TWI807004B - Conductive particles with insulating particles, conductive materials and connection structures - Google Patents

Abstract

The present invention provides conductive particles with insulating particles that can effectively improve conduction reliability and further effectively improve insulation reliability when electrodes are electrically connected. The conductive particle with insulating particle of the present invention includes: a conductive particle having at least a conductive portion on its surface; and a plurality of insulating particles arranged on the surface of the conductive particle; and the insulating particle has a phosphorus atom on the surface, and the phosphorus atom is coordinately bonded to the conductive portion.

Description

Conductive particles with insulating particles, conductive material and connection structure

The present invention relates to conductive particles with insulating particles arranged on the surface of conductive particles. Moreover, this invention relates to the electrically-conductive material and bonded structure using the said electroconductive particle with insulating particle.

Anisotropic conductive materials such as anisotropic conductive paste and anisotropic conductive film are widely known. In this anisotropic conductive material, conductive particles are dispersed in a binder resin. Moreover, as electroconductive particle, the electroconductive particle in which the surface of the electroconductive layer was insulating-processed may be used.

The aforementioned anisotropic conductive materials are used to obtain various connection structures. As the connection using the above-mentioned anisotropic conductive material, for example, the connection between a flexible printed substrate and a glass substrate (FOG (Film on Glass)), the connection between a semiconductor chip and a flexible printed substrate (COF (Chip on Film)), the connection between a semiconductor chip and a glass substrate (COG (Chip on Glass)), and the connection between a flexible printed substrate and a glass epoxy substrate (FOB (Film on Board)).

Moreover, the electroconductive particle with insulating particle which arrange|positioned the insulating particle on the surface of electroconductive particle may be used as said electroconductive particle. Furthermore, the coated electroconductive particle which arrange|positioned the insulating layer on the surface of a conductive layer may also be used.

As an example of the conductive particle with insulating particle mentioned above, the following patent document 1 discloses the conductive particle with insulating particle as follows, which comprises: a conductive particle which has a conductive layer on the surface; and an insulating particle which adheres to the surface of the said conductive particle. The above-mentioned insulating particles have hydroxyl groups directly bonded to phosphorus atoms or hydroxyl groups directly bonded to silicon atoms on the surface. [Prior Art Literature] [Patent Document]

[Patent Document 1] WO2011/030715A1

[Problem to be solved by the invention]

In conventional conductive particles with insulating particles, when the conductive particles with insulating particles are mixed with a binder resin to produce an anisotropic conductive material, the insulating particles may detach from the surface of the conductive particles.

In the conventional conductive particles with insulating particles, in order to solve the above problems, a method of introducing phosphoric acid groups or the like to the surface of the insulating particles to chemically bond the conductive layer on the surface of the conductive particles to the insulating particles has been proposed. However, when acidic functional groups such as a phosphoric acid group are introduced into the surface of insulating particles, the conductive layer on the surface of the conductive particles may be corroded. Due to the corrosion of the conductive layer on the surface of the conductive particles, it may be difficult to greatly improve the conduction reliability between the upper and lower electrodes to be connected in the case of conductive connection using an anisotropic conductive material.

In addition, the surface of the conductive particles with insulating particles becomes hydrophilic by introducing phosphoric acid groups or the like to the surface of the insulating particles. Therefore, when an anisotropic conductive material is produced by mixing with a binder resin, the conductive particles with insulating particles may have low dispersibility and aggregate. In the conductive connection using such an anisotropic conductive material, electroconductive particles may not be arrange|positioned between the upper and lower electrodes which should be connected in the state with rather high uniformity after coating of an anisotropic conductive material.

Moreover, in the conventional electroconductive particle with insulating particle, a phosphonium salt etc. are used when introducing a phosphoric acid group etc. to the surface of an insulating particle. Phosphonium salts may contain halogen elements such as chloride ions. If the anisotropic conductive material contains halogen elements such as chloride ions, ion migration may occur between electrodes. As a result, it may be difficult to significantly improve the insulation reliability between electrodes that should not be connected and that are adjacent in the lateral direction.

An object of the present invention is to provide conductive particles with insulating particles that can effectively improve conduction reliability and further effectively improve insulation reliability when electrodes are electrically connected. Moreover, the object of this invention is to provide the electrically-conductive material and bonded structure using the said electroconductive particle with insulating particle. [Technical means to solve the problem]

According to a broad aspect of the present invention, there is provided a conductive particle with insulating particles, which includes: a conductive particle having a conductive portion at least on its surface; and a plurality of insulating particles arranged on the surface of the conductive particle; and the insulating particle has a phosphorus atom on the surface, and the phosphorus atom is coordinated to the conductive portion.

According to a broad aspect of the present invention, there is provided a conductive particle with insulating particles, which includes: a conductive particle having a conductive portion at least on its surface; and a plurality of insulating particles arranged on the surface of the conductive particle; and the insulating particle has a phosphorus atom on the surface, and the insulating particle includes a structure represented by the following formula (1) or (2).

[chemical 1]

In the above formula (1), R1 and R2 independently represent a saturated or unsaturated alkyl group having 1 to 10 carbons, a substituent bonded to a saturated or unsaturated alkyl group having 1 to 10 carbons, an alkoxy group, or an aryl group, or independently represent a saturated or unsaturated alkylene group having 1 to 10 carbons, a saturated or unsaturated alkylene group having a substituent bonded to a saturated or unsaturated alkylene group having 1 to 10 carbons, an alkoxyl group, or an aryl group. R1 and R2 may also be bonded to each other to form a ring together with the adjacent phosphorus atom in formula (1). In the above formula (1), the left end represents a bonding site.

[Chem 2]

In the above formula (2), R1 and R2 independently represent a saturated or unsaturated alkyl group having 1 to 10 carbons, a substituent bonded to a saturated or unsaturated alkyl group having 1 to 10 carbons, an alkoxyl group, or an aryl group, or independently represent a saturated or unsaturated alkylene group having 1 to 10 carbons, a saturated or unsaturated alkylene group having a substituent bonded to a saturated or unsaturated alkylene group having 1 to 10 carbons, an alkoxyl group, or an aryl group. R1 and R2 may also be bonded to each other to form a ring together with the adjacent phosphorus atom in formula (2). In the above formula (2), the left end represents a bonding site.

In a specific aspect of the conductive particle with insulating particle of this invention, the said electroconductive part contains nickel or palladium.

In a specific aspect of the conductive particles with insulating particles of the present invention, the content of chloride ions is 300 ppm or less.

In a specific aspect of the conductive particle with insulating particle of this invention, the glass transition temperature of the said insulating particle is 40 degreeC or more and 110 degreeC or less.

In a specific aspect of the conductive particle with insulating particle of this invention, the said phosphorus atom and the said electroconductive part are not ionically bonded.

In a specific aspect of the conductive particle with insulating particle of this invention, the said insulating particle does not have the halogen group directly bonded to the said phosphorus atom.

In a specific aspect of the conductive particle with insulating particle of this invention, the particle diameter of the said conductive particle is 1 micrometer or more and 5 micrometers or less.

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

According to a broad aspect of the present invention, there is provided a connection structure comprising: a first connection object member having a first electrode on its surface; a second connection object member having a second electrode on its surface; and a connection portion connecting the first connection object member to the second connection object member; and the material of the connection portion is the conductive particle with insulating particles, or a conductive material including the conductive particle with insulating particles and a binder resin. The first electrode and the second electrode are connected by the conductive particle with insulating particles. The above-mentioned conductive parts are electrically connected. [Effect of Invention]

The electroconductive particle with insulating particle of this invention is equipped with: electroconductive particle which has a conductive part on the surface at least; and a plurality of insulating particles arrange|positioned on the surface of the said electroconductive particle. In the electroconductive particle with insulating particle of this invention, the said insulating particle has a phosphorus atom on the surface. In the electroconductive particle with insulating particle of this invention, the said phosphorus atom coordinate-bonds with the said electroconductive part. In the conductive particle with insulating particle of this invention, since it has the said structure, when electrically connecting between electrodes, conduction reliability can be improved effectively, and insulation reliability can be improved effectively further.

The electroconductive particle with insulating particle of this invention is equipped with: electroconductive particle which has a conductive part on the surface at least; and a plurality of insulating particles arrange|positioned on the surface of the said electroconductive particle. In the electroconductive particle with insulating particle of this invention, the said insulating particle has a phosphorus atom on the surface. In the electroconductive particle with insulating particle of this invention, the said insulating particle contains the structure represented by said formula (1) or (2). In the above formulas (1) and (2), R1 and R2 each independently represent the following (a) or (b). (a) A saturated or unsaturated alkyl group having 1 to 10 carbon atoms, a substituent bonded to a saturated or unsaturated alkyl group having 1 to 10 carbon atoms, an alkoxy group, or an aryl group. (b) A saturated or unsaturated alkylene group having 1 to 10 carbon atoms, a substituent bonded to a saturated or unsaturated alkylene group having 1 to 10 carbon atoms, an alkylene group, or an aryl group. R1 and R2 may also be bonded to each other to form a ring together with the adjacent phosphorus atom in formula (1) or (2). In the above formula (1) or (2), the left end represents a bonding site. In the conductive particle with insulating particle of this invention, since it has the said structure, when electrically connecting between electrodes, conduction reliability can be improved effectively, and insulation reliability can be improved effectively further.

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

(conductive particles with insulating particles) The electroconductive particle with insulating particle of this invention is equipped with: electroconductive particle which has a conductive part on the surface at least; and a plurality of insulating particles arrange|positioned on the surface of the said electroconductive particle. In the electroconductive particle with insulating particle of this invention, the said insulating particle has a phosphorus atom on the surface. In the electroconductive particle with insulating particle of this invention, the said phosphorus atom coordinate-bonds with the said electroconductive part.

In the conductive particle with insulating particle of this invention, since it has the said structure, when electrically connecting between electrodes, conduction reliability can be improved effectively, and insulation reliability can be improved effectively further.

The electroconductive particle with insulating particle of this invention is equipped with: electroconductive particle which has a conductive part on the surface at least; and a plurality of insulating particles arrange|positioned on the surface of the said electroconductive particle. In the electroconductive particle with insulating particle of this invention, the said insulating particle has a phosphorus atom on the surface. In the electroconductive particle with insulating particle of this invention, the said insulating particle contains the structure represented by following formula (1) or (2).

[chemical 3]

In the above formula (1), R1 and R2 each independently represent the following (a) or (b). (a) A saturated or unsaturated alkyl group having 1 to 10 carbon atoms, a substituent bonded to a saturated or unsaturated alkyl group having 1 to 10 carbon atoms, an alkoxy group, or an aryl group. (b) A saturated or unsaturated alkylene group having 1 to 10 carbon atoms, a substituent bonded to a saturated or unsaturated alkylene group having 1 to 10 carbon atoms, an alkylene group, or an aryl group. R1 and R2 may also be bonded to each other to form a ring together with the adjacent phosphorus atom in formula (1). In the above formula (1), the left end represents a bonding site.

[chemical 4]

In the above formula (2), R1 and R2 each independently represent the following (a) or (b). (a) A saturated or unsaturated alkyl group having 1 to 10 carbon atoms, a substituent bonded to a saturated or unsaturated alkyl group having 1 to 10 carbon atoms, an alkoxy group, or an aryl group. (b) A saturated or unsaturated alkylene group having 1 to 10 carbon atoms, a substituent bonded to a saturated or unsaturated alkylene group having 1 to 10 carbon atoms, an alkylene group, or an aryl group. R1 and R2 may also be bonded to each other to form a ring together with the adjacent phosphorus atom in formula (2). In the above formula (2), the left end represents a bonding site.

In the conductive particle with insulating particle of this invention, since it has the said structure, when electrically connecting between electrodes, conduction reliability can be improved effectively, and insulation reliability can be improved effectively further.

In conventional conductive particles with insulating particles, when the conductive particles with insulating particles are mixed with a binder resin to produce an anisotropic conductive material, insulating particles may detach from the surface of the conductive particles.

In conventional conductive particles with insulating particles, in order to prevent the insulating particles from detaching from the surface of the conductive particles, phosphonium salts, phosphoric acid groups, etc. may be introduced into the surface of the insulating particles. However, when an acidic functional group such as a phosphoric acid group is introduced into the surface of insulating particles, the conductive portion on the surface of the conductive particle may be corroded. Due to the corrosion of the conductive portion on the surface of the conductive particles, it may be difficult to greatly improve the conduction reliability between the upper and lower electrodes to be connected when conducting a conductive connection using an anisotropic conductive material. Moreover, halogen elements, such as a chloride ion, may be contained in a phosphonium salt. If the anisotropic conductive material contains halogen elements such as chloride ions, ion migration may occur between electrodes, and it may be difficult to sufficiently improve the insulation reliability between electrodes that should not be connected and that are adjacent in the lateral direction.

The inventors of the present invention found that corrosion of the conductive portion on the surface of the conductive particles and ion migration between electrodes can be effectively prevented by using specific conductive particles with insulating particles. In the present invention, since the above configuration is provided, when electrically connecting electrodes, conduction reliability and insulation reliability can be more effectively improved.

Also, in the present invention, when the anisotropic conductive material is produced by mixing with a binder resin, the dispersibility of the conductive particles with insulating particles can be effectively improved, and aggregation of the conductive particles with insulating particles can be effectively prevented. As a result, the conduction reliability between the upper and lower electrodes to be connected can be effectively improved.

In this invention, in order to acquire the above-mentioned effect, using the electroconductive particle with specific insulating particle can exert a large effect.

The portion of the surface of the conductive portion covered with the insulating particles accounts for an area of the entire surface area of the conductive portion (hereinafter also referred to as “coverage rate”), preferably at least 20%, more preferably at least 40%, further preferably at least 50%, still more preferably at least 50%, and especially preferably at least 60%. The above coverage rate is preferably at most 95%, more preferably at most 90%, further preferably at most 80%, particularly preferably at most 70%. The said coverage rate may be 99% or less. Adjacent electroconductive particles are more difficult to contact as the said coverage is more than the said minimum. When the said coverage is below the said upper limit, the insulating particle between an electrode and electroconductive particle can fully be excluded, even if it does not apply heat and pressure more than necessary at the time of connection between electrodes.

The area of the surface of the conductive part covered with the insulating particles, that is, the coverage rate, is calculated as follows.

Conductive particles with insulating particles are observed from one direction with a scanning electron microscope (SEM), and calculated from the total area occupied by the insulating particles in the circle of the outer peripheral portion of the surface of the conductive portion in the total area of the area in the circle of the outer peripheral portion of the surface of the conductive portion in the observation image. The above-mentioned coverage is preferably calculated as an average coverage obtained by observing 20 conductive particles with insulating particles and averaging the measurement results of conductive particles with insulating particles.

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

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

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

The shape of the conductive particle with the said insulating particle is not specifically limited. The shape of the electroconductive particle with the said insulating particle may be spherical, a shape other than spherical, flat, etc. may be sufficient as it.

In the conductive particles with insulating particles of the present invention, the content of chloride ions is preferably at most 300 ppm, more preferably at most 60 ppm, and still more preferably at most 10 ppm. If the content of the above-mentioned chloride ions is below the above-mentioned upper limit, when the conductive particles with insulating particles are used to electrically connect electrodes, ion migration can be prevented more effectively, and insulation reliability can be improved more effectively.

The content of the above-mentioned chloride ions can be measured in the following manner.

10 g of distilled water and 1 g of conductive particles with insulating particles were added to a heat-resistant and pressure-resistant measurement container, and heated at 120°C, 2 atm, and 24 hours using a PCT (Pressure Cooker Test, pressure cooker test) device ("EHS-221M" manufactured by ESPEC). Thereafter, it was cooled to normal temperature, and conductive particles with insulating particles were removed by filtration to obtain an extract as a measurement sample. The amount of chloride ions was measured for the obtained extract using ion chromatography ("DIONEX ICS-2100" manufactured by Dionex Co., Ltd.), and the content of chloride ions was calculated per 1 g of conductive particles with insulating particles.

The above-mentioned conductive particles with insulating particles can be preferably dispersed in a binder resin to obtain a conductive material.

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

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

The electroconductive particle 1 with insulating particle shown in FIG. 1 is provided with the electroconductive particle 2; The insulating particles 3 are formed of an insulating material.

The electroconductive particle 2 has the electroconductive part 12 arrange|positioned on the surface of the base material particle 11 and the base material particle 11. In the electroconductive particle 1 with an insulating particle, the electroconductive part 12 is an electroconductive layer. The conductive part 12 covers the surface of the substrate particle 11 . The electroconductive particle 2 is a coated particle obtained by coating the surface of the substrate particle 11 with the electroconductive part 12 . The electroconductive particle 2 has the electroconductive part 12 on the surface. In the said electroconductive particle, the said electroconductive part may cover the whole surface of the said base material particle, and may make the said electroconductive part cover a part of the surface of the said base material particle. In the conductive particle with insulating particle mentioned above, it is preferable that the said insulating particle is arrange|positioned on the surface of the said conductive part.

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

The electroconductive particle 21 with insulating particle shown in FIG. 2 is provided with the electroconductive particle 22;

The electroconductive particle 22 has the base material particle 11 and the electroconductive part 31 arrange|positioned on the surface of the base material particle 11. In the electroconductive particle 21 with an insulating particle, the electroconductive part 31 is an electroconductive layer. The conductive particle 22 has a plurality of core substances 32 on the surface of the substrate particle 11 . The conductive part 31 covers the base material particle 11 and the core substance 32 . By coating the core substance 32 with the conductive part 31, the conductive particle 22 has a plurality of protrusions 33 on the surface. In the electroconductive particle 22, the surface of the electroconductive part 31 is raised by the core substance 32, and the several processus|protrusion 33 is formed. In the said electroconductive particle, the said electroconductive part may cover the whole surface of the said base material particle, and may make the said electroconductive part cover a part of the surface of the said base material particle. In the conductive particle with insulating particle mentioned above, it is preferable that the said insulating particle is arrange|positioned on the surface of the said conductive part.

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

The electroconductive particle 41 with insulating particle shown in FIG. 3 is equipped with the electroconductive particle 42;

The electroconductive particle 42 has the base material particle 11 and the electroconductive part 51 arrange|positioned on the surface of the base material particle 11. In the electroconductive particle 41 with an insulating particle, the electroconductive part 51 is an electroconductive layer. The electroconductive particle 42 does not have a core substance like the electroconductive particle 22 . The conductive part 51 has a 1st part and a 2nd part thicker than this 1st part. The conductive particle 42 has a plurality of protrusions 52 on the surface. The portion other than the plurality of protrusions 52 is the above-mentioned first portion of the conductive portion 51 . The plurality of protrusions 52 are the above-mentioned second part where the thickness of the conductive part 51 is relatively thick. In the said electroconductive particle, the said electroconductive part may cover the whole surface of the said base material particle, and may make the said electroconductive part cover a part of the surface of the said base material particle. In the conductive particle with insulating particle mentioned above, it is preferable that the said insulating particle is arrange|positioned on the surface of the said conductive part.

Hereinafter, other details of the electroconductive particle with insulating particle are demonstrated.

Conductive Particles: It is preferable that the said electroconductive particle has a base material particle, and the electroconductive part arrange|positioned on the surface of the said base material particle. The above-mentioned conductive portion may have a single-layer structure, or may have a multi-layer structure of two or more layers.

The particle size of the conductive particles is preferably 0.5 μm or more, more preferably 1 μm or more, and preferably 100 μm or less, more preferably 60 μm or less, further preferably 30 μm or less, further preferably 10 μm or less, and especially preferably 5 μm or less. If the particle size of the above-mentioned conductive particles is more than the above-mentioned lower limit and below the above-mentioned upper limit, when the above-mentioned conductive particles are used to connect electrodes, the contact area between the conductive particles and the electrodes is sufficiently large, and it is difficult to form agglomerated conductive particles when forming the conductive part. Moreover, the distance between the electrodes connected via the electroconductive particle does not become too large, and the electroconductive part becomes difficult to peel off from the surface of a base material particle.

The particle size of the above-mentioned conductive particles is preferably an average particle size, more preferably a number average particle size. The particle diameter of electroconductive particle can be calculated|required by observing arbitrary 50 electroconductive particles with an electron microscope or an optical microscope, calculating the average value of the particle diameter of each electroconductive particle, or performing a laser diffraction particle size distribution measurement, for example. In the observation with an electron microscope or an optical microscope, the particle diameter of each electroconductive particle was calculated|required as the particle diameter in circle-equivalent diameter. In observation with an electron microscope or an optical microscope, the average particle diameter in terms of circle equivalent diameter and the average particle diameter in terms of spherical equivalent diameter of arbitrary 50 electroconductive particles are substantially equal. In the laser diffraction particle size distribution measurement, the particle diameter of each conductive particle is obtained as a particle diameter in terms of spherical equivalent diameter. It is preferable to calculate the particle diameter of the said electroconductive particle by laser diffraction particle size distribution measurement.

The coefficient of variation (CV value) of the particle diameter of the said electroconductive particle becomes like this. Preferably it is 10% or less, More preferably, it is 5% or less. The conduction reliability and insulation reliability between electrodes can be improved more effectively that the coefficient of variation of the particle diameter of the said electroconductive particle is below the said upper limit.

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

CV value (%)=(ρ/Dn)×100 ρ: Standard deviation of particle size of conductive particles Dn: The average value of the particle diameter of conductive particles

The shape of the said electroconductive particle is not specifically limited. The shape of the said electroconductive particle may be spherical, a shape other than spherical, flat, etc. may be sufficient as it.

Substrate particles: Examples of the substrate particles include resin particles, inorganic particles other than metal particles, organic-inorganic hybrid particles, metal particles, and the like. The aforementioned substrate particles are preferably substrate particles other than metal particles, more preferably resin particles, inorganic particles other than metal particles, or organic-inorganic hybrid particles. The aforementioned substrate particle may also be a core-shell particle having a core and a shell arranged on the surface of the core. The aforementioned core may also be an organic core, and the aforementioned shell may also be an inorganic shell.

Various organic substances can be preferably used as the material of the above-mentioned resin particles. Examples of materials for the resin particles include polyolefin resins such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyisobutylene, and polybutadiene; acrylic resins such as polymethyl methacrylate and polymethyl acrylate; Unsaturated polyester resin, saturated polyester resin, polyethylene terephthalate, polyethylene, polyphenylene ether, polyacetal, polyimide, polyamideimide, polyether ether ketone, polyether ketone, divinylbenzene polymer, and divinylbenzene copolymer, etc. As said divinylbenzene type copolymer etc., a divinylbenzene-styrene copolymer, a divinylbenzene-(meth)acrylate copolymer, etc. are mentioned. Since the hardness of the resin particles can be easily controlled within a preferred range, the material of the resin particles is preferably a polymer obtained by polymerizing one or more polymerizable monomers having ethylenically unsaturated groups.

When polymerizing a polymerizable monomer having an ethylenically unsaturated group to obtain the aforementioned resin particles, examples of the polymerizable monomer having an ethylenically unsaturated group include non-crosslinkable monomers and crosslinkable monomers.

Examples of non-crosslinkable monomers include: styrene-based monomers such as styrene and α-methylstyrene; carboxyl-containing monomers such as (meth)acrylic acid, maleic acid, and maleic anhydride; methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, cetyl (meth)acrylate, stearyl (meth)acrylate, and cyclohexyl (meth)acrylate Alkyl (meth)acrylate compounds such as esters and iso-(meth)acrylate; oxygen-containing (meth)acrylate compounds such as 2-hydroxyethyl (meth)acrylate, glycerol (meth)acrylate, polyoxyethylene (meth)acrylate, and glycidyl (meth)acrylate; nitrile-containing monomers such as (meth)acrylonitrile; vinyl ether compounds such as methyl vinyl ether, ethyl vinyl ether, and propyl vinyl ether; vinyl acetate, vinyl butyrate, vinyl laurate, and vinyl stearate, etc. Vinyl ester compounds; unsaturated hydrocarbons such as ethylene, propylene, isoprene, and butadiene; halogen-containing monomers such as methyl trifluoro(meth)acrylate, ethyl pentafluoro(meth)acrylate, vinyl chloride, vinyl fluoride, and chlorostyrene, etc.

Examples of the crosslinkable monomer include tetramethylolmethane tetra(meth)acrylate, tetramethylolmethane tri(meth)acrylate, tetramethylolmethane di(meth)acrylate, trimethylolpropane tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol penta(meth)acrylate, glycerin tri(meth)acrylate, glycerin di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate ) acrylate, (poly)tetramethylene glycol di(meth)acrylate, and 1,4-butanediol di(meth)acrylate and other polyfunctional (meth)acrylate compounds; (iso)triallyl cyanurate, triallyl trimellitate, divinylbenzene, diallyl phthalate, diallyl acrylamide, diallyl ether, and γ-(meth)acryloxypropyltrimethoxysilane, trimethoxysilylstyrene, and vinyl Silane-containing monomers such as trimethoxysilane, etc.

The term "(meth)acrylate" means acrylate and methacrylate. The term "(meth)acrylic acid" means acrylic acid and methacrylic acid. The term "(meth)acryl" means acryl and methacryl.

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

When the above-mentioned substrate particles are inorganic particles other than metals or organic-inorganic hybrid particles, examples of inorganic substances used to form the substrate particles include silicon oxide, aluminum oxide, barium titanate, zirconium oxide, and carbon black. The above-mentioned inorganic substances are preferably not metals. The particles made of silicon oxide are not particularly limited, and examples thereof include particles obtained by hydrolyzing a silicon compound having two or more hydrolyzable alkoxysilyl groups to form crosslinked polymer particles, and then calcining as necessary. Examples of the above-mentioned organic-inorganic hybrid particles include organic-inorganic hybrid particles formed of a crosslinked alkoxysilyl polymer and an acrylic resin.

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

As a material of the said organic core, the material of the said resin particle etc. are mentioned.

Examples of the material of the inorganic shell include the inorganic substances listed as the material of the base particle. The material of the above-mentioned inorganic shell is preferably silicon oxide. The above-mentioned inorganic shell is preferably formed by a method of calcining the shell after forming a shell of a metal alkoxide on the surface of the above-mentioned core by a sol-gel method. The aforementioned metal alkoxide is preferably a silane alkoxide. The above-mentioned inorganic shell is preferably formed of silane alkoxide.

When the above-mentioned substrate particle is a metal particle, examples of the metal as a material of the metal particle include silver, copper, nickel, silicon, gold, and titanium.

The particle size of the substrate particles is preferably at least 0.5 μm, more preferably at least 1 μm, further preferably at least 2 μm, and preferably at most 100 μm, more preferably at most 60 μm, and even more preferably at most 50 μm. Even if the particle diameter of the said base material particle is more than the said minimum and below the said upper limit, the gap between electrodes will become small, and even if it thickens the thickness of a conductive layer, small electroconductive particle can be obtained. Furthermore, when forming an electroconductive part on the surface of a base material particle, it becomes difficult to aggregate, and it becomes difficult to form aggregated electroconductive particle.

The particle diameter of the above-mentioned substrate particles is preferably not less than 2 μm and not more than 50 μm. When the particle diameter of the said substrate particle is in the range of 2 micrometers - 50 micrometers, it becomes difficult to aggregate when forming a conductive part on the surface of a substrate particle, and it becomes difficult to form aggregated electroconductive particle.

The particle diameter of the above-mentioned substrate particles means the diameter when the substrate particles are true spherical, and represents the maximum diameter when the substrate particles are not true spherical.

The particle diameter of the above-mentioned substrate particles represents a number average particle diameter. The particle diameter of the above-mentioned substrate particles is determined using a particle size distribution measuring device or the like. The particle diameter of the substrate particles is preferably determined by observing arbitrary 50 substrate particles with an electron microscope or an optical microscope and calculating the average value. In observation with an electron microscope or an optical microscope, the particle diameter of each substrate particle is determined as a particle diameter in terms of circle-equivalent diameter. In observation with an electron microscope or an optical microscope, the average particle diameter in terms of circle equivalent diameter and the average particle diameter in terms of spherical equivalent diameter of arbitrary 50 substrate particles are substantially equal. In the particle size distribution measuring device, the particle diameter of each substrate particle is determined as a particle diameter in terms of spherical equivalent diameter. The particle diameter of the substrate particles is preferably calculated with a particle size distribution measuring device. In electroconductive particle, when measuring the particle diameter of the said base material particle, it can measure as follows, for example.

It was added to "Technovit 4000" manufactured by Kulzer Corporation so that the content of the conductive particles would be 30% by weight, and dispersed to prepare an embedding resin for conductive particle inspection. The cross section of the conductive particle was cut using an ion mill ("IM4000" manufactured by Hitachi High-Technologies Co., Ltd.) so as to pass through the vicinity of the center of the conductive particle in the embedded resin for inspection. Then, using a field emission type scanning electron microscope (FE-SEM), the image magnification was set to 25000 times, 50 electroconductive particles were randomly selected, and the base particle of each electroconductive particle was observed. The particle diameter of the substrate particle in each electroconductive particle was measured, and these were arithmetically averaged, and it was set as the particle diameter of a substrate particle.

Conductive part: In this invention, the said electroconductive particle has an electroconductive part in the surface at least. It is preferable that the said conductive part contains metal. The metal constituting the above-mentioned conductive portion is not particularly limited. Examples of the metal include gold, silver, copper, platinum, palladium, zinc, lead, aluminum, cobalt, indium, nickel, chromium, titanium, antimony, bismuth, germanium, and cadmium, and alloys thereof. Moreover, tin-doped indium oxide (ITO) can also be used as said metal. The said metal may use only 1 type, and may use 2 or more types together. From the viewpoint of further reducing connection resistance between electrodes, the above-mentioned metal is preferably an alloy containing tin, nickel, palladium, copper or gold, more preferably nickel or palladium.

Also, from the viewpoint of effectively improving conduction reliability, it is preferable that the conductive portion and the outer surface portion of the conductive portion contain nickel. The nickel content in 100% by weight of the conductive part containing nickel is preferably at least 10% by weight, more preferably at least 50% by weight, further preferably at least 60% by weight, further preferably at least 70% by weight, and most preferably at least 90% by weight. The content of nickel in 100% by weight of the conductive portion containing nickel may be 97% by weight or more, may be 97.5% by weight or more, or may be 98% by weight or more.

Furthermore, on the surface of the conductive part, hydroxyl groups are often present due to oxidation. In general, hydroxyl groups exist on the surface of the conductive part formed of nickel due to oxidation. Insulating particles can be arranged on the surface of the conductive part (surface of the conductive particle) having such a hydroxyl group through chemical bonding.

The said conductive part can be formed with 1 layer. The above-mentioned conductive part may also be formed by a plurality of layers. That is, the said electroconductive part may have the laminated structure of 2 or more layers. When the above-mentioned conductive portion is formed of a plurality of layers, the metal constituting the outermost layer is preferably gold, nickel, palladium, copper, or an alloy including tin and silver, more preferably gold. In the case where the metal constituting the outermost layer is such a preferable metal, the connection resistance between electrodes is further reduced. Also, when the metal constituting the outermost layer is gold, the corrosion resistance is further improved.

The method for forming the conductive portion on the surface of the substrate particle is not particularly limited. As the method of forming the above-mentioned conductive portion, for example, a method using electroless plating, a method using electroplating, a method using physical collision, a method using mechanochemical reaction, a method using physical vapor deposition or physical adsorption, and a method of applying metal powder or a paste containing metal powder and a binder to the surface of the substrate particle, etc. The method of forming the above-mentioned conductive portion is preferably a method utilizing electroless plating, electroplating or physical collision. As a method using the said physical vapor deposition, methods, such as vacuum vapor deposition, ion plating, and ion sputtering, are mentioned. In addition, in the above-mentioned method using physical collision, for example, theta composer (manufactured by Tokusu Works Co., Ltd.) or the like is used.

The thickness of the conductive portion is preferably at least 0.005 μm, more preferably at least 0.01 μm, more preferably at most 10 μm, more preferably at most 1 μm, and still more preferably at most 0.3 μm. Sufficient electroconductivity is acquired as the thickness of the said electroconductive part is more than the said minimum and below the said upper limit, and electroconductive particle does not become hard too much, and can fully deform electroconductive particle at the time of connection between electrodes.

When the aforementioned conductive portion is formed of a plurality of layers, the thickness of the outermost conductive portion is preferably at least 0.001 μm, more preferably at least 0.01 μm, and preferably at most 0.5 μm, more preferably at most 0.1 μm. When the thickness of the conductive part of the outermost layer is more than the above-mentioned lower limit and not more than the above-mentioned upper limit, the conductive part of the outermost layer becomes uniform, the corrosion resistance becomes sufficiently high, and the connection resistance between electrodes can be sufficiently reduced.

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

Core substance: It is preferable that the said electroconductive particle has several protrusions on the outer surface of the said conductive part. An oxide film is often formed on the surface of electrodes connected by conductive particles with insulating particles. In the case of using conductive particles with insulating particles having protrusions on the surface of the conductive part, the above-mentioned oxide film can be effectively removed by the protrusions by arranging and crimping the conductive particles with insulating particles between electrodes. Therefore, the electrodes and the conductive parts are in more reliable contact, and the connection resistance between the electrodes is further reduced. Furthermore, at the time of connection between electrodes, the protrusion of an electroconductive particle can effectively exclude the insulating particle between electroconductive particle and an electrode. Therefore, the conduction reliability between electrodes is further improved.

As a method of forming the above-mentioned protrusions, a method of forming a conductive portion by electroless plating after attaching a core substance to the surface of the base particle, and a method of forming a conductive portion by electroless plating after forming a conductive portion on the surface of the substrate particle by attaching a core substance, and the like. As another method of forming the above-mentioned protrusions, there may be mentioned: a method of disposing a core substance on the first conductive portion after forming the first conductive portion on the surface of the substrate particle, and then forming a second conductive portion; and a method of adding a core substance during the formation of the conductive portion (first conductive portion or second conductive portion, etc.) on the surface of the substrate particle. In addition, in order to form the protrusions, a method may be used in which, instead of using the above-mentioned core substance, after forming the conductive part by electroless plating on the substrate particles, the plating is deposited in the form of protrusions on the surface of the conductive part, and the conductive part is further formed by electroless plating.

As a method of attaching the core substance to the surface of the substrate particle, for example, a method of adding the core substance to the dispersion of the substrate particle, integrating and adhering the core substance to the surface of the substrate particle by Van der Waals force, and a method of adding the core substance to a container containing the substrate particle, and attaching the core substance to the surface of the substrate particle by mechanical action caused by rotation of the container, etc. From the viewpoint of controlling the amount of the adhered core substance, the method of attaching the core substance to the surface of the substrate particle is preferably a method of integrating and attaching the core substance to the surface of the substrate particle in the dispersion.

As a substance which comprises the said core substance, a conductive substance, a nonconductive substance, etc. are mentioned. Examples of the conductive substance include conductive nonmetals such as metals, metal oxides, and graphite, and conductive polymers. Polyacetylene etc. are mentioned as said electroconductive polymer. As said non-conductive substance, silicon oxide, aluminum oxide, zirconium oxide, etc. are mentioned. From the viewpoint of further improving conduction reliability between electrodes, the core material is preferably metal.

The aforementioned metals are not particularly limited. Examples of the aforementioned metals include metals such as gold, silver, copper, platinum, zinc, iron, lead, tin, aluminum, cobalt, indium, nickel, chromium, titanium, antimony, bismuth, germanium, and cadmium, and alloys composed of two or more metals such as tin-lead alloys, tin-copper alloys, tin-silver alloys, tin-lead-silver alloys, and tungsten carbide. From the viewpoint of further improving conduction reliability between electrodes, the above-mentioned metal is preferably nickel, copper, silver or gold. The said metal may be the same as the metal which comprises the said conductive part (conductive layer), and may differ.

The shape of the above-mentioned core substance is not particularly limited. The shape of the core substance is preferably block. Examples of the core substance include granular lumps, aggregated lumps in which a plurality of fine particles are aggregated, amorphous lumps, and the like.

The average diameter (average particle diameter) of the core substance is preferably at least 0.001 μm, more preferably at least 0.05 μm, and preferably at most 0.9 μm, more preferably at most 0.2 μm. The connection resistance between electrodes can be effectively reduced as the average diameter of the said core substance is more than the said minimum and below the said upper limit.

The average particle diameter of the above-mentioned core substance is preferably a number average particle diameter. The average particle diameter of the core substance can be obtained, for example, by observing arbitrary 50 core substances with an electron microscope or an optical microscope, calculating the average value of the particle diameter of each core substance, or performing a laser diffraction particle size distribution measurement. In observation with an electron microscope or an optical microscope, the particle diameter of each core substance is determined as a particle diameter in terms of circle-equivalent diameter. In observation with an electron microscope or an optical microscope, the average particle diameter in terms of circle equivalent diameter and the average particle diameter in terms of spherical equivalent diameter of arbitrary 50 core substances are substantially equal. In the laser diffraction particle size distribution measurement, the particle diameter of each core substance is determined as a particle diameter in terms of spherical equivalent diameter. The average particle diameter of the above-mentioned core substance is preferably calculated by laser diffraction particle size distribution measurement.

Insulating particles: The electroconductive particle with insulating particle of this invention is equipped with the some insulating particle arrange|positioned on the surface of the said electroconductive particle. In this case, if the electroconductive particle with the said insulating particle is used for connection between electrodes, the short circuit between adjacent electrodes can be prevented. Specifically, when a plurality of conductive particles with insulating particles are in contact, since the insulating particles exist between a plurality of electrodes, it is possible to prevent a short circuit not between upper and lower electrodes but between laterally adjacent electrodes. Furthermore, at the time of connection between electrodes, by pressurizing the electroconductive particle with insulating particle with two electrodes, the insulating particle between the electroconductive part of electroconductive particle and an electrode can be easily excluded. Furthermore, in the case of the electroconductive particle which has several protrusions on the outer surface of an electroconductive part, the insulating particle between the electroconductive part of electroconductive particle and an electrode can be excluded more easily.

The material of the above-mentioned insulating particles is not particularly limited. As a material of the said insulating particle, the inorganic substance etc. which were mentioned as the material of the said resin particle and the material of the said base material particle are mentioned. The material of the above-mentioned insulating particles is preferably the material of the above-mentioned resin particles. The insulating particles are preferably the resin particles or the organic-inorganic hybrid particles, and may be resin particles or organic-inorganic hybrid particles.

Examples of other materials for the insulating particles include polyolefin compounds, (meth)acrylate polymers, (meth)acrylate copolymers, block polymers, thermoplastic resins, cross-linked thermoplastic resins, thermosetting resins, and water-soluble resins. The material of the said insulating particle may use only 1 type, and may use 2 or more types together.

As said polyolefin compound, polyethylene, an ethylene-vinyl acetate copolymer, an ethylene-acrylate copolymer, etc. are mentioned. As said (meth)acrylate polymer, polymethyl (meth)acrylate, polylauryl (meth)acrylate, polystearyl (meth)acrylate, etc. are mentioned. Examples of the above-mentioned block polymers include polystyrene, styrene-acrylate copolymers, SB-type styrene-butadiene block copolymers, SBS-type styrene-butadiene block copolymers, and hydrogenated products thereof. As said thermoplastic resin, a vinyl polymer, a vinyl copolymer, etc. are mentioned. As said thermosetting resin, an epoxy resin, a phenol resin, a melamine resin, etc. are mentioned. Examples of the cross-linked product of the thermoplastic resin include introduction of polyethylene glycol methacrylate, alkoxylated trimethylolpropane methacrylate, or alkoxylated pentaerythritol methacrylate. Examples of the water-soluble resin include polyvinyl alcohol, polyacrylic acid, polyacrylamide, polyvinylpyrrolidone, polyethylene oxide, and methylcellulose. In addition, a chain transfer agent can also be used for adjustment of the degree of polymerization. As a chain transfer agent, a mercaptan, carbon tetrachloride, etc. are mentioned.

In the electroconductive particle with insulating particle of this invention, the said insulating particle has a phosphorus atom on the surface. Examples of methods for introducing phosphorus atoms to the surface of the above-mentioned insulating particles include: a method of surface-treating insulating particles with a compound containing phosphorus atoms; From the viewpoint of efficiently introducing phosphorus atoms to the surface of the insulating particles, the method of introducing phosphorus atoms to the surface of the insulating particles is preferably a method of making the material of the insulating particles contain a compound containing phosphorus atoms when producing the insulating particles.

The compound containing the above-mentioned phosphorus atom is not particularly limited. It is preferable that the above-mentioned compound containing a phosphorus atom reacts with the material of the above-mentioned insulating particles. The above-mentioned compound containing a phosphorus atom preferably has an ethylenically unsaturated double bond, and preferably has a (meth)acryloyl group, a (meth)acryloyloxy group, or a vinyl group. The above-mentioned compound containing a phosphorus atom preferably has a (meth)acryloxy group or a vinyl group.

Examples of the above compound containing a phosphorus atom include: p-styryl diethylphosphine, p-styryl dibutylphosphine, p-styryl dioctyl phosphine, p-styryl diphenylphosphine, di-tert-butyl (2-butenyl) phosphine, di-tert-butyl (3-methyl-2-butenyl) phosphine, 2-acryloyl ethyl diethyl phosphine, 2-methacryl ethyl diethyl phosphine, 2-acryloyl ethyl dibutyl phosphine, 2-methyl acryl Acryloylethyldibutylphosphine, 2-acryloylethyldioctylphosphine, 2-methacryloylethyldioctylphosphine, 2-acryloylethyldiphenylphosphine, 2-methacryloylethyldiphenylphosphine, (acryloyloxymethyl)phosphonic acid dimethyl ester, (methacryloyloxymethyl)phosphonic acid dimethyl ester, (methacryloyloxymethyl)phosphonic acid diethyl ester, (methacryloyloxymethyl)phosphonic acid diethyl Ethyl ester, diphenyl (acryloxymethyl)phosphonate, diphenyl (methacryloxymethyl)phosphonate, (acryloxymethyl)diphenylphosphine oxide, (methacryloxymethyl)diphenylphosphine oxide, 10-(acryloxymethyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, and 10-(methacryloxymethyl)-9,10-dihydro-9-oxa- 10-phosphaphenanthrene-10-oxide, etc.

From the viewpoint of efficiently introducing phosphorus atoms to the surface of the insulating particles, the material of the insulating particles is preferably a polymerizable monomer having an ethylenically unsaturated group that reacts with the compound containing the phosphorus atoms. The material of the above-mentioned insulating particles is preferably the material of the above-mentioned resin particles.

In the electroconductive particle with insulating particle of this invention, the said phosphorus atom coordinate-bonds with the said electroconductive part. When the said phosphorus atom coordinate-bonds with the said electroconductive part, it can prevent insulating particle|grains from detaching from the surface of electroconductive particle more effectively. In order to make the said phosphorus atom coordinate-bond with the said electroconductive part, it is preferable that the compound which has the said phosphorus atom is the following compound. Preferable compounds having a phosphorus atom include p-styryl diethylphosphine, p-styryl dibutylphosphine, 2-acrylethyl diethylphosphine, 2-methacrylylethyl diethylphosphine, 2-acrylylethyl dibutylphosphine, 2-methacrylylethyl dibutylphosphine, (acryloxymethyl)phosphonic acid dimethyl ester, (methacrylyloxymethyl)phosphonic acid dimethyl ester, (methacrylyloxymethyl)phosphonic acid dimethyl ester, (acyloxymethyl)phosphonic acid diethyl ester, (methacryloxymethyl)phosphonic acid diethyl ester, etc. By using the above-mentioned preferable compound having a phosphorus atom, the above-mentioned phosphorus atom and the above-mentioned conductive portion can be easily coordinated and bonded.

Moreover, it is preferable that the said phosphorus atom and the said electroconductive part are not ionically bonded. In the conductive particles with insulating particles in which the phosphorus atoms are ionically bonded to the conductive portion, ionic impurities may be generated, making it difficult to improve ion migration between electrodes or insulation reliability. If the above-mentioned phosphorus atoms and the above-mentioned conductive parts satisfy the above-mentioned preferred aspects, when the conductive particles with insulating particles are used to electrically connect the electrodes, ion migration can be more effectively prevented from occurring, and the insulation reliability can be more effectively improved.

In the electroconductive particle with insulating particle of this invention, the said insulating particle contains the structure represented by following formula (1) or (2). The insulating particles may contain only the structure represented by the following formula (1), may contain only the structure represented by the following formula (2), or may contain both the structure represented by the following formula (1) and the structure represented by the following formula (2).

[chemical 5]

In the above formula (1), R1 and R2 each independently represent the following (a) or (b). (a) A saturated or unsaturated alkyl group having 1 to 10 carbon atoms, a substituent bonded to a saturated or unsaturated alkyl group having 1 to 10 carbon atoms, an alkoxy group, or an aryl group. (b) A saturated or unsaturated alkylene group having 1 to 10 carbon atoms, a substituent bonded to a saturated or unsaturated alkylene group having 1 to 10 carbon atoms, an alkylene group, or an aryl group. R1 and R2 may also be bonded to each other to form a ring together with the adjacent phosphorus atom in formula (1). In the above formula (1), the left end represents a bonding site.

When R1 and R2 are not bonded to each other but form a ring with the adjacent phosphorus atom in the formula (1), in the above formula (1), R1 and R2 independently represent a saturated or unsaturated alkyl group with 1 to 10 carbon atoms, a substituent bonded to a saturated or unsaturated alkyl group with 1 to 10 carbon atoms, an alkoxy group, or an aryl group. When R1 and R2 are bonded to each other to form a ring together with the adjacent phosphorus atom in the formula (1), in the above formula (1), R1 and R2 independently represent a saturated or unsaturated alkylene group with 1 to 10 carbon atoms, a substituent bonded to a saturated or unsaturated alkylene group with 1 to 10 carbon atoms, an alkyleneoxy group, or an arylylene group.

[chemical 6]

In the above formula (2), R1 and R2 each independently represent the following (a) or (b). (a) A saturated or unsaturated alkyl group having 1 to 10 carbon atoms, a substituent bonded to a saturated or unsaturated alkyl group having 1 to 10 carbon atoms, an alkoxy group, or an aryl group. (b) A saturated or unsaturated alkylene group having 1 to 10 carbon atoms, a substituent bonded to a saturated or unsaturated alkylene group having 1 to 10 carbon atoms, an alkylene group, or an aryl group. R1 and R2 may also be bonded to each other to form a ring together with the adjacent phosphorus atom in formula (2). In the above formula (2), the left end represents a bonding site.

When R1 and R2 are not bonded to each other but form a ring with the adjacent phosphorus atom in the formula (1), in the above formula (1), R1 and R2 independently represent a saturated or unsaturated alkyl group with 1 to 10 carbon atoms, a substituent bonded to a saturated or unsaturated alkyl group with 1 to 10 carbon atoms, an alkoxy group, or an aryl group. When R1 and R2 are bonded to each other to form a ring together with the adjacent phosphorus atom in the formula (1), in the above formula (1), R1 and R2 independently represent a saturated or unsaturated alkylene group with 1 to 10 carbon atoms, a substituent bonded to a saturated or unsaturated alkylene group with 1 to 10 carbon atoms, an alkyleneoxy group, or an arylylene group.

Examples of the substituent in the group having a substituent bonded to the saturated or unsaturated alkyl group having 1 to 10 carbon atoms include a halogen atom and the like. Examples of the substituent in the group having a substituent bonded to the saturated or unsaturated C 1-10 alkylene group include a halogen atom and the like.

The bonding sites in the above formulas (1) and (2) are preferably bonding sites with the insulating particles. The structure of the above-mentioned bonding site is not particularly limited.

As a method of introducing the structure represented by the above-mentioned formula (1) or (2) into the above-mentioned insulating particles, there may be mentioned: a method of surface-treating the insulating particles with a compound having the structure represented by the above-mentioned formula (1) or (2); and a method of making the material of the insulating particles contain the compound having the structure represented by the above-mentioned formula (1) or (2) when producing the insulating particles. From the viewpoint of efficiently introducing phosphorus atoms to the surface of the insulating particles, the method of introducing phosphorus atoms to the surface of the insulating particles is preferably a method in which the material of the insulating particles contains a compound having the structure represented by the above formula (1) or (2) when producing the insulating particles.

The compound having the structure represented by the above formula (1) or (2) is not particularly limited. It is preferable that the compound which has the structure represented by said formula (1) or (2) reacts with the material of the said insulating particle. The compound having the structure represented by the above formula (1) or (2) preferably has an ethylenically unsaturated double bond, and preferably has a (meth)acryl group, (meth)acryloxy group, or vinyl group. The compound having the structure represented by the above formula (1) or (2) preferably has a (meth)acryloxy group or a vinyl group.

Examples of compounds having a structure represented by the above formula (1) include: p-styryl diethylphosphine, p-styryl dibutylphosphine, p-styryl dioctyl phosphine, p-styryl diphenyl phosphine, di-tert-butyl (2-butenyl) phosphine, di-tert-butyl (3-methyl-2-butenyl) phosphine, 2-acryloylethyl diethylphosphine, 2-methacryloylethyl diethylphosphine, 2-acryloylethyl dibutyl Phosphine, 2-methacrylethyldibutylphosphine, 2-acrylethyldioctylphosphine, 2-methacrylethyldioctylphosphine, 2-acrylethyldiphenylphosphine, and 2-methacrylethyldiphenylphosphine, etc.

As a compound having a structure represented by the above formula (2), dimethyl (acryloxymethyl)phosphonate, dimethyl (methacryloxymethyl)phosphonate, diethyl (acryloxymethyl)phosphonate, diethyl (methacryloxymethyl)phosphonate, diphenyl (acryloxymethyl)phosphonate, diphenyl (methacryloxymethyl)phosphonate, (acryloxymethyl)diphenylphosphine oxide, (methacryloxymethyl)diphenylphosphonate, Acyloxymethyl)diphenylphosphine oxide, 10-(acryloxymethyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, and 10-(methacryloxymethyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, etc.

From the viewpoint of efficiently introducing phosphorus atoms to the surface of the insulating particles, the material of the insulating particles is preferably a polymerizable monomer having an ethylenically unsaturated group that reacts with a compound having a structure represented by the above formula (1) or (2). The material of the above-mentioned insulating particles is preferably the material of the above-mentioned resin particles.

It is preferable that the said insulating particle does not have the halogen group directly bonded to the said phosphorus atom. When the insulating particles have a halogen group directly bonded to the phosphorus atom, impurities derived from the halogen group may be generated, and it may be difficult to improve ion migration between electrodes or insulation reliability. If the above-mentioned insulating particles satisfy the above-mentioned preferable aspect, when the conductive particles with insulating particles are used to electrically connect electrodes, ion migration can be prevented more effectively, and insulation reliability can be improved more effectively.

The glass transition temperature of the insulating particles is preferably at least 40°C, more preferably at least 50°C, and preferably at most 110°C, more preferably at most 100°C. When the glass transition temperature of the said insulating particle is more than the said minimum and below the said upper limit, insulating particle can be softened by heating, and the contact area of electroconductive particle and insulating particle can be enlarged. As a result, detachment of insulating particles from the surface of conductive particles can be prevented more effectively.

As a method of arranging the said insulating particle on the surface of the said electroconductive part, a chemical method, and a physical or mechanical method etc. are mentioned. As said chemical method, the interfacial polymerization method, the suspension polymerization method in particle presence, and the emulsion polymerization method etc. are mentioned, for example. Examples of the above-mentioned physical or mechanical methods include spray drying, mixing, electrostatic adhesion, spraying, immersion, and methods using vacuum deposition. The method of arranging the insulating particles on the surface of the conductive part through chemical bonding is preferable from the point that the insulating particles are not easy to detach.

The outer surface of the conductive part and the outer surface of the insulating particle may be coated with a compound having a reactive functional group, respectively. The outer surface of the conductive portion and the outer surface of the insulating particle may not be chemically bonded directly, but may be chemically bonded indirectly via a compound having a reactive functional group. After the carboxyl group is introduced into the outer surface of the conductive part, the carboxyl group may be chemically bonded to the functional group on the outer surface of the insulating particle via a polymer electrolyte such as polyethyleneimine.

The particle diameter of the said insulating particle can be suitably selected according to the particle diameter of the said electroconductive particle with an insulating particle, the use of the said electroconductive particle with an insulating particle, etc. The particle size of the above-mentioned insulating particles is preferably at least 10 nm, more preferably at least 100 nm, further preferably at least 200 nm, especially preferably at least 300 nm, and preferably at most 4000 nm, more preferably at most 2000 nm, further preferably at most 1500 nm, especially preferably at most 1000 nm. When the particle diameter of the said insulating particle is more than the said minimum, when disperse|distributing the said conductive particle with insulating particle in a binder resin, the conductive part among several said conductive particle with insulating particle is hard to contact. If the particle size of the insulating particles is below the upper limit, it is not necessary to increase the pressure too much or to heat to a high temperature in order to remove the insulating particles between the electrodes and the conductive particles during the connection between the electrodes.

The particle diameter of the said insulating particle represents a number average particle diameter. The particle diameter of the said insulating particle is calculated|required using a particle size distribution measuring apparatus etc. The particle size of the insulating particles is preferably obtained by observing arbitrary 50 insulating particles with an electron microscope or an optical microscope, and calculating an average value. In observation with an electron microscope or an optical microscope, the particle diameter of each insulating particle is calculated|required as the particle diameter in circle-equivalent diameter. In observation with an electron microscope or an optical microscope, the average particle diameter in terms of circle equivalent diameter and the average particle diameter in terms of spherical equivalent diameter of arbitrary 50 insulating particles are substantially equal. In the particle size distribution measuring device, the particle diameter of each insulating particle is obtained as a particle diameter in terms of spherical equivalent diameter. The particle size of the insulating particles is preferably calculated with a particle size distribution measuring device. In the electroconductive particle with the said insulating particle, when measuring the particle diameter of the said insulating particle, it can measure as follows, for example.

Conductive particles with insulating particles were added to "Technovit 4000" manufactured by Kulzer Corporation so that the content would be 30% by weight, and dispersed to prepare an embedding resin for conductive particle inspection. The cross section of the conductive particles with insulating particles was cut using an ion mill ("IM4000" manufactured by Hitachi High-Technologies Co., Ltd.) so as to pass through the vicinity of the center of the conductive particles with insulating particles dispersed in the embedding resin for inspection. Then, using a field emission scanning electron microscope (FE-SEM), set the image magnification to 50,000 times, randomly select 50 conductive particles with insulating particles, and observe the insulating particles of each conductive particle with insulating particles. The particle diameters of the insulating particles among the conductive particles with insulating particles were measured, and the arithmetic mean was taken as the particle diameter of the insulating particles.

The electroconductive particle with insulating particle of this invention can also use together the insulating particle of 2 or more types from which a particle diameter differs. By using together two or more types of insulating particles with different particle diameters, the insulating particles with smaller particle diameters enter the gaps covered with the insulating particles with larger particle diameters, so that the above-mentioned coverage can be improved more effectively. When two or more types of insulating particles having different particle sizes are used in combination, the insulating particles preferably include first insulating particles having a particle size of 0.1 μm or more and less than 0.25 μm, and second insulating particles having a particle size of 0.25 μm or more and 0.8 μm or less. It is preferable that the particle size distribution of the first insulating particles does not overlap with the particle size distribution of the second insulating particles. It is preferable that the average particle diameter of the said 1st insulating particle is different from the average particle diameter of the said 2nd insulating particle.

The coefficient of variation (CV value) of the particle diameter of the insulating particles is preferably 20% or less. If the coefficient of variation of the particle diameter of the insulating particles is below the above upper limit, the thickness of the insulating particles of the obtained conductive particles with insulating particles becomes more uniform, and uniform pressure can be more easily applied during conductive connection, and the connection resistance between electrodes can be further reduced.

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

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

The shape of the above-mentioned insulating particles is not particularly limited. The shape of the said insulating particle may be spherical, a shape other than spherical, flat, etc. may be sufficient as it.

(conductive material) The conductive material of the present invention includes the above-mentioned conductive particles with insulating particles and a binder resin. It is preferable to disperse|distribute and use the said electroconductive particle with insulating particle|grains in a binder resin, and it is preferable to disperse|distribute and use it as a conductive material in a binder resin. The above-mentioned conductive material is preferably an anisotropic conductive material. The above-mentioned conductive material is preferably used for electrical connection between electrodes. The above-mentioned conductive material is preferably a conductive material for circuit connection. In the above-mentioned conductive material, since the above-mentioned conductive particles with insulating particles are used, it is possible to prevent the insulating particles from unintended detachment from the surface of the conductive particles with insulating particles before the conductive particles with insulating particles are dispersed in a binder resin or the like, and the insulation reliability between electrodes can be further improved.

The above-mentioned binder resin is not particularly limited. As the binder resin, known insulating resins can be used. The above-mentioned binder resin preferably contains a thermoplastic component (thermoplastic compound) or a curable component, and more preferably contains a curable component. As said curable component, a photocurable component and a thermosetting component are mentioned. It is preferable that the said photocurable component contains a photocurable compound and a photoinitiator. The above-mentioned thermosetting component preferably contains a thermosetting compound and a thermosetting agent.

Examples of the binder resin include vinyl resins, thermoplastic resins, curable resins, thermoplastic block copolymers, elastomers, and the like. The said binder resin may use only 1 type, and may use 2 or more types together.

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

In addition to the above-mentioned conductive particles with insulating particles and the above-mentioned binder resin, the above-mentioned conductive material may also contain various additives such as fillers, extenders, softeners, plasticizers, polymerization catalysts, hardening catalysts, colorants, antioxidants, heat stabilizers, light stabilizers, ultraviolet absorbers, lubricants, antistatic agents, and flame retardants.

As a method for dispersing the conductive particles with insulating particles in the binder resin, a conventionally known dispersion method can be used, and it is not particularly limited. As a method of dispersing the electroconductive particle with the said insulating particle in the said binder resin, the following method etc. are mentioned, for example. A method of kneading and dispersing the above-mentioned conductive particles with insulating particles to the above-mentioned binder resin, using a planetary mixer or the like. A method in which the conductive particles with insulating particles are uniformly dispersed in water or an organic solvent using a homogenizer, etc., then added to the binder resin, and kneaded with a planetary mixer to disperse them. A method in which the above-mentioned binder resin is diluted with water or an organic solvent, and then the above-mentioned conductive particles with insulating particles are added, kneaded and dispersed by a planetary mixer or the like.

The viscosity (η25) at 25° C. of the conductive material is preferably 30 Pa·s or more, more preferably 50 Pa·s or more, and preferably 400 Pa·s or less, more preferably 300 Pa·s or less. When the viscosity at 25° C. of the conductive material is more than the above-mentioned lower limit and below the above-mentioned upper limit, the insulation reliability between electrodes can be improved more effectively, and the conduction reliability between electrodes can be improved more effectively. The above-mentioned viscosity (η25) can be appropriately adjusted by the type and amount of the compounded ingredients.

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

The conductive material of the present invention can be used in the form of conductive paste, conductive film, and the like. When the conductive material of the present invention is a conductive film, a film not containing conductive particles may be laminated on a conductive film containing conductive particles. The above-mentioned conductive paste is preferably anisotropic conductive paste. The above-mentioned conductive film is preferably an anisotropic conductive film.

In 100% by weight of the conductive material, the content of the binder resin is preferably at least 10% by weight, more preferably at least 30% by weight, further preferably at least 50% by weight, especially preferably at least 70% by weight, and is preferably at most 99.99% by weight, more preferably at most 99.9% by weight. When content of the said binder resin is more than the said minimum and below the said upper limit, electroconductive particle can be efficiently arrange|positioned between electrodes, and the connection reliability of the connection object member connected by a conductive material can be further improved.

In 100% by weight of the conductive material, the content of the conductive particles with insulating particles is preferably at least 0.01% by weight, more preferably at least 0.1% by weight, and is preferably at most 80% by weight, more preferably at most 60% by weight, further preferably at most 40% by weight, especially preferably at most 20% by weight, and most preferably at most 10% by weight. The conduction reliability and insulation reliability between electrodes can be further improved that content of the electroconductive particle with the said insulating particle is more than the said minimum and below the said upper limit.

(connection structure) The bonded structure of the present invention includes: a first connection object member having a first electrode on its surface; a second connection object member having a second electrode on its surface; and a connection portion connecting the first connection object member to the second connection object member. In the connection structure of this invention, the material of the said connection part is the said conductive particle with insulating particle, or the conductive material containing the said conductive particle with insulating particle and binder resin. In the connection structure of this invention, the said 1st electrode and the said 2nd electrode are electrically connected by the said electroconductive part in the said electroconductive particle with insulating particle.

The bonded structure can be obtained through the steps of disposing the conductive particles with insulating particles or the conductive material between the first member to be connected and the second member to be connected, and conducting conductive connection by thermocompression bonding. It is preferable that the said insulating particle is detached from the said electroconductive particle with insulating particle at the time of the said thermocompression bonding.

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

The connection structure 81 shown in FIG. 4 is equipped with the 1st connection object member 82, the 2nd connection object member 83, and the connection part 84 which connects the 1st connection object member 82 and the 2nd connection object member 83. The connection portion 84 is formed of a conductive material including the conductive particles 1 with insulating particles. The connection part 84 is preferably formed by hardening the conductive material including the conductive particles 1 with insulating particles. In addition, in FIG. 4, the electroconductive particle 1 with an insulating particle is shown schematically for convenience. It is also possible to use not only the electroconductive particle 1 with an insulating particle but also the electroconductive particle 21 or 41 with an insulating particle.

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

The manufacturing method of the said bonded structure is not specifically limited. As an example of the method of manufacturing the bonded structure, a method of arranging the above-mentioned conductive material between the first member to be connected and the second member to be connected to obtain a laminate, and then heating and pressing the laminate, etc. are mentioned. The pressure of the thermocompression bonding is preferably at least 40 MPa, more preferably at least 60 MPa, and is preferably at most 90 MPa, more preferably at most 70 MPa. The heating temperature for the thermocompression bonding is preferably 80°C or higher, more preferably 100°C or higher, and preferably 140°C or lower, more preferably 120°C or lower. If the pressure and temperature of the above-mentioned thermocompression bonding are above the above-mentioned lower limit and below the above-mentioned upper limit, the insulating particles can be easily detached from the surface of the conductive particles with insulating particles during conductive connection, and the conduction reliability between electrodes can be further improved.

When heating and pressurizing the said laminated body, the said insulating particle which exists between the said electroconductive particle and the said 1st electrode, and the said 2nd electrode can be excluded. For example, during the heating and pressurization, the insulating particles present between the conductive particles, the first electrode, and the second electrode are easily detached from the surface of the conductive particle with insulating particles. In addition, at the time of the said heating and pressurization, a part of said insulating particle|grains detaches from the surface of the said electroconductive particle with insulating particle, and the surface of the said electroconductive part may be exposed partially. When the exposed portion of the surface of the conductive portion contacts the first electrode and the second electrode, the first electrode and the second electrode can be electrically connected via the conductive particles.

The said 1st connection object member and the 2nd connection object member are not specifically limited. Specific examples of the first connection object member and the second connection object member include electronic components such as semiconductor wafers, semiconductor packages, LED (Light Emitting Diode) chips, LED packages, capacitors, and diodes, and electronic components such as circuit boards such as resin films, printed circuit boards, flexible printed circuit boards, flexible flat cables, rigid flexible substrates, glass epoxy substrates, and glass substrates. It is preferable that the said 1st connection object member and the 2nd connection object member are electronic components.

Examples of electrodes provided on the member to be connected include metal electrodes such as gold electrodes, nickel electrodes, tin electrodes, aluminum electrodes, copper electrodes, molybdenum electrodes, silver electrodes, SUS (stainless steel) electrodes, and tungsten electrodes. When the above-mentioned member to be connected is a flexible printed circuit board, the above-mentioned electrode is preferably a gold electrode, a nickel electrode, a tin electrode, a silver electrode or a copper electrode. When the member to be connected is a glass substrate, the electrode is preferably an aluminum electrode, a copper electrode, a molybdenum electrode, a silver electrode, or a tungsten electrode. Furthermore, when the above-mentioned electrode is an aluminum electrode, it may be an electrode formed only of aluminum, or an electrode formed by laminating an aluminum layer on the surface of a metal oxide layer. Examples of the material for the metal oxide layer include indium oxide doped with a trivalent metal element, zinc oxide doped with a trivalent metal element, and the like. As said trivalent metal element, Sn, Al, Ga, etc. are mentioned.

Hereinafter, an Example and a comparative example are given, and this invention is demonstrated concretely. The present invention is not limited to the following examples.

(Example 1) (1) Production of conductive particles Resin particles having a particle diameter of 3 μm and comprising a copolymer resin of tetramethylolmethane tetraacrylate and divinylbenzene were prepared. After dispersing 10 parts by weight of the substrate particles into 100 parts by weight of an alkali solution containing a 5% by weight palladium catalyst solution using an ultrasonic disperser, the solution was filtered to extract the substrate particles. Next, the substrate particles were added to 100 parts by weight of a 1% by weight solution of dimethylamine borane to activate the surface of the substrate particles. After sufficiently washing the surface-activated substrate particles with water, 500 parts by weight of distilled water was added and dispersed to obtain a dispersion. Next, 1 g of nickel particle slurry (average particle diameter: 100 nm) was added to the above-mentioned dispersion over 3 minutes to obtain a suspension containing substrate particles to which the core substance was attached.

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

While stirring the obtained suspension at 60° C., the nickel plating solution was slowly added dropwise to the suspension to perform electroless nickel plating. Thereafter, the particles were extracted by filtering the suspension, washed with water and dried to form a nickel-nickel boron conductive layer (thickness 0.15 μm) on the surface of the substrate particles, thereby obtaining conductive particles with conductive parts on the surface.

(2) Production of insulating particles Into a 1000 ml separable flask equipped with a four-mouth separable lid, a stirring blade, a three-way cock, a cooling tube, and a temperature probe, after adding the following monomer composition, distilled water was added so that the solid content of the following monomer composition became 10% by weight, stirred at 200 rpm, and polymerized at 60° C. for 24 hours under a nitrogen atmosphere. The above monomer composition comprises: 360 mmol of methyl methacrylate, 45 mmol of glycidyl methacrylate, 20 mmol of p-styryl diethylphosphine, 13 mmol of ethylene glycol dimethacrylate, 0.5 mmol of polyvinylpyrrolidone, and 1 mmol of 2,2'-azobis{2-[N-(2-carboxyethyl)amidino]propane}. After the reaction, freeze-drying was performed to obtain insulating particles (particle diameter: 360 nm) having phosphorus atoms derived from p-styryldiethylphosphine on the surface.

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

(4) Production of conductive materials (anisotropic conductive paste) 7 parts by weight of conductive particles with insulating particles, 25 parts by weight of bisphenol A-type phenoxy resin, 4 parts by weight of fennel-type epoxy resin, 30 parts by weight of phenolic novolac-type epoxy resin, and SI-60L (manufactured by Sanshin Chemical Industry Co., Ltd.) were prepared, and defoaming and stirring were performed for 3 minutes to obtain a conductive material (anisotropic conductive paste).

(5) Fabrication of connection structure Prepare a transparent glass substrate with an IZO (Indium Zinc Oxide, Indium Zinc Oxide) electrode pattern (the first electrode, the metal on the electrode surface having a Vickers hardness of 100 Hv) with an L/S of 10 μm/10 μm formed on the upper surface. Also, a semiconductor wafer with an Au electrode pattern (second electrode, Vickers hardness of the metal on the electrode surface: 50 Hv) formed on the lower surface with an L/S of 10 μm/10 μm was prepared.

The obtained anisotropic conductive paste was applied so that the thickness may become 30 micrometers on the said transparent glass substrate, and the anisotropic conductive paste layer was formed. Next, the above-mentioned semiconductor wafer is laminated on the anisotropic conductive paste layer so that the electrodes face each other. Thereafter, while adjusting the temperature of the head so that the temperature of the anisotropic conductive paste layer becomes 100°C, a pressurized heating head was placed on the upper surface of the semiconductor wafer, and a pressure of 60 MPa was applied to harden the anisotropic conductive paste layer at 100°C to obtain a bonded structure.

(Example 2) When producing conductive particles, a palladium plating solution (pH 8) containing 0.4 mol/L of palladium sulfate, 1 mol/L of ethylenediamine, 0.6 mol/L of sodium formate, and 0.03 mol/L of sodium gluconate was prepared. Electroless palladium plating was performed using the prepared palladium plating solution to form a palladium conductive layer (thickness: 0.15 μm) on the surface of the substrate particle, thereby obtaining conductive particles having a conductive portion on the surface. Moreover, except having used the electroconductive particle obtained, it carried out similarly to Example 1, and obtained the electroconductive particle with insulating particle, an insulating particle, a conductive material, and bonded structure.

(Example 3) When producing insulating particles, p-styryldiethylphosphine was changed to 2-methacryloylethyldibutylphosphine. Except the above-mentioned change, it carried out similarly to Example 1, and obtained the electroconductive particle, the electroconductive particle with an insulating particle, a conductive material, and a bonded structure.

(Example 4) When producing conductive particles, a palladium plating solution (pH 8) containing 0.4 mol/L of palladium sulfate, 1 mol/L of ethylenediamine, 0.6 mol/L of sodium formate, and 0.03 mol/L of sodium gluconate was prepared. Electroless palladium plating was performed using the prepared palladium plating solution to form a palladium conductive layer (thickness: 0.15 μm) on the surface of the substrate particle, thereby obtaining conductive particles having a conductive portion on the surface. Except having used the obtained electroconductive particle, it carried out similarly to Example 3, and obtained the electroconductive particle with insulating particle, an insulating particle, a conductive material, and bonded structure.

(Example 5) When producing insulating particles, p-styryldiethylphosphine was changed to (methacryloxymethyl)phosphonic acid diphenyl ester. Except the above-mentioned change, it carried out similarly to Example 1, and obtained the electroconductive particle, the electroconductive particle with an insulating particle, a conductive material, and a bonded structure.

(Example 6) When producing conductive particles, a palladium plating solution (pH 8) containing 0.4 mol/L of palladium sulfate, 1 mol/L of ethylenediamine, 0.6 mol/L of sodium formate, and 0.03 mol/L of sodium gluconate was prepared. Electroless palladium plating was performed using the prepared palladium plating solution to form a palladium conductive layer (thickness: 0.15 μm) on the surface of the substrate particle, thereby obtaining conductive particles having a conductive portion on the surface. Except having used the obtained electroconductive particle, it carried out similarly to Example 5, and obtained the electroconductive particle with insulating particle, an insulating particle, a conductive material, and bonded structure.

(Example 7) When producing insulating particles, p-styryldiethylphosphine was changed to 2-methacryloylethyldioctylphosphine. Except the above-mentioned change, it carried out similarly to Example 1, and obtained the electroconductive particle, the electroconductive particle with an insulating particle, a conductive material, and a bonded structure.

(Embodiment 8) When producing conductive particles, a palladium plating solution (pH 8) containing 0.4 mol/L of palladium sulfate, 1 mol/L of ethylenediamine, 0.6 mol/L of sodium formate, and 0.03 mol/L of sodium gluconate was prepared. Electroless palladium plating was performed using the prepared palladium plating solution to form a palladium conductive layer (thickness: 0.15 μm) on the surface of the substrate particle, thereby obtaining conductive particles having a conductive portion on the surface. Except having used the obtained electroconductive particle, it carried out similarly to Example 7, and obtained insulating particle, the electroconductive particle with insulating particle, a conductive material, and bonded structure.

(comparative example 1) When producing insulating particles, p-styryldiethylphosphine was changed to (4-vinylbenzyl)triethylphosphonium chloride. Except the above-mentioned change, it carried out similarly to Example 1, and obtained the electroconductive particle, the electroconductive particle with an insulating particle, a conductive material, and a bonded structure.

(comparative example 2) When producing insulating particles, the monomer composition was changed as follows. The above-mentioned monomer composition includes: 380 mmol of methyl methacrylate, 45 mmol of glycidyl methacrylate, 13 mmol of ethylene glycol dimethacrylate, 0.5 mmol of acid phosphatoxypolyoxyethylene glycol methacrylate, and 1 mmol of 2,2'-azobis{2-[N-(2-carboxyethyl)amidino]propane}. Except the above-mentioned change, it carried out similarly to Example 1, and obtained the electroconductive particle, the electroconductive particle with an insulating particle, a conductive material, and a bonded structure.

(comparative example 3) When producing insulating particles, p-styryldiethylphosphine was changed to 2-methacryloylethyldi(dodecyl)phosphine. Except the above-mentioned change, it carried out similarly to Example 1, and obtained the electroconductive particle, the electroconductive particle with an insulating particle, a conductive material, and a bonded structure.

(Evaluate) (1) Coverage (the area of the surface of the conductive part covered with insulating particles to the total surface area of the conductive part) For the obtained conductive particles with insulating particles, the conductive particles with insulating particles were observed from one direction with a scanning electron microscope (SEM), and the total area inside the circle (area 1) of the outer peripheral portion of the surface of the conductive portion in the observation image and the total area of the insulating particles in the circle of the outer peripheral portion of the conductive portion (area 2) were calculated. From the obtained area 1 and area 2, the said coverage rate was calculated. The above-mentioned coverage rate was calculated as an average coverage rate obtained by observing 20 conductive particles with insulating particles and averaging the measurement results of the conductive particles with insulating particles.

(2) Adhesion of insulating particles The adhesiveness of the insulating particles was evaluated as follows. Adhesiveness of the insulating particles was judged by the following criteria.

Evaluation method for the adhesion of insulating particles: Immediately after production, 50 conductive particles with insulating particles were observed using a scanning electron microscope (SEM). Moreover, after the electroconductive particle dispersion liquid with insulating particle was prepared using the obtained electrically-conductive material, arbitrary 50 electroconductive particle with insulating particle was also observed using SEM. Based on the observation results obtained by SEM, the number of coated insulating particles in conductive particles with insulating particles immediately after production was compared with the number of coated insulating particles in conductive particles with insulating particles after the dispersion liquid was adjusted. In addition, in SEM observation, let the total number of the insulating particle|grains observed be the number of coatings.

[Criteria for judging the adhesion of insulating particles] ○○○: The ratio of the number of coated insulating particles in conductive particles with insulating particles after dispersion adjustment to the number of covered insulating particles in conductive particles with insulating particles immediately after production is 90% or more ○○: The ratio of the number of coated insulating particles in conductive particles with insulating particles after dispersion adjustment to the number of covered insulating particles in conductive particles with insulating particles immediately after production is 70% or more and less than 90% ○: The ratio of the number of coated insulating particles in conductive particles with insulating particles after dispersion adjustment to the number of covered insulating particles in conductive particles with insulating particles immediately after production is 50% or more and less than 70% ×: The ratio of the number of coated insulating particles in conductive particles with insulating particles after dispersion adjustment to the number of covered insulating particles in conductive particles with insulating particles immediately after production is less than 50%

(3) Dispersion (dispersibility of conductive particles with insulating particles) The obtained conductive material (anisotropic conductive paste) was observed to confirm whether or not aggregated conductive particles with insulating particles were generated. The dispersibility of the conductive particle with insulating particle was judged by the following criteria.

[Criteria for judging the dispersion of conductive particles with insulating particles] ○○: Conductive particles with insulating particles without aggregation ○: Conductive particles with insulating particles with a little aggregation (no problem in actual use) ×: Agglomerated conductive particles with insulating particles

(4) Chloride ion content (chloride ion content of conductive particles with insulating particles) 1 g of the obtained conductive particles with insulating particles was weighed, put together with 10 g of distilled water into a heat-resistant and pressure-resistant container, and heated at 120°C, 2 atm, and 24 hours using a PCT device ("EHS-221M" manufactured by ESPEC). Thereafter, it was cooled to normal temperature, and conductive particles with insulating particles were removed by filtration to obtain an extract as a measurement sample. For the obtained extract, the amount of chloride ions was measured using ion chromatography ("DIONEX ICS-2100" manufactured by Dionex Corporation), etc., and the content of chloride ions was calculated per 1 g of conductive particles with insulating particles.

(5) Conduction reliability (between upper and lower electrodes) The connection resistances between the upper and lower electrodes of the obtained 20 connection structures were respectively measured by the four-terminal method. Furthermore, according to the relationship of voltage=current×resistance, the connection resistance can be obtained by measuring the voltage when a certain current flows. Conduction reliability was judged according to the following criteria.

[Criteria for judging conduction reliability] ○○○: The connection resistance is 1.5 Ω or less ○○: The connection resistance exceeds 1.5 Ω and is 2.0 Ω or less ○: The connection resistance exceeds 2.0 Ω and is 5.0 Ω or less △: The connection resistance exceeds 5.0 Ω and is 10 Ω or less ×: Connection resistance exceeds 10 Ω

(6) Insulation reliability (between electrodes adjacent in the lateral direction) In the above (5) evaluation of conduction reliability, for the 20 connection structures obtained, the presence or absence of leakage between adjacent electrodes was evaluated by measuring the resistance value with a testing machine. Insulation reliability was evaluated with the following criteria.

[Criteria for judging insulation reliability] ○○○: The number of connection structures with a resistance value of 10 ⁸ Ω or more is 20 ○○: The number of connection structures with a resistance value of 10 ⁸ Ω or more is 18 or more and less than 20 ○: The number of connection structures with a resistance value of 10 ⁸ Ω or more is 15 or more and less than 18 △: The number of connection structures with a resistance value of 10 ⁸ Ω or more is 10 or more and less than 15 ×: The number of connection structures with a resistance value of 10 ⁸ Ω or more is 5 or more and less than 10 ××: The number of connection structures with a resistance value of 10 ⁸ Ω or more is less than 5

(7) Migration In the above (6) evaluation of insulation reliability, a migration test was performed on the 20 bonded structures obtained (placed under conditions of temperature 60°C, humidity 90%, and application of 20 V for 2000 hours). Measure the resistance value between adjacent electrodes after the migration test. Migration was judged by the following criteria.

[Criteria for judging migration] 〇: Resistance value is 10 ⁸ Ω or more ×: Resistance value is less than 10 ⁸ Ω

The results are shown in Table 1 below.

[Table 1]

1‧‧‧Conductive particles with insulating particles 2‧‧‧Conductive particles 3‧‧‧Insulating particles 11‧‧‧Substrate particles 12‧‧‧conductive part 21‧‧‧Conductive particles with insulating particles 22‧‧‧Conductive particles 31‧‧‧conductive part 32‧‧‧core substance 33‧‧‧Protrusion 41‧‧‧Conductive particles with insulating particles 42‧‧‧Conductive particles 51‧‧‧Conductive part 52‧‧‧Protrusion 81‧‧‧connection structure 82‧‧‧The first connection object component 82a‧‧‧First electrode 83‧‧‧The second connection object component 83a‧‧‧Second electrode 84‧‧‧Connection

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

Claims (9)

A conductive particle with insulating particles, comprising: a conductive particle having at least a conductive portion on its surface; and a plurality of insulating particles arranged on the surface of the conductive particle; and the insulating particle has a phosphorus atom on the surface, and the insulating particle includes a structure represented by the following formula (1) or (2);

In the above formula (1), R1 and R2 independently represent a saturated alkyl group with 1-10 carbons, a substituent-bonded base, alkoxy group, or aryl group on a saturated alkyl group with 1-10 carbons, or are independently bonded to each other to form a ring with the adjacent phosphorus atom in the formula (1), and represent a saturated alkylene group with 1-10 carbons, a substituent group, alkoxyl group, or aryl group that is bonded to a saturated alkylene group with 1-10 carbons; In (1), the left end represents the bonding site;

In the above formula (2), R1 and R2 independently represent a saturated alkyl group with 1-10 carbons, a substituent-bonded base, an alkoxy group, or an aryl group on a saturated alkyl group with a carbon number 1-10, or independently bond to each other to form a ring with the adjacent phosphorus atom in the formula (2), and represent a saturated alkylene group with 1-10 carbons, a substituent group, an alkoxyl group, or an aryl group that is bonded to a saturated alkylene group with 1-10 carbons; In (2), the left end portion represents a bonding site. Conductive particles with insulating particles according to claim 1, wherein the conductive part contains nickel or palladium. The conductive particles with insulating particles according to claim 1 or 2, wherein the content of chloride ions is 300ppm or less. The conductive particle with insulating particles according to claim 1 or 2, wherein the glass transition temperature of the insulating particles is not less than 40°C and not more than 110°C. The conductive particle with insulating particle according to claim 1 or 2, wherein the phosphorus atom is not ionically bonded to the conductive part. The conductive particle with insulating particle according to claim 1 or 2, wherein the insulating particle does not have a halogen group directly bonded to the phosphorus atom. The conductive particles with insulating particles according to Claim 1 or 2, wherein the particle diameter of the above-mentioned conductive particles is not less than 1 μm and not more than 5 μm. A conductive material comprising conductive particles with insulating particles according to any one of claims 1 to 7, and a binder resin. A connection structure, which has: The first connection object member has a first electrode on its surface; the second connection object member has a second electrode on its surface; and a connection part, which connects the first connection object member to the second connection object member; and the material of the above connection part is conductive particles with insulating particles according to any one of claims 1 to 7, or a conductive material including the conductive particles with insulating particles and a binder resin. The first electrode and the second electrode are electrically connected through the conductive part of the conductive particles with insulating particles. .