TW202236310A - Conductive particle, socket, conductive material, and connecting structural body in which the conductive particle can maintain high connection reliability even if it is compressed for a long time - Google Patents

Abstract

The present invention provides a conductive particle that can maintain high connection reliability even if it is compressed for a long time. The conductive particle according to the present invention includes a base particle and a conductive portion arranged on the surface of the base particle. After the conductive particle is held for 168 hours in a state of 20% compression, the compression recovery rate will be 85% or more.

Description

Conductive particle, socket, conductive material and connection structure

The present invention relates to a conductive particle having a conductive part disposed on the surface of a substrate particle. Also, the present invention relates to a socket, a conductive material, and a connection structure using the above-mentioned conductive particles.

Anisotropic conductive materials such as anisotropic conductive paste and anisotropic conductive film are widely known. In the aforementioned anisotropic conductive material, conductive particles are dispersed in the binder.

The above-mentioned anisotropic conductive material is used to electrically connect the electrodes of various connection object components such as flexible printed circuit board (FPC), glass substrate, glass epoxy substrate and semiconductor chip to obtain a connection structure. Moreover, the electroconductive particle which has a substrate particle and the electroconductive part arrange|positioned on the surface of this substrate particle may be used as said electroconductive particle.

In recent years, with the development of IOT (Internet of Things, Internet of Things), 5G communication (5th Generation Mobile Communication, fifth generation mobile communication), VR (Virtual Reality, virtual reality), AR (Augmented Reality, augmented reality) The market expansion of , artificial intelligence, and automatic driving systems, etc., the increase in the amount of information or the increase in communication speed, thus requires further increase in information processing speed for processors such as data services, PCs (personal computers, computers), and mobile terminals.

As a method of high-speed processing of large-capacity information, for example, a method of increasing the processing capability of a CPU (Central Processing Unit, central processing unit), etc. can be mentioned. In order to improve the processing capability of the CPU, the metal terminals (metal pins) of the socket (CPU socket) connecting the CPU and the motherboard are continuously promoted to have more pins and narrow pitches.

An example of a socket using metal terminals (metal pins) is disclosed in Patent Document 1 below. In the following patent document 1, there is disclosed a socket for electronic parts, which is interposed between electronic parts such as semiconductor elements or semiconductor devices and a mounting board, and the electronic parts are detachably mounted, and the electronic parts are electrically connected to the mounting board. connect. In the above-mentioned socket for electronic components, the connection terminal is provided on the mounting surface side of the socket body made of resin. The connecting terminal is formed by covering the outer surface of the resin bump with a conductive film, and the resin bump is arranged integrally with the socket body and protrudes from the socket body. In the electronic component socket described above, the connection terminal is provided such that its base end is bonded to the inner surface of the conductor film, and the base end side is embedded in the resin bump and the socket body to be sealed. The connecting terminal is formed by extending the head end in a curved shape from the side opposite to the mounting surface of the socket body. [Prior Art Literature] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open No. 2003-297507

[Problem to be solved by the invention]

For conventional sockets such as those described in Patent Document 1, it is difficult to process fine metal terminals (metal pins) to cope with further multi-pins and narrower pitches. In addition, miniaturization of metal terminals (metal pins) reduces the strength of metal terminals (metal pins), and when CPUs are connected, etc., metal terminals (metal pins) may be broken or bent, which may cause connection bad. For sockets using the previous metal terminals (metal pins), it is difficult to cope with further multi-pins and narrow pitches, and it is difficult to achieve an increase in information processing speed.

The object of this invention is to provide the electroconductive particle which can maintain high connection reliability even if it is compressed for a long time. Moreover, the object of this invention is to provide the electrically-conductive material and connection structure using the said electroconductive particle. [Technical means to solve the problem]

The inventors of the present invention earnestly studied the above-mentioned problems, and as a result, found that the above-mentioned problems can be solved by using specific conductive particles instead of metal terminals (metal pins).

According to a broad aspect of the present invention, there is provided a conductive particle comprising a substrate particle and a conductive portion arranged on the surface of the substrate particle, and the conductive particle is kept in a state compressed by 20% for 168 hours. The post-compression recovery rate is over 85%.

In a specific aspect of the conductive particle of the present invention, the conductive part has a first conductive layer, the material of the first conductive layer includes a ductile metal, and the particle size of the conductive particle is smaller than that of the first conductive layer. The thickness ratio is 50 to 1000.

In a specific aspect of the conductive particles of the present invention, the compressive deformation rate when the conductive particles are compressed with a load of 1000 mN is 10% or more.

In a specific aspect of the conductive particles of the present invention, after the substrate particles are loaded to 1961 mN at a loading speed of 14.12 mN/s, and then unloaded at an unloading speed of 14.12 mN/s, the compression during loading is The ratio of the compression displacement when the load is 500 mN to the compression displacement when the compression load is 500 mN when unloading is 0.7 or more, and the compression displacement when the compression load is 1000 mN is 1000 when the compression load is 1000 mN when it is unloaded The compression displacement ratio at mN is 0.7 or more.

In a specific aspect of the conductive particle of the present invention, the material of the above-mentioned substrate particle includes polyfunctional (meth)acrylate having a polyether skeleton, and in 100% by weight of the material of the above-mentioned substrate particle, the above-mentioned polyfunctional (meth)acrylate The content of the polyfunctional (meth)acrylate of the ether skeleton is 5% by weight or more.

In a specific aspect of the electroconductive particle of this invention, the particle diameter of the said electroconductive particle is 100 micrometers or more and 1000 micrometers or less.

In a specific aspect of the conductive particle of the present invention, the above-mentioned conductive part has a laminated structure of two or more layers, and the material of the outer surface of the above-mentioned conductive part is gold, silver, copper, tin, zinc, nickel, beryllium, cobalt , palladium, platinum, rhodium, ruthenium, iridium, or their alloys.

In a specific aspect of the conductive particle of the present invention, the above-mentioned conductive particle is used to obtain a socket or a connector.

According to a broad aspect of the present invention, there is provided a socket including a socket body and the above-mentioned conductive particles, and the above-mentioned conductive particles constitute connection terminals.

According to a broad aspect of the present invention, a conductive material is provided, which includes the above-mentioned conductive particles, and a binder.

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 an insulating member and conductive particles. In the connection part, the above-mentioned conductive particles are the above-mentioned conductive particles, and the above-mentioned first electrode and the above-mentioned second electrode are electrically connected by the above-mentioned conductive particles. [Effect of Invention]

The electroconductive particle of this invention is provided with the electroconductive part arrange|positioned on the surface of the base material particle and the said base material particle. The conductive particles of the present invention have a compression recovery rate of 85% or more after the conductive particles are compressed by 20% and kept for 168 hours. Since the electroconductive particle of this invention has the said structure, even if it is compressed for a long time, it can maintain high connection reliability.

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

(conductive particle) The electroconductive particle of this invention is provided with the electroconductive part arrange|positioned on the surface of the base material particle and the said base material particle. The conductive particles of the present invention have a compression recovery rate of 85% or more after the conductive particles are compressed by 20% and kept for 168 hours.

Since the electroconductive particle of this invention has the said structure, even if it is compressed for a long time, it can maintain high connection reliability.

In addition, when using conductive particles instead of metal terminals (metal pins), the previous conductive particles only considered temporarily improving the connection reliability, but did not consider maintaining the height after being subjected to a compressive load for a long time (for example, about a week). Connection reliability. When conventional conductive particles are used instead of metal terminals (metal pins), there is a problem that connection reliability decreases when a compressive load is applied for a long time (for example, about one week).

The inventors of the present invention have studied the above-mentioned problems intensively, and as a result, found that when the conventional conductive particles are used to connect the structure and receive a compressive load for a long time from the member to be connected, etc., the conductive particles may be damaged. Possibility of maintaining deformation and insufficient recovery of shape after unloading. That is, after the connection structure using the conventional electroconductive particle is used for a long time (compression of electroconductive particle), conduction failure may generate|occur|produce at the next connection.

On the other hand, since the electroconductive particle of this invention has the said structure, even if it is compressed for a long time, it can maintain high connection reliability. In the present invention, the use of specific conductive particles is very helpful to obtain the above-mentioned effects.

The compression recovery rate after compressing the conductive particles by 20% for 168 hours was over 85%. The compression recovery rate after the conductive particles are compressed by 20% for 168 hours is preferably at least 90%, more preferably at least 95%, further preferably at least 97%, most preferably at least 100%. When the compression recovery rate after keeping the conductive particles compressed by 20% for 168 hours is more than the above lower limit, the conductive particles are less likely to be damaged for a long time. As a result, even if the electroconductive particle is compressed for a long time, it is possible to maintain high connection reliability more effectively.

The compression recovery rate after compressing the above-mentioned conductive particles by 20% for 168 hours can be measured by the following compression test A.

＜Compression Test A＞ Conductive particles are dispersed on the surface of the first slide glass, and the second slide glass is further laminated to obtain a laminate. Next, the laminate was sandwiched by a micrometer, and a load was applied at 25° C. until the particle size of the conductive particles was compressed and deformed by 20%. After keeping the conductive particles compressed by 20% for 168 hours, take out the conductive particles, observe the conductive particles with an electron microscope or an optical microscope, and measure the particle diameter of the conductive particles. The compression recovery rate after holding|maintaining for 168 hours in the state which compressed the said electroconductive particle by 20% was calculated|required from the following formula. Furthermore, it is preferable to measure arbitrary 50 electroconductive particles, and calculate the average value of the particle diameter of electroconductive particle. The particle size of the conductive particles before the compression test A is the particle size of the conductive particles before compression in the compression direction during subsequent compression. The particle diameter of the electroconductive particle after compression test A is the particle diameter of the electroconductive particle after compression in the compression direction. Moreover, the particle diameter of the electroconductive particle after compression test A is the particle diameter measured 30 minutes after taking out electroconductive particle. As said micrometer, "MDC-25PXT" by Mitutoyo Corporation etc. are mentioned, for example. The particle size of the conductive particles before and after the compression test A can be measured by, for example, the diameter measurement function of the software attached to the optical microscope. As said optical microscope, "Digital Microscope VHX series" by Keyence Corporation etc. are mentioned.

Compression recovery rate (%) = (H2/H1) × 100 H1: Particle size of conductive particles before compression test A H2: Particle size of conductive particles after compression test A

Also, from the viewpoint of improving initial connection reliability, the compression recovery rate (compression recovery rate measured without maintaining the compressed state) of the above-mentioned conductive particles when compressed by 20% is preferably 90% or more, more preferably 95% Above, more preferably above 97%, most preferably 100%.

The compression recovery rate (the compression recovery rate measured in the state without maintaining compression) when the above-mentioned conductive particles are compressed by 20% can be measured by the following compression test B.

＜Compression test B＞ In the above-mentioned compression test A, after holding the conductive particles under 20% compression for 5 minutes, the conductive particles were taken out, and the conductive particles were observed with an electron microscope or an optical microscope to measure the particle diameter of the conductive particles. The compression recovery rate (compression recovery rate measured without maintaining the compressed state) when the above-mentioned conductive particles were compressed by 20% was obtained from the following formula. Furthermore, it is preferable to measure arbitrary 50 electroconductive particles, and calculate the average value of the particle diameter of electroconductive particle. The particle size of the conductive particles before the compression test B is the particle size of the conductive particles before compression in the compression direction during subsequent compression. The particle diameter of the electroconductive particle after compression test B is the particle diameter of the electroconductive particle after compression in the compression direction. Moreover, the particle diameter of the electroconductive particle after compression test B is the particle diameter measured 30 minutes after taking out electroconductive particle.

Compression recovery rate (%) = (J2/J1) × 100 J1: Particle size of conductive particles before compression test B J2: Particle size of conductive particles after compression test B

The compression set ratio when the conductive particles are compressed with a load of 1000 mN is preferably at least 10%, more preferably at least 15%, further preferably at least 20%, preferably at most 50%, more preferably at most 45% , and more preferably 40% or less. When the compression set rate when the said electroconductive particle is compressed by the load of 1000 mN is more than the said minimum and below the said upper limit, electroconductive particle is hard to be damaged for a long time. As a result, even if the electroconductive particle is compressed for a long time, it is possible to maintain high connection reliability more effectively. In addition, the said compression set rate shows the ratio (%) of the particle diameter of the compression direction after the compression of the said electroconductive particle with respect to the particle diameter before the compression of the said electroconductive particle.

The compressive elastic modulus (10% K value) of the above-mentioned conductive particles when compressed by 10% is preferably at least 10 N/mm ² , more preferably at least 50 N/mm ² , more preferably at most 1000 N/mm ² , more preferably 500 N/mm ² or less. When the above-mentioned 10% K value is not less than the above-mentioned lower limit and not more than the above-mentioned upper limit, initial connection reliability can be improved.

The compressive elastic modulus (20% K value) of the conductive particles when compressed by 20% is preferably at least 10 N/mm ² , more preferably at least 50 N/mm ² , more preferably at most 1000 N/mm ² , and more preferably 500 N/mm ² or less. When the above-mentioned 20% K value is not less than the above-mentioned lower limit and not more than the above-mentioned upper limit, initial connection reliability can be improved.

The said compression modulus (10%K value and 20%K value) of the said electroconductive particle can be measured as follows.

Using a micro-compression testing machine, use a cylinder (diameter 2 mm, made of stainless steel and BeCu/Au) with a smooth indenter end face to compress a conductive tube under the conditions of 25°C, compression speed 0.3 mN/s, and maximum test load 20 mN. sex particles. Measure the load value (N) and compression displacement (mm) at this time. The compressive modulus of elasticity can be obtained from the obtained measured value by the following formula. As the micro-compression tester, for example, "4000 Plus Bondtester" manufactured by Nordson Co., Ltd. is used.

10% K value or 20% K value (N/mm ² )＝(3/2 ^1/2 )・F・S ^-3/2・R ^-1/2 F: 10% or 20% compression deformation of conductive particles Load value at time (N) S: Compression displacement of conductive particles when compression deformation is 10% or 20% (mm) R: Radius of conductive particles (mm)

The above compressive modulus generally and quantitatively represents the hardness of the conductive particles. By using the said compression modulus, the hardness of electroconductive particle can be expressed quantitatively and without ambiguity.

The resistance value (R1) of the above-mentioned conductive particles in a state where the above-mentioned conductive particles are compressed by 20% is preferably 0.1 mΩ or more, more preferably 1 mΩ or more, preferably 100 mΩ or less, more preferably 50 mΩ or less, and further Preferably it is 25 mΩ or less, particularly preferably 20 mΩ or less. Initial connection reliability can be improved as the said resistance value (R1) is more than the said minimum and below the said upper limit.

The resistance value (R2) of the conductive particles after the conductive particles are compressed by 20% for 168 hours is preferably at least 0.1 mΩ, more preferably at least 1 mΩ, more preferably at most 100 mΩ, and more preferably at least 100 mΩ. 50 mΩ or less, more preferably 25 mΩ or less, particularly preferably 20 mΩ or less. When the said resistance value (R2) is more than the said minimum and below the said upper limit, even if electroconductive particle is compressed for a long time, high connection reliability can be maintained more effectively.

The said resistance value (R1) and the said resistance value (R2) can be measured as follows.

Using a micro-compression testing machine, apply a load along the center of the conductive particles at 25°C with a smooth indenter end face of a cylinder (2 mm in diameter, made of stainless steel plus BeCu/Au) until the conductive particles compress and deform by 20%. The on-resistance was measured in the state where the conductive particles were compressed by 20%, and it was set as the resistance value (R1). Moreover, the conduction resistance after holding|maintaining for 168 hours in the state which compressed electroconductive particle by 20% was measured, and it was set as resistance value (R2). "4000Plus Bondtester" manufactured by Nordson Co., Ltd. was used as the above-mentioned micro-compression tester.

The particle diameter of the above-mentioned conductive particles is preferably at least 100 μm, more preferably at least 150 μm, further preferably at least 300 μm, more preferably at most 1000 μm, more preferably at most 800 μm, further preferably at most 700 μm . The effect of this invention can be exhibited more effectively as the particle diameter of the said electroconductive particle is more than the said minimum and below the said upper limit. Also, conductive particles are suitable for obtaining sockets or connectors.

The particle diameter of the above-mentioned conductive particles is preferably an average particle diameter, and is preferably a number average particle diameter. The particle diameter of the said electroconductive particle is obtained, for example 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 using a particle size distribution measuring apparatus. When observing with an electron microscope or an optical microscope, the particle diameter of each electroconductive particle is calculated|required as the particle diameter of a circular equivalent diameter. When observed with an electron microscope or an optical microscope, the average particle diameter of 50 arbitrary electroconductive particles in terms of circle equivalent diameter and the average particle diameter of spherical equivalent diameter are almost equal. In the particle size distribution measuring device, the particle diameter of each conductive particle is calculated as the particle diameter in spherical equivalent diameter. It is preferable to calculate the average particle diameter of the said electroconductive particle using the particle size distribution measuring apparatus.

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 contact area of electroconductive particle and an electrode can be fully enlarged as the coefficient of variation of the particle diameter of the said electroconductive particle is below the said upper limit.

The said 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 above-mentioned conductive particles may be spherical, or other than spherical, and may also be rectangular, columnar, flat, and other shapes.

Hereinafter, the present invention will be specifically described with reference to the drawings.

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

The electroconductive particle 1 shown in FIG. 1 has the base material particle 2, and the electroconductive part 3. As shown in FIG. The conductive part 3 is arranged on the surface of the substrate particle 2 . In the electroconductive particle 1, the electroconductive part 3 and the surface of the base material particle 2 are in contact. The conductive particle 1 is a coated particle in which the surface of the substrate particle 2 is covered with the conductive part 3 .

In the conductive particle 1, the conductive part 3 is a single-layer conductive layer. In the said electroconductive particle, the said electroconductive part may cover the whole surface of the said base material particle, and the said conductive part may cover a part of the surface of the said base material particle. In the said electroconductive particle, the said electroconductive part may be a single-layer electroconductive layer, and may be a multilayer electroconductive layer containing two or more layers.

The electroconductive particle 1 does not have a core substance unlike the electroconductive particle 11 mentioned later. The electroconductive particle 1 does not have a protrusion on the surface. The electroconductive particle 1 is spherical. The conductive portion 3 has no protrusions on the outer surface. Thus, the electroconductive particle of this invention may not have a processus|protrusion on the surface of an electroconductive part, and may be spherical.

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

The electroconductive particle 11 shown in FIG. 2 has the base material particle 2, the electroconductive part 12, and the several core substance 13. As shown in FIG. The conductive part 12 is arranged on the surface of the substrate particle 2 so as to be in contact with the substrate particle 2 .

In the conductive particle 11, the conductive part 12 is a single-layer conductive layer. In the said electroconductive particle, the said electroconductive part may cover the whole surface of the said base material particle, and the said conductive part may cover a part of the surface of the said base material particle. In the said electroconductive particle, the said electroconductive part may be a single-layer electroconductive layer, and may be a multilayer electroconductive layer containing two or more layers.

The conductive particle 11 has a plurality of protrusions 11a on the surface of the conductive part. The conductive part 12 has a plurality of protrusions 12a on the outer surface. A plurality of core substances 13 are arranged on the surface of the substrate particle 2 . A plurality of core substances 13 are embedded in the conductive portion 12 . The core material 13 is arranged inside the protrusions 11a, 12a. The conductive part 12 is covered with a plurality of core substances 13 . The outer surface of the conductive part 12 is raised by a plurality of core materials 13, and protrusions 11a, 12a are formed.

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

The electroconductive particle 21 shown in FIG. 3 has the base material particle 2 and the electroconductive part 23. As shown in FIG. The conductive part 23 has the 1st conductive layer 23A on the base material particle 2 side as a whole, and has the 2nd conductive layer 23B on the side opposite to the base material particle 2 side.

The electroconductive particle 1 differs from the electroconductive particle 21 only in an electroconductive part. That is, in the electroconductive particle 1, the electroconductive part 3 of 1-layer structure is formed, and the electroconductive part 21 of the electroconductive particle 21 is formed in the electroconductive part 23 (the 1st electroconductive layer 23A and the 2nd electroconductive layer 23B). The first conductive layer 23A and the second conductive layer 23B are formed as different conductive parts.

The first conductive layer 23A is arranged on the surface of the substrate particle 2 . Between the substrate particle 2 and the second conductive layer 23B, the first conductive layer 23A is disposed. The first conductive layer 23A is in contact with the substrate particles 2 . The second conductive layer 23B is in contact with the first conductive layer 23A. Therefore, 23 A of 1st conductive layers are arrange|positioned on the surface of the base material particle 2, and 23 B of 2nd conductive layers are arrange|positioned on the surface of 23 A of 1st conductive layers.

Unlike the electroconductive particle 11, the electroconductive particle 21 does not have a core substance. The electroconductive particle 21 does not have a protrusion on the surface. The electroconductive particle 21 is spherical. The conductive portion 23 has no protrusions on the outer surface.

Hereinafter, other details of electroconductive particle are demonstrated.

(substrate particles) The material of the above-mentioned substrate particles is not particularly limited.

The material of the above-mentioned substrate particle may be organic material or inorganic material. Resin particles etc. are mentioned as a base material particle which consists only of the said organic material. Inorganic particles other than metals etc. are mentioned as a base particle which consists only of the said inorganic material. As the substrate particle formed from both the above-mentioned organic material and the above-mentioned inorganic material, organic-inorganic hybrid particles and the like may, for example, be mentioned. From the viewpoint of improving both the flexibility and the compressibility of the substrate particles, the substrate particles are preferably resin particles or organic-inorganic hybrid particles, more preferably resin particles.

Examples of the above-mentioned organic material include polyolefin resins such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyisobutylene, and polybutadiene; polymethyl methacrylate and polyacrylic acid; Acrylic resin such as methyl ester; polycarbonate, polyamide, phenol-formaldehyde resin, melamine-formaldehyde resin, benzoguanamine-formaldehyde resin, urea-formaldehyde resin, phenol resin, melamine resin, benzoguanamine resin, urea Resin, epoxy resin, unsaturated polyester resin, saturated polyester resin, polyethylene terephthalate, polyethylene, polyphenylene ether, polyacetal, polyimide, polyamide imide, poly Ether ether ketone, polyether ketone, and divinylbenzene polymer, etc. The vinylbenzene polymer mentioned above may be a divinylbenzene copolymer. As said divinylbenzene copolymer, a divinylbenzene-styrene copolymer, a divinylbenzene-(meth)acrylate copolymer, etc. are mentioned. Since the compression characteristics of the above-mentioned substrate particles can be easily controlled within an appropriate range, the material of the above-mentioned substrate particles is preferably a polymer obtained by polymerizing one or more polymerizable monomers having ethylenically unsaturated groups. thing.

The above-mentioned substrate particles can be obtained by polymerizing the above-mentioned polymerizable monomer having an ethylenically unsaturated group. The above-mentioned polymerization method is not particularly limited, and known methods such as radical polymerization, ionic polymerization, polycondensation (condensation polymerization, polycondensation), addition condensation, living polymerization, and living radical polymerization may be mentioned. method. Moreover, as another polymerization method, the suspension polymerization in presence of a radical polymerization initiator is mentioned.

In the case of polymerizing a polymerizable monomer having an ethylenically unsaturated group to obtain the above-mentioned substrate particles, examples of the above-mentioned polymerizable monomer having an ethylenically unsaturated group include non-crosslinkable monomers and crosslinkable monomers. sexual monomer.

Regarding the above-mentioned non-crosslinkable monomers, examples of vinyl compounds include styrene monomers such as styrene, α-methylstyrene, and chlorostyrene; methyl vinyl ether, ethyl vinyl ether, acrylic acid, etc. vinyl ether compounds such as vinyl vinyl ether; acid vinyl ester compounds such as vinyl acetate, vinyl butyrate, vinyl laurate, and vinyl stearate; halogen-containing monomers such as vinyl chloride and vinyl fluoride; as (methyl) Acrylic compounds, for example: methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate Esters, lauryl (meth)acrylate, cetyl (meth)acrylate, stearyl (meth)acrylate, cyclohexyl (meth)acrylate, iso(meth)acrylate, etc. (meth) Alkyl acrylate compounds; 2-hydroxyethyl (meth)acrylate, glycerol (meth)acrylate, polyoxyethylene (meth)acrylate, glycidyl (meth)acrylate, etc. (meth)acrylonitrile and other nitrile-containing monomers; trifluoromethyl (meth)acrylate, pentafluoroethyl (meth)acrylate and other halogen-containing (meth)acrylates; as α - Olefin compounds, for example: olefin compounds such as diisobutylene, isobutylene, linear long-chain polymers with terminal double bonds, ethylene, propylene; examples of conjugated diene compounds: isoprene, butadiene Wait.

Regarding the above-mentioned crosslinkable monomers, examples of vinyl compounds include: vinyl monomers such as divinylbenzene, 1,4-divinyloxybutane, and divinylsulfone; as (meth)acrylic compounds , for example: tetramethylolmethane tetra(meth)acrylate, polytetramethylene glycol diacrylate, tetramethylolmethane tri(meth)acrylate, tetramethylolmethane di(meth)acrylate base) acrylate, trimethylolpropane tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol penta(meth)acrylate, tri(meth)acrylic acid glyceryl ester, di(meth)acrylate base) glyceryl acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, polytetramethylene glycol di(meth)acrylate, 1,4-butanediol Polyfunctional (meth)acrylates such as di(meth)acrylates; examples of allyl compounds include triallyl (iso)cyanurate, triallyl trimellitate, and phthalic acid Diallyl ester, diallyl acrylamide, diallyl ether; Examples of silane compounds include: tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethylsilane Oxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, isopropyltrimethoxysilane, isobutyltrimethoxysilane, cyclohexyltrimethoxysilane, n-hexyltrimethoxysilane, n- Octyltriethoxysilane, n-decyltrimethoxysilane, phenyltrimethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diisopropyldimethoxysilane , trimethoxysilyl styrene, γ-(meth)acryloxypropyltrimethoxysilane, 1,3-divinyltetramethyldisiloxane, methylphenyldimethoxysilane , Diphenyldimethoxysilane and other silane alkoxide compounds; vinyltrimethoxysilane, vinyltriethoxysilane, dimethoxymethylvinylsilane, dimethoxyethylvinylsilane , diethoxymethylvinylsilane, diethoxyethylvinylsilane, ethylmethyldivinylsilane, methylvinyldimethoxysilane, ethylvinyldimethoxysilane, Methylvinyldiethoxysilane, ethylvinyldiethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methyl 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltriethoxysilane Silane alkoxides containing polymerizable double bonds such as oxypropyltrimethoxysilane; cyclic siloxanes such as decamethylcyclopentasiloxane; single-end modified polysiloxane oil, double-end capped polysiloxane Modified (reactive) polysiloxane oils such as polysiloxane oils and side chain polysiloxane oils; and carboxyl group-containing monomers such as (meth)acrylic acid, maleic acid, and maleic anhydride.

When polymerizing a polymerizable monomer having an ethylenically unsaturated group to obtain the above-mentioned substrate particles, the above-mentioned polymerizable monomer having an ethylenically unsaturated group preferably includes a crosslinkable monomer, more preferably includes Multifunctional cross-linking monomer. The above-mentioned polymerizable monomer having an ethylenically unsaturated group further preferably contains polypropylene glycol di(meth)acrylate, and particularly preferably contains a monomer represented by the following formula (1). From the viewpoint of further effectively exerting the effect of the present invention, the material of the above-mentioned substrate particles preferably includes polyfunctional (meth)acrylate, more preferably polyfunctional (meth)acrylic acid having a polyether skeleton. ester. From the viewpoint of further effectively exerting the effect of the present invention, the material of the above-mentioned substrate particle is further preferably composed of a polyfunctional (meth)acrylate having a polyalkylene glycol skeleton, particularly preferably polypropylene glycol. Di(meth)acrylate preferably contains a monomer represented by the following formula (1) (hereinafter sometimes described as "monomer X"). The number of carbon atoms in the alkylene group of the polyalkylene glycol skeleton is preferably 2 or more, preferably 4 or less, more preferably 3 or less, from the viewpoint of more effectively exhibiting the effect of the present invention. When the material of the above-mentioned substrate particles includes the above-mentioned preferred monomer X, it can further effectively improve the compression recovery rate after the above-mentioned conductive particles are compressed by 20% and kept for 168 hours, so it can be further effective to play the effect of the present invention.

[chemical 1]

In the above formula (1), n represents an integer of 5 to 20. In the above formula (1), n is preferably 7 or more, more preferably 10 or more, preferably 17 or less, more preferably 15 or less.

In 100% by weight of the material of the above-mentioned substrate particles, the content of the polyfunctional (meth)acrylate having a polyether skeleton is preferably at least 5% by weight, more preferably at least 10% by weight, and even more preferably at least 30% by weight Above, preferably 100% by weight or less, more preferably 90% by weight or less, further preferably 80% by weight or less, particularly preferably 60% by weight or less. The effect of this invention can be exhibited more effectively as content of the polyfunctional (meth)acrylate which has the said polyether skeleton is more than the said minimum and below the said upper limit. The content of the polyfunctional (meth)acrylate having a polyether skeleton may be 100% by weight (total amount) in 100% by weight of the material of the substrate particle.

In 100% by weight of the material of the substrate particles, the content of the polyfunctional (meth)acrylate having a polyalkylene glycol skeleton is preferably at least 5% by weight, more preferably at least 10% by weight, and even more preferably It is 30 weight% or more, Preferably it is 100 weight% or less, More preferably, it is 90 weight% or less, More preferably, it is 80 weight% or less, Most preferably, it is 60 weight% or less. The effect of this invention can be exhibited more effectively as content of the polyfunctional (meth)acrylate which has the said polyalkylene glycol frame|skeleton is more than the said minimum and below the said upper limit. In 100% by weight of the material of the substrate particles, the content of the polyfunctional (meth)acrylate having a polyalkylene glycol skeleton may be 100% by weight (total amount).

In 100% by weight of the material of the substrate particle, the content of the above-mentioned monomer X is preferably at least 5% by weight, more preferably at least 10% by weight, further preferably at least 30% by weight, more preferably at most 100% by weight, More preferably, it is 90 weight% or less, More preferably, it is 80 weight% or less, Most preferably, it is 60 weight% or less. When content of the said monomer X is more than the said minimum and below the said upper limit, the effect of this invention can be exhibited more effectively. The content of the monomer X may be 100% by weight (total amount) in 100% by weight of the material of the substrate particles.

The material of the above-mentioned substrate particles may contain monomers other than the above-mentioned monomer X. Examples of monomers other than the above-mentioned monomer X include styrene, divinylbenzene, methyl (meth)acrylate, polytetramethylene glycol di(meth)acrylate, and 1,9-nonane Diol di(meth)acrylate, etc. The monomer other than the above-mentioned monomer X is preferably polytetramethylene glycol di(meth)acrylate or 1,9-nonanediol di(meth)acrylate, more preferably polytetramethylene glycol di(meth)acrylate Diol di(meth)acrylate. When the monomer other than the above-mentioned monomer X is the above-mentioned preferred monomer, it can further effectively improve the compression recovery rate after the above-mentioned conductive particles are compressed by 20% for 168 hours, and can further effectively Bring into play the effect of the present invention.

From the viewpoint of reducing the viscosity of the material of the above-mentioned base particle and improving the formability of the base particle, the content of monomers other than the above-mentioned monomer X in 100% by weight of the material of the above-mentioned base particle is preferably 10 % by weight or more, more preferably not less than 20% by weight, still more preferably not less than 40% by weight, preferably not more than 95% by weight, more preferably not more than 90% by weight, still more preferably not more than 70% by weight.

Examples of the inorganic material include silica, alumina, barium titanate, zirconia, carbon black, silica glass, borosilicate glass, lead glass, soda lime glass, and aluminosilicate glass ( aluminum silicate glass), etc.

The aforementioned substrate particles may also be organic-inorganic hybrid particles. The aforementioned substrate particles may also be core-shell particles. When the above-mentioned substrate particle is an organic-inorganic hybrid particle, examples of the inorganic substance as the material of the above-mentioned substrate particle include silica, alumina, barium titanate, zirconia, and carbon black. The above-mentioned inorganic substances are preferably nonmetals. The substrate particles formed from the above-mentioned silica are not particularly limited, and for example, cross-linked polymer particles are formed by hydrolyzing a silicon compound having two or more hydrolyzable alkoxysilyl groups, and then fired if necessary. The resulting substrate particles. 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. The aforementioned substrate particles are preferably organic-inorganic hybrid particles having an organic core and an inorganic shell disposed on the surface of the organic core.

As the material of the above-mentioned organic core, the above-mentioned organic materials and the like may, for example, be mentioned.

As the material of the above-mentioned inorganic shell, the inorganic substances mentioned above as the material of the base particle can be exemplified. The material of the above-mentioned inorganic shell is preferably silicon dioxide. The inorganic shell is preferably formed by forming a shell of a metal alkoxide on the surface of the core by a sol-gel method, and then firing the shell. The aforementioned metal alkoxide is preferably a silane alkoxide. The above-mentioned inorganic shell is preferably formed of silane alkoxide.

In the above-mentioned substrate particles, when the above-mentioned substrate particles were loaded to 1961 mN at a loading speed of 14.12 mN/s, and then unloaded at an unloading speed of 14.12 mN/s, the compressive deformation when the compressive load at the time of loading was 500 mN The ratio (L1/L2) of the position (L1) to the compression displacement (L2) when the compression load is 500 mN at the time of unloading preferably satisfies the following range. That is, the ratio (L1/L2) is preferably at least 0.6, more preferably at least 0.7, still more preferably at least 0.8, particularly preferably at least 0.9. The effect of this invention can be exhibited more effectively as the said ratio (L1/L2) is more than the said minimum. The upper limit of the ratio (L1/L2) is not particularly limited. The said ratio (L1/L2) may be 1.0 or less, and may be less than 1.0.

In addition, in the above-mentioned substrate particles, when the above-mentioned substrate particles were loaded to 1961 mN at a loading speed of 14.12 mN/s, and then unloaded at an unloading speed of 14.12 mN/s, the compressive load at the time of loading was 1000 mN. The ratio (L3/L4) of the compression displacement (L3) to the compression displacement (L4) when the compression load is 1000 mN at the time of unloading preferably satisfies the following range. That is, the ratio (L3/L4) is preferably at least 0.6, more preferably at least 0.7, still more preferably at least 0.8, particularly preferably at least 0.9. The effect of this invention can be exhibited more effectively as the said ratio (L3/L4) is more than the said minimum. The upper limit of the ratio (L3/L4) is not particularly limited. The said ratio (L3/L4) may be 1.0 or less, and may be less than 1.0.

From the viewpoint of exhibiting the effects of the present invention more effectively, in the substrate particles, the ratio (L1/L2) is preferably 0.7 or more and the ratio (L3/L4) is 0.7 or more. From the viewpoint of exerting the effect of the present invention more effectively, among the above-mentioned substrate particles, it is preferable that the compressive displacement under load is relatively small compared to that under unloading within the entire range of compressive load under load from 500 mN to 1000 mN. The compression displacement ratio of the time is 0.7 or more. In the above-mentioned substrate particles, the ratio of the compression displacement during loading to the compression displacement during unloading may be 1.0 or less or less than 1.0 within the entire range of the compression load during loading from 500 mN to 1000 mN.

The said compression displacement (L1), the said compression displacement (L2), the said compression displacement (L3), and the said compression displacement (L4) can be measured by the following compression test C.

＜Compression Test C＞ Spread the substrate particles on the sample stage. With respect to one dispersed substrate particle, it was loaded to 1961 mN (reverse load value) along the center direction of the substrate particle at a load speed of 14.12 mN/s using a micro compression tester. Thereafter, unload at an unloading speed of 14.12 mN/s until reaching the load value (20.2 mN) for the origin. Measure the load-compression displacement during this period, and draw the compression displacement-compression load curve (compression displacement curve). Calculate the compression displacement (L1) when the compression load is 500 mN when loaded, the compression displacement (L2) when the compression load is 500 mN when unloaded, and the compression displacement (L2) when the compression load is 1000 mN when the load is loaded ( L3), and the compression displacement (L4) when the compression load is 1000 mN when unloading. As said micro-compression testing machine, "Micro Autograph MST-I" manufactured by Shimadzu Corporation may, for example, be mentioned. In addition, the above-mentioned compression displacement (L1), the above-mentioned compression displacement (L2), the above-mentioned compression displacement (L3), and the above-mentioned compression displacement (L4) are the compression displacement at the load value (20.2 mN) for the origin. bit as the basis.

The particle diameter of the above-mentioned substrate particles is preferably 30 μm or more, more preferably 100 μm or more, further preferably 200 μm or more, particularly preferably 300 μm or more, preferably 2000 μm or less, more preferably 1000 μm or less, Furthermore, it is preferably 600 μm or less. When the particle diameter of the said base material particle is more than the said minimum and below the said upper limit, a socket or a connector can be obtained using electroconductive particle more suitably. When the particle diameter of the above-mentioned substrate particles is more than the above-mentioned lower limit and below the above-mentioned upper limit, the contact area between the conductive particles and the electrode can be sufficiently increased, and the conductive particles that are not easily aggregated when forming the conductive part are difficult to form. The surface of the substrate particles is peeled off.

The particle size of the substrate particles is particularly preferably from 100 μm to 1000 μm. When the particle size of the substrate particles is in the range of 100 μm to 1000 μm, the conductive particles are less likely to aggregate when the conductive portion is formed on the surface of the substrate particles, and aggregated conductive particles are less likely to be formed. Moreover, when the particle diameter of the said base material particle exists in the range of 100 micrometers or more and 800 micrometers or less, a socket or a connector can be obtained using electroconductive particle more suitably.

The particle diameter of the above-mentioned substrate particle represents the diameter when the substrate particle is a true spherical shape, and represents the diameter when the substrate particle is not a true spherical shape when it is assumed to be a true sphere corresponding to its volume.

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 obtained by observing arbitrary 50 substrate particles with an electron microscope or an optical microscope, calculating the average value of the particle diameters of each substrate particle, or using a particle size distribution measuring device. When observing with an electron microscope or an optical microscope, the particle diameter of each substrate particle is obtained as a particle diameter in terms of a circle equivalent diameter. When observed with an electron microscope or an optical microscope, the average particle diameter in terms of circular equivalent diameter and the average particle diameter in terms of spherical equivalent diameter of arbitrary 50 substrate particles are almost equal. In the particle size distribution measuring device, the particle diameter of each substrate particle is calculated as the particle diameter in terms of spherical equivalent diameter. The average particle diameter of the substrate particles is preferably calculated using a particle size distribution measuring device. When measuring the particle diameter of the said base material particle in electroconductive particle, it can measure as follows, for example.

The conductive particles were added to "Technovit 4000" manufactured by Kulzer Co., Ltd., and dispersed so that the content thereof became 30% by weight, to prepare an embedding resin body for conductive particle inspection. Cut out the cross section of the conductive particles using an ion mill ("IM4000" manufactured by Hitachi High-Tech Co., Ltd.) so as to pass through the vicinity of the center of the conductive particles (preferably substrate particles) dispersed in the embedding resin . Then, 50 conductive particles were randomly selected using a field emission scanning electron microscope (FE-SEM), and the substrate particles of each conductive particle were observed. The particle diameter of the substrate particle in each electroconductive particle was measured, and the arithmetic mean thereof was taken as the particle diameter of the substrate particle.

(conductive part) The electroconductive particle of this invention is provided with the electroconductive part arrange|positioned on the surface of the base material particle and the said base material particle. 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 constituting the conductive portion include gold, silver, palladium, copper, platinum, zinc, iron, tin, lead, aluminum, cobalt, indium, nickel, chromium, titanium, antimony, beryllium, rhodium, ruthenium, and iridium. , bismuth, thallium, germanium, cadmium, silicon, tungsten, molybdenum and their alloys. Moreover, as a metal which comprises the said conductive part, tin-doped indium oxide (ITO), solder, etc. are mentioned. Only 1 type may be used for the metal which comprises the said electroconductive part, and 2 or more types may be used together.

It is preferable that the said conductive part contains ductile metal from a viewpoint of reducing connection resistance more effectively and making the compression characteristic of a base material particle and electroconductive particle favorable. The above-mentioned ductile metal has ductility. Examples of the ductile metal include copper, zinc, tin, aluminum, nickel, gold, silver, lead, platinum, titanium, and alloys thereof.

From the viewpoint of further effectively reducing connection resistance, the conductive portion preferably contains nickel, gold, palladium, beryllium, cobalt, tin, silver, or copper, and more preferably contains nickel, gold, or copper.

It is preferable that the said conductive part has a 1st conductive layer. It is preferable that the said 1st conductive layer is arrange|positioned on the surface of the said base material particle. It is preferable that the said 1st conductive layer is in contact with the said base material particle.

It is preferable that the said 1st conductive layer contains metal. As a material of the said 1st conductive layer, the said metal is mentioned. From the viewpoint of further effectively reducing the connection resistance, the material of the first conductive layer preferably includes a ductile metal, more preferably includes nickel, gold or copper, and still more preferably includes copper. The material of the above-mentioned first conductive layer is further preferably copper from the viewpoint of suppressing cracks in the conductive portion and suppressing the occurrence of poor connection.

The above-mentioned conductive portion may be formed of a single layer. The above-mentioned conductive part may also be formed by a plurality of layers. The above-mentioned conductive part may have a laminated structure of 2 layers, may have a laminated structure of 2 or more layers, may have a laminated structure of 3 layers, or may have a laminated structure of 3 or more layers. From the standpoint of suppressing cracks in the conductive portion and suppressing connection failure, the conductive portion preferably has a laminated structure of two or more layers.

When the above-mentioned conductive part has a laminated structure of two or more layers, the material of the outer surface of the above-mentioned conductive part is preferably gold, silver, copper, tin, zinc, nickel, beryllium, cobalt, palladium, platinum, rhodium, ruthenium, Iridium, or alloys thereof, more preferably gold, copper, or alloys thereof. When the material of the outer surface of the above-mentioned conductive part is the above-mentioned preferable metal, oxidation of the above-mentioned first conductive part can be suppressed, so the effect of the present invention can be exhibited more effectively.

The method for forming the conductive portion on the surface of the substrate particle is not particularly limited. As a method of forming the above-mentioned conductive portion, 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 coating metal powder or a paste containing metal powder and a binder on the surface of substrate particles, etc. The method of forming the above-mentioned conductive part is preferably the method of 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, Theta Composer (manufactured by Tokusu Works Co., Ltd.) and the like can be used for the above-mentioned method using physical collision.

The thickness of the conductive portion is preferably at least 0.2 μm, more preferably at least 1 μm, more preferably at most 15 μm, more preferably at most 10 μm, further preferably at most 8 μm, particularly preferably at most 7 μm. The thickness of the above-mentioned conductive part means the thickness of the entire conductive part when the conductive part has a laminated structure of two or more layers. When the thickness of the said electroconductive part is more than the said minimum and below the said upper limit, generation|occurrence|production of a crack in a electroconductive part can be suppressed, and generation|occurrence|production of connection failure can be suppressed. Moreover, sufficient electroconductivity can be obtained, and hardening of electroconductive particle can be prevented.

The thickness of the first conductive layer is preferably at least 0.2 μm, more preferably at least 1 μm, more preferably at most 15 μm, more preferably at most 10 μm, and still more preferably at most 8 μm. When the thickness of the above-mentioned first conductive layer is more than the above-mentioned lower limit and below the above-mentioned upper limit, the compression recovery rate after holding the above-mentioned conductive particles in a state compressed by 20% for 168 hours can be further effectively improved, so it can be further effective. to play the effect of the present invention.

When the conductive portion has a laminated structure of two or more layers, the thickness of the outermost conductive portion is preferably at least 0.001 μm, more preferably at least 0.01 μm, preferably at most 10 μm, more preferably at most 7 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 coating of the conductive part of the outermost layer becomes uniform, and corrosion resistance can be effectively improved. Also, when the metal constituting the outermost layer is gold, the thinner the thickness of the outermost layer, the more cost can be reduced.

The thickness of the said electroconductive part can be measured by observing the cross-section of electroconductive particle using a scanning electron microscope (SEM), for example. Regarding the thickness of the above-mentioned conductive part, it is preferable to calculate the average value of the thickness of any five conductive parts as the thickness of the conductive part of one conductive particle, and it is more preferable to calculate the average value of the thickness of the entire conductive part as one conductive part. The thickness of the conductive part of the particle. It is preferable that the thickness of the said electroconductive part is calculated|required by calculating the average value of the thickness of the electroconductive part of each electroconductive particle about arbitrary 10 electroconductive particles.

The ratio of the particle size of the conductive particles to the thickness of the first conductive layer (particle size of the conductive particles/thickness of the first conductive layer) is preferably 40 or more, more preferably 50 or more, still more preferably 100 Above, preferably 1500 or less, more preferably 1000 or less, still more preferably 800 or less. When the above-mentioned ratio (particle diameter of conductive particles/thickness of the first conductive layer) is more than the above-mentioned lower limit and below the above-mentioned upper limit, it can be further effectively improved after the above-mentioned conductive particles are compressed by 20%. Compression recovery rate, so the effect of the present invention can be further effectively exerted.

The ratio of the particle size of the conductive particles to the thickness of the conductive portion (particle size of the conductive particles/thickness of the conductive portion) is preferably 5 or more, more preferably 10 or more, further preferably 20 or more, and more preferably It is 800 or less, more preferably 650 or less, still more preferably 300 or less. When the above-mentioned ratio (particle size of the conductive particles/thickness of the conductive portion) is more than the above-mentioned lower limit and below the above-mentioned upper limit, the compression recovery rate of the above-mentioned conductive particles can be further improved, so that the advantages of the present invention can be further effectively exerted. Effect.

(core substance) The said conductive particle may have a protrusion on the outer surface of the said conductive part. The said electroconductive particle may have a processus|protrusion on the surface of an electroconductive part. It is preferable that there are plural number of said protrusions. An oxide film is often formed on the surface of the electrode in contact with the conductive particles. When using the electroconductive particle which has a protrusion on the surface of an electroconductive part, by crimping electroconductive particle and an electrode, the said oxide film can be removed effectively by a protrusion. Therefore, the electrode and the electroconductive part contact more reliably, the contact area of electroconductive particle and an electrode can be fully enlarged, and connection resistance can be reduced more effectively. Furthermore, when conductive particles are dispersed in a binder and used as a conductive material, the protrusions of the conductive particles can be used to more effectively exclude the binder between the conductive particles and the electrodes. Therefore, the contact area of electroconductive particle and an electrode can be fully enlarged, and connection resistance can be reduced more effectively.

As a method of forming the above-mentioned protrusions, a method of forming a conductive part by electroless plating after attaching a core substance to the surface of the base particle; After the conductive part, the method of attaching the core material, and then forming the conductive part by electroless plating, etc. In addition, the above-mentioned protrusions may be formed without using the above-mentioned core substance.

As another method of forming the above-mentioned protrusions, a method of adding a core substance in the middle of forming the conductive part on the surface of the substrate particle, etc. may be mentioned. In addition, instead of using the above-mentioned core substance, the protrusions can be formed by using a method such as forming a conductive part on the substrate particle by electroless plating, and then forming a protrusion on the surface of the conductive part to perform plating chromatography. out, and further by electroless plating to form a conductive portion.

As a method for attaching the core substance to the surface of the substrate particle, a method of adding the core substance to the dispersion liquid of the substrate particle, and accumulating the core substance by van der Waals force and adhering to the surface of the substrate particle ; and a method of adding a core substance to a container containing substrate particles, and attaching the core substance to the surface of the substrate particles by mechanical action based on the rotation of the container, etc. From the viewpoint of controlling the amount of the adhered core substance, the method of adhering the core substance to the surface of the substrate particle is preferably a method of accumulating and adhering 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 and a nonconductive substance are mentioned. Examples of the conductive substance include conductive nonmetals such as metals, metal oxides, and graphite, and conductive polymers. As said conductive polymer, polyacetylene etc. are mentioned. Silica, alumina, titania, zirconia, etc. are mentioned as said nonconductive substance. From the viewpoint of further effectively removing the oxide film, the above-mentioned core substance is preferably relatively hard. From the viewpoint of further effectively reducing the connection resistance between electrodes, the core material is preferably a 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 tin-lead Alloys, tin-copper alloys, tin-silver alloys, tin-lead-silver alloys, and tungsten carbide alloys containing two or more metals, etc. From the viewpoint of further effectively reducing the connection resistance 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. The core substance may, for example, be a granular mass, an aggregate formed by aggregating a plurality of fine particles, or an amorphous mass.

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

The particle diameter of the above-mentioned core material means the diameter when the core material is a true spherical shape, and the diameter when the core material is not a true spherical shape when it is assumed to be a true sphere equivalent to its volume.

The particle diameter of the aforementioned core substance is preferably an average particle diameter, more preferably a number average particle diameter. The particle diameter of the core substance was obtained 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 using a particle size distribution measuring device. When observed with an electron microscope or an optical microscope, the particle diameter of each core substance is obtained as a particle diameter in terms of a circle equivalent diameter. When observed with an electron microscope or an optical microscope, the average particle diameter of any 50 core substances in terms of circular equivalent diameters is almost equal to the average particle diameter in terms of spherical equivalent diameters. In the particle size distribution measuring device, the particle diameter of each core substance is calculated as the particle diameter in spherical equivalent diameter. The average particle diameter of the above-mentioned core substance is preferably calculated using a particle size distribution measuring device.

The number of the said protrusion per said electroconductive particle is like this. Preferably it is 3 or more, More preferably, it is 5 or more. The upper limit of the number of the above-mentioned protrusions is not particularly limited. The upper limit of the number of said protrusions can consider the particle diameter of electroconductive particle, etc., and can select suitably. The connection resistance between electrodes can be reduced more effectively as the number of the said protrusion is more than the said minimum.

The number of the above-mentioned protrusions can be calculated by observing arbitrary conductive particles with an electron microscope or an optical microscope. The number of the above-mentioned protrusions is preferably obtained by observing arbitrary 50 conductive particles with an electron microscope or an optical microscope, and calculating the average value of the number of protrusions in each conductive particle.

The height of the protrusions is preferably at least 0.001 μm, more preferably at least 0.05 μm, more preferably at most 0.9 μm, more preferably at most 0.2 μm. The connection resistance between electrodes can be reduced more effectively as the height of the said protrusion is more than the said minimum and below the said upper limit.

The height of the said protrusion can be calculated by observing the protrusion in arbitrary electroconductive particle with an electron microscope or an optical microscope. As for the height of the said protrusion, it is preferable to calculate the average value of the height of all the protrusions per electroconductive particle as the height of the protrusion of one electroconductive particle. It is preferable that the height of the said protrusion is calculated|required by calculating the average value of the height of the protrusion of each electroconductive particle about arbitrary 50 electroconductive particles.

The above-mentioned conductive particles are suitable for obtaining sockets or connectors. The above-mentioned conductive particles are suitable for obtaining sockets or connectors instead of metal terminals (metal pins). The above-mentioned conductive particles are preferably used for sockets or connectors, particularly preferably used for sockets. The above-mentioned conductive particles are preferably used for sockets or connectors instead of metal terminals (metal pins). By using the above-mentioned electroconductive particles instead of metal terminals (metal pins), it is possible to cope with further narrowing of the pitch, and it is possible to effectively suppress occurrence of poor connection at the time of CPU connection or the like. As the above-mentioned socket, CPU socket, IC (Integrated Circuit, integrated circuit) socket, DIP (Dual In-line Package, double in-line package) socket, PGA (Pin Grid Array, pin grid array) socket, SiP (Single In-Line Package, single in-line package) socket, LGA (Land Grid Array, planar grid array) socket, CSP (Chip Scale Package, chip level package) socket, QFN (Quad Flat No-lead Package, square Flat leadless package), QFP (Quad Flat Package, quadrilateral flat package) socket, SOP (Small Out-Line Package, small outline package) socket, and BGA (Ball Grid Array, ball grid array) socket, etc. Furthermore, DIP sockets, PGA sockets, SiP sockets, LGA sockets, CSP sockets, QFN, QFP sockets, SOP sockets, and BGA sockets can be part of the IC sockets respectively. As the above-mentioned connector, FPC connector, board-to-board connector, narrow-pitch connector, DIN (Deutsche Industrie Norm, German Industrial Standard) connector, compression connector (compression connector), integral connector ( one piece connector), and card edge connector (card edge connector), etc.

(socket) The socket of the present invention includes a socket body and the above-mentioned conductive particles, and the above-mentioned conductive particles constitute connection terminals. In other words, the socket of the present invention includes a socket body and connection terminals, and the connection terminals are composed of the above-mentioned conductive particles. Since the socket of the present invention has the above structure, it can maintain high connection reliability even if the conductive particles are compressed for a long time. The above-mentioned connecting terminals are preferably arranged on the surface of the above-mentioned socket body. The above-mentioned conductive particles are preferably arranged on the surface of the above-mentioned socket body.

In the said socket, it is preferable that the said electroconductive particle is a connection terminal. The above sockets are suitable for electronic parts. The above-mentioned socket is preferably a socket for electronic components.

(conductive material) The above-mentioned conductive particles are preferably dispersed in a binder to be used as a conductive material. The above-mentioned conductive material includes the above-mentioned conductive particles and a binder. The above-mentioned conductive particles are preferably used by being dispersed in a binder, and are preferably used as a conductive material by being dispersed in a binder. The above-mentioned conductive material is preferably used for electrical connection between electrodes. Since the said electrically-conductive material uses the said electroconductive particle, it can reduce the connection resistance between electrodes more effectively, and can suppress aggregation of electroconductive particle more effectively. Since the above-mentioned conductive material uses the above-mentioned conductive particles, it is possible to further effectively suppress the occurrence of poor connection.

The above-mentioned binder is not particularly limited. A known insulating resin or solvent can be used for the above-mentioned adhesive. The above adhesive preferably contains a thermoplastic component (thermoplastic compound) or a curable component, more preferably 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 include vinyl resins, thermoplastic resins, curable resins, thermoplastic block copolymers, elastomers, and solvents. The said binder 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. As said thermoplastic resin, a polyolefin resin, an ethylene-vinyl acetate copolymer, a polyamide resin, etc. are mentioned. As said curable resin, an epoxy resin, a polyurethane resin, a polyimide resin, an unsaturated polyester resin, etc. are mentioned. 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 resins may also be used in combination with a curing agent. Examples of the above-mentioned thermoplastic block copolymers include styrene-butadiene-styrene block copolymers, styrene-isoprene-styrene block copolymers, styrene-butadiene-styrene block copolymers, and styrene-butadiene-styrene block copolymers. Hydrogenated products of block copolymers, hydrogenated products of styrene-isoprene-styrene block copolymers, etc. As said elastomer, a styrene-butadiene copolymer rubber, an acrylonitrile-styrene block copolymer rubber, etc. are mentioned.

As said solvent, water, an organic solvent, etc. are mentioned. An organic solvent is preferable at the point that it can be easily removed. Examples of the organic solvent include: alcohol compounds such as ethanol; ketone compounds such as acetone, methyl ethyl ketone, and cyclohexanone; aromatic hydrocarbon compounds such as toluene, xylene, and tetramethylbenzene; Cellosolve, butyl cellosolve, carbitol, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol diethyl ether, tripropylene glycol monomethyl ether and other glycol ether compounds ; Ethyl acetate, butyl acetate, butyl lactate, acetic acid cellosolve, butyl cellosolve acetate (Butylcellosolve acetate), carbitol acetate, butyl carbitol acetate, propylene glycol monomethyl ether ethyl ester compounds such as esters, dipropylene glycol monomethyl ether acetate, and propylene carbonate; aliphatic hydrocarbon compounds such as octane and decane; and petroleum-based solvents such as petroleum ether and naphtha.

The conductive material may contain, for example, fillers, extenders, softeners, plasticizers, polymerization catalysts, hardening catalysts, colorants, antioxidants, heat stabilizers, in addition to the conductive particles and the binder. Various additives such as light stabilizers, ultraviolet absorbers, lubricants, antistatic agents, and flame retardants.

The method of dispersing the above-mentioned conductive particles in the above-mentioned binder can use a previously known dispersion method, and it is not particularly limited. As a method of dispersing the said electroconductive particle in the said binder, the following method etc. are mentioned. A method of kneading and dispersing the above-mentioned conductive particles with a planetary mixer or the like after adding the above-mentioned conductive particles to the above-mentioned binder. A method in which the above-mentioned conductive particles are uniformly dispersed in water or an organic solvent using a homogenizer, etc., then added to the above-mentioned binder, and kneaded by a planetary mixer to disperse them. After diluting the above-mentioned binder with water or an organic solvent, etc., adding the above-mentioned conductive particles, kneading and dispersing with a planetary mixer or the like.

The viscosity (η25) at 25°C of the conductive material is preferably 30 Pa·s or more, more preferably 50 Pa·s or more, preferably 400 Pa·s or less, more preferably 300 Pa·s or less. When the viscosity at 25° C. of the conductive material is more than the above lower limit and not more than the above upper limit, the conductive material can be evenly coated on the member to be connected, and the occurrence of poor connection can be further effectively suppressed. The above-mentioned viscosity (η25) can be appropriately adjusted according to the type and amount of 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 above-mentioned conductive material can be used as a conductive paste, a conductive film, and the like. When the above-mentioned conductive material 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 above-mentioned conductive material, the content of the above-mentioned binder is preferably at least 10% by weight, more preferably at least 30% by weight, further preferably at least 50% by weight, particularly preferably at least 70% by weight, more preferably 99.99% by weight % by weight or less, more preferably 99.9% by weight or less. When content of the said binder is more than the said minimum and below the said upper limit, electroconductive particle can be arrange|positioned efficiently on the connection object member, and generation|occurrence|production of connection failure can be suppressed more effectively.

In 100% by weight of the above-mentioned conductive material, the content of the above-mentioned conductive particles is preferably at least 0.01% by weight, more preferably at least 0.1% by weight, preferably at most 80% by weight, more preferably at most 60% by weight, and even more preferably at least 60% by weight. 40% by weight or less, particularly preferably 20% by weight or less, most preferably 10% by weight or less. Electroconductive particles can be efficiently arrange|positioned on the connection object member as content of the said electroconductive particle is more than the said minimum and below the said upper limit, and generation|occurrence|production of connection failure can be suppressed.

(connection structure) The connection structure of this invention is equipped with the 1st connection object member which has a 1st electrode on the surface, the 2nd connection object member which has a 2nd electrode on the surface, and the connection part which has an insulating member and electroconductive particle. In the connection structure of this invention, the said electroconductive particle is the said electroconductive particle. In the connection structure of this invention, the said 1st electrode and the said 2nd electrode are electrically connected by the said electroconductive particle.

The above-mentioned connecting portion is preferably a socket portion formed of a socket, or a connector portion formed of a connector.

Fig. 4 is a front cross-sectional view schematically showing an example of a connection structure using conductive particles according to the first embodiment of the present invention.

A connection structure 51 shown in FIG. 4 includes a first connection object member 52 , a second connection object member 53 , and a connection portion 54 . The first connection object member 52 has a plurality of first electrodes 52a on the surface (upper surface). The 2nd connection object member 53 has some 2nd electrode 53a on the surface (lower surface). Connection portion 54 has conductive particle 1 , insulating member 31 , solder paste portion 32 , electrode 33 , and solder ball 34 . The connection part 54 is a socket part. The insulating member 31 has a through hole 31a passing through the upper surface and the lower surface.

On the first electrode 52a, the solder ball 34 is arranged. The insulating member 31 is arranged on the solder ball 34 . Electrodes 33 are arranged on the insulating member 31 . On the electrode 33, the solder paste part 32 is arrange|positioned. On the solder paste part 32, the electroconductive particle 1 is arrange|positioned. On the electroconductive particle 1, the 2nd electrode 53a is arrange|positioned. Inside the through hole 31a, a conductive paste for via fill is arranged.

One solder ball 34, one electrode 33, one solder paste portion 32, one conductive particle 1, and one second electrode 53a are electrically connected to one first electrode 52a. Therefore, in the connection structure 51, the 1st electrode 52a and the 2nd electrode 53a are electrically connected by the electroconductive particle 1. As shown in FIG.

In addition, in FIG. 4, the electroconductive particle 1 is shown schematically for convenience of illustration. Instead of the electroconductive particle 1, you may use other electroconductive particle, such as electroconductive particle 11,21.

Since the said connection structure uses the said electroconductive particle, even if electroconductive particle is compressed for a long time, it can maintain high connection reliability. Therefore, it can be used instead of metal terminals (metal pins), and can cope with further narrowing of the pitch. In addition, it is possible to effectively suppress the occurrence of poor connection at the time of CPU connection or the like.

As a material of the said insulating member, ceramics, resin, etc. are mentioned. As said resin, a fluororesin, a phenol resin, an epoxy resin, a polyimide resin, etc. are mentioned. In addition, examples of substrates on which the insulating member is provided include FR-1, FR-2, FR-3, FR-4, FR-5, XPC, CEM-1, CEM-3, and glass polyimide substrates. , glass PPO substrate, and BT substrate, etc.

Fig. 5 is a front cross-sectional view schematically showing another example of the connection structure using the conductive particles according to the first embodiment of the present invention.

The connection structure 81 shown in FIG. 5 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. As shown in FIG. The connecting portion 84 is formed of a conductive material including conductive particles 1 .

The first connection object member 82 has a plurality of first electrodes 82a on the surface (upper surface). The 2nd connection object member 83 has some 2nd electrode 83a on the surface (lower surface). The first electrode 82a and the second electrode 83a are electrically connected by one or a plurality of conductive particles 1 .

In addition, in FIG. 5, the electroconductive particle 1 is shown schematically for convenience of illustration. Instead of the electroconductive particle 1, you may use other electroconductive particle, such as electroconductive particle 11,21.

The said 1st connection object member and the 2nd connection object member are not specifically limited. As said 1st connection object member, a motherboard etc. are mentioned, for example. As said 2nd connection object member, a semiconductor wafer, IC package, CPU etc. are mentioned.

Examples of electrodes provided on the first and second connection object members include gold electrodes, nickel electrodes, tin electrodes, aluminum electrodes, copper electrodes, molybdenum electrodes, silver electrodes, and SUS (Steel Use Stainless, Japan Stainless Steel Standard) electrodes. , And metal electrodes such as tungsten electrodes. Furthermore, when the above-mentioned electrode is an aluminum electrode, it may be an electrode formed only of aluminum, or may be an electrode in which an aluminum layer is deposited on the surface of the metal oxide layer. As a material of the said metal oxide layer, the indium oxide doped with the trivalent metal element, the zinc oxide doped with the trivalent metal element, etc. are mentioned, for example. 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 only to the following examples.

The following were prepared as the material of the substrate particle.

(monomer X) Polypropylene glycol #700 diacrylate ("APG-700" manufactured by Shin-Nakamura Chemical Industry Co., Ltd., n=12) Polypropylene glycol #400 diacrylate ("APG-400" manufactured by Shin-Nakamura Chemical Industry Co., Ltd., n=7)

(monomers other than monomer X) Monomer A: Polytetramethylene glycol diacrylate ("LIGHT ACRYLATE PTMGA-250" manufactured by Kyoeisha Chemical Co., Ltd.) Monomer B: Styrene ("St" manufactured by NS Styrene Monomer Co., Ltd.) Monomer C: divinylbenzene (DVB)

(Example 1) Production of conductive particles: Substrate particles (particle size: 500 μm) formed of a copolymer resin of polypropylene glycol #700 diacrylate (monomer X) and polytetramethylene glycol diacrylate (monomer A) were prepared. Electrolytic copper plating was performed on the above-mentioned substrate particles to form a copper-plated layer (first conductive layer) with an average thickness of 5.0 μm on the surface of the substrate particles. Next, electrolytic gold plating was performed on the outer surface of the copper plating layer to form a gold plating layer (second conductive layer) with an average thickness of 0.5 μm. Thus, the electroconductive particle which has the 2-layer laminated structure of a copper plating layer and a gold plating layer as a conductive part was obtained.

(Examples 2-13 and Comparative Examples 1-3) The type, content, and particle size of the material of the substrate particle, and the material and thickness of the conductive portion were set as shown in Tables 1 to 4 below to obtain conductive particles. In Example 12, the first conductive layer, the second conductive layer, and the third conductive layer were sequentially formed.

(Evaluation) (1) The thickness of the conductive part of the conductive particles The obtained electroconductive particles were added to "Technovit 4000" manufactured by Kulzer Corporation, and dispersed so that the content thereof became 30% by weight, to prepare an embedding resin body for inspection. The cross section of the conductive particle was cut out using an ion mill ("IM4000" manufactured by Hitachi High-Tech Co., Ltd.) so as to pass through the vicinity of the center of the conductive particle dispersed in the embedding resin.

Then, using a field emission scanning electron microscope (FE-SEM) (manufactured by Hitachi High-Tech Co., Ltd. "S-4800"), set the image magnification to 15,000 times, randomly select 10 conductive particles, and observe each conductive particle. The conductive part of the particle. The thickness of the conductive part and the thickness of each conductive layer in each conductive particle were measured, and the arithmetic average was carried out as the thickness of the conductive part and the thickness of each conductive layer.

(2) Particle size of conductive particles The particle diameter of the obtained electroconductive particle was calculated using the particle size distribution measuring apparatus ("Multisizer4" by Beckman Coulter). Specifically, it can obtain|require by measuring the particle diameter of about 100000 electroconductive particles, and calculating an average value. Moreover, the ratio of the particle diameter of electroconductive particle with respect to the thickness of a 1st electroconductive layer (the particle diameter of electroconductive particle/thickness of a 1st electroconductive layer) was computed from the obtained result.

(3) Compression recovery rate of conductive particles (compression test A and compression test B) The above-mentioned compression test A and compression test B were carried out on the obtained conductive particles, and the compression recovery rate after holding the conductive particles compressed by 20% for 168 hours, and the compression recovery rate when the conductive particles were compressed by 20% were measured (Compression recovery measured without maintaining compression).

(4) Compression test of substrate particles (compression test C) The above-mentioned compression test C was carried out on the obtained substrate particles, and the compression displacement (L1) when the compression load was 500 mN when loaded, the compression displacement (L2) when the compression load was 500 mN when unloading, and the load The compression displacement (L3) when the compression load is 1000 mN, and the compression displacement (L4) when the compression load is 1000 mN when unloading. Also, the ratio (L1/L2) and the ratio (L3/L4) are calculated.

(5) Initial connection reliability and long-term connection reliability For the obtained conductive particles, the resistance value (R1) of the conductive particles in the state of compressing the conductive particles by 20% was measured by the above method, and the resistance value (R1) of the conductive particles in the state of compressing the conductive particles by 20% was kept for 168 hours. The resistance value (R2) of conductive particles.

The initial connection reliability and long-term connection reliability are judged according to the following criteria.

[Criteria for judging initial connection reliability] ○○: The resistance value (R1) is more than 0 mΩ and less than 20 mΩ ○: The resistance value (R1) is more than 20 mΩ and less than 50 mΩ ×: The resistance value (R1) is 50 mΩ or more

[Criteria for judging long-term connection reliability] ○○: The resistance value (R2) is 0 mΩ or more and less than 20 mΩ ○: The resistance value (R2) is more than 20 mΩ and less than 50 mΩ ×: The resistance value (R2) is 50 mΩ or more

(6) The state of the conductive particles in the connection structure Using the obtained electroconductive particle, the connection structure (the connection structure which has the structure shown in FIG. 4) was produced as follows.

Prepare a BGA substrate in which solder balls and metal pads (hereinafter referred to as LAND) are electrically connected through through holes. In this BGA board, the conductive paste for via filling is arrange|positioned in the inside of a via hole.

The BGA substrate is assembled into a package receiving unit provided with a package fixing unit for fixing an IC package. Then, on the LAND on the upper surface of the BGA substrate, solder paste was applied using a dispenser. On the applied solder paste, the obtained conductive particles were placed using a ball planter. Then, in a reflow furnace, heating was performed at 280° C. for 3 minutes under a nitrogen atmosphere. In this way, the IC socket in which the LAND and the conductive particles are bonded by soldering and the lower part of the BGA substrate incorporated in the package receiving unit is bonded to the circuit board (mother board) by soldering is obtained.

In order to mount the IC package (CPU) on the obtained IC socket, pull up the lever of the package fixing unit to open the pressure cover, and connect the LAND part of the lower part of the IC package with the conductive particles arranged on the BGA substrate. way, place the IC socket on the package receiving unit. When the pressure cover is lowered, the rod is pushed down, whereby the pressure cover presses down the IC package from above, and a vertical load is applied to the IC package toward the contacts to obtain a connection structure.

The obtained connection structure was unloaded after continuous operation for 168 hours. Using an optical microscope ("Digital Microscope VHX series" manufactured by KEYENCE Corporation), set the image magnification to 200 times, randomly select 50 conductive particles, and measure the damaged conductive particles and the conductive particles that have not recovered but have been deformed. The total number of sexual particles. The state of the conductive particles in the connection structure was judged according to the following criteria.

[Criteria for judging the state of the conductive particles in the connection structure] ○○: The number of damaged or deformed conductive particles is less than 3 ○: The number of damaged or deformed conductive particles is 3 or more and less than 6 ×: The number of damaged or deformed conductive particles is 6 or more

The results are shown in Tables 1 to 4 below.

[Table 1] Example 1 Example 2 Example 3 Substrate particles Monomer X type - APG-700 APG-700 APG-700 content weight% 50 50 50 Monomer A type - PTMGA250 PTMGA250 PTMGA250 content weight% 50 50 50 Monomer B type - - - - content weight% - - - Monomer C type - - - - content weight% - - - particle size μm 500 300 150 500 mN Compression displacement under load (L1) μm 107.6 64.1 31.5 Compression displacement at unloading (L2) μm 108.3 63.8 32.4 Ratio (L1/L2) - 0.99 1.00 0.97 1000 mN Compression displacement under load (L3) μm 153.1 89.8 46.2 Compression displacement during unloading (L4) μm 152.4 90.1 48.5 Ratio (L3/L4) - 1.00 1.00 0.95 Conductive part 1st conductive layer Material - Cu Cu Cu thickness μm 5.0 2.4 1.2 2nd conductive layer Material - Au Au Au thickness μm 0.5 0.3 0.2 3rd conductive layer Material - - - - thickness μm - - - Conductive particles particle size μm 505.5 302.7 151.4 Ratio (particle size of conductive particles/thickness of the first conductive layer) - 101 126 126 Resistance value (R1) under 20% compression mΩ 3.1 4.5 10.8 Compression recovery rate when compressed by 20% % 100 100 100 Resistance value (R2) after 168 hours under 20% compression mΩ 3.1 4.6 10.8 Compression recovery rate after 168 hours under 20% compression % 100 100 100 Evaluation initial connection reliability - ○○ ○○ ○○ Long-term connection reliability - ○○ ○○ ○○ The state of the conductive particles in the connection structure - ○○ ○○ ○○

[Table 2] Example 4 Example 5 Example 6 Example 7 Example 8 Substrate particles Monomer X type - APG-700 APG-700 APG-400 APG-400 - content weight% 100 10 80 30 - Monomer A type - - PTMGA250 - PTMGA250 PTMGA250 content weight% - 80 - 70 80 Monomer B type - - St. St. - St. content weight% - 10 20 - 20 Monomer C type - - - - - - content weight% - - - - - particle size μm 500 500 500 500 500 500mN Compression displacement under load (L1) μm 119.4 64.3 61.4 80.1 49.5 Compression displacement at unloading (L2) μm 123.1 72.2 68.7 81.1 61.9 Ratio (L1/L2) - 0.97 0.89 0.89 0.99 0.80 1000 mN Compression displacement under load (L3) μm 191.1 97.8 92.8 119.4 75.0 Compression displacement during unloading (L4) μm 191.0 108.7 100.2 120.1 92.1 Ratio (L3/L4) - 1.00 0.90 0.93 0.99 0.81 Conductive part 1st conductive layer Material - Cu Cu Cu Cu Cu thickness μm 5.0 5.0 5.0 5.0 5.0 2nd conductive layer Material - Au Au Au Au Au thickness μm 0.5 0.5 0.5 0.5 0.5 3rd conductive layer Material - - - - - - thickness μm - - - - - Conductive particles particle size μm 505.5 505.5 505.5 505.5 505.5 Ratio (particle size of conductive particles/thickness of the first conductive layer) - 101 101 101 101 101 Resistance value (R1) under 20% compression mΩ 2.9 6.0 5.8 3.4 18.5 Compression recovery rate when compressed by 20% % 100 98.1 100 100 97.5 Resistance value (R2) after 168 hours under 20% compression mΩ 2.9 4.3 9.9 6.2 22.1 Compression recovery rate after 168 hours under 20% compression % 100 90.1 98.8 95.3 85.6 Evaluation initial connection reliability - ○○ ○○ ○○ ○○ ○○ Long-term connection reliability - ○○ ○○ ○○ ○○ ○ The state of the conductive particles in the connection structure - ○○ ○○ ○○ ○○ ○

[table 3] Example 9 Example 10 Example 11 Example 12 Example 13 Substrate particles Monomer X type - APG-700 APG-700 APG-700 APG-700 APG-700 content weight% 50 50 50 50 50 Monomer A type - PTMGA250 PTMGA250 PTMGA250 PTMGA250 PTMGA250 content weight% 50 50 50 50 50 Monomer B type - - - - - - content weight% - - - - - Monomer C type - - - - - - content weight% - - - - - particle size μm 500 500 500 500 500 500mN Compression displacement under load (L1) μm 107.6 107.6 107.6 107.6 107.6 Compression displacement at unloading (L2) μm 108.3 108.3 108.3 108.3 108.3 Ratio (L1/L2) - 0.99 0.99 0.99 0.99 0.99 1000 mN Compression displacement under load (L3) μm 153.1 153.1 153.1 153.1 153.1 Compression displacement during unloading (L4) μm 152.4 152.4 152.4 152.4 152.4 Ratio (L3/L4) - 1.00 1.00 1.00 1.00 1.00 Conductive part 1st conductive layer Material - Cu Cu Cu Ni Cu thickness μm 0.8 3.1 9.0 0.3 5.0 2nd conductive layer Material - Au Au Au Cu PD thickness μm 0.8 0.5 0.8 4.7 0.5 3rd conductive layer Material - - - - Au - thickness μm - - - 0.5 - Conductive particles particle size μm 501.6 503.6 509.8 505.5 505.5 Ratio (particle size of conductive particles/thickness of the first conductive layer) - 627 162 57 1685 101 Resistance value (R1) under 20% compression mΩ 31.2 4.7 28.2 3.3 3.0 Compression recovery rate when compressed by 20% % 95.0 100 93.2 100 100.0 Resistance value (R2) after 168 hours under 20% compression mΩ 43.4 4.7 44.9 3.3 3.1 Compression recovery rate after 168 hours under 20% compression % 90.9 100 91.1 99.1 100 Evaluation initial connection reliability - ○ ○○ ○ ○○ ○○ Long-term connection reliability - ○ ○○ ○ ○○ ○○ The state of the conductive particles in the connection structure - ○ ○○ ○ ○○ ○○

[Table 4] Comparative example 1 Comparative example 2 Comparative example 3 Substrate particles Monomer X type - APG-700 APG-700 - content weight% 50 50 - Monomer A type - PTMGA250 PTMGA250 content weight% 50 50 - Monomer B type - - - St. content weight% - - 90 Monomer C type - - - DVB content weight% - - 10 particle size μm 500 500 500 500 mN Compression displacement under load (L1) μm 107.6 107.6 5.2 Compression displacement at unloading (L2) μm 108.3 108.3 7.6 Ratio (L1/L2) - 0.99 0.99 0.68 1000 mN Compression displacement under load (L3) μm 153.1 153.1 8.6 Compression displacement during unloading (L4) μm 152.4 152.4 11.9 Ratio (L3/L4) - 1.00 1.00 0.72 Conductive part 1st conductive layer Material - Ni Cu Cu thickness μm 5.0 11.1 5.0 2nd conductive layer Material - Au Au Au thickness μm 0.5 0.5 0.5 3rd conductive layer Material - - - - thickness μm - - - Conductive particles particle size μm 505.5 511.6 505.5 Ratio (particle size of conductive particles/thickness of the first conductive layer) - 101 46 101 Resistance value (R1) under 20% compression mΩ 25.2 39.2 - Compression recovery rate when compressed by 20% % 79.7 82.2 - Resistance value (R2) after 168 hours under 20% compression mΩ 54.3 67.6 - Compression recovery rate after 168 hours under 20% compression % 76.8 73.4 - Evaluation initial connection reliability - ○ ○ x Long-term connection reliability - x x x The state of the conductive particles in the connection structure - x x x

1: Conductive particles 2: Substrate particles 3: Conductive part 11: Conductive particles 11a: Protrusion 12: Conductive part 12a: Protrusion 13: core substance 21: Conductive particles 23: Conductive part 23A: The first conductive layer 23B: The second conductive layer 31: Insulation member 31a: through hole 32: Solder paste department 33: electrode 34: Solder ball 51: Connection Construct 52: The first connection target member 52a: 1st electrode 53: The second connection target member 53a: 2nd electrode 54: Connecting part 81: Connection Construct 82: The first connection object member 82a: 1st electrode 83: The second connection target member 83a: 2nd electrode 84: connection part

Fig. 1 is a cross-sectional view showing conductive particles according to the first embodiment of the present invention. Fig. 2 is a cross-sectional view showing conductive particles according to a second embodiment of the present invention. Fig. 3 is a cross-sectional view showing conductive particles according to a third embodiment of the present invention. Fig. 4 is a front cross-sectional view schematically showing a connection structure using conductive particles according to the first embodiment of the present invention. Fig. 5 is a front cross-sectional view schematically showing another example of the connection structure using the conductive particles according to the first embodiment of the present invention.

Claims (11)

A conductive particle comprising a substrate particle and a conductive portion disposed on the surface of the substrate particle, and The compression recovery rate after compressing the conductive particles by 20% for 168 hours was over 85%. The conductive particle according to claim 1, wherein the above-mentioned conductive part has a first conductive layer, The material of the first conductive layer includes ductile metal, The ratio of the particle diameter of the said electroconductive particle with respect to the thickness of the said 1st conductive layer is 50-1000. The conductive particle according to claim 1 or 2, wherein the compressive deformation rate of the conductive particle is 10% or more when compressed with a load of 1000 mN. The conductive particle according to claim 1 or 2, wherein after the substrate particle is loaded to 1961 mN at a loading speed of 14.12 mN/s, and then unloaded at an unloading speed of 14.12 mN/s, The ratio of the compression displacement when the compression load is 500 mN when loaded to the compression displacement when the compression load is 500 mN when unloaded is 0.7 or more, The ratio of the compression displacement when the compression load is 1000 mN when loaded to the compression displacement when the compression load is 1000 mN when unloading is 0.7 or more. The conductive particle according to claim 1 or 2, wherein the material of the above-mentioned substrate particle comprises polyfunctional (meth)acrylate having a polyether skeleton, The content of the polyfunctional (meth)acrylate having a polyether skeleton is 5% by weight or more in 100% by weight of the material of the substrate particles. The conductive particle according to claim 1 or 2, wherein the particle diameter of the above-mentioned conductive particle is not less than 100 μm and not more than 1000 μm. The conductive particle according to claim 1 or 2, wherein the above-mentioned conductive part has a laminated structure of two or more layers, The material of the outer surface of the conductive portion is gold, silver, copper, tin, zinc, nickel, beryllium, cobalt, palladium, platinum, rhodium, ruthenium, iridium, or their alloys. The conductive particle according to claim 1 or 2, which is used to obtain a socket or a connector. A socket, which has a socket body, and conductive particles according to any one of claims 1 to 8, The said electroconductive particle comprises a connection terminal. A conductive material comprising the conductive particle according to any one of claims 1 to 8, and a binder. 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 There is a connecting part with an insulating member and conductive particles, The above-mentioned conductive particle is the conductive particle according to any one of claims 1 to 8, The first electrode and the second electrode are electrically connected through the conductive particles.

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