids such as maleic acid, itaconic acid, succinic acid, fumaric acid and citraconic acid. Examples thereof include acids, their salts and anhydrides. As the polymerizable compound having a carboxyl group, only one type may be used, or two or more types 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 and maleimide. As the polymerizable compound having an imide group, only one type may be used, or two or more types 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. As the polymerizable compound having an amino group, only one type may be used, or two or more types may be used in combination.

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

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

The glass transition temperature (Tg(H)) of the above homopolymer is less than 100° C. from the viewpoint of more effectively enhancing the conduction reliability and the insulation reliability even when external vibration or shock is applied. Is preferably 90° C. or lower, more preferably 70° C. or lower. Further, from the viewpoint that the adjacent insulating portions are fused and the aggregation of the conductive particles with the insulating portion is suppressed more effectively, the glass transition temperature of the homopolymer is 0° C. or higher. It is preferably 20° C. or higher.

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

The glass transition temperature (Tg(H)) can be measured according to 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 Co., Ltd.

Examples of the polymerizable compound include isobornyl acrylate (Tg(H): 92°C), t-butyl acrylate (Tg(H): 14°C), stearyl acrylate (Tg(H): 30°C), 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.degree. C.), cyclohexyl methacrylate (Tg(H): 66.degree. C.), tetrahydrofurfuryl methacrylate (Tg(H): 60.degree. 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) C), 2-methacryloyloxyethyl phthalate (Tg(H): 75° C.), and 2-methacryloyloxyethyl hexahydrophthalate (Tg(H): 70° C.) and other methacrylate compounds; vinyl acetate (Tg(H) ): 28° C.), vinyl pivalate (Tg(H): 86° C.), and vinyl chloride monoesters (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, more preferably the following compound B. Examples of the compound A include 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.), tetrahydroflu 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.). Examples of the compound B include ethyl methacrylate (Tg(H):65° C.), isobutyl methacrylate (Tg(H):48° 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.), glycidyl methacrylate (Tg(H): 46° C.), and dicyclopentenyloxy. Ethyl methacrylate (Tg(H): 50° C.) may be mentioned. As for the said compound A, only 1 type may be used and 2 or more types may be used together. As for the said compound B, only 1 type may be used and 2 or more types may be used together.

In the electrically conductive particles with an insulating portion according to the present invention, the polymerizable component does not contain a crosslinking agent, and the polymerizable component is 100% by weight of the polymerizable component, the glass transition temperature of the homopolymer is It contains 10% by weight or more of a polymerizable compound having a temperature of less than 100°C. The polymerizable component preferably contains 20% by weight or more, more preferably 30% by weight or more, of a polymerizable compound having a homopolymer glass transition temperature of less than 100° C. in 100% by weight of the polymerizable component. preferable. When the content of the polymerizable compound in which the glass transition temperature of the homopolymer is less than 100° C. is equal to or more than the above lower limit, conduction reliability and insulation reliability are further improved even when external vibration or shock is applied. It can be increased more effectively. The upper limit of the content of the polymerizable compound whose glass transition temperature of the homopolymer is lower 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 the homopolymer of less than 100° C. is not more than the above upper limit, the degree of crosslinking of the insulating portion can be increased and the solvent resistance can be further enhanced. .. 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 can be formed. .. Therefore, when a connection structure is manufactured using an anisotropic conductive material containing the conductive particles with an insulating portion according to the present invention, since the insulating portion is relatively flexible, it is not subject to external vibration or impact due to falling or the like. The impact resistance of the connecting portion can be effectively increased. As a result, it is possible to effectively prevent the occurrence of cracks or peeling at the connection portion even when external vibration or impact is applied due to a drop or the like, and between the upper and lower electrodes to be connected. Conduction reliability and insulation reliability between laterally adjacent electrodes that must not be connected can be effectively improved.

In addition, in the conductive particles with an insulating portion, the type of the polymerizable compound or the like contained in the polymerizable component that is the material of the insulating portion can be specified according to the following procedure. After dispersing the electrically conductive particles with an insulating portion in methanol, vibration is applied for 30 minutes with an ultrasonic homogenizer (“UX-050” manufactured by Mitsui Electric Seiki Co., Ltd.). Then, centrifugation is performed to separate the insulating part and the conductive particles. The solution containing the separated insulating part is concentrated to obtain a sample sample. The kind of the polymerizable compound or the like contained in the polymerizable component can be specified by analyzing the constituent components of the insulating portion of the obtained sample sample using GC-MS and NMR. Further, the glass transition temperature of the homopolymer can be measured by preparing a homopolymer of the specified polymerizable compound monomer.

In the conductive particle with an insulating portion 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 different from the first reactive functional group in the second reactive compound. The polymerizable compound does not correspond to the polymerizable compound having a reactive functional group (second polymerizable compound). When the polymerizable component contains the third polymerizable compound, for example, the homopolymer of the first polymerizable compound has a glass transition temperature of less than 100° C. or the second polymerizable compound of the second polymerizable compound. 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 glass transition temperature of the homopolymer of the third polymerizable compound is preferably less than 100°C.

In the electrically conductive particles with an insulating part according to the present invention, the degree of crosslinking of the insulating part, which is determined by the following formula (1), is preferably 10 or more, and more preferably 20 or more. When the degree of cross-linking of the insulating portion is equal to or more than the lower limit, the insulation reliability can be more effectively enhanced when the electrodes are electrically connected using the electrically conductive particles with the insulating portion.

Crosslinking degree=[(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 polymerizable compound. Is the total number of moles of.

In the conductive particle with an insulating portion according to the present invention, the polymer has a configuration (first configuration) in which the polymer has the first reactive functional group and the second reactive functional group, or A configuration (second configuration) in which the polymer includes a structure in which the first reactive functional group and the second reactive functional group react with each other is provided.

When the electrically conductive particles with an insulating portion 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 with each other. When the electrically conductive particles with an insulating portion according to the present invention have the first configuration, the first reactive functional group and the second reactive functional group do not react with each other. It has a low degree of cross-linking and flexibility, and can enhance the adhesiveness between the insulating portion and the surface of the conductive particles.

When the electrically conductive particles with an insulating portion according to the present invention have the first configuration, the first reactive functional group and the second reactive functional group have a property capable of reacting by stimulation. It is preferable. The stimulus is preferably heating or light irradiation, and more preferably heating.

When the electrically conductive particles with an insulating portion 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 have been reacted with each other. When the electrically conductive particles with an insulating portion according to the present invention have the second configuration, the first reactive functional group and the second reactive functional group react with each other, so that The degree of crosslinking can be increased, and the solvent resistance of the insulating portion can be increased.

In the conductive particles with an insulating part according to the present invention, the conductive particles with an insulating part having the first structure are heated or irradiated with light to obtain conductive particles with an insulating part having the second structure. Is preferred. It is more preferable that the insulating-part-containing conductive particles having the second structure be obtained by heating the insulating-part-containing conductive particles having the first structure. When the electrically conductive particles with an insulating part satisfy the above-described preferred embodiments, both the adhesion of the insulating part to the surface of the electrically conductive particles and the solvent resistance can be made compatible with each other. As a result, when the electrodes are electrically connected using the conductive particles with an insulating portion, the insulation reliability can be more effectively enhanced.

Examples of the method of disposing the insulating portion on the surface of the conductive portion include a chemical method and a physical or mechanical method. Examples of the chemical method include an interfacial polymerization method, a suspension polymerization method in the presence of particles, and an emulsion polymerization method. Examples of the physical or mechanical method include spray drying, hybridization, electrostatic adhesion method, spraying method, dipping method and vacuum deposition method. Since it is difficult to detach the insulating portion, it is preferable to dispose the insulating portion on the surface of the conductive portion through a chemical bond. In the conductive particles with an insulating part according to the present invention, it is preferable that the hydroxyl group and the like present on the surface of the conductive part and the polymerizable compound having the first reactive functional group are chemically bonded, It is preferable that the hydroxyl group and the like present on the surface of the part are chemically bonded to the polymerizable compound having the second reactive functional group. In the electrically conductive particles with an insulating portion according to the present invention, a hydroxyl group or the like present on the surface of the electrically conductive portion may be chemically bonded to the first reactive functional group, and is present on the surface of the electrically conductive portion. The hydroxyl group and the like may not be chemically bonded to the first reactive functional group. In the conductive particles with an insulating portion according to the present invention, the hydroxyl group or the like existing on the surface of the conductive portion and the second reactive functional group may be chemically bonded to each other, and are present on the surface of the conductive portion. The hydroxyl group and the like may not be chemically bonded to the second reactive functional group.

The outer surface of the conductive portion and the outer surface of the insulating portion may 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, or may be indirectly chemically bonded by a compound having a reactive functional group. After introducing a carboxyl group to the outer surface of the conductive portion, the carboxyl group may be chemically bonded to a functional group on the outer surface of the insulating 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 conductive particle with the insulating part, the use of the conductive particle with the insulating part, and the like. The particle diameter of the insulating particles is preferably 10 nm or more, more preferably 100 nm or more, further preferably 200 nm or more, particularly preferably 300 nm or more, preferably 4000 nm or less, more preferably 2000 nm or less, further preferably 1500 nm or less. It is particularly preferably 1000 nm or less. The particle diameter of the insulating particles is equal to or more than the lower limit, when the conductive particles with an insulating portion are dispersed in the binder resin, the conductive portions of the plurality of conductive particles with an insulating portion contact each other. It will be difficult. When the particle diameter of the insulating particles is not more than the upper limit, in connecting the electrodes, in order to eliminate the insulating particles between the electrodes and the conductive particles, it is not necessary to increase the pressure too high. No need to heat to high temperature.

The particle size of the insulating particles is preferably an average particle size, and more preferably a number average particle size. The particle size of the insulating particles is preferably obtained by observing 50 arbitrary insulating particles with an electron microscope or an optical microscope and calculating an average value. In the case of measuring the particle diameter of the insulating particles in the above-mentioned conductive particles with an insulating portion, for example, it can be measured as follows.

The conductive particles with an insulating portion are added to "Technobit 4000" manufactured by Kulzer Co., Ltd. so that the content of the conductive particles is 30% by weight, and dispersed to prepare an embedded resin for conductive particle inspection. An ion milling device (“IM4000” manufactured by Hitachi High-Technologies Corporation) is used to cut a cross section of the conductive particles with an insulating portion so that the conductive particles dispersed with an insulating portion in the embedded resin for inspection pass through the vicinity of the center. Then, using a field emission scanning electron microscope (FE-SEM), the image magnification was set to 50,000 times, and 50 conductive particles with insulating parts were randomly selected, and conductive particles with each insulating part were selected. Observe the insulating particles of. The particle size of the insulating particles in each conductive particle with an insulating part is measured, and they are arithmetically averaged to obtain the particle size of the insulating particles.

When the insulating part is insulating particles, the ratio of the particle diameter of the conductive particles to the particle diameter of the insulating particles (particle diameter of conductive particles/particle diameter of insulating particles) is preferably 3 Or more, more preferably 5 or more, preferably 100 or less, more preferably 50 or less. When the ratio (particle diameter of conductive particles/particle diameter of insulating particles) is not less than the lower limit and not more than the upper limit, conduction reliability and insulation reliability are ensured even when external vibration or shock is applied. It can be enhanced more effectively. When the ratio (particle diameter of conductive particles/particle diameter of insulating particles) is equal to or more than the lower limit and equal to or less than the upper limit, when the electrically conductive particles with an insulating portion are dispersed in a binder resin, a plurality of It becomes difficult for the conductive parts of the conductive particles with insulating parts to come into contact with each other. Further, when connecting the electrodes, it is not necessary to raise the pressure too much and to heat to a high temperature in order to eliminate the insulating particles between the electrodes and the conductive particles.

When the insulating part is an insulating particle, the conductive particle with an insulating part may be a combination of two or more kinds of insulating particles having different particle sizes. By using two or more kinds of insulating particles having different particle sizes in combination, the insulating particles having a small particle size enter the gap covered with the insulating particles having a large particle size, and the above-mentioned coverage rate is further improved. Can be increased. When the insulating particles are used as the insulating portion, the insulating particles include first insulating particles having a particle diameter of 0.1 μm or more and less than 0.25 μm and particle diameters of 0.25 μm or more and 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 does not overlap with the particle size distribution of the second insulating particles. The average particle size of the first insulating particles and the average particle size of the second insulating particles are preferably different.

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

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

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

When the insulating part is an insulating particle, the shape of the insulating particle is not particularly limited. The insulating particles may have a spherical shape, a shape other than a spherical shape, 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 size 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, further preferably 200 nm or more, particularly preferably 300 nm or more, preferably 4000 nm or less, more preferably 2000 nm or less, further preferably 1500 nm or less, particularly It is preferably 1000 nm or less. When the thickness of the insulating layer is equal to or more than the lower limit, when the insulating part-containing conductive particles are dispersed in the binder resin, it becomes difficult for the conductive parts of the plurality of insulating part-containing conductive particles to come into contact with each other. .. When the thickness of the insulating layer is less than or equal to the upper limit, when connecting the electrodes, in order to eliminate the insulating layer between the electrode and the conductive particles, it is not necessary to increase the pressure too high, high temperature No need to heat.

The thickness of the insulating layer is preferably obtained by observing the cross section of the conductive particles with an insulating portion with an electron microscope or an optical microscope, and averaging the thicknesses of the insulating layers at arbitrary 50 places to calculate the thickness. In the case of measuring the thickness of the insulating layer in the conductive particle with an insulating portion, it can be measured as follows, for example.

The conductive particles with an insulating portion are added to "Technobit 4000" manufactured by Kulzer Co., Ltd. so that the content of the conductive particles is 30% by weight, and dispersed to prepare an embedded resin for conductive particle inspection. An ion milling device (“IM4000” manufactured by Hitachi High-Technologies Corporation) is used to cut a cross section of the conductive particles with an insulating portion so that the conductive particles dispersed with an insulating portion in the embedded resin for inspection pass through the vicinity of the center. Then, using a field emission scanning electron microscope (FE-SEM), the image magnification was set to 50,000 times, the conductive particles with insulating parts were randomly selected, and the insulating layer of the conductive particles with insulating parts was formed. Observe. The thickness of the insulating layer is measured at arbitrary 50 places, and the arithmetic mean of these is used as the thickness of the insulating layer.

(Conductive material)
The conductive material according to the present invention includes the above-mentioned conductive particles with an insulating portion and a binder resin. The conductive particles with an insulating portion are preferably used by being dispersed in a binder resin, and are preferably dispersed in a binder resin and used as a conductive material. The conductive material is preferably an anisotropic conductive material. The conductive material is preferably used for electrical connection between electrodes. The conductive material is preferably a conductive material for circuit connection. In the conductive material, since the conductive particles with the insulating portion described above is used, it is insulated from the surface of the conductive particles with the insulating portion before the conductive connection such as dispersing the conductive particles with the insulating portion in the binder resin. The parts can be prevented from being unintentionally detached, and the insulation reliability between the electrodes can be further enhanced.

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

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

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

The conductive material may be, for example, a filler, an extender, a softening agent, a plasticizer, a polymerization catalyst, a curing catalyst, a colorant, an antioxidant, or a heat stabilizer, in addition to the conductive particles with the insulating portion and the binder resin. , Light stabilizers, ultraviolet absorbers, lubricants, antistatic agents, flame retardants and other various additives.

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

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

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

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

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

In 100% by weight of the conductive material, the content of the conductive particles with an insulating part is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, 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, and most preferably 10% by weight or less. When the content of the conductive particles with an insulating part is equal to or more than the lower limit and equal to or less than the upper limit, conduction reliability between electrodes and insulation reliability can be further improved.

(Connection structure)
A connection structure according to the present invention includes a first connection target member having a first electrode on the surface, a second connection target member having a second electrode on the surface, and the first connection target member, And a connecting portion connecting the second connection target member. In the connection 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 conductive particles with an insulating part and a binder resin. In the connection structure according to the present invention, the first electrode and the second electrode are electrically connected by the conductive part in the conductive particle with an insulating part.

The connection structure has a step of arranging the conductive particles with an insulating portion or the conductive material between the first connection target member and the second connection target member, and thermocompression bonding so that the conductive structure is formed. It can be obtained through the step of connecting. At the time of the thermocompression bonding, it is preferable that the insulating portion is detached from the conductive particles with the insulating portion.

FIG. 5: is sectional drawing which shows typically the connection structure using the electrically conductive particle with an insulation part which concerns on the 1st Embodiment of this invention.

The connection structure 81 shown in FIG. 5 has 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. And 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 conductive particles 1 with an insulating portion. In addition, in FIG. 5, the conductive particles 1 with an insulating portion are schematically illustrated for convenience of illustration. Instead of the conductive particles 1 having an insulating portion, the conductive particles 21, 41 or 61 having an insulating portion may be used.

The first connection target member 82 has a plurality of first electrodes 82a on the surface (upper surface). The second connection target member 83 has a plurality of second electrodes 83a on the surface (lower surface). The 1st electrode 82a and the 2nd electrode 83a are electrically connected by the electroconductive particle 2 in the electroconductive particle 1 with one or several insulating part. Therefore, the first connection target member 82 and the second connection target member 83 are electrically connected to each other by the conductive portion of the conductive particle 1 with the insulating portion.

The method for manufacturing the connection structure is not particularly limited. As an example of the method for manufacturing the connection structure, the conductive material is arranged between the first connection target member and the second connection target member to obtain a laminated body, and then the laminated body is heated and pressed. Methods and the like. The pressure for the thermocompression bonding is preferably 40 MPa or more, more preferably 60 MPa or more, preferably 90 MPa or less, more preferably 70 MPa or less. The heating temperature of the thermocompression bonding is preferably 80° C. or higher, more preferably 100° C. or higher, preferably 140° C. or lower, more preferably 120° C. or lower. The pressure and temperature of the thermocompression bonding is not less than the above lower limit and not more than the above upper limit, the insulating portion can be easily detached from the surface of the conductive particles with the insulating portion during conductive connection, and the conduction reliability between the electrodes is further improved. Can be increased.

When the laminated body is heated and pressed, the insulating portion existing between the conductive particles and the first electrode and the second electrode can be eliminated. For example, at the time of heating and pressurizing, the conductive particles and the insulating portion existing between the first electrode and the second electrode are the conductive particles with the insulating portion. Easily detached from the surface. During the heating and pressurization, a part of the insulating part may be detached from the surface of the conductive particle with the insulating part, and the surface of the conductive part may be partially exposed. The exposed portion of the surface of the conductive portion contacts the first electrode and the second electrode, thereby electrically connecting the first electrode and the second electrode through the conductive particles. can do.

The first connection target member and the second connection target member are not particularly limited. Specific examples of the first connection target member and the second connection target member include semiconductor chips, semiconductor packages, LED chips, LED packages, electronic components such as capacitors and diodes, and resin films, printed circuit boards, and flexible parts. Examples include electronic components such as printed circuit boards, flexible flat cables, rigid flexible substrates, circuit boards such as glass epoxy substrates and glass substrates. 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 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. When the electrode is an aluminum electrode, it may be an electrode formed of only aluminum or an electrode in which an aluminum layer is laminated on the surface of a metal oxide layer. Examples of the material for the metal oxide layer include indium oxide doped with a trivalent metal element and zinc oxide doped with a trivalent metal element. Examples of the trivalent metal element include Sn, Al and Ga.

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

(Example 1)
(1) Preparation of Conductive Particles Resin particles (particle diameter 3 μm) formed of a copolymer resin of tetramethylolmethane tetraacrylate 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 solution using an ultrasonic disperser, the solution was filtered to take out the base particles. 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 substrate particles with water, the dispersion liquid was obtained by adding 500 parts by weight of distilled water and dispersing. Next, 1 g of nickel particle slurry (average particle size 100 nm) was added to the above dispersion over 3 minutes to obtain a suspension containing base material particles to which the core substance was attached.

Further, 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 obtained suspension at 60° C., the above nickel plating solution was gradually added dropwise to the suspension to perform electroless nickel plating. Then, the suspension is filtered to take out the particles, washed with water, and dried to form a nickel-boron conductive layer (thickness 0.15 μm) on the surface of the base material particle, and to have a conductive portion on the surface. Conductive particles were obtained.

(2) Preparation of Insulating Part (Insulating Particles) A 1000 mL separable flask equipped with a 4-neck separable cover, a stirring blade, a three-way cock, a condenser and a temperature probe was charged with the composition containing the following polymerizable compound. After that, the mixture was stirred at 200 rpm and polymerized at 50° C. for 5 hours in a nitrogen atmosphere. The composition is 500 mL of distilled water, 0.2 parts by weight of acid phosphooxypolyoxyethylene glycol methacrylate (0.5 mmol), 2,2'-azobis{2-[N-(2-carboxyethyl)amidino]propane}. It contains 0.2 parts by weight (0.5 mmol) and a polymerizable component containing a plurality of kinds of polymerizable compounds. The polymerizable component contains 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. As the polymerizable compound, 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 were included. After completion of the reaction, it was freeze-dried to obtain insulating particles (particle diameter 300 nm) having an amide group derived from methacrylamide and an epoxy group derived from glycidyl methacrylate on the surface.

(3) Preparation of Conductive Particles with Insulating Part (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 with a 3 μm mesh filter, the particles were further washed with methanol and dried to obtain conductive particles (A) with insulating parts (insulating particles). In this electrically conductive particle (A) with an insulating part, the insulating part has an amide group and an epoxy group.

(4) Production of conductive material (anisotropic conductive paste) 7 parts by weight of the conductive particles (A) thus obtained, 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 mixing 30 parts by weight of a phenol novolac type epoxy resin and SI-60L (manufactured by Sanshin Chemical Industry Co., Ltd.) and defoaming and stirring for 3 minutes.

(5) Fabrication of Connection Structure A glass-epoxy substrate having a Cu electrode pattern (first electrode) having an L/S of 7 μm/13 μm formed on its upper surface was prepared. Further, a polyimide substrate having an Au electrode pattern (second electrode) having an L/S of 7 μm/13 μm formed on the lower surface was prepared.

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

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

(Example 3)
When the insulating part (insulating particles) was produced, the compounding amount of methyl methacrylate was changed to 75 parts by weight (0.75 mol) with respect to the polymerizable compound. 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). In the same manner as in Example 1 except for the above changes, conductive particles (A) with an insulating portion (insulating particles) were obtained. In this conductive particle with an insulating part (A), the insulating part has an amide group and an epoxy group. In addition, the insulating part (insulating particles) obtained by heating the conductive particles (A) with an insulating part under the conditions of 90° C. and 2 hours to react the amide group and the epoxy group on the surface of the insulating part (insulating particles) ) Attached conductive particles (B) were obtained. The electrically conductive particles (B) with an insulating portion include a structure in which the insulating portion reacts with an amide group and an epoxy group. A conductive material and a connection structure were obtained in the same manner as in Example 1 except that the obtained conductive particles (A) and (B) with an insulating portion were used.

(Example 4)
During the production of the insulating part (insulating particles), the compounding amount of methyl methacrylate was changed to 60 parts by weight (0.6 mol) with respect to the polymerizable compound. Furthermore, the compounding amount of glycidyl methacrylate was changed to 14 parts by weight (0.1 mol), the compounding amount of methacrylamide was changed to 9 parts by weight (0.1 mol), and the compounding amount of benzyl methacrylate was 36 parts by weight ( 0.2 mol). In the same manner as in Example 1 except for the above changes, conductive particles (A) with an insulating portion (insulating particles) 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 particles). A conductive material and a connection structure were prepared in the same manner as in Example 1 except that the obtained conductive particles (A) and (B) with an insulating portion were used.

(Example 5)
At the time of producing 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 in the polymerizable compound. In the same manner as in Example 4 except for the above changes, conductive particles (A) and (B) with an insulating portion (insulating particles), a conductive material and a connection structure were obtained.

(Example 6)
When the insulating part (insulating particles) was produced, the compounding amount of methyl methacrylate was changed to 50 parts by weight (0.5 mol) with respect to the polymerizable compound. Furthermore, the compounding amount of glycidyl methacrylate was changed to 14 parts by weight (0.1 mol), the compounding amount of methacrylamide was changed to 9 parts by weight (0.1 mol), and the compounding amount of benzyl methacrylate was 54 parts by weight ( 0.3 mol). In the same manner as in Example 1 except for the above changes, conductive particles (A) with an insulating portion (insulating particles) 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 particles). A conductive material and a connection structure were prepared in the same manner as in Example 1 except that the obtained conductive particles (A) and (B) with an insulating portion were used.

(Example 7)
When the insulating part (insulating particles) was produced, the compounding amount of methyl methacrylate was changed to 10 parts by weight (0.1 mol) with respect to the polymerizable compound. 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 ( 0.7 mol). In the same manner as in Example 1 except for the above changes, conductive particles (A) with an insulating portion (insulating particles) 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 particles). A conductive material and a connection structure were prepared in the same manner as in Example 1 except that the obtained conductive particles (A) and (B) with an insulating portion were used.

(Example 8)
Fabrication of conductive particles with insulating part (insulating layer):
A 1000 mL separable flask equipped with a 4-neck separable cover, a stirring blade, a three-way cock, a cooling tube, and a temperature probe was charged with the composition containing the following polymerizable compound, and then thoroughly sonicated. Emulsified. Then, the mixture was stirred at 200 rpm, and polymerization was carried out at 48° C. for 5 hours in a nitrogen atmosphere. The above composition was prepared by using 200 mL of distilled water, 20 parts by weight of conductive particles, 0.02 part (2,2′-azobis{2-[N-(2-carboxyethyl)amidino]propane} (0.05 mmol), and an emulsifier. It contains a polyoxyethylene lauryl ether ("Emulgen 106" manufactured by Kao Corporation) 0.1 part by weight and a polymerizable component containing a plurality of kinds of polymerizable compounds. The polymerizable component contains 0.6 part 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. As the polymerizable compound, 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 were included. After the completion of the reaction, the mixture is cooled, solid-liquid separation is performed twice with a centrifuge, excess polymerizable compound is removed by washing, and the surface of the conductive particles is covered by the insulating layer formed by the polymer of the polymerizable compound. The covered conductive particles (A) with an insulating part (insulating layer) (insulating layer thickness 200 nm) were obtained. Further, the conductive particles (A) with an insulating part were heated under the conditions of 90° C. and 2 hours to obtain conductive particles (B) with an insulating part (insulating layer). A conductive material and a connection structure were produced in the same manner as in Example 1 except that the obtained conductive particles (A) and (B) with an insulating portion were used.

(Example 9)
In the production of 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 with respect to the polymerizable compound. In the same manner as in Example 4 except for the above changes, conductive particles (A) and (B) with an insulating portion (insulating particles), a conductive material and a connection structure were obtained.

(Example 10)
In the production of the insulating part (insulating particles), 7 parts by weight (0.1 mol) of methacrylonitrile was used in place of 14 parts by weight (0.1 mol) of glycidyl methacrylate for the polymerizable compound. Furthermore, instead of 9 parts by weight (0.1 mol) of methacrylamide, 9 parts by weight (0.1 mol) of methacrylic acid was used. In the same manner as in Example 4 except for the above changes, conductive particles (A) and (B) with an insulating portion (insulating particles), a conductive material and a connection structure were obtained.

(Comparative Example 1)
When the insulating part (insulating particles) was produced, the compounding amount of methyl methacrylate was changed to 95 parts by weight (0.95 mol) with respect to the polymerizable compound. Also, glycidyl methacrylate, methacrylamide, and benzyl methacrylate were not added. Further, 10 parts by weight (0.05 mol) of ethylene glycol dimethacrylate, which is a crosslinking agent, was added. In the same manner as in Example 1 except for the above changes, conductive particles (A) with an insulating portion (insulating particles), a conductive material, and a connection structure were obtained.

(Comparative example 2)
When the insulating part (insulating particles) was produced, the compounding amount of methyl methacrylate was changed to 90 parts by weight (0.9 mol) with respect to the polymerizable compound. Also, no benzyl methacrylate was added. In the same manner as in Example 1 except for the above changes, conductive particles (A) with an insulating portion (insulating particles) 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 particles). A conductive material and a connection structure were prepared in the same manner as in Example 1 except that the obtained conductive particles (A) and (B) with an insulating portion were used.

(Comparative example 3)
When the insulating part (insulating particles) was produced, the compounding amount of methyl methacrylate was changed to 57 parts by weight (0.57 mol) with respect to the polymerizable compound. Furthermore, the compounding amount of glycidyl methacrylate was changed to 14 parts by weight (0.1 mol), the compounding amount of methacrylamide was changed to 9 parts by weight (0.1 mol), and the compounding amount of benzyl methacrylate was 36 parts by weight ( 0.2 mol). Further, 6 parts by weight (0.03 mol) of ethylene glycol dimethacrylate, which is a crosslinking agent, was added. In the same manner as in Example 1 except for the above changes, conductive particles (A) with an insulating portion (insulating particles) 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 particles). A conductive material and a connection structure were prepared in the same manner as in Example 1 except that the obtained conductive particles (A) and (B) with an insulating portion were used.

(Calculation of degree of crosslinking)
The degree of crosslinking of the obtained insulating portion (insulating particles or insulating layer) was calculated by the following formula (1).

Crosslinking degree=[(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 polymerizable compounds. The number of moles.

When the insulating portion (insulating particles or insulating layer) contains a crosslinking agent, the degree of crosslinking of the obtained insulating portion (insulating particles or insulating layer) was calculated by the following formula (2).

Crosslinking degree=C×[(D/B)×100]+[(A/B)×100] Formula (2)

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

(Evaluation)
(1) Adhesiveness of Insulating Part The adhesiveness of the insulating part was evaluated as follows. The adhesion of the insulating part was judged according to the following criteria.

Insulation adhesion evaluation method:
Immediately after the production, 50 arbitrary conductive particles with an insulating portion were observed using a scanning electron microscope (SEM). In addition, even after preparing a conductive particle dispersion liquid with an insulating part using the obtained conductive material, 50 arbitrary conductive particles with an insulating part were observed using an SEM. From the results of these observations by SEM, the insulating part in the conductive particles with an insulating part immediately after production was compared with the insulating part in the conductive particles with an insulating part after the dispersion liquid was adjusted.

Further, when the insulating portion is an insulating particle, the number of coating of the insulating particles in the conductive particles with the insulating particles immediately after production, and the insulating particles in the conductive particles with the insulating particles after the dispersion liquid adjustment The number of coatings was compared. The total number of insulating particles observed in the SEM observation was defined as the number of coatings.

Further, when the insulating portion is an insulating layer, the covering area of the insulating layer in the conductive particles with an insulating layer immediately after production is compared with the covering area of the insulating layer in the conductive particles with an insulating layer after dispersion adjustment. did. In the SEM observation, the total area covered by the observed insulating layer was defined as the covered area.

[Criteria for Adhesion of Insulating Part (Insulating Particle)]
○ ○ ○: The ratio of the number of coatings of the insulating particles in the conductive particles with the insulating particles after the dispersion is adjusted to the number of coatings of the insulating particles in the conductive particles with the insulating particles immediately after preparation is 90% or more. The ratio of the number of coatings of the insulating particles in the conductive particles with the insulating particles after the dispersion is adjusted to the number of coatings of the insulating particles in the conductive particles with the insulating particles immediately after the production is 70% or more and less than 90%. The ratio of the number of coatings of the insulating particles in the conductive particles with the insulating particles after the dispersion is adjusted to the number of coatings of the insulating particles in the conductive particles with the insulating particles is 50% or more and less than 70%. The ratio of the number of coating of the insulating particles in the conductive particles with the insulating particles after the dispersion is adjusted to the number of coating of the insulating particles in the conductive particles with the conductive particles is less than 50%

[Criteria for Adhesion of Insulating Part (Insulating Layer)]
○ ○ ○: The ratio of the covering area of the insulating layer in the conductive particles with an insulating layer after the dispersion liquid preparation is 90% or more to the covering area of the insulating layer in the conductive particles with an insulating layer immediately after preparation ○ ○: Insulation immediately after preparation The ratio of the coating area of the insulating layer in the conductive particles with an insulating layer after adjusting the dispersion to the coating area of the insulating layer in the conductive particles with a layer is 70% or more and less than 90%. The ratio of the coating area of the insulating layer in the conductive particles with an insulating layer after adjusting the dispersion liquid to the coating area of the insulating layer is 50% or more and less than 70% x: to the coating area of the insulating layer in the conductive particles with an insulating layer immediately after production The ratio of the covering area of the insulating layer in the conductive particles with the insulating layer after the dispersion is adjusted is less than 50%.

(2) Conduction reliability after impact (between upper and lower electrodes)
The 20 connection structures thus obtained were dropped from a position having a height of 70 cm, and a shock (and vibration) was applied to the connection structures. The connection resistance between the upper and lower electrodes of the connection structure after impact was measured by the four-terminal method. From the relationship of voltage=current×resistance, the connection resistance can be obtained by measuring the voltage when a constant current is applied. The continuity reliability after impact was judged according to the following criteria.

[Criteria for 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 adjacent electrodes in the lateral direction)
The 20 connection structures thus obtained were dropped from a position having a height of 70 cm, and a shock (and vibration) was applied to the connection structures. In the connection structure after the impact was given, the presence or absence of leakage between adjacent electrodes was evaluated by measuring the resistance value with a tester. The insulation reliability after impact was evaluated according to the following criteria.

[Criteria for insulation reliability after impact]
○○○: number of resistance 10 ⁸ Omega more connections structures, 20 ○○: the number of the resistance value is 10 ⁸ Omega more connections structures, less than 20 18 or more ○: resistance the number of 10 ⁸ Omega more connection structure is less than 15 or more 18 △: number of resistance 10 ⁸ Omega more connections structures, 10 or more 15 than ×: resistance 10 ⁸ Omega more 5 or more and less than 10 XX: the number of connection structures having a resistance value of 10 ⁸ Ω or more is less than 5

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

The rate of increase in the connection resistance of the connection structure after the impact was applied from the connection resistance of the connection structure before the impact was applied was used to determine the change in conduction reliability before and after the application of the impact according to the following criteria.

[Criteria for continuity reliability after impact]
◯: Rate of increase in resistance value from average value of connection resistance is 20% or less. ◯: Rate of increase in resistance value from average value of connection resistance exceeds 20% and 35% or less. Δ: From average value of connection resistance. The rate of increase in resistance exceeds 35% and 50% or less x: The rate of increase in resistance from the average value of connection resistance exceeds 50%

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

[Solvent resistance criteria]
A: Insulation part is not deformed B: Insulation part is deformed, but it does not melt and holds the prototype C: Insulation part is completely melted

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

DESCRIPTION OF SYMBOLS 1... Conductive particle with insulating part 2... Conductive particle 3... Insulating part 11... Base material particle 12... Conductive part 21... Conductive particle with insulating part 22... Conductive particle 31... Conductive part 32... Core substance 33... Protrusion 41... Conductive particles 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 (16)

Conductive particles having a conductive portion on at least the surface,
An insulating portion disposed on the surface of the conductive particles,
The insulating portion is a polymer of a polymerizable component containing a plurality of 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 include a crosslinking agent, and the polymerizable component is 10% by weight of a polymerizable compound having a glass transition temperature of a homopolymer of less than 100° C. in 100% by weight of the polymerizable component. Including the above,
Conductive particles with an insulating part, wherein the polymer has the first reactive functional group and the second reactive functional group. The electrically conductive particle with an insulating part according to claim 1, wherein the first reactive functional group and the second reactive functional group have a property of being capable of reacting by stimulation. The electrically conductive particles with an insulating portion according to claim 2, wherein the stimulus is heating or irradiation of light. Conductive particles having a conductive portion on at least the surface,
An insulating portion disposed on the surface of the conductive particles,
The insulating portion is a polymer of a polymerizable component containing a plurality of 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 include a crosslinking agent, and the polymerizable component is 10% by weight of a polymerizable compound having a glass transition temperature of a homopolymer of less than 100° C. in 100% by weight of the polymerizable component. Including the above,
Conductive particles with an insulating part, wherein the polymer includes a structure in which the first reactive functional group reacts with the second reactive functional group. The conductive particles with an insulating part according to any one of claims 1 to 4, wherein the degree of crosslinking of the insulating part, which is obtained by the following formula (1), is 10 or more.
Crosslinking degree=[(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 polymerizable compound. Is the total number of moles of. The conductive particle with an insulating part according to claim 1, 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 6, wherein the cyclic ether group is an epoxy group or an oxetanyl group. The electrically conductive particles with an insulating part according to claim 1, wherein the second reactive functional group is an amide group, a hydroxyl group, a carboxyl group, an imide group or an amino group. The electrically conductive particles with an insulating part according to claim 1, wherein the insulating part is an insulating particle. The conductive particle with an insulating part according to claim 9, wherein a ratio of a particle diameter of the conductive particle to a particle diameter of the insulating particle is 3 or more and 100 or less. The particle diameter of the said electroconductive particle is 1 micrometer or more and 5 micrometers or less, The electroconductive particle with an insulation part of any one of Claims 1-10. Conductive particles having a conductive portion on at least the surface, and using an insulating material, a method for producing conductive particles with an insulating portion,
An insulating portion forming step of forming an insulating portion by disposing the insulating material on the surface of the conductive particles,
The insulating portion is a polymer of a polymerizable component containing a plurality of 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 include a crosslinking agent, and the polymerizable component is 10% by weight of a polymerizable compound having a glass transition temperature of a homopolymer of less than 100° C. in 100% by weight of the polymerizable component. A method for producing conductive particles with an insulating portion, including the above. The temperature of the insulating part forming step is less than 50° C.,
The method for producing conductive particles with an insulating part according to claim 12, wherein the polymer obtains conductive particles with an insulating part having the first reactive functional group and the second reactive functional group. After the insulating portion forming step, a heating step of heating the insulating portion-attached conductive particles is provided,
The heating temperature in the heating step is 70° C. or higher, the heating time in the heating step is 1 hour or longer,
The conductive material with an insulating part according to claim 12 or 13, wherein the polymer obtains a conductive particle with an insulating part including a structure in which the first reactive functional group and the second reactive functional group react with each other. Of producing hydrophilic particles. A conductive material comprising the conductive particles with an insulating portion according to any one of claims 1 to 11 and a binder resin. A first connection target member having a first electrode on its surface;
A second connection target member having a second electrode on the surface;
A first connection target member, and a connection portion connecting the second connection target member,
The material of the connection portion is the conductive particles with an insulating portion according to any one of claims 1 to 11, or a conductive material containing the conductive particles with an insulating portion and a binder resin,
A connection structure in which the first electrode and the second electrode are electrically connected by the conductive portion in the conductive particle with an insulating portion.

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