KR102095826B1 - Conductive particles with insulating particles, conductive material, and connection structure - Google Patents

Abstract

The present invention provides conductive particles with insulating particles capable of increasing insulation reliability when connecting between electrodes. The electroconductive particle 1 with insulating particle which concerns on this invention is the electroconductive particle 2 which has the electroconductive part 12 at least on the surface, and the some 1st insulating particle 3 arrange | positioned on the surface of the electroconductive particle 2 ) And a plurality of second insulating particles 4 disposed on the surface of the conductive particles 2. The average particle diameter of the second insulating particles 4 is smaller than the average particle diameter of the first insulating particles 3. More than 50% of the total number of the second insulating particles 4 is disposed on the surface of the conductive particles 2 so as not to contact the first insulating particles 3.

Description

CONDUCTIVE PARTICLES WITH INSULATING PARTICLES, CONDUCTIVE MATERIAL, AND CONNECTION STRUCTURE}

The present invention relates to conductive particles with insulating particles that can be used, for example, for electrical connection between electrodes. Further, the present invention relates to a conductive material and a connecting structure using the conductive particles with insulating particles.

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

The anisotropic conductive material is used for connection between an IC chip and a flexible printed circuit board, connection between an IC chip and a circuit board having an ITO electrode, and the like. For example, after disposing an anisotropic conductive material between the electrode of the IC chip and the electrode of the circuit board, these electrodes can be electrically connected by heating and pressing.

As an example of the conductive particles, the following Patent Document 1 discloses conductive particles with insulating particles comprising particles having a conductive metal surface and insulating particles covering surfaces of particles having the conductive metal surfaces. . Patent Document 1 discloses that by using two or more kinds of insulating particles having different particle diameters in combination, small insulating particles are introduced into a gap covered by large insulating particles, and the coating density is improved.

Japanese Patent Publication No. 2005-44773

In the conductive particles with insulating particles described in Patent Document 1, since the conductive metal surface is covered with the insulating particles, electrical connection between adjacent electrodes in the horizontal direction that should not be connected after the upper and lower conductive connections can be suppressed. . That is, the insulation reliability in the connection structure connected electrically can be improved. In addition, when two or more kinds of insulating particles having different particle diameters are used together, small insulating particles are introduced into the gap covered by the large insulating particles, and as a result, the coating density becomes high, and the insulation reliability can be increased. However, in Patent Document 1, it is only described that a small insulating particle is introduced into a gap covered with a large insulating particle.

On the other hand, in recent years, miniaturization of electronic components is progressing. As a result, in the wiring connected by the conductive particles in the electronic component, the L / S indicating the width of the line L where the wiring is formed and the space S where the wiring is not formed are reduced. . When such fine wiring is formed, it is difficult to sufficiently secure insulation reliability when conducting a conductive connection using conventional conductive particles with insulating particles.

In addition, in the conventional conductive particles with insulating particles, before the conductive connection, the insulating particles are likely to unintentionally detach from the surface of the conductive particles. For example, when the conductive particles with insulating particles are dispersed in a binder resin, the insulating particles are easily detached from the surface of the conductive particles, and the surface of the conductive particles may be exposed. As a result, there is a problem that the insulation reliability is lowered.

An object of the present invention is to provide conductive particles with insulating particles capable of increasing insulation reliability when connecting between electrodes, and conductive materials and connecting structures using the conductive particles with insulating particles.

The limited object of the present invention is that conductive particles with insulating particles are difficult to unintentionally detach from the surface of the conductive particles even when an impact is applied before conductive connection, etc., and conductive materials and connections using the conductive particles with insulating particles Is to provide a structure.

According to the broad aspect of the present invention, conductive particles having at least a conductive portion on a surface, a plurality of first insulating particles disposed on the surface of the conductive particles, and a plurality of second insulating particles disposed on the surface of the conductive particles And the average particle diameter of the second insulating particles is smaller than the average particle diameter of the first insulating particles, and 50% or more of the total number of the second insulating particles does not contact the first insulating particles. , Conductive particles with insulating particles disposed on the surface of the conductive particles are provided.

In a specific aspect of the conductive particles with insulating particles according to the present invention, 70% or more of the total number of the second insulating particles is disposed on the surface of the conductive particles so as not to contact the first insulating particles.

In a specific aspect of the conductive particles with insulating particles according to the present invention, 50% or more of the total number of the second insulating particles does not contact the first insulating particles and also contacts the conductive particles. It is placed on the surface.

In a specific aspect of the conductive particles with insulating particles according to the present invention, the first insulating particles are attached to the surface of the conductive particles through chemical bonding.

In a specific aspect of the conductive particles with insulating particles according to the present invention, the second insulating particles are attached to the surface of the conductive particles through chemical bonding.

In a specific aspect of the conductive particles with insulating particles according to the present invention, the first insulating particles and the second insulating particles are not respectively arranged on the surface of the conductive particles by a hybridization method. .

In a specific aspect of the conductive particles with insulating particles according to the present invention, the conductive particles have projections on the outer surface of the conductive portion.

According to the broad aspect of the present invention, there is provided a conductive material comprising the above-described conductive particles with insulating particles and a binder resin.

According to the broad aspect of the present invention, a first connection object member having a first electrode on a surface, a second connection object member having a second electrode on a surface, the first connection object member, and the second connection object member It is provided with the connection part which connects, The said connection part is formed by the electroconductive particle with the above-mentioned insulating particle, or is formed by the electroconductive material containing the said electroconductive particle with insulating particle and a binder resin, and the said 1st. A connection structure is provided in which the electrode and the second electrode are electrically connected by the conductive particles in the conductive particles with the insulating particles.

The conductive particles with insulating particles according to the present invention include conductive particles having at least a conductive portion on a surface, a plurality of first insulating particles arranged on the surface of the conductive particles, and second insulating properties arranged on the surface of the conductive particles It is provided with particles, and the average particle diameter of the second insulating particles is smaller than the average particle diameter of the first insulating particles, and 50% or more of the total number of the second insulating particles contacts the first insulating particles. Since it is not disposed on the surface of the conductive particles, insulation reliability can be improved when the electrodes are connected using the conductive particles with insulating particles according to the present invention.

1 is a cross-sectional view showing conductive particles with insulating particles according to a first embodiment of the present invention.
2 is a cross-sectional view showing conductive particles with insulating particles according to a second embodiment of the present invention.
3 is a cross-sectional view showing conductive particles with insulating particles according to a third embodiment of the present invention.
4 is a front sectional view schematically showing a connection structure using conductive particles with insulating particles shown in FIG. 1.
It is a schematic diagram for demonstrating the evaluation method of a covering rate.

Hereinafter, the present invention will be clarified by describing specific embodiments and examples of the present invention with reference to the drawings.

(Conductive particles with insulating particles)

1, the electroconductive particle with insulating particle which concerns on 1st Embodiment of this invention is shown by sectional drawing.

The electroconductive particle 1 with insulating particle shown in FIG. 1 is equipped with the electroconductive particle 2, the some 1st insulating particle 3, and the some 2nd insulating particle 4.

The electroconductive particle 2 has the electroconductive part 12 at least on the surface. The first insulating particles 3 are disposed on the surface of the conductive particles 2. The second insulating particles 4 are disposed on the surface of the conductive particles 2.

More than 50% of the total number of the second insulating particles 4 is disposed on the surface of the conductive particles 2 so as not to contact the first insulating particles 3. The entire second insulating particles 4 may be disposed on the surface of the conductive particles 2 so as not to contact the first insulating particles 3. A part of the second insulating particles 4 may be disposed on the surface of the conductive particles 2 so as to contact the first insulating particles 3.

The plurality of first insulating particles 3 are in contact with the surface of the conductive particles 2 and are adhered to the surface of the conductive particles 2. The plurality of first insulating particles 3 are in contact with the outer surface of the conductive portion 12 in the conductive particles 2 and are attached to the outer surface of the conductive portion 12. The plurality of second insulating particles 4 are in contact with the surface of the conductive particles 2 and are adhered to the surface of the conductive particles 2. The plurality of second insulating particles 4 are in contact with the outer surface of the conductive portion 12 in the conductive particles 2 and are attached to the outer surface of the conductive portion 12.

The electroconductive particle 2 has the base particle 11 and the conductive part 12 arrange | positioned on the surface of the base particle 11. The conductive portion 12 is a conductive layer. The conductive portion 12 covers the surface of the substrate particle 11. The conductive particles 2 are coated particles on which the surface of the substrate particles 11 is covered with the conductive portion 12. The conductive particles 2 have a conductive portion 12 on the surface.

Each of the first insulating particles 3 and the second insulating particles 4 is formed of a material having insulating properties. The average particle diameter of the second insulating particles 4 is smaller than the average particle diameter of the first insulating particles 3.

2, the electroconductive particle with insulating particle which concerns on 2nd embodiment of this invention is shown by sectional drawing.

The electroconductive particle 21 with insulating particle shown in FIG. 2 is equipped with the electroconductive particle 22, the some 1st insulating particle 3, and the some 2nd insulating particle 4.

The electroconductive particle 22 has the electroconductive part 26 at least on the surface. The first insulating particles 3 are disposed on the surface of the conductive particles 22. The second insulating particles 4 are disposed on the surface of the conductive particles 22.

More than 50% of the total number of the second insulating particles 4 is disposed on the surface of the conductive particles 22 so as not to contact the first insulating particles 3.

As for the electroconductive particle 1 with insulating particle and the electroconductive particle 21 with insulating particle, only electroconductive particle 2, 22 differs. The electroconductive particle 22 has the base particle 11 and the electroconductive part 26 arrange | positioned on the surface of the base particle 11. The conductive particles 22 have a plurality of core materials 27 on the surface of the substrate particles 11. The conductive portion 26 covers the substrate particles 11 and the core material 27. By covering the core material 27 with the conductive portion 26, the conductive particles 22 have a plurality of projections 28 on the surface. The surface of the conductive portion 26 is raised by the core material 27, and a plurality of protrusions 28 are formed.

3, the electroconductive particle with insulating particle which concerns on 3rd embodiment of this invention is shown in sectional drawing.

The electroconductive particle 31 with insulating particle shown in FIG. 3 is equipped with the electroconductive particle 32, the some 1st insulating particle 3, and the some 2nd insulating particle 4.

The conductive particles 32 have a conductive portion 36 on at least a surface. The first insulating particles 3 are disposed on the surface of the conductive particles 32. The second insulating particles 4 are disposed on the surface of the conductive particles 32.

More than 50% of the total number of the second insulating particles 4 is disposed on the surface of the conductive particles 32 so as not to contact the first insulating particles 3.

As for the electroconductive particle 1 with insulating particle and the electroconductive particle 31 with insulating particle, only electroconductive particle 2, 32 differs. The electroconductive particle 32 has the base particle 11 and the electroconductive part 36 arrange | positioned on the surface of the base particle 11. The conductive particles 22 have a core material 27, but the conductive particles 32 do not have a core material. The conductive portion 36 has a first portion and a second portion thicker than the first portion. The conductive particles 32 have a plurality of protrusions 37 on the surface. The portion excluding the plurality of protrusions 37 is the first portion in the conductive portion 36. The plurality of protrusions 37 is the second portion where the thickness of the conductive portion 36 is thick.

In the conductive particles (1, 21, 31) with insulating particles, the average particle diameter of the second insulating particles (4) is smaller than the average particle diameter of the first insulating particles (3), and the entirety of the second insulating particles (4) 50% or more of the number is disposed on the surface of the conductive particles 2, 22, 32 so as not to contact the first insulating particles 3. When the second insulating particles 4 do not contact the first insulating particles 3, the gap between the exposed surfaces of the conductive particles 2 is narrowed. For this reason, when the upper and lower electrodes are electrically connected using the conductive particles 1, 21, 31 with insulating particles, it is possible to suppress the electrical connection between adjacent electrodes in the horizontal direction that should not be connected. That is, insulation reliability can be improved. In addition, as a result of applying a large force affecting the desorption of the first and second insulating particles 3 and 4 during normal conductive connection, the first and second insulating particles 3 and 4 are detached and exposed. The conductive particles (2, 22, 32) are brought into contact with the electrode.

Further, before the conductive connection, it is also possible to effectively prevent unintentional detachment of the relatively large first insulating particles from the surface of the conductive particles by impact. For example, when dispersing the conductive particles with insulating particles in the binder resin, it is possible to suppress the detachment of the first insulating particles from the surface of the conductive particles. Further, when a plurality of conductive particles with insulating particles are in contact, it is difficult to detach the first insulating particles from the surface of the conductive particles due to the impact upon contact. In addition, by electrically connecting the upper and lower electrodes using conductive particles with insulating particles to obtain a connecting structure, even if an impact is applied to the connecting structure, unintentional detachment of the first insulating particles is suppressed, so that adjacent electrodes are electrically connected. Connection can be suppressed, and sufficient insulation reliability can be secured.

From the viewpoint of further increasing the insulation reliability and the insulation reliability against impact, the coverage Z of the total area of the first insulating particles and the portions covered by the second insulating particles occupying the entire surface area of the conductive particles is preferably 20% or more, more preferably 30% or more, even more preferably 40% or more, still more preferably 50% or more, still more preferably 60% or more, particularly preferably 70% or more, and most preferably It is 80% or more.

The coverage of the total area of the portion covered by the first insulating particles and the second insulating particles occupying the entire surface area of the conductive particles is determined as follows.

Conductive particles with 20 insulating particles are observed by observation with a scanning electron microscope (SEM), and coverage Z (%) of the conductive particles in the conductive particles with insulating particles (also referred to as adhesion rate Z (%)) To get The coverage is the total area (projection area) of portions covered by the first and second insulating particles occupied by the surface area of the conductive particles.

Specifically, the coverage rate is when the conductive particles with insulating particles are observed from one direction with a scanning electron microscope (SEM). The total area of the first and second insulating particles in the circle of the outer periphery of the surface of the conductive particles, which occupies the entire area of the diagonal portion of Fig. 5 (a) (the diagonal portion of Fig. 5 (b)), it means.

From the viewpoint of further increasing the conduction reliability, insulation reliability and insulation reliability against impact, the average particle diameter of the second insulating particles is preferably 9/10 or less of the average particle diameter of the first insulating particles, and 4/5 It is more preferable that it is the following, more preferably 2/3 or less, and particularly preferably 1/2 or less. The average particle diameter of the second insulating particles is preferably 1/30 or more of the average particle diameter of the first insulating particles, more preferably 1/20 or more, and even more preferably 1/10 or more.

The "average particle diameter" of the said 1st and 2nd insulating particle respectively shows number average particle diameter. The average particle diameter of the first and second insulating particles is determined by observing 50 arbitrary conductive particles with an electron microscope or an optical microscope and calculating an average value.

From the viewpoint of further increasing the conduction reliability, it is preferable that at least a part of the second insulating particles are disposed on the surface of the conductive particles so as to contact the first insulating particles. From the viewpoint of further increasing the conduction reliability, the number of the second insulating particles arranged on the surface of the conductive particles is preferably larger so as to contact the first insulating particles. From the viewpoint of further increasing the conduction reliability, it is preferable that 10% or more of the total number of the second insulating particles is disposed on the surface of the conductive particles so as to contact the first insulating particles. The number ratio X1 of the second insulating particles arranged on the surface of the conductive particles so as to contact the first insulating particles is more preferably 20% or more, still more preferably 30% or more. When the second insulating particles are in contact with the first insulating particles, upon conductive connection, with the detachment of the first insulating particles, the second insulating particles that are in contact with the first insulating particles also tend to detach. As a result, conduction reliability is further enhanced. In addition, the total number of second insulating particles indicates the number of second insulating particles per conductive particle. In addition, the number of second insulating particles that are disposed on the surface of the conductive particles so as to contact the first insulating particles is the number of second insulating particles that are in contact with the conductive particles, and the second insulating properties that are not in contact with the conductive particles. Both of the number of particles are included.

As a method of bringing the second insulating particles into contact with the first insulating particles, a method of surface-treating the first insulating particles so that the second insulating particles are easily adhered, and a surface treatment of the second insulating particles so that the first insulating particles are easily adhered And a method of attaching the second insulating particles to the surface of the first insulating particles and then attaching the first insulating particles to which the second insulating particles are attached to the surface of the conductive particles.

In order to increase insulation reliability and insulation reliability against impact, 50% or more of the total number of the second insulating particles is disposed on the surface of the conductive particles so as not to contact the first insulating particles. The number ratio X2 of the second insulating particles arranged on the surface of the conductive particles so as not to contact the first insulating particles is more preferably more than 50%, even more preferably 55% or more, still more preferably 60% Above, more preferably 65% or more, particularly preferably 70% or more, and most preferably more than 80%. In addition, the total number of second insulating particles indicates the number of second insulating particles per conductive particle. In addition, the number of second insulating particles that are disposed on the surface of the conductive particles so as not to contact the first insulating particles is the number of second insulating particles that are in contact with the conductive particles, and the second that is not in contact with the conductive particles. Both of the number of insulating particles are included.

In order to increase insulation reliability and insulation reliability against impact, 50% or more of the total number of the second insulating particles is disposed on the surface of the conductive particles so as not to contact the first insulating particles and to contact the conductive particles. desirable. The number ratio X3 of the second insulating particles disposed on the surface of the conductive particles so as not to contact the first insulating particles and to contact the conductive particles is more preferably 70% or more, still more preferably 75% or more, It is particularly preferably 80% or more, and preferably 100% or less. The ratio of the number may be 99% or less, 95% or less, or 90% or less. In addition, the total number of second insulating particles indicates the number of second insulating particles per conductive particle.

As a method of not contacting the second insulating particles with the first insulating particles, a method of surface treating the first insulating particles so that the second insulating particles are hard to adhere, and the second insulating particles are surfaced so that the first insulating particles are hard to adhere. And a method of treating, and a method of surface-treating the second insulating particles so that the second insulating particles are more easily attached to the conductive particles than the first insulating particles.

From the viewpoint of further increasing the conduction reliability, insulation reliability, and insulation reliability against impact, the average number Y1 of the first insulating particles disposed on the surface of the conductive particles per conductive particle is preferably 1 Or more, more preferably 2 or more, more preferably 3 or more, particularly preferably 5 or more, most preferably 10 or more, preferably 100 or less, more preferably 50 or less, further It is preferably 20 or less. The average number Y1 may be less than 10. The average number of the first insulating particles disposed on the surface of the conductive particles per conductive particle is the number average of the first insulating particles per conductive particle.

From the viewpoint of further increasing the conduction reliability, the insulation reliability and the insulation reliability against impact, the average number Y2 of the second insulating particles disposed on the surface of the conductive particles per one of the conductive particles is preferably one Or more, more preferably 4 or more, more preferably 6 or more, particularly preferably 10 or more, most preferably 20 or more, preferably 1000 or less, more preferably 500 or less, further Preferably it is 100 or less. The average number of the second insulating particles disposed on the surface of the conductive particles per conductive particle is the number average of the second insulating particles per conductive particle.

In the electroconductive particle according to the present invention, per electroconductive particle, on the surface of the electroconductive particle, per one electroconductive particle of the average number Y1 of the first insulating particles disposed on the surface of the electroconductive particle The ratio (average number Y1 / average number Y2) to the average number Y2 of the second insulating particles arranged in is preferably 0.001 or more, more preferably 0.005 or more, further preferably 0.05 or more, preferably 1 or less, more preferably 0.5 or less. The ratio (average number Y1 / average number Y2) may exceed 0.5. In addition, the number of the first and second insulating particles that are disposed on the surface of the conductive particles includes the number of the first and second insulating particles that are not in contact with the conductive particles.

From the viewpoint of further increasing insulation reliability and insulation reliability against impact, it is preferable that the second insulating particles are attached to the surface of the conductive particles through chemical bonding.

From the viewpoint of further suppressing unintentional detachment of the first insulating particles from the surface of the conductive particles by impact, it is preferable that the first insulating particles are attached to the surface of the conductive particles through chemical bonding. Do. In addition, if the first insulating particles are attached to the surface of the conductive particles through chemical bonding, the insulation reliability of the connection structure is further enhanced.

It is preferable that the said electroconductive particle has a processus | protrusion on the outer surface of the said electroconductive part from a viewpoint of raising the conduction reliability between electrodes. In general, in conductive particles having projections on the outer surface of the conductive portion, the larger the projections, the lower the insulation reliability. In the conductive particles with insulating particles according to the present invention, the first and second insulating particles are provided, so that even if the protrusions are large, insulation reliability can be sufficiently secured.

The details of the conductive particles, the first insulating particles and the second insulating particles in the conductive particles with insulating particles will be described below.

[Conductive particle]

The said electroconductive particle should just have a conductive part on the surface at least. It is preferable that the conductive portion is a conductive layer. The conductive particles may be conductive particles having a substrate particle and a conductive layer disposed on the surface of the substrate particles, or may be metal particles that are entirely conductive parts. Among these, from the viewpoint of reducing the cost, increasing the flexibility of the conductive particles, and increasing the reliability of conduction between electrodes, conductive particles having a substrate particle and a conductive portion disposed on the surface of the substrate particle are preferable.

Examples of the substrate particles include resin particles, inorganic particles other than metal particles, organic-inorganic hybrid particles, and metal particles. The base particles may be core shell particles. Especially, it is preferable that the said substrate particle is base particle except metal particle, It is more preferable that it is resin particle, inorganic particle except metal particle, or organic-inorganic hybrid particle.

It is preferable that the said substrate particle is resin particle formed with resin. When connecting between electrodes using electroconductive particle with insulating particle, electroconductive particle with insulating particle is arrange | positioned between electrodes, and after pressing, the electroconductive particle with insulating particle is compressed. When the base particles are resin particles, the conductive particles are easily deformed during the pressing, and the contact area between the conductive particles and the electrode is large. For this reason, the reliability of conduction between the electrodes is further increased.

Various organic materials are suitably used as a resin for forming the resin particles. Examples of the resin for forming the resin particles include polyolefin resins such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyisobutylene, and polybutadiene; Acrylic resins such as polymethyl methacrylate and polymethyl acrylate; Polyalkylene terephthalate, polycarbonate, polyamide, phenol formaldehyde resin, melamine formaldehyde resin, benzoguanamine formaldehyde resin, urea formaldehyde resin, phenol resin, melamine resin, benzoguanamine resin, urea resin, Epoxy resin, unsaturated polyester resin, saturated polyester resin, polysulfone, polyphenylene oxide, polyacetal, polyimide, polyamideimide, polyether ether ketone, polyether sulfone, and various polymerizable monomers having ethylenically unsaturated groups And polymers obtained by polymerizing one or two or more polymers. Since the hardness of the substrate particles can be easily controlled within a suitable range, the resin for forming the resin particles is preferably a polymer obtained by polymerizing one or two or more polymerizable monomers having an ethylenically unsaturated group.

When the said resin particle is obtained by superposing | polymerizing the monomer which has an ethylenically unsaturated group, a non-crosslinkable monomer and a crosslinkable monomer are mentioned as a monomer which has the said ethylenic unsaturated group.

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

Examples of the crosslinkable monomer include tetramethylolmethanetetra (meth) acrylate, tetramethylolmethanetri (meth) acrylate, tetramethylolmethanedi (meth) acrylate, and trimethylolpropanetri (meth) acrylic. Rate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, glycerol tri (meth) acrylate, glycerol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylic Polyfunctional (meth) acrylates such as acrylate, (poly) propylene glycol di (meth) acrylate, (poly) tetramethylene di (meth) acrylate, and 1,4-butanediol di (meth) acrylate; Triallyl (iso) cyanurate, triallyl trimellitate, divinylbenzene, diallyl phthalate, diallyl acrylamide, diallyl ether, γ- (meth) acryloxypropyl trimethoxysilane, trimethoxysilylstyrene And silane-containing monomers such as vinyl trimethoxysilane.

The said resin particle can be obtained by polymerizing the polymerizable monomer which has the said ethylenically unsaturated group by a well-known method. Examples of this method include suspension polymerization in the presence of a radical polymerization initiator, and method of polymerization by swelling a monomer together with a radical polymerization initiator using non-crosslinked seed particles.

When the base particles are inorganic particles or organic-inorganic hybrid particles other than metals, silica and carbon black may be mentioned as inorganic substances for forming the base particles. The particles formed by the silica are not particularly limited, but, for example, particles obtained by hydrolyzing a silicon compound having two or more hydrolyzable alkoxysilyl groups to form crosslinked polymer particles, and then firing as necessary. You can. Examples of the organic-inorganic hybrid particles include organic-inorganic hybrid particles formed of a crosslinked alkoxysilyl polymer and an acrylic resin.

When the said substrate particle is a metal particle, silver, copper, nickel, silicon, gold, titanium, etc. are mentioned as a metal for forming this metal particle. However, it is preferable that the said substrate particle is not a metal particle.

The metal for forming the conductive portion is not particularly limited. In addition, when the electroconductive particle is a metal particle which is a conductive part as a whole, the metal for forming the metal particle is not specifically limited. Examples of the metal include gold, silver, palladium, copper, platinum, zinc, iron, tin, lead, aluminum, cobalt, indium, nickel, chromium, titanium, antimony, bismuth, thallium, germanium, cadmium, silicon and these And alloys thereof. In addition, tin-doped indium oxide (ITO), solder, etc. are mentioned as said metal. Among them, an alloy containing tin, nickel, palladium, copper or gold is preferable, and nickel or palladium is preferable because the connection resistance between the electrodes is further lowered. The melting point of the conductive portion is preferably 300 ° C or higher, and more preferably 450 ° C or higher. The conductive portion may be a conductive portion other than solder.

In addition, a hydroxyl group is often present on the surface of the conductive portion due to oxidation. Generally, a hydroxyl group is present on the surface of the conductive portion formed of nickel by oxidation. The first insulating particles can be attached to the surface of the conductive portion having the hydroxyl group (the surface of the conductive particles) through chemical bonding. In addition, the second insulating particles may be attached to the surface of the conductive portion having the hydroxyl group (the surface of the conductive particles) through chemical bonding.

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

The method of forming a conductive layer on the surface of the substrate particles is not particularly limited. As a method for forming the conductive layer, for example, a method by electroless plating, a method by electroplating, a method by physical vapor deposition, and a paste containing a metal powder or a metal powder and a binder are coated on the surface of the substrate particles. And methods. Especially, since the formation of a conductive layer is easy, the method by electroless plating is preferable. Examples of the method by physical vapor deposition include vacuum vapor deposition, ion plating and ion sputtering.

The average particle diameter of the conductive particles is preferably 0.5 μm or more, more preferably 1 μm or more, preferably 500 μm or less, more preferably 100 μm or less, still more preferably 50 μm or less, particularly preferably Is 20 µm or less. When the average particle diameter of the conductive particles is greater than or equal to the above lower limit and less than or equal to the above upper limit, when connecting the electrodes using conductive particles with insulating particles, the contact area between the conductive particles and the electrode is sufficiently large, and when forming the conductive layer It is difficult to form aggregated conductive particles. In addition, the interval between the electrodes connected through the conductive particles does not become too large, and the conductive layer is unlikely to peel off from the surface of the substrate particles.

The "average particle diameter" of the said electroconductive particle shows the number average particle diameter. The average particle diameter of the conductive particles is obtained by observing 50 arbitrary conductive particles with an electron microscope or an optical microscope and calculating the average value.

The thickness of the conductive layer is preferably 0.005 μm or more, more preferably 0.01 μm or more, preferably 10 μm or less, more preferably 1 μm or less, and even more preferably 0.3 μm or less. When the thickness of the conductive layer is greater than or equal to the above lower limit and less than or equal to the above upper limit, sufficient conductivity is obtained, and the conductive particles are not too hard, and the conductive particles are sufficiently deformed during connection between the electrodes.

When the conductive layer is formed of a plurality of layers, the thickness of the conductive layer of the outermost layer, particularly the thickness of the gold layer when the outermost layer is a gold layer, is preferably 0.001 µm or more, more preferably 0.01 µm or more , Preferably 0.5 µm or less, and more preferably 0.1 µm or less. When the thickness of the conductive layer in the outermost layer is equal to or greater than the lower limit and the upper limit, the coating by the conductive layer in the outermost layer becomes uniform, corrosion resistance is sufficiently high, and the connection resistance between electrodes is sufficiently lowered. In addition, the thinner the thickness of the gold layer when the outermost layer is the gold layer, the lower the cost.

The thickness of the said conductive layer can be measured by observing the cross section of electroconductive particle or electroconductive particle with insulating particle using a transmission electron microscope (TEM), for example.

It is preferable that the electroconductive particle has a processus | protrusion on the outer surface of an electroconductive part, and it is preferable that the processus | protrusion is plural. In many cases, an oxide film is formed on the surface of the electrode connected by the conductive particles with insulating particles. In the case where conductive particles with insulating particles having protrusions are used on the surface of the conductive portion, the conductive coating particles with insulating particles are disposed between the electrodes and compressed, whereby the oxide film can be effectively removed by the protrusions. For this reason, the electrode and the conductive portion are more reliably contacted, and the connection resistance between the electrodes is further lowered. In addition, at the time of connection between the electrodes, protrusions of the conductive particles can effectively exclude the insulating particles between the conductive particles and the electrode. For this reason, the reliability of conduction between the electrodes is further increased.

As a method of forming a protrusion on the surface of the conductive particles, a method of forming a conductive layer by electroless plating after attaching a core material to the surface of the substrate particle, a first conductive layer by electroless plating or the like on the surface of the substrate particle After forming, the core material is disposed on the first conductive layer, followed by a method of forming a second conductive layer by electroless plating or the like, and a core during the step of forming the conductive layer on the surface of the substrate particle And a method of adding a substance.

As a method of attaching the core material to the surface of the substrate particle, for example, a core material is added to the dispersion of the substrate particle, and the core material is accumulated on the surface of the substrate particle by, for example, van der Waals force and attached. And a method in which a core material is added to a container containing the substrate particles, and the core material is attached to the surface of the substrate particles by mechanical action such as rotation of the container. Especially, since it is easy to control the amount of the core substance to adhere, the method of integrating and attaching a core substance to the surface of the base particle in a dispersion liquid is preferable.

The said conductive particle has a 1st conductive layer on the surface of a base material particle, You may have a 2nd conductive layer on this 1st conductive layer. In this case, a core material may be attached to the surface of the first conductive layer. It is preferable that the core material is covered with a second conductive layer. The thickness of the first conductive layer is preferably 0.05 μm or more, preferably 0.5 μm or less. The conductive particles form a first conductive layer on the surface of the substrate particle, and then adhere the core material on the surface of the first conductive layer, and then the second conductive layer on the surface of the first conductive layer and the core material It is preferable that it is obtained by forming a layer.

Examples of the material constituting the core material include a conductive material and a non-conductive material. Examples of the conductive material include conductive nonmetals and conductive polymers such as metals, metal oxides, and graphite. Polyacetylene etc. are mentioned as said electroconductive polymer. Silica, alumina, zirconia, etc. are mentioned as said non-conductive substance. Especially, since electroconductivity becomes high, a metal is preferable.

Examples of the metal include metals such as gold, silver, copper, platinum, zinc, iron, lead, tin, aluminum, cobalt, indium, nickel, chromium, titanium, antimony, bismuth, germanium and cadmium, and tin-lead And alloys composed of two or more types of metals such as alloys, tin-copper alloys, tin-silver alloys, tin-lead-silver alloys, and tungsten carbide. Among them, nickel, copper, silver or gold is preferred. The metal constituting the core material may be the same as or different from the metal constituting the conductive portion (conductive layer).

The shape of the core material is not particularly limited. The shape of the core material is preferably bulky. Examples of the core material include granular lumps, agglomerated lumps in which a plurality of fine particles are aggregated, and irregular lumps.

The average diameter (average particle diameter) of the core material is preferably 0.001 μm or more, more preferably 0.05 μm or more, preferably 0.9 μm or less, and more preferably 0.2 μm or less. If the average diameter of the core material is greater than or equal to the lower limit and less than or equal to the upper limit, the connection resistance between the electrodes is effectively lowered.

The "average diameter (average particle diameter)" of the core material represents a number average diameter (number average particle diameter). The average diameter of the core material is obtained by observing 50 arbitrary core materials with an electron microscope or an optical microscope and calculating the average value.

The said projections per one said electroconductive particle are preferably 3 or more, More preferably, they are 5 or more. The upper limit of the number of projections is not particularly limited. The upper limit of the number of protrusions can be appropriately selected in consideration of the particle diameter of the conductive particles and the like.

From the viewpoint of further increasing insulation reliability and insulation reliability against impact, the average particle diameter of the second insulating particles is preferably 0.7 times or more, more preferably 1 time or more, and preferably 1 times or more, preferably the average height of the projections. 5 times or less, More preferably, it is 3 times or less.

The average height of the projections represents the average value of the plurality of projection heights, and the projection height is assumed to be free from projections on a line (dash line L1 shown in FIG. 2) connecting the center of the conductive particle and the tip of the projection. The distance from the conductive layer virtual line (dashed line L2 shown in Fig. 2) (on the outer surface of the spherical conductive particles in the case where there are no protrusions) to the tip of the protrusion is shown. That is, in Fig. 2, the distance from the intersection of the broken line L1 and the broken line L2 to the tip of the projection is shown.

(First and second insulating particles)

The first and second insulating particles are particles having insulating properties. The first and second insulating particles are smaller than the conductive particles, respectively. When the electrodes are connected using conductive particles with insulating particles, short circuits between adjacent electrodes can be prevented by the first and second insulating particles. Specifically, when the conductive particles with a plurality of insulating particles are in contact, the first and second insulating particles are present between the conductive particles in the conductive particles with a plurality of insulating particles, and thus, not between the upper and lower electrodes, but adjacent in the lateral direction. Short circuit between the electrodes can be prevented. Further, at the time of connection between the electrodes, the first and second insulating particles between the conductive portion and the electrode can be easily removed by pressing the conductive particles with insulating particles with two electrodes. When protrusions are formed on the surface of the conductive particles, the first and second insulating particles between the conductive portion and the electrode can be more easily excluded.

Examples of materials constituting the first and second insulating particles include insulating resins and insulating inorganic substances. Examples of the insulating resin include the resins exemplified as resins for forming resin particles that can be used as substrate particles. Examples of the insulating inorganic material include the inorganic materials exemplified as inorganic materials for forming inorganic particles that can be used as the substrate particles.

Specific examples of the insulating resin as the material of the first and second insulating particles include polyolefins, (meth) acrylate polymers, (meth) acrylate copolymers, block polymers, thermoplastic resins, crosslinked products of thermoplastic resins, thermosetting resins, and Water-soluble resins and the like.

Examples of the polyolefins include polyethylene, ethylene-vinyl acetate copolymer and ethylene-acrylic acid ester copolymer. As said (meth) acrylate polymer, polymethyl (meth) acrylate, polyethyl (meth) acrylate, polybutyl (meth) acrylate, etc. are mentioned. Examples of the block polymers include polystyrene, styrene-acrylic acid ester copolymers, SB type styrene-butadiene block copolymers, SBS type styrene-butadiene block copolymers, and hydrogenated products thereof. Vinyl polymer, vinyl copolymer, etc. are mentioned as said thermoplastic resin. An epoxy resin, a phenol resin, a melamine resin, etc. are mentioned as said thermosetting resin. Examples of the water-soluble resin include polyvinyl alcohol, polyacrylic acid, polyacrylamide, polyvinylpyrrolidone, polyethylene oxide and methyl cellulose. Especially, water-soluble resin is preferable and polyvinyl alcohol is more preferable.

From the viewpoint of further improving the desorption property of the first and second insulating particles during compression, the first and second insulating particles are preferably inorganic particles, and preferably silica particles.

Examples of the inorganic particles include shirasu particles, hydroxyapatite particles, magnesia particles, zirconium oxide particles, and silica particles. Examples of the silica particles include pulverized silica and spherical silica. It is preferable to use spherical silica. In addition, it is preferable that the silica particles have a functional group capable of chemically bonding to the surface, for example, a carboxyl group or a hydroxyl group, and more preferably have a hydroxyl group. The inorganic particles are relatively hard, especially the silica particles are relatively hard. When conductive particles with insulating particles having such hard insulating particles are used, when the conductive particles with insulating particles and the binder resin are kneaded, there is a tendency that hard insulating particles are easily detached from the surface of the conductive particles. On the other hand, in the case of using the conductive particles with insulating particles according to the present invention, even if the first insulating particles are hard, even when the first insulating particles are detached during the kneading, the second insulating particles remain, resulting in insulation Reliability can be secured.

It is preferable that the second insulating particles are attached to the surface of the first insulating particles through chemical bonding. It is preferable that the first insulating particles are attached to the surface of the conductive particles through chemical bonding. The chemical bond includes covalent bonds, hydrogen bonds, ionic bonds, and coordinate bonds. Among them, covalent bonds are preferred, and chemical bonds using reactive functional groups are preferred.

As the reactive functional group forming the chemical bond, for example, vinyl group, (meth) acryloyl group, silane group, silanol group, carboxyl group, amino group, ammonium group, nitro group, hydroxyl group, carbonyl group, thiol group, sulfonic acid group, sulfonium group , Boric acid group, oxazoline group, pyrrolidone group, phosphoric acid group and nitrile group. Especially, a vinyl group and a (meth) acryloyl group are preferable.

From the viewpoint of further suppressing the desorption of the first insulating particles and further increasing the insulation reliability in the connection structure, it is preferable to use insulating particles having a reactive functional group on the surface as the first insulating particles. From the viewpoint of further suppressing the detachment of the insulating particles and further increasing the insulation reliability in the connection structure, it is preferable to use the first insulating particles surface-treated with a compound having a reactive functional group as the first insulating particles. desirable. In addition, from the viewpoint of further enhancing insulation reliability, it is preferable to use insulating particles having a reactive functional group on the surface as the second insulating particles. From the viewpoint of further enhancing insulation reliability, it is preferable to use the second insulating particles surface-treated using a compound having a reactive functional group as the second insulating particles.

(Meth) acryloyl group, glycidyl group, hydroxyl group, vinyl group and amino group etc. are mentioned as said reactive functional group which can be introduce | transduced to the surface of the said 1st, 2nd insulating particle. It is preferable that the reactive functional groups possessed by the first and second insulating particles on the surface are at least one reactive functional group selected from the group consisting of (meth) acryloyl group, glycidyl group, hydroxyl group, vinyl group and amino group.

Examples of the compound (surface treatment material) for introducing the reactive functional group include a compound having a (meth) acryloyl group, a compound having an epoxy group, a compound having a vinyl group, and the like.

Examples of the compound (surface treatment material) for introducing a vinyl group include a silane compound having a vinyl group, a titanium compound having a vinyl group, and a phosphoric acid compound having a vinyl group. It is preferable that the surface treatment material is a silane compound having a vinyl group. Examples of the silane compound having the vinyl group include vinyl trimethoxysilane, vinyl triethoxysilane, vinyl triacetoxysilane, and vinyl triisopropoxysilane.

As a compound (surface treatment material) for introducing a (meth) acryloyl group, a silane compound having a (meth) acryloyl group, a titanium compound having a (meth) acryloyl group, and a phosphoric acid compound having a (meth) acryloyl group And the like. It is also preferable that the surface treatment material is a silane compound having a (meth) acryloyl group. Examples of the silane compound having the (meth) acryloyl group include (meth) acryloxypropyl triethoxysilane, (meth) acryloxypropyl trimethoxysilane, and (meth) acryloxypropyl tridimethoxysilane. .

As a method of attaching the first and second insulating particles to the surfaces of the conductive particles and the conductive portion, chemical methods, physical or mechanical methods, and the like can be mentioned. Examples of the chemical method include interfacial polymerization, suspension polymerization in the presence of particles, and emulsion polymerization. Examples of the physical or mechanical method include spray drying, hybridization, electrostatic adhesion, spraying, dipping and vacuum deposition. However, in the hybridization method, since the first and second insulating particles tend to be easily desorbed, the method of arranging the first and second insulating particles is preferably a method other than the hybridization method. . It is preferable that the 1st insulating particle is not arrange | positioned by the hybridization method on the surface of electroconductive particle. It is preferable that the 2nd insulating particle | grains are not arrange | positioned by the hybridization method on the surface of electroconductive particle. Since the first insulating particles are more difficult to detach, the method of arranging the first insulating particles on the surface of the conductive particles through chemical bonding is preferable. Since the second insulating particles are more likely to be detached, a method of disposing the second insulating particles on the surface of the conductive particles through chemical bonding is preferable.

The following methods are mentioned as an example of the method of attaching a 1st, 2nd insulating particle to the surface of the said electroconductive particle and the surface of the said electroconductive part.

First, the conductive particles are placed in 3 L of a solvent such as water, and the first and second insulating particles are gradually added while stirring. After sufficiently stirring, the conductive particles with insulating particles are separated and dried by a vacuum dryer or the like to obtain conductive particles with insulating particles.

It is preferable that the conductive portion has a reactive functional group capable of reacting with the first insulating particle on the surface. It is preferable that the first insulating particles have a reactive functional group capable of reacting with a conductive portion on the surface. By introducing a chemical bond by this reactive functional group, it is difficult to unintentionally detach the first insulating particles from the surface of the conductive particles. In addition, insulation reliability and insulation reliability against impact are further increased. It is preferable that the conductive portion has a reactive functional group capable of reacting with the second insulating particle on the surface. It is preferable that the second insulating particles have a reactive functional group capable of reacting with a conductive portion on the surface. By introducing a chemical bond by this reactive functional group, it is difficult to unintentionally detach the second insulating particles from the surface of the conductive particles. In addition, insulation reliability and insulation reliability against impact are further increased.

As the reactive functional group, an appropriate group is selected in consideration of reactivity. A hydroxyl group, a vinyl group, an amino group, etc. are mentioned as said reactive functional group. Since the reactivity is excellent, the reactive functional group is preferably a hydroxyl group. It is preferable that the said electroconductive particle has a hydroxyl group on the surface. It is preferable that the conductive portion has a hydroxyl group on the surface. It is preferable that the insulating particles have a hydroxyl group on the surface.

When a hydroxyl group is present on the surface of the insulating particles and the conductive particles, the adhesion between the first and second insulating particles and the conductive particles is appropriately increased by a dehydration reaction.

Examples of the compound having a hydroxyl group include a P-OH group-containing compound and a Si-OH group-containing compound. Examples of the compound having a hydroxyl group for introducing a hydroxyl group to the surface of the insulating particles include a P-OH group-containing compound, a Si-OH group-containing compound, and the like.

Specific examples of the P-OH group-containing compound include acid phosphooxyethyl methacrylate, acid phosphooxypropyl methacrylate, acid phosphooxy polyoxyethylene glycol monomethacrylate and acid phosphooxypolyoxypropylene glycol And monomethacrylate. As for the said P-OH group containing compound, only 1 type may be used and 2 or more types may be used together.

Vinyl trihydroxysilane, 3-methacryloxypropyl trihydroxysilane, etc. are mentioned as a specific example of the said Si-OH group containing compound. As for the said Si-OH group containing compound, only 1 type may be used and 2 or more types may be used together.

For example, insulating particles having a hydroxyl group on the surface can be obtained by treatment with a silane coupling agent. As said silane coupling agent, hydroxytrimethoxysilane etc. are mentioned, for example.

(Challenge material)

The conductive material according to the present invention includes conductive particles with insulating particles according to the present invention and a binder resin. When dispersing the conductive particles with insulating particles according to the present invention in a binder resin, it is difficult to detach the first and second insulating particles from the surface of the conductive particles. It is preferable that the electroconductive particle with insulating particle which concerns on this invention is disperse | distributed in binder resin, and can be used as a conductive material. It is preferable that the said conductive material is an anisotropic conductive material.

The binder resin is not particularly limited. As the binder resin, an insulating resin is generally used. As said binder resin, vinyl resin, a thermoplastic resin, curable resin, a thermoplastic block copolymer, an elastomer, etc. are mentioned, for example. As for the said binder resin, only 1 type may be used and 2 or more types may be used together.

As said vinyl resin, vinyl acetate resin, acrylic resin, styrene resin, etc. are mentioned, for example. As said thermoplastic resin, polyolefin resin, ethylene-vinyl acetate copolymer, polyamide resin, etc. are mentioned, for example. Examples of the curable resin include epoxy resins, urethane resins, polyimide resins, and unsaturated polyester resins. Moreover, the said curable resin may be a normal 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. As the thermoplastic block copolymer, for example, styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, hydrogenation of styrene-butadiene-styrene block copolymer and hydrogen of styrene-isoprene-styrene block copolymer And additives. Examples of the elastomers include styrene-butadiene copolymer rubber, acrylonitrile-styrene block copolymer rubber, and the like.

The conductive material, in addition to the conductive particles with the insulating particles and the binder resin, for example, fillers, extenders, softeners, plasticizers, polymerization catalysts, curing catalysts, colorants, antioxidants, thermal stabilizers, light stabilizers, ultraviolet absorbers, lubricants, Various additives, such as an antistatic agent and a flame retardant, may be included.

The method for dispersing the conductive particles with insulating particles in the binder resin can use a conventionally known dispersion method and is not particularly limited. As a method for dispersing the conductive particles with insulating particles in the binder resin, for example, after adding the conductive particles with insulating particles in the binder resin, kneading and dispersing with a planetary mixer or the like, the conductive particles with insulating particles are water or After dispersing uniformly using a homogenizer or the like in an organic solvent, adding it to a binder resin, kneading and dispersing it with a planetary mixer, etc., and after diluting the binder resin with water or an organic solvent, insulating particles And a method in which adhered conductive particles are added, kneaded and dispersed with a planetary mixer or the like.

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

It is preferable that the conductive material according to the present invention is a conductive paste. The conductive paste is excellent in handling properties and circuit filling properties. When obtaining a conductive paste, a relatively large force is applied to the conductive particles with insulating particles, but the presence of the second insulating particles can suppress the separation of the insulating particles from the surface of the conductive particles.

The content of the binder resin in 100% by weight of the conductive material is preferably 10% by weight or more, more preferably 30% by weight or more, still more preferably 50% by weight or more, particularly preferably 70% by weight or more, preferably Is 99.99% by weight or less, and more preferably 99.9% by weight or less. When the content of the binder resin is equal to or greater than the lower limit and less than or equal to the upper limit, conductive particles with insulating particles are efficiently disposed between the electrodes, and the conduction reliability of the connection target member connected by the conductive material is further increased.

The content of the conductive particles with insulating particles in 100% by weight of the conductive material is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, preferably 40% by weight or less, more preferably 20% by weight or less, More preferably, it is 15% by weight or less. When the content of the conductive particles with insulating particles is greater than or equal to the above lower limit and less than or equal to the above upper limit, the reliability of conduction between the electrodes is further increased.

(Connection structure)

The connection structure can be obtained by using the above-described conductive particles with insulating particles or by connecting the member to be connected using the conductive particles with insulating particles and a conductive material containing a binder resin.

The said connection structure is provided with the 1st connection target member, the 2nd connection target member, and the connection part which connects the 1st connection target member and the 2nd connection target member, and the connection part is attached to the electroconductive particle with insulating particle mentioned above. It is preferable that it is a connection structure formed of or formed of a conductive material (anisotropic conductive material, etc.) containing the conductive particles and insulating resin with insulating particles. It is preferable that the first connection object member has a first electrode on its surface. It is preferable that the second connection object member has a second electrode on its surface. It is preferable that the first electrode and the second electrode are electrically connected by the conductive particles in the conductive particles with the insulating particles. When the conductive particles with insulating particles described above are used, the connection portion itself is formed of conductive particles with insulating particles. That is, the 1st, 2nd connection target member is electrically connected by the electroconductive particle in the electroconductive particle with insulating particle.

4 is a cross-sectional view schematically showing a connection structure using the conductive particles 1 with insulating particles shown in FIG. 1.

The connection structure 81 shown in FIG. 4 includes the first connection target member 82, the second connection target member 83, and the first connection target member 82 and the second connection target member 83. A connecting portion 84 that is connected is provided. The connecting portion 84 is formed of a conductive material containing the conductive particles 1 with insulating particles and a binder resin. In Fig. 4, for convenience of illustration, the conductive particles 1 with insulating particles are schematically illustrated. Instead of the conductive particles 1 with insulating particles, conductive particles 21 and 31 with insulating particles may be used.

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

The manufacturing method of the said connection structure is not specifically limited. As an example of a method for manufacturing the connection structure, a method of arranging the conductive material between the first connection target member and the second connection target member, obtaining a laminate, and then heating and pressing the laminate can be given. The pressurized pressure is about 9.8 × 10 ⁴ to 4.9 × 10 ⁶ Pa. The heating temperature is about 120 to 220 ° C.

When heating and pressing the laminate, the first and second insulating particles 3 and 4 existing between the conductive particles 2 and the first and second electrodes 82a and 83a may be excluded. For example, during the heating and pressurization, the first and second insulating particles 3 and 4 existing between the conductive particles 2 and the first and second electrodes 82a and 83a are melted or deformed. Thus, the surface of the conductive particles 2 is partially exposed. Also, during the heating and pressurization, since a large force is applied, a part of the first and second insulating particles 3 and 4 are detached from the surface of the conductive particles 2, and the surface of the conductive particles 2 is partially It is also exposed. The portion where the surface of the conductive particles 2 is exposed contacts the first and second electrodes 82a and 83a to electrically connect the first and second electrodes 82a and 83a through the conductive particles 2. You can.

Specific examples of the connection target member include electronic components such as semiconductor chips, capacitors and diodes, and electronic components such as printed circuit boards, flexible printed circuit boards, glass epoxy substrates, and circuit boards such as glass substrates. The said conductive material is paste form, and it is preferable to apply | coat on the connection object member in a paste state. It is preferable that the said electroconductive particle with insulating particle and conductive material are used for connection of the member to be connected which is an electronic component. It is preferable that the said connection target member is an electronic component. It is preferable that the said electroconductive particle with insulating particle is used for the electrical connection of the electrode in an electronic component.

The electroconductive particle with insulating particle which concerns on this invention is used suitably, especially for COG which uses a glass substrate and a semiconductor chip as a connection object member, or FOG which uses a glass substrate and a flexible printed circuit board (FPC) as a connection object member. The conductive particles with insulating particles according to the present invention may be used for COG or FOG. In the connection structure according to the present invention, it is preferable that the first and second connection target members are glass substrates and semiconductor chips, or glass substrates and flexible printed substrates. The first and second connection target members may be a glass substrate and a semiconductor chip, or a glass substrate and a flexible printed circuit board.

It is preferable that bumps are provided in the semiconductor chip used in COG using a glass substrate and a semiconductor chip as a connection target member. The bump size is preferably an electrode area of 1000 µm ² or more and 10000 µm ² or less. The electrode space in the semiconductor chip provided with the bump (electrode) is preferably 30 µm or less, more preferably 20 µm or less, still more preferably 10 µm or less. For such COG use, the conductive particles with insulating particles according to the present invention are suitably used. In the FPC used in the FOG using the glass substrate and the flexible printed substrate as a connection target member, the electrode space is preferably 30 µm or less, more preferably 20 µm or less.

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, and tungsten electrodes. When the member to be connected is a flexible printed circuit board, the electrode is preferably a gold electrode, a nickel electrode, a tin electrode, 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, or a tungsten electrode. Moreover, when the said electrode is an aluminum electrode, it may be an electrode formed only of aluminum, or an electrode in which an aluminum layer is laminated on the surface of a metal oxide layer. Examples of the material of the metal oxide layer include indium oxide doped with a trivalent metal element, zinc oxide doped with a trivalent metal element, and the like. Sn, Al, Ga, etc. are mentioned as said trivalent metal element.

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

(Example 1)

(Electroless plating pretreatment process)

About 10 g of resin particles (average particle diameter: 3 µm) formed of a copolymerized resin of tetramethylolmethanetetraacrylate and divinylbenzene, the sensor in an alkali degreasing with an aqueous sodium hydroxide solution, acid neutralization, and tin dichloride solution Tising was performed.

The resin particles were treated with an ion adsorbent for 5 minutes, and then added to an aqueous palladium sulfate solution. Thereafter, dimethylamine borane was added, reduced, filtered, and washed to obtain palladium-adhered resin particles.

(Core material complexation process)

10 g of resin particles to which palladium catalyst was imparted was dispersed in 300 mL of ion-exchanged water to prepare a dispersion. 1 g of metal nickel particles (average particle diameter 50 nm) was added to the dispersion liquid over 3 minutes to prepare resin particles with metal nickel particles attached thereto.

(Electroless nickel plating process)

Subsequently, a 1% by weight solution of sodium succinate in which sodium succinate was dissolved in 500 mL of ion-exchanged water was prepared. To this solution, 10 g of metal nickel particles and palladium-attached resin particles were added and mixed to prepare a slurry. Sulfuric acid was added to the slurry, and the pH of the slurry was adjusted to 5.

As a nickel plating solution, an electric nickel plating solution containing 10% by weight of nickel sulfate, 10% by weight of sodium hypophosphite, 4% by weight of sodium hydroxide, and 20% by weight of sodium succinate was prepared. After heating the slurry adjusted to pH 5 to 80 ° C, the electrolytic nickel plating solution was continuously added dropwise to the slurry, and the plating reaction was performed by stirring for 20 minutes. It was confirmed that no hydrogen was generated, and the plating reaction was terminated.

Subsequently, a late nickel plating solution containing 20% by weight of nickel sulfate, 5% by weight of dimethylamine borane and 5% by weight of sodium hydroxide was prepared. The plating reaction was advanced by continuously dropping the late nickel plating solution and stirring for 1 hour in the solution where the plating reaction with the electrolytic nickel plating solution had been completed. In this way, a nickel layer was formed on the surface of the resin particles to obtain conductive particles A. Further, the thickness of the nickel layer was 0.1 µm.

(Process for producing insulating particles)

In a 1000 mL separable flask equipped with a 4-neck separable cover, stirring blade, three-way cock, cooling tube, and temperature probe, 45 mmol of glycidyl methacrylate, 380 mmol of methyl methacrylate, 13 mmol of ethylene glycol dimethacrylate, and acid force A monomer composition containing 0.5 mmol of pooxypolyoxyethylene glycol methacrylate and 1 mmol of 2,2'-azobis {2- [N- (2-carboxyethyl) amidino] propane} was added. Distilled water was added to the monomer composition so that the solid content became 10% by weight, followed by stirring at 150 rpm, and polymerization was performed at 60 ° C for 24 hours under a nitrogen atmosphere. After completion of the reaction, freeze-drying was performed to obtain first insulating particles (average particle diameter 400 nm) having P-OH groups derived from acid phosphooxypolyoxyethylene glycol methacrylate on the surface.

In addition, the second insulating particles (average particle diameter 180 nm) were obtained in the same manner except that the above-mentioned stirring speed was changed to 300 rpm and the polymerization temperature was changed to 80 ° C.

(Process for producing conductive particles with insulating particles)

The insulating particles obtained above were each dispersed in distilled water under ultrasonic irradiation to obtain a 10% by weight aqueous dispersion of the insulating particles. 10 g of the obtained conductive particles A were dispersed in 500 mL of distilled water, 3 g of an aqueous dispersion of the first insulating particles were added, and the mixture was stirred at room temperature for 3 hours. Further, 2 g of an aqueous dispersion of the second insulating particles was added and stirred at room temperature for 6 hours. After filtration through a 3 µm mesh filter, further washed with methanol and dried to obtain conductive particles with insulating particles.

As observed with a scanning electron microscope (SEM), the conductive particles with insulating particles had a coating layer formed of insulating particles on the surface of the conductive particles having projections.

(Examples 2 to 4 and Comparative Examples 1 to 3)

Conductive particles with insulating particles were obtained in the same manner as in Example 1, except that the addition amount of the aqueous dispersion of the first and second insulating particles was changed as shown in Table 1 below.

(evaluation)

(1) Coverage rate Z of the total area of the portions covered by the first and second insulating particles occupying the entire surface area of the conductive particles

Conductive particles with 20 insulating particles were observed by observation by SEM. The coverage ratio of the total projection area of the portions covered by the first and second insulating particles occupying the entire surface area of the conductive particles was determined. The average value of the 20 coverages was referred to as coverage Z.

(2) Of the total number of second insulating particles, the ratio of the number of second conductive particles X2 disposed on the surface of the conductive particles so as not to contact the first insulating particles X2

In the obtained conductive particles with insulating particles, the proportion X2 (%) of the number of second insulating particles disposed on the surface of the conductive particles was determined from the total number of the second insulating particles so as not to contact the first insulating particles. The ratio X2 of the number was determined based on the following criteria.

[Of the total number of second insulating particles, the criterion for determining the number ratio X2 of the second insulating particles disposed on the surface of the conductive particles so as not to contact the first insulating particles]

A: The ratio X2 of the number is 70% or more

B: The ratio of the number X2 is 50% or more and less than 70%

C: The ratio of the number X2 is less than 50%

(3) Of the total number of the second insulating particles, the ratio of the number of the second insulating particles X3 disposed on the surface of the conductive particles so as not to contact the first insulating particles and to contact the conductive particles X3

In the obtained conductive particles with insulating particles, among the total number of the second insulating particles, the ratio of the number of the second insulating particles X3 disposed on the surface of the conductive particles so as not to contact the first insulating particles and to contact the conductive particles X3 (%) Was determined. The ratio X3 of the number was determined based on the following criteria.

[Criteria for judging the ratio of the number of second insulating particles X3 arranged on the surface of the conductive particles so as not to contact with the first insulating particles out of the total number of the second insulating particles and to contact the conductive particles]

A: The ratio of the number X3 is 65% or more

B: The ratio of the number X3 is 50% or more and less than 65%

C: The ratio of the number X3 is less than 50%

(4) The average number of first insulating particles Y1 disposed on the surface of the conductive particles per conductive particle Y1

In the obtained electroconductive particle with insulating particle, the average number Y1 of 1st insulating particle arrange | positioned on the surface of electroconductive particle per electroconductive particle was calculated | required. The average number Y1 was determined based on the following criteria.

[Criteria for determining the average number of first insulating particles Y1 per conductive particle disposed on the surface of the conductive particles Y1]

A: The average number of Y1 is 10 or more and 100 or less

B: The average number Y1 is 3 or more and less than 10

C: Average number Y1 is less than 3

(5) Average number Y2 of second insulating particles disposed on the surface of the conductive particles per conductive particle

In the obtained electroconductive particle with insulating particle, the average number Y2 of 2nd insulating particle arrange | positioned on the surface of electroconductive particle per electroconductive particle was calculated | required. The average number Y2 was determined based on the following criteria.

[Criteria for determination of average number Y2 of second insulating particles disposed on the surface of conductive particles per conductive particle]

A: The average number of Y2 is 20 or more and 1000 or less

B: The average number Y2 is 6 or more and less than 20

C: Average number Y2 is less than 6

(6) Average number of first insulating particles on the surface of the conductive particles per conductive particle Y1, Average number of second insulating particles on the surface of the conductive particles per Y conductive particle Ratio to Y2 (average number Y1 / average number Y2)

In the obtained electroconductive particle with insulating particle, the agent which is arrange | positioned on the surface of electroconductive particle per electroconductive particle of average number Y1 of 1st insulating particle arrange | positioned on the surface of electroconductive particle per electroconductive particle 2 The ratio (average number Y1 / average number Y2) of the insulating particles to the average number Y2 was determined. The ratio (average number Y1 / average number Y2) was determined based on the following criteria.

[Criteria for determining ratio (average number Y1 / average number Y2)]

A: The ratio of the ratio (average number Y1 / average number Y2) is 0.005 or more and 0.5 or less

B: Ratio of the ratio (average number Y1 / average number Y2) is greater than 0.5 and less than 1

C: Ratio of the ratio (average number Y1 / average number Y2) exceeds 1

(7) Conductivity (between upper and lower electrodes)

The obtained conductive particles with insulating particles were added to "Straight Bond XN-5A" manufactured by Mitsui Chemical Co., Ltd. so as to have a content of 10% by weight, and dispersed to obtain an anisotropic conductive paste.

A transparent glass substrate having an ITO electrode pattern having an L / S of 30 μm / 30 μm formed on an upper surface was prepared. In addition, a semiconductor chip formed on a lower surface of a copper electrode pattern having an L / S of 30 μm / 30 μm was prepared.

The anisotropic conductive paste obtained on the transparent glass substrate was coated and applied to a thickness of 30 μm to form an anisotropic conductive paste layer. Subsequently, the semiconductor chip was laminated on the anisotropic conductive paste layer so that the electrodes faced each other. Thereafter, while adjusting the temperature of the head so that the temperature of the anisotropic conductive paste layer was 185 ° C, a pressure heating head was placed on the upper surface of the semiconductor chip, and a pressure of 1 MPa was applied to cure the anisotropic conductive paste layer at 185 ° C to connect. A structure was obtained.

The connection resistance between the upper and lower electrodes of the obtained 20 connection structures was measured by a 4-terminal method, respectively. In addition, from the relationship of voltage = current × resistance, the connection resistance can be obtained by measuring the voltage when a constant current is passed. Conductivity was determined based on the following criteria.

[Determination criteria for conductivity]

○: The ratio of the number of connection structures having a resistance value of 5 Ω or less is 80% or more.

△: The ratio of the number of connection structures having a resistance value of 5 Ω or less is 60% or more and less than 80%.

×: The ratio of the number of connection structures having a resistance value of 5 Ω or less is less than 60%.

(8) Insulation (between adjacent electrodes in the horizontal direction)

In the 20 connection structures obtained in the above (7) conductivity evaluation, the presence or absence of leakage between adjacent electrodes was evaluated by measuring resistance with a tester. Insulation properties were judged based on the following criteria.

[Criteria for determining insulation properties]

○○: The ratio of the number of connection structures having a resistance value of 10 ⁸ Ω or more is 90% or more

○: The ratio of the number of connection structures having a resistance value of 10 ⁸ Ω or more is 80% or more and less than 90%.

△: The ratio of the number of connection structures having a resistance value of 10 ⁸ Ω or more is 60% or more and less than 80%.

×: The ratio of the number of connection structures having a resistance value of 10 ⁸ Ω or more is less than 60%

The results are shown in Table 1 below.

1 Conductive particles with insulating particles
2 conductive particles
3 1st insulating particle
4 Second insulating particles
11 substrate particles
12 Challenge
21 Conductive particles with insulating particles
22 conductive particles
26 Challenge
27 core material
28 turns
31 Conductive particles with insulating particles
32 conductive particles
36 Challenge
37 Turn
81 Connection structure
82 First connection target member
82a first electrode
83 2nd connection target member
83a second electrode
84 Connection

Claims (12)

Conductive particles having at least a conductive portion on the surface,
A plurality of first insulating particles disposed on the surface of the conductive particles,
It has a plurality of second insulating particles disposed on the surface of the conductive particles,
The average particle diameter of the second insulating particles is smaller than the average particle diameter of the first insulating particles,
The first insulating particles and the second insulating particles are polymers by soap-free polymerization,
The average particle diameter of the second insulating particles is 2/3 or less of the average particle diameter of the first insulating particles,
The electroconductive particle with insulating particle arrange | positioned on the surface of the said electroconductive particle so that 50% or more of the total number of the said 2nd insulating particle does not contact the said 1st insulating particle. Conductive particles having at least a conductive portion on the surface,
A plurality of first insulating particles disposed on the surface of the conductive particles (except for insulating particles having a particle diameter distribution overlapping the particle diameter distribution of the second insulating particles),
A plurality of second insulating particles disposed on the surface of the conductive particles (however, except for the insulating particles having a particle diameter distribution overlapping the particle diameter distribution of the first insulating particles),
The average particle diameter of the second insulating particles is smaller than the average particle diameter of the first insulating particles,
The electroconductive particle with insulating particle arrange | positioned on the surface of the said electroconductive particle so that 50% or more of the total number of the said 2nd insulating particle does not contact the said 1st insulating particle. Conductive particles having at least a conductive portion on the surface,
A plurality of first insulating particles disposed on the surface of the conductive particles,
It has a plurality of second insulating particles disposed on the surface of the conductive particles,
The average particle diameter of the second insulating particles is smaller than the average particle diameter of the first insulating particles,
The minimum particle diameter of the first insulating particles is larger than the maximum particle diameter of the second insulating particles,
The electroconductive particle with insulating particle arrange | positioned on the surface of the said electroconductive particle so that 50% or more of the total number of the said 2nd insulating particle does not contact the said 1st insulating particle. The electroconductive particle with insulating particle of Claim 2 or 3 whose average particle diameter of the said 2nd insulating particle is 2/3 or less of the average particle diameter of the said 1st insulating particle. The insulating property according to any one of claims 1 to 3, wherein 70% or more of the total number of the second insulating particles is disposed on the surface of the conductive particles so as not to contact the first insulating particles. Conductive particles with particles. The surface of the conductive particles according to any one of claims 1 to 3, wherein 50% or more of the total number of the second insulating particles does not contact the first insulating particles and also contacts the conductive particles. Conductive particles with insulating particles disposed on the phase. According to any one of claims 1 to 3, The first insulating particles are attached to the surface of the conductive particles through a chemical bond, and the chemical bond is a covalent bond, a hydrogen bond, an ionic bond or a coordination. Conductive particles with an insulating particle that is a bond. According to any one of claims 1 to 3, The second insulating particles are attached to the surface of the conductive particles through a chemical bond, and the chemical bond is a covalent bond, a hydrogen bond, an ionic bond or a coordination. Conductive particles with an insulating particle that is a bond. The said 1st insulating particle and the said 2nd insulating particle are respectively not arrange | positioned by the hybridization method on the surface of the said electroconductive particle of any one of Claims 1-3, Conductive particles with insulating particles. The conductive particle with insulating particles according to any one of claims 1 to 3, wherein the conductive particle has a projection on an outer surface of the conductive portion. A conductive material comprising the conductive particles with insulating particles according to any one of claims 1 to 3 and a binder resin. A first connection target member having a first electrode on its surface,
A second connection target member having a second electrode on its surface,
And a connecting portion connecting the first connection target member and the second connection target member,
The said connection part is formed by the electroconductive particle with insulating particle of any one of Claims 1-3, or is formed with the electroconductive particle containing the said electroconductive particle and conductive resin containing a binder resin,
The connection structure in which the said 1st electrode and said 2nd electrode are electrically connected by the said electroconductive particle in the electroconductive particle with the said insulating particle.

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