JP2016167449A - Conductive particle, method for producing conductive particle, conductive material and connection structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conductive particle that prevents cracks from occurring in a conductive part, can improve acid resistance, and thus can improve connection reliability.SOLUTION: A conductive particle has a base particle, and a conductive part disposed on the surface of the base particle. The conductive part comprises no hydrogen atom, or the conductive part comprises hydrogen atoms at the rate of 80 μg/g or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a conductive particle in which a conductive portion is disposed on the surface of a base particle and a method for producing the conductive particle. The present invention also relates to a conductive material and a connection structure using the conductive particles.

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

  In order to obtain various connection structures, the anisotropic conductive material is, for example, a connection between a flexible printed circuit board and a glass substrate (FOG (Film on Glass)) or a connection between a semiconductor chip and a flexible printed circuit board (COF ( Chip on Film)), connection between a semiconductor chip and a glass substrate (COG (Chip on Glass)), connection between a flexible printed circuit board and a glass epoxy substrate (FOB (Film on Board)), and the like.

  As an example of the conductive particles, Patent Document 1 below discloses conductive particles having base particles and a conductive metal layer covering the surface of the base particles. The conductive metal layer includes a nickel layer. In the conductive particles, the crystallite diameter in the [111] direction of nickel measured by powder X-ray analysis is 3 nm or less.

WO2013 / 042785A1

  For example, when an electrode of a semiconductor chip and an electrode of a glass substrate are electrically connected using an anisotropic conductive material, an anisotropic conductive material including conductive particles is disposed on the glass substrate. Next, the semiconductor chips are stacked, and heated and pressurized. Accordingly, the anisotropic conductive material is cured, and the electrodes are electrically connected through the conductive particles to obtain a connection structure. A liquid crystal display element is mentioned as an example of the connection structure obtained by such a method.

  In the liquid crystal display element, the narrowing of the frame of the liquid crystal panel and the thinning of the glass substrate are in progress. For this reason, the mounting portion is distorted, and display unevenness is likely to occur. In order to suppress display unevenness, it is required to perform pressure bonding at a low temperature during pressure bonding.

  However, when the pressure bonding is performed at a low temperature, the melt viscosity of the anisotropic conductive material increases. For this reason, at the time of pressure bonding at a low temperature, it is necessary to increase the pressure in order to make it difficult for voids to occur. As a result, a large stress is applied to the conductive particles. In addition, in manufacturing methods other than the manufacturing method of said connection structure, before use of electroconductive particle, a big stress may be provided to electroconductive particle.

  In the conventional conductive particles as described in Patent Document 1, when stress is applied to the conductive particles, the conductive layer may be cracked. As a result, when the connection structure is obtained by connecting the electrodes, the initial connection resistance may increase or the conduction reliability may decrease.

  Furthermore, when a connection structure in which conductive connection is performed using conventional conductive particles is exposed in the presence of an acid, the connection resistance between the electrodes may increase.

  Furthermore, when conventional conductive particles as described in Patent Document 1 are exposed in the presence of an acid, the conductive layer may be corroded. In addition, when a connection structure is obtained by connecting electrodes using conventional conductive particles, the connection resistance between the electrodes increases when the connection structure is exposed to the presence of an acid. There is.

  An object of the present invention is to provide a conductive particle and a method for producing the conductive particle that can make it difficult to cause cracks in the conductive part, can improve acid resistance, and thus can improve connection reliability. is there.

  Another object of the present invention is to provide a conductive material and a connection structure using the conductive particles.

  According to a wide aspect of the present invention, the method includes a base particle and a conductive portion disposed on a surface of the base particle, and the conductive portion does not include a hydrogen atom, or the conductive portion is a hydrogen atom. Is provided at 80 μg / g or less.

  In a specific aspect of the conductive particle according to the present invention, the conductive part includes a conductive part having a crystal structure, and in a cross-sectional observation of the conductive part having the crystal structure, a crystallite size in the conductive part having the crystal structure Is 50 nm or more.

  In a specific aspect of the conductive particle according to the present invention, the conductive part includes a conductive part having a crystal structure, and in the conductive part having the crystal structure, a half width of a diffraction peak obtained by X-ray diffraction and Scherrer's The crystallite size by the average value of the crystallite sizes of the (111) plane, (200) plane, (220) plane, (311) plane and (222) plane determined from the formula is 50 nm or more.

  In a specific aspect of the conductive particle according to the present invention, the conductive part includes a conductive part having a crystal structure, and in the conductive part having the crystal structure, a half width of a diffraction peak obtained by X-ray diffraction and Williamson -The crystallite size calculated | required from a Hall type | formula is 50 nm or more.

On the specific situation with the electroconductive particle which concerns on this invention, the compression elastic modulus when compressed 10% is 3000 N / mm < ² > or more.

  On the specific situation with the electroconductive particle which concerns on this invention, the Vickers hardness of the said electroconductive part is 200 or more.

  On the specific situation with the electroconductive particle which concerns on this invention, the said electroconductive part contains nickel, palladium, ruthenium, copper, tungsten, molybdenum, phosphorus, boron, gold | metal | money, platinum, or tin at least.

  On the specific situation with the electroconductive particle which concerns on this invention, the said electroconductive part contains nickel at least.

  On the specific situation with the electroconductive particle which concerns on this invention, the said base material particle is a resin particle or an organic inorganic hybrid particle.

  On the specific situation with the electroconductive particle which concerns on this invention, the said electroconductive particle has several protrusion on the outer surface of the said electroconductive part.

  On the specific situation with the electroconductive particle which concerns on this invention, the said electroconductive particle is provided with the insulating substance arrange | positioned on the outer surface of the said electroconductive part.

  According to a wide aspect of the present invention, there is provided a method for producing the above-described conductive particles, wherein the conductive particles are formed using base particles and conductive particles disposed on the surfaces of the base particles. A process of annealing the conductive particles to 200 ° C. or higher, and the conductive part obtains conductive particles in which the conductive part does not contain hydrogen atoms or the conductive part contains hydrogen atoms at 80 μg / g or less by the annealing treatment. A method for producing a conductive particle is provided.

  According to a wide aspect of the present invention, there is provided a conductive material including the above-described conductive particles and a binder resin.

  According to a wide aspect of the present invention, the first connection target member, the second connection target member, the connection portion connecting the first connection target member, and the second connection target member; There is provided a connection structure in which the material of the connection portion is the above-described conductive particles or a conductive material containing the conductive particles and a binder resin.

  In the electroconductive particle which concerns on this invention, the electroconductive part is arrange | positioned on the surface of base material particle, The said electroconductive part does not contain a hydrogen atom, or the said electroconductive part contains a hydrogen atom at 80 microgram / g or less. Therefore, it is possible to make it difficult to cause cracks in the conductive portion, and it is possible to increase the acid resistance, and thus to improve the connection reliability.

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

  Details of the present invention will be described below.

(Conductive particles)
The electroconductive particle which concerns on this invention is equipped with base material particle and the electroconductive part arrange | positioned on the surface of this base material particle.

  In the electroconductive particle which concerns on this invention, the said electroconductive part does not contain a hydrogen atom, or the said electroconductive part contains a hydrogen atom at 80 microgram / g or less. That is, in the conductive particles according to the present invention, the content of hydrogen atoms in the conductive part is extremely small.

  In the present invention, since the above-described configuration is provided, it is possible to make it difficult for the conductive portion to be cracked, to improve acid resistance, and thus to improve connection reliability.

  In addition, by making the conductive part less susceptible to cracking, even when the conductive material is cured at a relatively low temperature and crimped in a state where the melt viscosity of the conductive material is high, the connection resistance between the electrodes is sufficiently low, A connection structure having excellent reliability can be obtained. Use of the conductive particles according to the present invention can cope with narrowing and thinning of the connection target member.

  Furthermore, in the present invention, since the conductive portion is not easily cracked, the connection structure is obtained using the conductive particles exposed in the presence of acid, or the connection structure is exposed in the presence of acid. However, the connection resistance can be kept low.

  From the viewpoint of further suppressing cracking of the conductive part and further increasing the acid resistance, the smaller the hydrogen atom content in the conductive part, the better. The hydrogen atom content in the conductive part is preferably 60 μg / g or less, more preferably 40 μg / g or less, and most preferably 0 μg / g (not contained).

  Examples of the method for measuring the hydrogen atom content in the conductive part include a temperature programmed desorption method, a high temperature dissolved hydrogen extraction method, a glycerol substitution method, and an electrochemical release method. A temperature programmed desorption method is preferred, and a temperature programmed desorption method using a temperature programmed desorption hydrogen analyzer is more preferred.

  The hydrogen atom content in the conductive part can be measured as follows.

  In the temperature-programmed desorption method using a temperature-programmed desorption hydrogen analyzer, a conductive portion is heated by heating using a temperature-programmed desorption device, and the generated trace amount of hydrogen is measured by a sensor gas chromatograph. Under a constant pressure of 3 GPa, the evacuated conductive part is gradually heated from 50 ° C. to 400 ° C. at a rate of temperature increase of 5 ° C./min. The released hydrogen atoms are measured with a sensor gas chromatograph.

  Regarding the method for calculating the hydrogen atom content in the conductive part, first, the hydrogen atom content in the conductive particles is measured to obtain a measured value of the hydrogen atom content. Next, the content of hydrogen atoms in the substrate particles before forming the conductive part is measured to obtain a measurement value of the content of hydrogen atoms. By subtracting the measured value of the hydrogen atom content in the base particle from the measured value of the hydrogen atom content in the conductive particle, the numerical value of the hydrogen atom content in the conductive part can be obtained.

  Content of hydrogen atom in conductive part = content of hydrogen atom in conductive particle−content of hydrogen atom in substrate particle

  In addition, regarding the calculation method of the hydrogen atom content in the conductive part, the conductive part is peeled from the conductive particles, only the conductive part is sampled, the hydrogen atom content in the conductive part is measured, and the hydrogen atom content is determined. A measure of quantity can be obtained. As a method for collecting a sample of the conductive part to be measured, first, the conductive particles are pulverized using a ball mill with zirconia balls, and the conductive part is completely peeled off from the base particles to obtain a sample. The sample is separated into a conductive part and substrate particles by a dry sieve, and only the conductive part is collected.

  In general, the conductive portion of the conductive particle contains a relatively large amount of hydrogen atoms. For example, when the conductive portion is formed by electroless plating, a high concentration reducing agent is required because the plating particle surface area of the conductive particles is large. For this reason, since hydrogen is generated by oxidative decomposition of a large amount of the reducing agent, the conductive portion contains a relatively large amount of hydrogen atoms. In the present invention, hydrogen atoms in the conductive part are actively reduced.

  As a method for reducing the hydrogen atom content in the conductive part, a method of annealing after forming the conductive part, a method of reducing the concentration of reducing agent used during plating, a surfactant is added during plating, A method of lowering the surface tension of the particle surface and increasing hydrogen desorption, a method of increasing the stirring speed of the plating solution during plating and increasing hydrogen desorption, and controlling the reaction temperature and pH during plating, Examples thereof include a method for suppressing the self-decomposition reaction of the reducing agent. These methods can be used in combination so that the content of hydrogen atoms is sufficiently reduced.

  From the viewpoint of further suppressing cracking of the conductive part and further improving acid resistance, the crystallite size in the conductive part is preferably 50 nm or more, more preferably 100 nm or more. From the viewpoint of further suppressing cracking of the conductive portion and further improving acid resistance, it is preferable that the conductive portion includes a conductive portion having a crystal structure. From the viewpoint of further suppressing cracking of the conductive part and further improving acid resistance, the crystallite size in the conductive part having the above crystal structure is preferably 50 nm or more, more preferably 100 nm or more.

  From the viewpoint of further suppressing the cracking of the conductive part and further improving the acid resistance, in the conductive part having the above crystal structure, the crystallite obtained from the half width of the diffraction peak obtained by X-ray diffraction and the Williamson-Hole equation The size is preferably 50 nm or more, more preferably 100 nm or more.

  From the viewpoint of further suppressing the cracking of the conductive part and further improving the acid resistance, in the conductive part having the above crystal structure, the (111) plane is obtained from the half width of the diffraction peak obtained by X-ray diffraction and the Scherrer equation. , (200) plane, (220) plane, (311) plane, and (222) plane average crystallite size is preferably 50 nm or more, more preferably 100 nm or more.

  The crystallite size can be measured as follows.

  The obtained conductive particles are added to “Technobit 4000” manufactured by Kulzer so as to have a content of 30% by weight, and dispersed to prepare an embedded resin for testing conductive particles. A cross section of the conductive particles is cut out by using an ion milling device (“IM4000” manufactured by Hitachi High-Technologies Corporation) so as to pass near the center of the dispersed conductive particles in the embedding resin for inspection.

  Using FE-SEM-EBSP, crystal grain mapping measurement is performed on the cross section of the conductive portion having a crystal structure in the conductive particles. The crystallite size is determined by checking the particle size distribution chart of the crystallite size.

  The crystallite size can be measured as follows.

  Powder X-ray diffraction measurement is performed using an X-ray diffractometer (“RINT2500VHF” manufactured by Rigaku Corporation). The crystallite size of the (111) plane, (200) plane, (220) plane, (311) plane and (222) plane obtained from the half width of the diffraction peak obtained by X-ray diffraction with CuKα rays and the Scherrer equation The crystallite size is determined from the average value.

  The conductive particle includes a base particle and a conductive part, and the conductive part includes a first conductive part having a crystal structure and a second conductive part having a crystal structure. 1 conductive portion is disposed on the surface of the substrate particle, and the second conductive portion is disposed on the outer surface of the first conductive portion so as to be in contact with the first conductive portion. The conductive particles are preferably. You may measure the crystallite size of the 1st electroconductive part in this electroconductive particle.

  The conductive particle includes a base particle and a conductive part, and the conductive part is only a first conductive part having a crystal structure, and the first conductive part is formed of the base particle. The conductive particles are preferably disposed on the surface. You may measure the crystallite size of the 1st electroconductive part of this electroconductive particle.

  The crystallite size can be calculated by the following Scherrer equation.

D = kλ / βcosθ
D: crystallite size K: Scherrer constant λ: wavelength of X-ray β: half-value width [rad]
θ: Diffraction angle

  The crystallite size can be calculated by the following Williamson-Hole equation.

Δ2θ · cos θ / λ = 0.9 / D + 2ε · sin θ / λ
D: crystallite size λ: wavelength of X-ray Δ2θ: half-value width [rad]
θ: diffraction angle ε: lattice strain

  The crystallite size is plotted by taking 2 sin θ / λ on the horizontal axis and Δ2θ · cos θ / λ on the vertical axis according to the above-mentioned Williamson-Hole equation, and the crystallite size is calculated from the value of the intercept of the plot.

From the viewpoint of further suppressing cracking of the conductive part and further improving the acid resistance, the compressive elastic modulus (10% K value) when the conductive particles are compressed by 10% is preferably 3000 N / mm ² or more. Preferably it is 5000 N / mm ² or more, preferably 20000 N / mm ² or less, more preferably 10,000 N / mm ² or less.

  The 10% K value of the conductive particles can be measured as follows.

  Using a micro-compression tester, the conductive particles are compressed on a cylindrical indenter end face (diameter 50 μm, made of diamond) under conditions of applying a maximum test load of 90 mN over 30 seconds at 25 ° C. The load value (N) and compression displacement (mm) at this time are measured. From the measured value obtained, the compression elastic modulus can be obtained by the following formula. As the micro compression tester, for example, “Fischer Scope H-100” manufactured by Fischer is used.

K value (N / mm ² ) = (3/2 ^1/2 ) · F · S ⁻³ / ² · R ^−1/2
F: Load value when the conductive particles are 10% compressively deformed (N)
S: Compression displacement (mm) when the conductive particles are 10% compressively deformed
R: radius of conductive particles (mm)

  From the viewpoint of further suppressing cracking of the conductive part and further improving acid resistance, the Vickers hardness of the conductive part in the conductive particles is preferably 200 or more, more preferably 300 or more, and even more preferably 500 or more. , Preferably 1000 or less, more preferably 800 or less. From the viewpoint of further suppressing cracking of the conductive part and further improving acid resistance, the Vickers hardness of the conductive part having the crystal structure in the conductive particles is preferably 200 or more, more preferably 300 or more, and still more preferably. 500 or more, preferably 1000 or less, more preferably 800 or less.

  From the viewpoint of further reducing the connection resistance and further improving the conduction reliability, the conductive particles preferably have a plurality of protrusions on the outer surface of the conductive portion. Furthermore, it is preferable that the conductive particles include a plurality of core substances that protrude the outer surface of the conductive portion so as to form the plurality of protrusions in the conductive portion.

  From the viewpoint of further reducing the connection resistance and further improving the conduction reliability, the surface area of the portion having the protrusion is preferably 10% or more, more preferably 30% or more, out of the total surface area of 100% of the conductive particles. Preferably, it is 95% or less, more preferably 90% or less.

  The surface area of the portion with the protrusion is obtained by observing the conductive particles with an electron microscope or an optical microscope, and calculating the percentage of the surface area of the portion with the protrusion with respect to the projected area of the particle. In the case of a plurality of conductive particles, the surface area of the portion where the protrusions are present is preferably observed by observing 10 arbitrary conductive particles with an electron microscope or a field emission scanning electron microscope (FE-SEM), It is obtained by calculating the average value of the percentage of the surface area of the portion where the protrusion is present to the projected area of the particle.

  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 conductive particles 1 shown in FIG. 1 have base material particles 2 and conductive portions 3. The conductive portion 3 is disposed on the surface of the base particle 2. The conductive portion 3 is in contact with the surface of the base particle 2. The conductive particle 1 is a coated particle in which the surface of the base particle 2 is coated with the conductive portion 3. In the conductive particle 1, the conductive part 3 is a single-layer conductive part (conductive layer).

  Unlike the conductive particles 11 and 21 described later, the conductive particles 1 do not have a core substance. The conductive particles 1 do not have protrusions on the conductive surface, and do not have protrusions on the outer surface of the conductive portion 3. The conductive particles 1 are spherical.

  As described above, the conductive particles according to the present invention may not have protrusions on the conductive surface, may not have protrusions on the outer surface of the conductive portion, and may be spherical. . Moreover, the electroconductive particle 1 does not have an insulating substance unlike the electroconductive particles 11 and 21 mentioned later. However, the conductive particles 1 may have an insulating substance disposed on the outer surface of the conductive portion 3.

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

  A conductive particle 11 shown in FIG. 2 includes a base particle 2, a conductive portion 12, a plurality of core substances 13, and a plurality of insulating substances 14. The conductive portion 12 is disposed on the surface of the base particle 2 so as to be in contact with the base particle 2. In the conductive particles 11, the conductive portion 12 is a single-layer conductive portion (conductive layer).

  The conductive particles 11 have a plurality of protrusions 11a on the conductive surface. The conductive portion 12 has a plurality of protrusions 12a on the outer surface. A plurality of core substances 13 are arranged on the surface of the base particle 2. The plurality of core materials 13 are embedded in the conductive portion 12. The core substance 13 is disposed inside the protrusions 11a and 12a. The conductive portion 12 covers a plurality of core substances 13. The outer surface of the conductive portion 12 is raised by the plurality of core materials 13, and protrusions 11 a and 12 a are formed.

  The conductive particles 11 have an insulating substance 14 disposed on the outer surface of the conductive portion 12. At least a part of the outer surface of the conductive portion 12 is covered with the insulating material 14. The insulating substance 14 is made of an insulating material and is an insulating particle. Thus, the electroconductive particle which concerns on this invention may have the insulating substance arrange | positioned on the outer surface of an electroconductive part. However, the conductive particles according to the present invention do not necessarily have an insulating substance.

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

  The conductive particles 21 shown in FIG. 3 include base material particles 2, conductive portions 22, a plurality of core materials 13, and a plurality of insulating materials 14. The conductive part 22 as a whole has a first conductive part 22A on the base particle 2 side and a second conductive part 22B on the side opposite to the base particle 2 side.

  The conductive particles 11 and the conductive particles 21 differ only in the conductive part. That is, the conductive particles 11 are formed with the conductive portion 12 having a single-layer structure, whereas the conductive particles 21 are formed with the first conductive portion 22A and the second conductive portion 22B having a two-layer structure. ing. The first conductive portion 22A and the second conductive portion 22B are formed as separate conductive portions.

  The first conductive portion 22 </ b> A is disposed on the surface of the base particle 2. 22 A of 1st electroconductive parts are arrange | positioned between the base particle 2 and the 2nd electroconductive part 22B. The first conductive portion 22 </ b> A is in contact with the base material particle 2. Accordingly, the first conductive portion 22A is disposed on the surface of the base particle 2, and the second conductive portion 22B is disposed on the outer surface of the first conductive portion 22A. The second conductive portion 22B is not in contact with the base particle 2. The conductive particles 21 have a plurality of protrusions 21a on the conductive surface. The conductive portion 22 has a plurality of protrusions 22a on the outer surface. The first conductive portion 22A has a protrusion 22Aa on the outer surface. The second conductive portion 22B has a plurality of protrusions 22Ba on the outer surface. In the conductive particles 21, the conductive portion 22 is a two-layer conductive portion (conductive layer). The conductive particles may include a third conductive part disposed on the outer surface of the second conductive part. The conductive part may be a conductive part having three or more layers.

  Hereinafter, other details of the conductive particles will be described. In the following description, “(meth) acryl” means one or both of “acryl” and “methacryl”, and “(meth) acrylate” means one or both of “acrylate” and “methacrylate”. means.

[Base material particles]
Examples of the substrate particles include resin particles, inorganic particles excluding metal particles, organic-inorganic hybrid particles, and metal particles. The base particle may be a core-shell particle including a core and a shell disposed on the surface of the core. The core may be an organic core. The shell may be an inorganic shell. Of these, substrate particles excluding metal particles are preferable, and resin particles, inorganic particles excluding metal particles, or organic-inorganic hybrid particles are more preferable. Resin particles or organic-inorganic hybrid particles are particularly preferred because they are more excellent due to the effects of the present invention.

  The substrate particles are preferably resin particles formed of a resin. When connecting between electrodes using the said electroconductive particle, after arrange | positioning the said electroconductive particle between electrodes, the said electroconductive particle is compressed by crimping | bonding. When the substrate particles are resin particles, the conductive particles are easily deformed during the pressure bonding, and the contact area between the conductive particles and the electrode is increased. For this reason, the conduction | electrical_connection reliability between electrodes becomes high.

  Various organic materials are suitably used as the resin for forming the resin particles. Examples of the resin for forming the resin particles include polyolefin resins such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyisobutylene, and polybutadiene; acrylic resins such as polymethyl methacrylate and polymethyl acrylate; Alkylene terephthalate, polycarbonate, polyamide, phenol formaldehyde resin, melamine formaldehyde resin, benzoguanamine formaldehyde resin, urea formaldehyde resin, phenol resin, melamine resin, benzoguanamine resin, urea resin, epoxy resin, unsaturated polyester resin, saturated polyester resin, polysulfone, polyphenylene Oxide, polyacetal, polyimide, polyamideimide, polyether ether Ketones, polyether sulfones, and polymers such as obtained by a variety of polymerizable monomer having an ethylenically unsaturated group is polymerized with one or more thereof. Since the hardness of the substrate particles can be easily controlled within a suitable range, the resin for forming the resin particles is obtained by polymerizing one or more polymerizable monomers having a plurality of ethylenically unsaturated groups. A polymer is preferred.

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

  Examples of the non-crosslinkable monomer include styrene monomers such as styrene and α-methylstyrene; carboxyl group-containing monomers such as (meth) acrylic acid, maleic acid, and maleic anhydride; (Meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl ( Alkyl (meth) acrylates such as meth) acrylate and isobornyl (meth) acrylate; oxygen such as 2-hydroxyethyl (meth) acrylate, glycerol (meth) acrylate, polyoxyethylene (meth) acrylate and glycidyl (meth) acrylate (Meth) acrylates; nitrile-containing monomers such as (meth) acrylonitrile; vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether; vinyl acids such as vinyl acetate, vinyl butyrate, vinyl laurate, vinyl stearate Esters; Unsaturated hydrocarbons such as ethylene, propylene, isoprene and butadiene; Halogen-containing monomers such as trifluoromethyl (meth) acrylate, pentafluoroethyl (meth) acrylate, vinyl chloride, vinyl fluoride and chlorostyrene Is mentioned.

  Examples of the crosslinkable monomer include tetramethylolmethane tetra (meth) acrylate, tetramethylolmethane tri (meth) acrylate, tetramethylolmethane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, and dipenta Erythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, glycerol tri (meth) acrylate, glycerol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) Polyfunctional (meth) acrylates such as acrylate, (poly) tetramethylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate; triallyl (iso) cyanure And silane-containing monomers such as triallyl trimellitate, divinylbenzene, diallyl phthalate, diallylacrylamide, diallyl ether, γ- (meth) acryloxypropyltrimethoxysilane, trimethoxysilylstyrene, vinyltrimethoxysilane It is done.

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

  In the case where the substrate particles are inorganic particles or organic-inorganic hybrid particles excluding metal particles, examples of inorganic substances for forming the substrate particles include silica and carbon black. The inorganic substance is preferably not a metal. The particles formed from the silica are not particularly limited. For example, after forming a crosslinked polymer particle by hydrolyzing a silicon compound having two or more hydrolyzable alkoxysilyl groups, firing may be performed as necessary. The particle | grains obtained by performing are mentioned. Examples of the organic / inorganic hybrid particles include organic / inorganic hybrid particles formed of a crosslinked alkoxysilyl polymer and an acrylic resin.

  When the substrate particles are metal particles, examples of the metal that is a material of the metal particles include silver, copper, nickel, silicon, gold, and titanium. However, the substrate particles are preferably not metal particles, and preferably not copper particles.

  The particle diameter of the substrate particles is preferably 0.1 μm or more, more preferably 1.0 μm or more, further preferably 1.5 μm or more, particularly preferably 2.0 μm or more, preferably 1000 μm or less, more preferably It is 500 μm or less, more preferably 300 μm or less, further preferably 50 μm or less, still more preferably 30 μm or less, still more preferably 8.0 μm or less, particularly preferably 5.0 μm or less, and most preferably 4.0 μm or less. When the particle diameter of the substrate particles is equal to or greater than the lower limit, the contact area between the conductive particles and the electrodes is increased, so that the conduction reliability between the electrodes is further increased and the conductive particles are connected via the conductive particles. The connection resistance between the electrodes is further reduced. Further, when the conductive portion is formed on the surface of the base particle by electroless plating, it becomes difficult to aggregate, and the aggregated conductive particles are hardly formed. When the particle diameter of the substrate particles is not more than the above upper limit, cracking of the conductive part is further less likely to occur, the conductive particles are sufficiently compressed, the connection resistance between the electrodes is further reduced, and the inter-electrode resistance is further reduced. The interval is reduced.

  The particle diameter of the base particle indicates a diameter when the base particle is a true sphere, and indicates a maximum diameter when the base particle is not a true sphere.

  The particle diameter of the substrate particles is particularly preferably 2 μm or more and 5 μm or less. When the particle diameter of the substrate particles is in the range of 2 to 5 μm, even when the distance between the electrodes is small and the thickness of the conductive part is increased, small conductive particles can be obtained.

  Further, the particle diameter of the base particle is particularly preferably 1.0 μm or more and 4.0 μm or less. When the particle diameter of the substrate particles is satisfied, the conductive part is hardly cracked, and the connection resistance is further effectively reduced.

[Conductive part]
The metal for forming the conductive part is not particularly limited. Examples of the metal include gold, silver, palladium, copper, platinum, zinc, iron, tin, lead, ruthenium, aluminum, cobalt, indium, nickel, chromium, titanium, antimony, bismuth, thallium, germanium, cadmium, and silicon. And alloys thereof. Examples of the metal include tin-doped indium oxide (ITO) and solder. Especially, since the connection resistance between electrodes can be made still lower, an alloy containing tin, nickel, palladium, copper or gold is preferable, and nickel or palladium is preferable.

  From the viewpoint of further suppressing cracking of the conductive part and further improving acid resistance, the conductive part may contain at least nickel, palladium, ruthenium, copper, tungsten, molybdenum, phosphorus, boron, gold, platinum, or tin. Preferably, it contains at least nickel. The conductive portion preferably includes at least nickel, palladium, copper, tungsten, molybdenum, phosphorus, boron, gold, platinum, or tin, and may include at least nickel. From the viewpoint of further suppressing cracking of the conductive part and further improving acid resistance, the conductive part having the above crystal structure is made of nickel, palladium, ruthenium, copper, tungsten, molybdenum, phosphorus, boron, gold, platinum, or tin. It is preferable to contain at least nickel, more preferably at least nickel, nickel, palladium, copper, tungsten, molybdenum, phosphorus, boron, gold, platinum or tin is preferably contained, and nickel may be contained at least.

  Like the conductive particles 1 and 11, the conductive part may be formed of one layer. Like the electroconductive particle 21, the electroconductive part may be formed of the some layer. That is, the conductive part may have a laminated structure of two or more layers. When the conductive portion is formed of a plurality of layers, the outermost layer is preferably a gold layer, a nickel layer, a palladium layer, a copper layer, or an alloy layer containing tin and silver, and is a gold layer. Is more preferable. When the outermost layer is these preferred conductive layers, the connection resistance between the electrodes is further reduced. Moreover, when the outermost layer is a gold layer, the corrosion resistance is further enhanced.

  The method for forming the conductive part on the surface of the substrate particle is not particularly limited. As a method for forming the conductive portion, for example, a method by electroless plating, a method by electroplating, a method by physical vapor deposition, and a method of coating the surface of base particles with metal powder or a paste containing metal powder and a binder Etc. Especially, since formation of an electroconductive part is simple, the method by electroless plating is preferable. Examples of the method by physical vapor deposition include methods such as vacuum vapor deposition, ion plating, and ion sputtering.

  The particle diameter of the conductive particles is preferably 0.5 μm or more, more preferably 1 μm or more, preferably 520 μm or less, more preferably 500 μm or less, still more preferably 100 μm or less, still more preferably 50 μm or less, particularly preferably. Is 20 μm or less. When the particle diameter of the conductive particles is not less than the above lower limit and not more than the above upper limit, when the electrodes are connected using the conductive particles, the contact area between the conductive particles and the electrode becomes sufficiently large, and the conductive part When forming the conductive particles, it becomes difficult to form aggregated conductive particles. Further, the distance between the electrodes connected via the conductive particles does not become too large, and the conductive portion is difficult to peel from the surface of the base particle. Further, when the particle diameter of the conductive particles is not less than the above lower limit and not more than the above upper limit, the conductive particles can be suitably used for the use of the conductive material.

  The particle diameter of the conductive particles means the diameter when the conductive particles are true spherical, and means the maximum diameter when the conductive particles have a shape other than the true spherical shape.

  The thickness of the conductive part (total thickness of the conductive part) is preferably 0.005 μm or more, more preferably 0.01 μm or more, preferably 10 μm or less, more preferably 1 μm or less, and even more preferably 0.5 μm or less, Especially preferably, it is 0.3 micrometer or less. The thickness of the conductive portion is the thickness of the entire conductive layer when the conductive portion is a multilayer. When the thickness of the conductive part is not less than the above lower limit and not more than the above upper limit, sufficient conductivity can be obtained, and the conductive particles are not too hard, and the conductive particles are sufficiently deformed when connecting the electrodes. .

  When the conductive part is formed of a plurality of layers, the thickness of the outermost conductive layer is preferably 0.001 μm or more, more preferably 0.01 μm or more, preferably 0.5 μm or less, more preferably Is 0.1 μm or less. When the thickness of the outermost conductive layer is not less than the above lower limit and not more than the above upper limit, the coating with the outermost conductive layer becomes uniform, the corrosion resistance becomes sufficiently high, and the connection resistance between the electrodes is further increased. Lower. Further, when the outermost layer is a gold layer, the thinner the gold layer, the lower the cost.

  The thickness of the said electroconductive part can be measured by observing the cross section of electroconductive particle, for example using a field emission type | mold scanning electron microscope (FE-SEM).

  The obtained conductive particles are added to “Technobit 4000” manufactured by Kulzer so as to have a content of 30% by weight, and dispersed to prepare an embedded resin for testing conductive particles. A cross section of the conductive particles is cut out using an ion milling device ("IM4000" manufactured by Hitachi High-Technologies Corporation) so as to pass through the vicinity of the center of the conductive particles dispersed in the embedded resin for inspection.

  Then, using a field emission scanning electron microscope (FE-SEM), the image magnification is set to 50,000 times, 50 conductive particles are randomly selected, and the conductive portion of each conductive particle is observed. It is preferable to do. It is preferable to measure the thickness of the conductive part in the obtained conductive particles and arithmetically average it to obtain the thickness of the conductive part.

  From the viewpoint of effectively increasing the conductivity, the conductive particles preferably have a conductive portion containing nickel. In 100% by weight of the conductive part containing nickel, the nickel content is preferably 50% by weight or more, more preferably 65% by weight or more, still more preferably 70% by weight or more, still more preferably 75% by weight or more, and even more preferably. Is 80% by weight or more, particularly preferably 85% by weight or more, and most preferably 90% by weight or more. In 100% by weight of the conductive part containing nickel, the content of nickel is preferably 100% by weight (total amount) or less, 99% by weight or less, or 95% by weight or less. When the nickel content is at least the above lower limit, the connection resistance between the electrodes is further reduced. Moreover, when there are few oxide films in the surface of an electrode or an electroconductive part, there exists a tendency for the connection resistance between electrodes to become low, so that there is much content of nickel.

  The measuring method of content of the metal contained in the said electroconductive part can use various known analytical methods, and is not specifically limited. Examples of this measuring method include absorption spectrometry or spectrum analysis. In the above-mentioned absorption analysis method, a flame absorptiometer, an electric heating furnace absorptiometer, or the like can be used. Examples of the spectrum analysis method include a plasma emission analysis method and a plasma ion source mass spectrometry method.

  When measuring the average content of the metal contained in the conductive part, it is preferable to use an ICP emission analyzer. Examples of commercially available ICP emission analyzers include ICP emission analyzers manufactured by HORIBA.

  The conductive part may contain phosphorus or boron in addition to nickel. The conductive portion may contain a metal other than nickel. In the conductive part, when a plurality of metals are included, the plurality of metals may be alloyed.

  In 100% by weight of the conductive part containing nickel and phosphorus or boron, the content of phosphorus or boron is preferably 0.1% by weight or more, more preferably 1% by weight or more, preferably 10% by weight or less, more preferably Is 5% by weight or less. When the content of phosphorus or boron is not more than the above lower limit and the above upper limit, the resistance of the conductive portion is further reduced, and the conductive portion contributes to the reduction of connection resistance.

[Core material]
The conductive particles preferably have protrusions on the conductive surface. The conductive particles preferably have protrusions on the outer surface of the conductive part. It is preferable that there are a plurality of protrusions. An oxide film is often formed on the surface of the electrode connected by the conductive particles. Furthermore, an oxide film is often formed on the surface of the conductive part of the conductive particles. By using the conductive particles having the protrusions, the oxide film is effectively eliminated by the protrusions by placing the conductive particles between the electrodes and then pressing them. For this reason, an electrode and electroconductive particle can be contacted still more reliably and the connection resistance between electrodes can be made low. Furthermore, when the conductive particles have an insulating material on the surface, or when the conductive particles are dispersed in a binder resin and used as a conductive material, the conductive particles and the electrodes are separated by protrusions of the conductive particles. The resin in between can be effectively eliminated. For this reason, the conduction | electrical_connection reliability between electrodes becomes still higher.

  Since the core substance is embedded in the conductive portion, it is easy for the conductive portion to have a plurality of protrusions on the outer surface. However, the core substance is not necessarily used in order to form protrusions on the conductive surface of the conductive particles and the surface of the conductive portion.

  As a method for forming the protrusions, a method of forming a conductive part by electroless plating after attaching a core substance to the surface of the base particle, and a method of forming a conductive part by electroless plating on the surface of the base particle And a method of forming a conductive part by electroless plating, and a method of adding a core substance in the middle of forming the conductive part by electroless plating on the surface of the substrate particles.

  Examples of the material of the core substance include a conductive substance and a non-conductive substance. Examples of the conductive material include conductive non-metals such as metals, metal oxides, and graphite, and conductive polymers. Examples of the conductive polymer include polyacetylene. Examples of the non-conductive substance include silica, alumina, barium titanate, zirconia, and the like. Among them, metal is preferable because conductivity can be increased and connection resistance can be effectively reduced. The core substance is preferably metal particles. As the metal that is the material of the core substance, the metals mentioned as the material of the conductive material can be used as appropriate.

  Specific examples of the core material include barium titanate (Mohs hardness 4.5), nickel (Mohs hardness 5), silica (silicon dioxide, Mohs hardness 6-7), titanium oxide (Mohs hardness 7), zirconia. (Mohs hardness 8-9), alumina (Mohs hardness 9), tungsten carbide (Mohs hardness 9), diamond (Mohs hardness 10), and the like. The inorganic particles are preferably nickel, silica, titanium oxide, zirconia, alumina, tungsten carbide or diamond, more preferably silica, titanium oxide, zirconia, alumina, tungsten carbide or diamond, titanium oxide, zirconia. Alumina, tungsten carbide or diamond is more preferable, and zirconia, alumina, tungsten carbide or diamond is particularly preferable. The Mohs hardness of the core material is preferably 5 or more, more preferably 6 or more, still more preferably 7 or more, and particularly preferably 7.5 or more.

  The shape of the core material is not particularly limited. The shape of the core substance is preferably a lump. Examples of the core substance include a particulate lump, an agglomerate in which a plurality of fine particles are aggregated, and an irregular lump.

  The average diameter (average particle diameter) of the core substance is preferably 0.001 μm or more, more preferably 0.05 μm or more, preferably 0.9 μm or less, more preferably 0.2 μm or less. When the average diameter of the core substance is not less than the above lower limit and not more than the above upper limit, the connection resistance between the electrodes is effectively reduced.

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

  The number of the protrusions per conductive particle is preferably 3 or more, more preferably 5 or more. The upper limit of the number of protrusions is not particularly limited. The upper limit of the number of protrusions can be appropriately selected in consideration of the particle diameter of the conductive particles.

  The average height of the plurality of protrusions is preferably 0.001 μm or more, more preferably 0.05 μm or more, preferably 0.9 μm or less, more preferably 0.2 μm or less. When the average height of the protrusions is not less than the above lower limit and not more than the above upper limit, the connection resistance between the electrodes is effectively reduced.

[Insulating material]
The conductive particles preferably include an insulating material disposed on the surface of the conductive part. In this case, when the conductive particles are used for connection between the electrodes, a short circuit between adjacent electrodes can be further prevented. Specifically, when a plurality of conductive particles are in contact with each other, an insulating material is present between the plurality of electrodes, so that it is possible to prevent a short circuit between electrodes adjacent in the lateral direction instead of between the upper and lower electrodes. It should be noted that the insulating material between the conductive portion of the conductive particles and the electrode can be easily removed by pressurizing the conductive particles with the two electrodes when connecting the electrodes. When the conductive particles have a plurality of protrusions on the outer surface of the conductive part, the insulating substance between the conductive part of the conductive particles and the electrode can be more easily removed.

  The insulating substance is preferably an insulating particle because the insulating substance can be more easily removed when the electrodes are pressed.

  Specific examples of the insulating resin that is the material of the insulating material include polyolefins, (meth) acrylate polymers, (meth) acrylate copolymers, block polymers, thermoplastic resins, crosslinked thermoplastic resins, heat Examples thereof include curable resins and water-soluble resins.

  The average diameter (average particle diameter) of the insulating material can be appropriately selected depending on the particle diameter of the conductive particles, the use of the conductive particles, and the like. The average diameter (average particle diameter) of the insulating substance is preferably 0.005 μm or more, more preferably 0.01 μm or more, preferably 1 μm or less, more preferably 0.5 μm or less. When the average diameter of the insulating material is equal to or greater than the lower limit, when the conductive particles are dispersed in the binder resin, the conductive portions in the plurality of conductive particles are difficult to contact each other. When the average diameter of the insulating particles is not more than the above upper limit, it is not necessary to increase the pressure too much in order to eliminate the insulating substance between the electrodes and the conductive particles when connecting the electrodes, There is no need to heat to high temperatures.

  The “average diameter (average particle diameter)” of the insulating material indicates a number average diameter (number average particle diameter). The average diameter of the insulating material is determined using a particle size distribution measuring device or the like.

(Method for producing conductive particles)
The method for producing conductive particles according to the present invention uses the conductive particles (pre-annealed conductive particles) having base particles and conductive portions arranged on the surfaces of the base particles. A step of annealing the particles to 200 ° C. or higher. In the method for producing conductive particles according to the present invention, conductive particles in which the conductive part does not contain hydrogen atoms or the conductive part contains hydrogen atoms at 80 μg / g or less are obtained by the annealing treatment. In particular, the conductive portion having the crystal structure is preferably subjected to the annealing treatment.

  In order to reduce the content of hydrogen atoms in the conductive portion, the annealing temperature is preferably 200 ° C. or higher, more preferably 300 ° C. or higher. Moreover, the temperature of annealing treatment is below the thermal decomposition temperature of a base particle, and below the thermal decomposition temperature of an electroconductive part. The annealing temperature is preferably 30 ° C. or more lower than the thermal decomposition temperature of the base particles. The temperature of the annealing treatment is preferably 800 ° C. or lower, more preferably 500 ° C. or lower.

  In order to reduce the content of hydrogen atoms in the conductive part, the annealing time is preferably 0.5 hours or more, more preferably 1 hour or more, and further preferably 3 hours or more.

  In order to reduce the content of hydrogen atoms in the conductive part, the annealing treatment is preferably performed in a high-pressure atmosphere. The degree of vacuum during the annealing treatment is preferably 10 kPa or more, more preferably 50 kPa or more, and further preferably 100 kPa or more.

  In order to reduce the content of hydrogen atoms in the conductive portion, when annealing is performed under an atmospheric pressure atmosphere, it is preferable to perform the annealing treatment under an inert gas atmosphere such as nitrogen or argon.

  In order to form a uniform conductive portion, the conductive portion is preferably formed by electroless plating, and is preferably an electroless plating layer.

  When the conductive portion is formed by electroless plating, a high concentration reducing agent is required because the plating particle surface area of the conductive particles is large. Therefore, since hydrogen is generated by oxidative decomposition of a large amount of reducing agent, the conductive portion contains a relatively large number of hydrogen atoms.

  As a method for controlling the hydrogen content in the conductive part, for example, when forming the conductive part by electroless nickel plating, a method for adjusting the reducing agent concentration to a minimum, and a method for controlling the pH of the nickel plating solution , A method of controlling the temperature of the nickel plating solution, a method of adjusting the particle stirring speed of the nickel plating solution, a method of controlling the surface tension of the particles in the nickel plating solution, a method of adjusting the nickel concentration in the nickel plating solution, etc. Is mentioned.

  As a method for controlling the hydrogen content in the conductive part, there is a method for adjusting the reducing agent concentration to a minimum. As the reducing agent, a phosphorus-containing reducing agent is preferably used. In addition, a conductive layer containing boron can be formed by using a boron-containing reducing agent as the reducing agent.

  Examples of the phosphorus-containing reducing agent include sodium hypophosphite. Examples of the boron-containing reducing agent include dimethylamine borane, sodium borohydride, and potassium borohydride.

  By using a nickel plating solution in which the above reducing agent is adjusted to a concentration of 100 g / L or less and slowly dropping at 100 ml / min or less into a suspension in which resin particles are dispersed, the content of hydrogen atoms in the conductive part is reduced. can do.

  Examples of a method for controlling the hydrogen content in the conductive part include a method for controlling the pH of the nickel plating solution. When the pH of the nickel plating solution exceeds 8.0, the amount of hydrogen generation increases and the content of hydrogen atoms in the conductive portion increases because many reducing agents undergo autolysis reactions. Therefore, in order to reduce the content of hydrogen atoms in the conductive part, the pH of the nickel plating solution is set to 8.0 or less, and the self-decomposition reaction of the reducing agent that does not contribute to nickel plating deposition is suppressed, thereby reducing the hydrogen in the conductive part. The atomic content can be reduced.

  As a method for controlling the hydrogen content in the conductive part, there is a method for controlling the reaction temperature of the nickel plating solution. When the reaction temperature of the nickel plating solution exceeds 70 ° C., a large amount of reducing agent self-decomposition occurs, so that the amount of hydrogen generation increases and the content of hydrogen atoms in the conductive part increases. Therefore, in order to reduce the content of hydrogen atoms in the conductive part, the reaction temperature of the nickel plating solution is set to 70 ° C. or lower, and the self-decomposition reaction of the reducing agent that does not contribute to nickel plating deposition is suppressed, thereby reducing the hydrogen in the conductive part. The atomic content can be reduced.

(Conductive material)
The conductive material according to the present invention includes the conductive particles described above and a binder resin. The conductive particles are preferably dispersed in a binder resin and used as a conductive material. The conductive material is preferably an anisotropic conductive material. The conductive particles and the conductive material are each preferably used for electrical connection between electrodes. The conductive material is preferably a circuit connection material.

  The binder resin is not particularly limited. In general, an insulating resin is used as the binder resin. Examples of the binder resin include vinyl resins, thermoplastic resins, curable resins, thermoplastic block copolymers, and elastomers. As for the said binder resin, only 1 type may be used and 2 or more types may be used together.

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

  The conductive material and the binder resin preferably contain a thermoplastic component or a thermosetting component. The conductive material and the binder resin may contain a thermoplastic component or may contain a thermosetting component. The conductive material and the binder resin preferably contain a thermosetting component. The thermosetting component preferably contains a curable compound that can be cured by heating and a thermosetting agent. The thermosetting agent is preferably a thermal cation curing initiator. The curable compound curable by heating and the thermosetting agent are used in an appropriate blending ratio so that the binder resin is cured. When the binder resin contains a thermal cation curing initiator, an acid is easily contained in the cured product. However, the connection resistance between the electrodes can be kept low by using the conductive particles according to the present invention.

  In addition to the conductive particles and the binder resin, the conductive material includes, for example, a filler, an extender, a softener, a plasticizer, a polymerization catalyst, a curing catalyst, a colorant, an antioxidant, a heat stabilizer, and a light stabilizer. Various additives such as an agent, an ultraviolet absorber, a lubricant, an antistatic agent and a flame retardant may be contained.

  The conductive material can be used as a conductive paste and a conductive film. When the conductive material is a conductive film, a film that does not include conductive particles may be laminated on a conductive film that includes conductive particles. The conductive paste is preferably an anisotropic conductive paste. The conductive film is preferably an anisotropic conductive film.

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

  In 100% by weight of the conductive material, the content of the conductive particles is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, preferably 80% by weight or less, more preferably 60% by weight. Hereinafter, it is more preferably 40% by weight or less, particularly preferably 20% by weight or less, and most preferably 10% by weight or less. When the content of the conductive particles is not less than the above lower limit and not more than the above upper limit, the conduction reliability between the electrodes is further enhanced.

(Connection structure)
A connection structure can be obtained by connecting the connection object members using the conductive particles or using a conductive material containing the conductive particles and a binder resin. It is preferable that the connection part is formed of the above-described conductive particles or a conductive material containing the above-described conductive particles and a binder resin.

  The connection structure includes a first connection target member, a second connection target member, and a connection part connecting the first and second connection target members, and the material of the connection part has been described above. The connection structure is preferably a conductive particle or a conductive material containing the above-described conductive particles and a binder resin. It is preferable that the connection portion is formed of the conductive particles of the present invention, or a connection structure formed of a conductive material containing the conductive particles and a binder resin. In the case where conductive particles are used, the connection portion itself is conductive particles. That is, the first and second connection target members are connected by the conductive particles.

  In FIG. 4, the connection structure using the electroconductive particle which concerns on the 1st Embodiment of this invention is typically shown with front sectional drawing.

  4 includes a first connection target member 52, a second connection target member 53, and a connection portion 54 that connects the first and second connection target members 52 and 53. Prepare. The connection portion 54 is formed by curing a conductive material including the conductive particles 1. In FIG. 4, the conductive particles 1 are schematically shown for convenience of illustration. Instead of the conductive particles 1, conductive particles 11, 21, etc. may be used.

  The first connection target member 52 has a plurality of first electrodes 52a on the surface (upper surface). The second connection target member 53 has a plurality of second electrodes 53a on the surface (lower surface). The first electrode 52 a and the second electrode 53 a are electrically connected by one or a plurality of conductive particles 1. Therefore, the first and second connection target members 52 and 53 are electrically connected by the conductive particles 1.

The manufacturing method of the connection structure is not particularly limited. As an example of the manufacturing method of the connection structure, the conductive material is disposed between the first connection target member and the second connection target member to obtain a multilayer body, and then the multilayer body is heated. And a method of applying pressure. The pressure of the said pressurization is about 9.8 * 10 < ⁴ > -4.9 * 10 < ⁶ > Pa. The temperature of the said heating is about 120-220 degreeC.

  Specific examples of the connection target member include electronic components such as semiconductor chips, capacitors, and diodes, and electronic components such as printed boards, flexible printed boards, glass epoxy boards, and glass boards. The connection target member is preferably an electronic component. The conductive particles are preferably used for electrical connection of electrodes in an electronic component.

  Examples of the electrode provided on the connection target member include metal electrodes such as a gold electrode, a nickel electrode, a tin electrode, an aluminum electrode, a copper electrode, a silver electrode, a SUS electrode, a molybdenum electrode, and a tungsten electrode. When the connection object member is a flexible printed board, the electrode is preferably a gold electrode, a nickel electrode, a tin electrode, or a copper electrode. When the connection target member is a glass substrate, the electrode is preferably an aluminum electrode, a copper electrode, a molybdenum electrode, or a tungsten electrode. In addition, when the said electrode is an aluminum electrode, the electrode formed only with aluminum may be sufficient and the electrode by which the aluminum layer was laminated | stacked on the surface of the metal oxide layer may be sufficient. Examples of the material for the metal oxide layer include indium oxide doped with a trivalent metal element and zinc oxide doped with a trivalent metal element. Examples of the trivalent metal element include Sn, Al, and Ga.

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

Example 1
(1) Production of Conductive Particles Divinylbenzene copolymer resin particles having a particle diameter of 3.0 μm (base particle A, “Micropearl SP-203” manufactured by Sekisui Chemical Co., Ltd.) were prepared. After dispersing 10 parts by weight of the resin particles in 100 parts by weight of an alkaline solution containing 5% by weight of a palladium catalyst solution using an ultrasonic disperser, the resin particles were taken out by filtering the solution. Next, the resin particles were added to 100 parts by weight of a 1% by weight dimethylamine borane solution to activate the surface of the resin particles. The resin particles whose surface was activated were sufficiently washed with water, and then added to 500 parts by weight of distilled water and dispersed to obtain a suspension (A).

  Next, 1 g of nickel particle slurry (average particle diameter 150 nm) was added to the suspension (A) over 3 minutes to obtain base particles to which the core substance was adhered. Moreover, 3 L of nickel plating solution (pH 5.0) containing 50 g / L of nickel sulfate, 50 g / L of sodium hypophosphite and 20 g / L of sodium citrate was prepared.

  While stirring the obtained suspension (A) at 45 ° C., the above nickel plating solution is dropped onto the suspension (A) at 50 ml / min, electroless nickel plating is performed, and a nickel-phosphorus conductive layer is formed. After forming, particles were taken out by filtering the plating solution, washed with water, and dried to obtain conductive particles. Thus, the electroconductive particle by which the electroconductive part (thickness 102nm) was formed on the surface of the said base material particle A was obtained.

  Next, the conductive particles having a conductive portion formed on the surface of the base material particle A were subjected to an annealing treatment under a pressure atmosphere of 100 KPa at a temperature of 300 ° C. for 4 hours (annealing conditions) to obtain conductive particles. . The conductive particles were used for producing an anisotropic conductive paste.

(2) Production of anisotropic conductive paste 20 parts by weight of an epoxy compound (“EP-3300P” manufactured by Nagase ChemteX) that is a thermosetting compound and an epoxy compound (“EPICLON HP” manufactured by DIC) -4032D ") 15 parts by weight and 5 parts by weight of a thermal cation generator (San-Aid" SI-60 "manufactured by Sanshin Chemical Co., Ltd.) which is a thermosetting agent. After adding so that content in weight% might be 10 weight%, anisotropic conductive paste was obtained by stirring for 5 minutes at 2000 rpm using a planetary stirrer.

(3) Production of Connection Structure A A glass substrate having an Al—Ti 4% electrode pattern (Al—Ti 4% electrode thickness 1 μm) having an L / S of 20 μm / 20 μm on the upper surface was prepared. A semiconductor chip having a gold electrode pattern (gold electrode thickness 20 μm) with L / S of 20 μm / 20 μm on the lower surface was prepared.

  On the upper surface of the glass substrate, the anisotropic conductive paste immediately after fabrication was applied to a thickness of 20 μm to form an anisotropic conductive material layer. Next, the semiconductor chip was stacked on the upper surface of the anisotropic conductive material layer so that the electrodes face each other. Then, while adjusting the temperature of the head so that the temperature of the anisotropic conductive material layer becomes 170 ° C., a pressure heating head is placed on the upper surface of the semiconductor chip, and a pressure of 150 MPa is applied to apply the anisotropic conductive material layer. Was cured at 180 ° C. to obtain a connection structure A.

(4) Production of connection structure B Similar to connection structure A except that a pressure heating head was placed on the upper surface of the semiconductor chip, and a pressure of 100 MPa was applied to cure the anisotropic conductive material layer at 100 ° C. Thus, a connection structure B was obtained.

(Example 2)
Conductive particles, anisotropic conductive paste, and connection structure A, except that the nickel particle slurry (average particle size 150 nm) was changed to alumina particle slurry (average particle size 150 nm), in the same manner as in Example 1. B was obtained.

(Example 3)
3 L of nickel plating solution (pH 5.0) containing 50 g / L of nickel sulfate, 50 g / L of sodium hypophosphite and 20 g / L of sodium citrate was prepared.

  A projection forming plating solution (pH 10.0) 0.5 L containing 300 g / L of sodium hypophosphite was prepared.

  While the suspension (A) obtained in Example 1 was stirred at 45 ° C., the nickel plating solution was added dropwise to the suspension (A) at 25 ml / min, electroless nickel plating was performed, and nickel- After forming the phosphorous conductive layer, the protrusion forming plating solution was dropped at 5 ml / min to form protrusions. During the dropping of the plating solution for protrusion formation, nickel plating was performed while dispersing the generated Ni protrusion nuclei by ultrasonic stirring.

  Next, the nickel plating solution was added dropwise at 25 ml / min, and electroless nickel plating was performed to form a nickel-phosphorus conductive layer on the surface of the base particle A.

  The particles were taken out by filtering the plating solution, washed with water, and dried to obtain conductive particles. Thus, the electroconductive particle by which the electroconductive part (thickness 102nm) was formed on the surface of the said base material particle A was obtained.

  An anisotropic conductive paste and connection structures A and B were obtained in the same manner as in Example 1 except that the obtained conductive particles were used.

Example 4
3 L of nickel plating solution (pH 5.0) containing 50 g / L of nickel sulfate, 50 g / L of sodium hypophosphite and 20 g / L of sodium citrate was prepared.

  A projection forming plating solution (pH 10.0) 0.5 L containing 300 g / L of sodium hypophosphite was prepared.

  A gold plating solution (pH 9.0) containing 10 g / L of potassium gold cyanide, 20 g / L of sodium citrate, 10 g / L of ethylenediaminetetraacetic acid, and 15 g / L of sodium hydroxide was prepared.

  While the suspension (A) obtained in Example 1 was stirred at 45 ° C., the above nickel plating solution was added dropwise to the suspension (A) at 20 ml / min, and electroless nickel plating was performed. After forming the phosphorous conductive layer, the protrusion forming plating solution was dropped at 5 ml / min to form protrusions. During the dropping of the plating solution for protrusion formation, nickel plating was performed while dispersing the generated Ni protrusion nuclei by ultrasonic stirring.

  Next, the nickel plating solution was dropped at a rate of 20 ml / min, and electroless nickel plating was performed to form a nickel-phosphorus conductive layer on the surface of the base particle A.

  Thereafter, by filtering the suspension, the particles were taken out and washed with water to obtain particles on which a nickel-phosphorus conductive layer was formed. The particles were sufficiently washed with water, and then added to 500 parts by weight of distilled water and dispersed to obtain a suspension (B).

  Thereafter, the gold plating solution was gradually dropped onto the dispersed suspension (B) while stirring the suspension (B) obtained above at 55 ° C., and gold plating was performed. The gold plating solution was dropped at a rate of 2 mL / min for gold plating.

  By filtering the suspension, the particles were taken out, washed with water, and dried to obtain conductive particles.

  Thus, the electroconductive particle by which the electroconductive part (thickness 108nm) plated with nickel- phosphorus and gold | metal | money was formed on the surface of the said base material particle A was obtained.

  An anisotropic conductive paste and connection structures A and B were obtained in the same manner as in Example 1 except that the obtained conductive particles were used.

(Example 5)
3 L of nickel plating solution (pH 5.0) containing 50 g / L of nickel sulfate, 50 g / L of sodium hypophosphite and 20 g / L of sodium citrate was prepared.

  A projection forming plating solution (pH 10.0) 0.5 L containing 300 g / L of sodium hypophosphite was prepared.

  A palladium plating solution (pH 7.0) containing 5 g / L of palladium chloride, 20 g / L of sodium formate, 5 g / L of ethylenediamine, and 20 g / L of DL-malic acid was prepared.

  A gold plating solution (pH 9.0) containing 7 g / L of potassium gold cyanide, 15 g / L of sodium citrate, 7 g / L of ethylenediaminetetraacetic acid, and 12 g / L of sodium hydroxide was prepared.

  While the suspension (A) obtained in Example 1 was stirred at 45 ° C., the above nickel plating solution was added dropwise to the suspension (A) at 15 ml / min, and electroless nickel plating was performed. After forming the phosphorous conductive layer, the protrusion forming plating solution was dropped at 5 ml / min to form protrusions. During the dropping of the plating solution for protrusion formation, nickel plating was performed while dispersing the generated Ni protrusion nuclei by ultrasonic stirring.

  Next, the nickel plating solution was dropped at 15 ml / min, electroless nickel plating was performed, and a nickel-phosphorus conductive layer was formed on the surface of the base particle A.

  Thereafter, by filtering the suspension, the particles were taken out and washed with water to obtain particles on which a nickel-phosphorus conductive layer was formed. The particles were sufficiently washed with water, and then added to 500 parts by weight of distilled water and dispersed to obtain a suspension (B).

  Thereafter, while the suspension (B) obtained above was stirred at 50 ° C., the palladium plating solution was gradually added dropwise to the suspension (B) in a dispersed state to perform palladium plating. The palladium plating solution was dropped at a rate of 5 mL / min to perform palladium plating.

  Next, by filtering the suspension, the particles were taken out and washed with water to obtain particles on which nickel-phosphorous and palladium conductive layers were formed. The particles were sufficiently washed with water, and then added to 500 parts by weight of distilled water and dispersed to obtain a suspension (C).

  Thereafter, the gold plating solution was gradually dropped onto the dispersed suspension (C) while stirring the suspension (C) obtained above at 55 ° C., and gold plating was performed. The gold plating solution was dropped at a rate of 2 mL / min for gold plating.

  By filtering the suspension, the particles were taken out, washed with water, and dried to obtain conductive particles.

  Thus, the electroconductive particle by which the electroconductive part (thickness 106nm) plated with nickel- phosphorus, palladium, and gold | metal | money was formed on the surface of the said base particle A was obtained.

  An anisotropic conductive paste and connection structures A and B were obtained in the same manner as in Example 1 except that the obtained conductive particles were used.

(Example 6)
3 L of nickel plating solution (pH 6.0) containing 50 g / L of nickel sulfate, 20 g / L of dimethylamine borane and 30 g / L of sodium citrate was prepared.

  A protrusion forming plating solution (pH 10.0) containing 0.5 g of dimethylamine borane (120 g / L) was prepared.

  A palladium plating solution (pH 7.0) containing 5 g / L of palladium chloride, 20 g / L of sodium formate, 5 g / L of ethylenediamine, and 20 g / L of DL-malic acid was prepared.

  A gold plating solution (pH 9.0) containing 7 g / L of potassium gold cyanide, 15 g / L of sodium citrate, 7 g / L of ethylenediaminetetraacetic acid, and 12 g / L of sodium hydroxide was prepared.

  While the suspension (A) obtained in Example 1 was stirred at 45 ° C., the above nickel plating solution was dropped into the suspension at 15 ml / min to perform electroless nickel plating, and a nickel-boron conductive layer. After forming the protrusions, the protrusion forming plating solution was dropped at 5 ml / min to form protrusions. During the dropping of the plating solution for protrusion formation, nickel plating was performed while dispersing the generated Ni protrusion nuclei by ultrasonic stirring.

  Next, the nickel plating solution was dropped at 15 ml / min, electroless nickel plating was performed, and a nickel-boron conductive layer was formed on the surface of the substrate particles.

  Thereafter, the suspension was filtered to take out the particles, followed by washing with water to obtain particles on which the nickel-boron conductive layer was formed. The particles were sufficiently washed with water, and then added to 500 parts by weight of distilled water and dispersed to obtain a suspension (B).

  Thereafter, while the suspension (B) obtained above was stirred at 50 ° C., the palladium plating solution was gradually added dropwise to the suspension (B) in a dispersed state to perform palladium plating. The palladium plating solution was dropped at a rate of 5 mL / min to perform palladium plating.

  Next, by filtering the suspension, the particles were taken out and washed with water to obtain particles on which nickel-phosphorous and palladium conductive layers were formed. The particles were sufficiently washed with water, and then added to 500 parts by weight of distilled water and dispersed to obtain a suspension (C).

  Thereafter, the gold plating solution was gradually dropped onto the dispersed suspension (C) while stirring the suspension (C) obtained above at 55 ° C., and gold plating was performed. The gold plating solution was dropped at a rate of 2 mL / min for gold plating.

  By filtering the suspension, the particles were taken out, washed with water, and dried to obtain conductive particles.

  Thus, the electroconductive particle by which the electroconductive part (thickness 106nm) plated with nickel-boron, palladium, and gold was formed on the surface of the base material particle A was obtained.

  An anisotropic conductive paste and connection structures A and B were obtained in the same manner as in Example 1 except that the obtained conductive particles were used.

(Example 7)
The same as Example 1 except that the annealing conditions were changed so that the conductive particles having conductive portions formed on the surface of the substrate particles A were annealed at a temperature of 300 ° C. for 4 hours in a 10 KPa atmospheric pressure atmosphere. Thus, conductive particles, anisotropic conductive paste, and connection structures A and B were obtained.

(Example 8)
The same as Example 1 except that the annealing conditions were changed so that the conductive particles having the conductive portion formed on the surface of the base particle A were annealed at a temperature of 200 ° C. for 4 hours in a 100 KPa atmospheric pressure atmosphere. Thus, conductive particles, anisotropic conductive paste, and connection structures A and B were obtained.

Example 9
In the same manner as in Example 1 except that the base material particle A was changed to base material particle B having a particle diameter of 2.5 μm, which was different from the base material particle A only, conductive particles, anisotropic Conductive paste and connection structures A and B were obtained.

(Example 10)
In the same manner as in Example 1, except that the base particle A was changed to the base particle C having a particle diameter different from that of the base particle A and having a particle diameter of 3.5 μm, conductive particles, anisotropic Conductive paste and connection structures A and B were obtained.

(Example 11)
The surface of divinylbenzene copolymer resin particles having a particle diameter of 2.5 μm (“Micropearl SP-2025” manufactured by Sekisui Chemical Co., Ltd.) was coated with an inorganic shell (thickness 250 nm) using a condensation reaction by a sol-gel reaction. Core-shell type organic-inorganic hybrid particles (base material particles D) were obtained.

  The base material particle A is changed to the base material particle D, and the conductive particles having a conductive part formed on the surface of the base material particle D are annealed at a temperature of 400 ° C. for 4 hours in a 100 KPa atmospheric pressure atmosphere. Conductive particles, anisotropic conductive paste, and connection structures A and B were obtained in the same manner as in Example 1 except that the annealing treatment conditions were changed.

(Example 12)
In a 500 mL reaction vessel equipped with a stirrer and a thermometer, 300 g of a 0.13% by weight aqueous ammonia solution was placed. Next, 4.1 g of methyltrimethoxysilane, 19.2 g of vinyltrimethoxysilane, and 0.7 g of silicone alkoxy oligomer (“X-41-1053” manufactured by Shin-Etsu Chemical Co., Ltd.) in an aqueous ammonia solution in the reaction vessel. The mixture with was added slowly. After the hydrolysis and condensation reaction proceeded with stirring, 2.4 mL of a 25 wt% aqueous ammonia solution was added, and then the particles were isolated from the aqueous ammonia solution, and the resulting particles were subjected to an oxygen partial pressure of 10 ⁻¹⁷ atm. And calcination at 350 ° C. for 2 hours to obtain organic-inorganic hybrid particles (base particle E) having a particle size of 3.0 μm.

  The base particle A is changed to the base particle E, and the conductive particles having a conductive part formed on the surface of the base particle E are annealed at a temperature of 500 ° C. for 4 hours in a 100 KPa atmospheric pressure atmosphere. Conductive particles, anisotropic conductive paste, and connection structures A and B were obtained in the same manner as in Example 1 except that the annealing treatment conditions were changed.

(Example 13)
In the same manner as in Example 5, except that the base particle A was changed to the base particle F having a particle diameter different from that of the base particle A and having a particle diameter of 5.0 μm, conductive particles, anisotropy Conductive paste and connection structures A and B were obtained.

(Example 14)
In the same manner as in Example 5, except that the base particle A was changed to the base particle G which was different from the base particle A only in particle size and the particle size was 10.0 μm, conductive particles, anisotropic Conductive paste and connection structures A and B were obtained.

(Example 15)
To a 1000 mL separable flask equipped with a four-neck separable cover, stirring blade, three-way cock, condenser and temperature probe, 100 mmol of methyl methacrylate and N, N, N-trimethyl-N-2-methacryloyloxyethyl A monomer composition containing 1 mmol of ammonium chloride and 1 mmol of 2,2′-azobis (2-amidinopropane) dihydrochloride was weighed in ion-exchanged water so that the solid content was 5% by weight, and then at 200 rpm. The mixture was stirred and polymerized at a temperature of 70 ° C. for 24 hours under a nitrogen atmosphere. After completion of the reaction, it was freeze-dried to obtain insulating particles having an ammonium group on the surface, an average particle size of 220 nm, and a CV value of 10%.

  The insulating particles were dispersed in ion exchange water under ultrasonic irradiation to obtain a 10 wt% aqueous dispersion of insulating particles.

  10 g of the conductive particles obtained in Example 1 were dispersed in 500 mL of ion exchange water, 4 g of an aqueous dispersion of insulating particles was added, and the mixture was stirred at room temperature for 6 hours. After filtration through a 3 μm mesh filter, the particles were further washed with methanol and dried to obtain conductive particles having insulating particles attached thereto.

  When observed with a scanning electron microscope (SEM), only one coating layer of insulating particles was formed on the surface of the conductive particles. The coverage of the insulating particles with respect to the area of 2.5 μm from the center of the conductive particles by image analysis (that is, the projected area of the particle diameter of the insulating particles) was calculated to be 30%.

(Comparative Example 1)
The conductive particles, the anisotropic conductive paste, and the connection structure A are the same as in Example 1 except that the conductive particles having conductive portions formed on the surface of the base particle A are not annealed. , B was obtained.

(Comparative Example 2)
Except that the annealing treatment conditions were changed so that the conductive particles having conductive portions formed on the surface of the base particle A were annealed at a temperature of 280 ° C. for 2 hours in a nitrogen atmosphere, the same as in Example 1. , Conductive particles, anisotropic conductive paste, and connection structures A and B were obtained.

(Evaluation)
(1) Content of hydrogen atom in conductive part A sample of the conductive part (metal film) to be measured was collected as follows.

  The conductive particles were pulverized using a ball mill with zirconia balls, and the conductive portion was completely peeled from the base particles. A sample completely peeled from the conductive part and the base material particles was separated into a conductive part and base material particles with a sieve, and only the conductive part was collected.

  For the measurement of the hydrogen atom content, a temperature programmed desorption hydrogen analyzer (“PDHA-1000” manufactured by FIS Co., Ltd.) was used. The conductive part was heated and heated with a temperature desorption apparatus, and the generated trace amount of hydrogen was measured with a sensor gas chromatograph. Under a constant pressure of 3 GPa, the evacuated conductive part was gradually heated from 50 ° C. to 400 ° C. at a rate of temperature increase of 5 ° C./min. The released hydrogen atoms were measured with a detector.

  The content of hydrogen atoms in the conductive portion was the total amount of hydrogen atoms released from 50 ° C. to 400 ° C.

(2) Crystallite size in cross-sectional observation of conductive parts (first, second, and third conductive parts) "Technobit" manufactured by Kulzer so that the content of the obtained conductive particles is 30 wt% 4000 "was added and dispersed to prepare an embedding resin for inspecting conductive particles. A cross section of the conductive particles was cut out using an ion milling device (“IM4000” manufactured by Hitachi High-Technologies Corporation) so as to pass through the vicinity of the center of the conductive particles dispersed in the embedded resin for inspection.

  Using FE-SEM-EBSP (manufactured by TSL), crystal grain mapping measurement was performed on the cross section of the conductive part in the conductive particle. The crystallite size was determined by confirming the particle size distribution chart of the crystallite size. The crystallite size (1) in the first conductive part, the crystallite size (2) in the second conductive part, and the average value of the crystallite size (3) in the third conductive part The size was calculated.

(3) Crystallite size based on average value of crystallite size in each orientation Powder X-ray diffraction measurement was performed using an X-ray diffractometer (“RINT2500VHF” manufactured by Rigaku Corporation). The crystallite size of the (111) plane, (200) plane, (220) plane, (311) plane and (222) plane obtained from the half width of the diffraction peak obtained by X-ray diffraction with CuKα rays and the Scherrer equation The crystallite size was calculated from the average value.

  The XRD measurement conditions were 45 kV, 50 mA, and a scan rate of 4.0 deg / min. The scan step was 0.02 deg, and the measurement range was 2θ between 5.0 deg and 110.0 deg.

  The crystallite size was calculated by the following Scherrer equation.

D = Kλ / βcos θ
D: crystallite size K: Scherrer constant λ: wavelength of X-ray β: half-value width [rad]
θ: Diffraction angle

(4) Crystallite size of conductive part by XRD measurement Powder X-ray diffraction measurement was performed using an X-ray diffractometer (“RINT2500VHF” manufactured by Rigaku Corporation). The crystallite size was calculated from the half width of the diffraction peak obtained by X-ray diffraction using CuKα rays and the Williamson-Hole equation.

  The XRD measurement conditions were 45 kV, 50 mA, and a scan rate of 4.0 deg / min. The scan step was 0.02 deg, and the measurement range was 2θ between 5.0 deg and 110.0 deg.

  The crystallite size was calculated by the following Williamson-Hole equation.

Δ2θ · cos θ / λ = 0.9 / D + 2ε · sin θ / λ
D: crystallite size λ: wavelength of X-ray Δ2θ: half-value width [rad]
θ: diffraction angle ε: lattice strain

  The crystallite size was plotted by taking 2 sin θ / λ on the horizontal axis and Δ2θ · cos θ / λ on the vertical axis in the Williamson-Hole equation, and the crystallite size was calculated from the value of the intercept of the plot.

(5) Compression elastic modulus (10% K value) when conductive particles are compressed by 10%
The compression modulus (10% K value) of the obtained conductive particles was measured by the above-described method using a micro compression tester (“Fischerscope H-100” manufactured by Fischer).

(6) Cracking of conductive part In the obtained connection structures A and B, the peeled surface was observed after peeling the semiconductor chip. In 50 conductive particles, it was evaluated whether or not the conductive part was cracked. The crack of the conductive part was determined according to the following criteria.

[Criteria for cracking of conductive parts]
OO: The ratio of the number of conductive particles in which 50 conductive particles are cracked in the conductive part is 0 or more and less than 10 XX: In 50 conductive particles, the conductive part is cracked The ratio of the number of the conductive particles is 10 or more and less than 20 ○: The ratio of the number of the conductive particles in which the conductive part is cracked in 50 conductive particles is 20 or more and less than 30 Δ : The ratio of the number of conductive particles in which 50 conductive particles are cracked in the conductive portion is 30 or more and less than 40 ×: Conductivity in which the conductive portion is cracked in 50 conductive particles The ratio of the number of particles is 40 or more

(7) Initial connection resistance X
Connection resistance measurement:
The connection resistance X between the opposing electrodes of the obtained connection structures A and B was measured by the four-terminal method. The initial connection resistance X was determined according to the following criteria.

[Evaluation criteria for initial connection resistance X]
○○○: Connection resistance X is 2.0Ω or less ○○: Connection resistance X exceeds 2.0Ω, 3.0Ω or less ○: Connection resistance X exceeds 3.0Ω, 5.0Ω or less Δ: Connection resistance X Exceeds 5.0Ω and 10Ω or less ×: Connection resistance X exceeds 10Ω

(8) Connection resistance Y after exposure to acid conditions (long-term reliability)
The obtained connection structures A and B were left in a high-temperature and high-humidity tank at 85 ° C. and a humidity of 85% for 100 hours. By leaving the connection structures A and B under the above conditions, the connection portion between the electrodes in the connection structures A and B has an acid due to the reaction between the water that has entered the binder resin and the acid contained in the binder resin. It was exposed for a period of time. In the connection structures A and B after being left, the connection resistance Y between the opposing electrodes of the connection structure was measured by the four-terminal method. Moreover, the connection resistance Y after being exposed to the presence of an acid was determined according to the following criteria.

[Evaluation criteria of connection resistance Y after exposure to acid conditions]
○○○: Connection resistance Y is less than 1 time of connection resistance X ○○: Connection resistance Y is 1 time or more and less than 1.5 times of connection resistance X ○: Connection resistance Y is 1.5 times or more of connection resistance X Less than 2 times Δ: Connection resistance Y is 2 times or more of connection resistance X and less than 5 times ×: Connection resistance Y is 5 times or more of connection resistance X

  The results are shown in Table 1 below.

DESCRIPTION OF SYMBOLS 1 ... Conductive particle 2 ... Base material particle 3 ... Conductive part 11 ... Conductive particle 11a ... Protrusion 12 ... Conductive part 12a ... Protrusion 13 ... Core substance 14 ... Insulating substance 21 ... Conductive particle 21a ... Protrusion 22 ... Conductive part 22a ... projection 22A ... first conductive part 22Aa ... projection 22B ... second conductive part 22Ba ... projection 51 ... connection structure 52 ... first connection target member 52a ... first electrode 53 ... second connection target member 53a ... 2nd electrode 54 ... Connection part

Claims (14)

Comprising substrate particles and a conductive portion disposed on the surface of the substrate particles,
The electroconductive particle in which the said electroconductive part does not contain a hydrogen atom, or the said electroconductive part contains a hydrogen atom at 80 microgram / g or less. The conductive part includes a conductive part having a crystal structure;
2. The conductive particle according to claim 1, wherein, in cross-sectional observation of the conductive part having the crystal structure, the crystallite size in the conductive part having the crystal structure is 50 nm or more. The conductive part includes a conductive part having a crystal structure;
In the conductive part having the crystal structure, the (111) plane, the (200) plane, the (220) plane, the (311) plane, and the (222) calculated from the half width of the diffraction peak obtained by X-ray diffraction and the Scherrer equation. The electroconductive particle of Claim 1 or 2 whose crystallite size by the average value of the crystallite size of a surface is 50 nm or more. The conductive part includes a conductive part having a crystal structure;
The conductive part which has the said crystal structure WHEREIN: The crystallite size calculated | required from the half width of the diffraction peak obtained by X-ray diffraction and a Williamson-Hole type is 50 nm or more. Conductive particles. The electroconductive particle of any one of Claims 1-4 whose compression elastic modulus when compressed 10% is 3000 N / mm < ² > or more.   The electroconductive particle of any one of Claims 1-5 whose Vickers hardness of the said electroconductive part is 200 or more.   The conductive particle according to claim 1, wherein the conductive part includes at least nickel, palladium, ruthenium, copper, tungsten, molybdenum, phosphorus, boron, gold, platinum, or tin.   The conductive particle according to claim 1, wherein the conductive portion includes at least nickel.   The electroconductive particle of any one of Claims 1-8 whose said base material particle is a resin particle or an organic inorganic hybrid particle.   The electroconductive particle of any one of Claims 1-9 which has several protrusion on the outer surface of the said electroconductive part.   The electroconductive particle of any one of Claims 1-10 provided with the insulating substance arrange | positioned on the outer surface of the said electroconductive part. It is a manufacturing method of conductive particles given in any 1 paragraph of Claims 1-11,
Using the base particles and conductive particles having conductive portions arranged on the surface of the base particles, the step of annealing the conductive particles to 200 ° C. or more,
The method for producing conductive particles, wherein the conductive part does not contain a hydrogen atom or the conductive part contains a conductive atom containing a hydrogen atom at 80 μg / g or less by the annealing treatment.   The electroconductive material containing the electroconductive particle of any one of Claims 1-11, and binder resin. A first connection target member;
A second connection target member;
A connecting portion connecting the first connection target member and the second connection target member;
The connection structure whose material of the said connection part is the electroconductive particle of any one of Claims 1-11, or is an electroconductive material containing the said electroconductive particle and binder resin.

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