JP6777405B2 - Conductive particles, methods for producing conductive particles, conductive materials and connecting structures - Google Patents

Description

The present invention relates to a conductive particle in which a conductive portion is arranged on the surface of the base particle and a method for producing the conductive particle. The present invention also relates to a conductive material and a connecting structure using the above 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 the binder resin.

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

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

WO2013 / 042785A1

When, for example, the electrode of the semiconductor chip and the electrode of the glass substrate are electrically connected by using the anisotropic conductive material, the anisotropic conductive material containing the conductive particles is arranged on the glass substrate. Next, the semiconductor chips are laminated and heated and pressurized. As a result, the anisotropic conductive material is cured, and the electrodes are electrically connected to each other via the conductive particles to obtain a connecting structure. An example of a connection structure obtained by such a method is a liquid crystal display element.

In the liquid crystal display element, the frame of the liquid crystal panel is narrowed and the glass substrate is thinned. For this reason, distortion occurs in the mounting portion, and display unevenness is likely to occur. In order to suppress display unevenness, it is required to crimp at a low temperature during crimping.

However, crimping at a low temperature increases the melt viscosity of the anisotropic conductive material. Therefore, when crimping at a low temperature, it is necessary to increase the pressure in order to prevent voids from being generated. As a result, a large stress is applied to the conductive particles. In addition, in a manufacturing method other than the above-mentioned manufacturing method of the connecting structure, and even before the use of the conductive particles, a large stress may be applied to the conductive particles.

In the conventional conductive particles as described in Patent Document 1, cracks may occur in the conductive layer when stress is applied to the conductive particles. As a result, when the electrodes are connected to each other to obtain a connection structure, the initial connection resistance may increase or the conduction reliability may decrease.

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

Further, when conventional conductive particles as described in Patent Document 1 are exposed in the presence of an acid, corrosion of the conductive layer may occur. Further, when the electrodes are connected to each other using conventional conductive particles to obtain a connection structure, 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 method for producing conductive particles and conductive particles, which can make the conductive portion less likely to crack, enhance acid resistance, and therefore enhance connection reliability. is there.

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

According to a broad aspect of the present invention, the base particles are provided with a conductive portion arranged on the surface of the base particles, and the conductive portion does not contain a hydrogen atom, or the conductive portion contains a hydrogen atom. Conductive particles containing 80 μg / g or less are provided.

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

In a specific aspect of the conductive particles according to the present invention, the conductive portion includes a conductive portion having a crystal structure, and in the conductive portion having the crystal structure, the half-value width of the diffraction peak obtained by X-ray diffraction and the Scheller The crystallite size based on the average value of the crystallite sizes of the (111) plane, (200) plane, (220) plane, (311) plane, and (222) plane obtained from the equation is 50 nm or more.

In a specific aspect of the conductive particles according to the present invention, the conductive portion includes a conductive portion having a crystal structure, and in the conductive portion having the crystal structure, the half-value width of the diffraction peak obtained by X-ray diffraction and Williamson. -The crystallite size obtained from the Hall equation is 50 nm or more.

In a specific aspect of the conductive particles according to the present invention, the compressive elastic modulus when compressed by 10% is 3000 N / mm ² or more.

In a specific aspect of the conductive particles according to the present invention, the Vickers hardness of the conductive portion is 200 or more.

In certain aspects of the conductive particles according to the present invention, the conductive portion comprises at least nickel, palladium, ruthenium, copper, tungsten, molybdenum, phosphorus, boron, gold, platinum or tin.

In certain aspects of the conductive particles according to the present invention, the conductive portion comprises at least nickel.

In certain aspects of the conductive particles according to the present invention, the substrate particles are resin particles or organic-inorganic hybrid particles.

In certain aspects of the conductive particles according to the present invention, the conductive particles have a plurality of protrusions on the outer surface of the conductive portion.

In certain aspects of the conductive particles according to the present invention, the conductive particles include an insulating material disposed on the outer surface of the conductive portion.

According to a broad aspect of the present invention, in the above-described method for producing conductive particles, the conductive particles using the base particles and the conductive particles having a conductive portion arranged on the surface of the base particles are used. A step of annealing the sex particles to 200 ° C. or higher is provided, and the annealing treatment obtains conductive particles in which the conductive portion does not contain hydrogen atoms or the conductive portion contains hydrogen atoms at 80 μg / g or less. A method for producing sex particles is provided.

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

According to a broad aspect of the present invention, a connection portion connecting the first connection target member, the second connection target member, the first connection target member, and the second connection target member. Provided is a connecting structure in which the material of the connecting portion is the above-mentioned conductive particles or is a conductive material containing the conductive particles and a binder resin.

In the conductive particles according to the present invention, the conductive portion is arranged on the surface of the base particle, and the conductive portion does not contain a hydrogen atom, or the conductive portion contains a hydrogen atom at 80 μg / g or less. Therefore, the conductive portion can be made less likely to crack, the acid resistance can be increased, and therefore the connection reliability can be improved.

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

The details of the present invention will be described below.

(Conductive particles)
The conductive particles according to the present invention include base particles and conductive portions arranged on the surface of the base particles.

In the conductive particles according to the present invention, the conductive portion does not contain a hydrogen atom, or the conductive portion contains a hydrogen atom at 80 μg / g or less. That is, in the conductive particles according to the present invention, the content of hydrogen atoms in the conductive portion is extremely small.

In the present invention, since the above-described configuration is provided, the conductive portion can be less likely to crack, the acid resistance can be increased, and therefore the connection reliability can be improved.

Further, by making the conductive portion less likely to crack, even if the conductive material is cured at a relatively low temperature and crimping is performed in a state where the melt viscosity of the conductive material is high, the connection resistance between the electrodes is sufficiently low and conduction is achieved. It is possible to obtain a connection structure having excellent reliability. By using the conductive particles according to the present invention, it is possible to make the frame to be connected narrower and thinner.

Further, in the present invention, since the conductive portion is less likely to be cracked, the connecting structure may be obtained by using the conductive particles exposed in the presence of the acid, or the connecting structure may be exposed in the presence of the acid. However, the connection resistance can be kept low.

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

Methods for measuring the content of hydrogen atoms in the conductive portion include a temperature-temperature desorption method, a high-temperature dissolved hydrogen extraction method, a glycerin substitution method, and an electrochemical release method. The thermal desorption method is preferable, and the thermal desorption method using a thermal desorption hydrogen analyzer is more preferable.

The content of hydrogen atoms in the conductive portion can be measured as follows.

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

Regarding the method for calculating the content of hydrogen atoms in the conductive portion, first, the content of hydrogen atoms in the conductive particles is measured, and the measured value of the content of hydrogen atoms is obtained. Next, the content of hydrogen atoms in the base particles before forming the conductive portion is measured, and the measured value of the content of hydrogen atoms is obtained. 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 portion can be obtained.

Content of hydrogen atom in conductive part = Content of hydrogen atom in conductive particle-Content of hydrogen atom in base particle

Regarding the method of calculating the content of hydrogen atoms in the conductive part, the conductive part is peeled off from the conductive particles, only the conductive part is collected, the content of hydrogen atoms in the conductive part is measured, and the content of hydrogen atoms is contained. A quantity measurement can be obtained. In the method of sampling the conductive portion to be measured, first, the conductive particles are pulverized using a ball mill using zirconia balls, and the conductive portion is completely peeled from the base material particles to obtain a sample. The sample is separated into a conductive part and a base particle by a dry sieve, and only the conductive part is collected.

Generally, the conductive portion of the conductive particles 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 surface area of the conductive particles is large. For this reason, hydrogen is generated by oxidative decomposition of a large amount of reducing agent, so that the conductive portion contains a relatively large amount of hydrogen atoms. In the present invention, the number of hydrogen atoms in the conductive portion is positively reduced.

As a method of reducing the content of hydrogen atoms in the conductive portion, a method of annealing after forming the conductive portion, a method of reducing the concentration of the reducing agent used at the time of plating, a method of adding a surfactant at the time of plating, and a base material. A method of lowering the surface tension of the particle surface and increasing the hydrogen desorption property, a method of increasing the stirring speed of the plating solution during plating and increasing the hydrogen desorption property, and controlling the reaction temperature and pH during plating. Examples thereof include a method of suppressing the self-decomposition reaction of the reducing agent. These methods can be used together so that the content of hydrogen atoms is sufficiently low.

From the viewpoint of further suppressing cracking of the conductive portion and further enhancing acid resistance, the crystallite size in the conductive portion 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 enhancing acid resistance, it is preferable that the conductive portion contains a conductive portion having a crystal structure. From the viewpoint of further suppressing cracking of the conductive portion and further enhancing acid resistance, the crystallite size of the conductive portion having the crystal structure 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 enhancing acid resistance, the half width of the diffraction peak obtained by X-ray diffraction and the crystallite obtained from the Williamson-Hole equation in the conductive portion having the above crystal structure. The size 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 enhancing acid resistance, the half width of the diffraction peak obtained by X-ray diffraction and the (111) plane obtained from the Scheller's equation in the conductive portion having the above crystal structure. The crystallite size based on the average value of the crystallite sizes of the (200) plane, (220) plane, (311) plane and (222) plane 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 conducting conductive particle inspection. A cross section of the conductive particles is cut out using an ion milling device (“IM4000” manufactured by Hitachi High-Technologies Corporation) so as to pass near the center of the dispersed conductive particles in the embedded 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.

In addition, the crystallite size can be measured as follows.

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

The conductive particles include a base material particle and a conductive portion, and the conductive portion includes a first conductive portion having a crystal structure and a second conductive portion having a crystal structure. The conductive portion 1 is arranged on the surface of the base material particles, and the second conductive portion is arranged on the outer surface of the first conductive portion so as to be in contact with the first conductive portion. It is preferable that the conductive particles are formed. The crystallite size of the first conductive portion of the conductive particles may be measured.

The conductive particles include a base material particle and a conductive portion, and the conductive portion is only a first conductive portion having a crystal structure, and the first conductive portion is a base material particle. It is preferably conductive particles arranged on the surface. The crystallite size of the first conductive portion of the conductive particles may be measured.

The crystallite size can be calculated by the following Scheller's formula.

D = kλ / βcosθ
D: Crystallite size K: Scheller constant λ: X-ray wavelength β: Half width [rad]
θ: diffraction angle

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

Δ2θ ・ cosθ / λ = 0.9 / D + 2ε ・ sinθ / λ
D: Crystallite size λ: X-ray wavelength Δ2θ: Half width [rad]
θ: Diffraction angle ε: Lattice strain

The crystallite size is plotted by plotting 2 sinθ / λ on the horizontal axis and Δ2θ · cosθ / λ on the vertical axis according to the Williamson-Hall equation described above, and the crystallite size is calculated from the value of the intercept of the straight line of the plot.

From the viewpoint of further suppressing cracking of the conductive portion and further enhancing 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. It is preferably 5000 N / mm ² or more, preferably 20000 N / mm ² or less, and more preferably 10000 N / mm ² or less.

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

Using a microcompression tester, conductive particles are compressed on a smoothing indenter end face of a cylinder (diameter 50 μm, made of diamond) under the condition that a maximum test load of 90 mN is applied over 30 seconds at 25 ° C. The load value (N) and compressive displacement (mm) at this time are measured. From the obtained measured values, the compressive elastic modulus can be calculated by the following formula. As the microcompression tester, for example, "Fisherscope H-100" manufactured by Fisher Co., Ltd. is used.

K value (N / mm ² ) = (3/2 ^1/2 ) ・ F ・ S ^-3/2・ R- ^{1 / 2}
F: Load value (N) when conductive particles are compressed and deformed by 10%
S: Compressive displacement (mm) when conductive particles are compressed and deformed by 10%
R: Radius of conductive particles (mm)

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

From the viewpoint of further lowering the connection resistance and further increasing the conduction reliability, it is preferable that the conductive particles have a plurality of protrusions on the outer surface of the conductive portion. Further, it is preferable that the conductive particles include a plurality of core substances in which the outer surface of the conductive portion is raised so as to form the plurality of protrusions in the conductive portion.

From the viewpoint of further lowering the connection resistance and further increasing the conduction reliability, the surface area of the portion having the protrusions is preferably 10% or more, more preferably 30% or more, of the total surface area of the conductive particles of 100%. It is preferably 95% or less, more preferably 90% or less.

The surface area of the portion with protrusions 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 protrusions with respect to the projected area of the particles. 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 an electric field radiation scanning electron microscope (FE-SEM). It is obtained by calculating the average value of the percentage of the surface area of the protrusions to the projected area of the particles.

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 particle 1 shown in FIG. 1 has a base particle 2 and a conductive portion 3. The conductive portion 3 is arranged 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 particles 1 are coated particles in which the surface of the base particle 2 is coated with the conductive portion 3. In the conductive particles 1, the conductive portion 3 is a single-layer conductive portion (conductive layer).

The conductive particles 1 do not have a core substance, unlike the conductive particles 11 and 21 described later. 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. .. Further, the conductive particles 1 do not have an insulating substance, unlike the conductive particles 11 and 21 described later. However, the conductive particles 1 may have an insulating substance arranged on the outer surface of the conductive portion 3.

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

The conductive particle 11 shown in FIG. 2 has 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 arranged 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 substances 13 are embedded in the conductive portion 12. The core material 13 is arranged 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 substances 13, and protrusions 11a and 12a are formed.

The conductive particles 11 have an insulating substance 14 arranged 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 substance 14. The insulating substance 14 is formed of a material having an insulating property and is an insulating particle. As described above, the conductive particles according to the present invention may have an insulating substance arranged on the outer surface of the conductive portion. However, the conductive particles according to the present invention do not necessarily have an insulating substance.

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

The conductive particle 21 shown in FIG. 3 has a base particle 2, a conductive portion 22, a plurality of core substances 13, and a plurality of insulating substances 14. As a whole, the conductive portion 22 has a first conductive portion 22A on the base particle 2 side and a second conductive portion 22B on the side opposite to the base particle 2 side.

Only the conductive portion is different between the conductive particles 11 and the conductive particles 21. That is, in the conductive particles 11, the conductive portion 12 having a one-layer structure is formed, whereas in the conductive particles 21, the first conductive portion 22A and the second conductive portion 22B having a two-layer structure are formed. ing. The first conductive portion 22A and the second conductive portion 22B are formed as separate conductive portions.

The first conductive portion 22A is arranged on the surface of the base particle 2. The first conductive portion 22A is arranged between the base particle 2 and the second conductive portion 22B. The first conductive portion 22A is in contact with the base particle 2. Therefore, the first conductive portion 22A is arranged on the surface of the base particle 2, and the second conductive portion 22B is arranged 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 portion arranged on the outer surface of the second conductive portion. The conductive portion may be a conductive portion having three or more layers.

Hereinafter, other details of the conductive particles will be described. In the following description, "(meth) acrylic" means one or both of "acrylic" and "methacrylic", and "(meth) acrylate" means one or both of "acrylate" and "methacrylate". means.

[Base particles]
Examples of the base material particles include resin particles, inorganic particles other than metal particles, organic-inorganic hybrid particles, and metal particles. The base particle may be a core-shell particle having a core and a shell arranged on the surface of the core. The core may be an organic core. The shell may be an inorganic shell. Of these, base particle 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 preferable because they are more excellent due to the effects of the present invention.

The base material particles are preferably resin particles formed of a resin. When connecting the electrodes using the conductive particles, the conductive particles are placed between the electrodes and then pressure-bonded to compress the conductive particles. When the base material particles are resin particles, the conductive particles are easily deformed during the crimping, and the contact area between the conductive particles and the electrode becomes large. Therefore, the continuity reliability between the electrodes is high.

Various organic substances are preferably 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 polymethylmethacrylate and polymethylacrylate; poly. 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 Polymers obtained by polymerizing one or more of various polymerizable monomers having an oxide, polyacetal, polyimide, polyamideimide, polyether ether ketone, polyether sulfone, and ethylenically unsaturated group, etc. Can be mentioned. Since the hardness of the base material 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. It is preferably a polymer.

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

Examples of the non-crosslinkable monomer include styrene-based monomers such as styrene and α-methylstyrene; carboxyl group-containing monomers such as (meth) acrylic acid, maleic acid, and maleic anhydride; and methyl ( Meta) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) Alkyl (meth) acrylates such as meta) acrylate and isobornyl (meth) acrylate; oxygen atoms such as 2-hydroxyethyl (meth) acrylate, glycerol (meth) acrylate, polyoxyethylene (meth) acrylate and glycidyl (meth) acrylate. Contains (meth) acrylates; nitrile-containing monomers such as (meth) acrylonitrile; vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, and propyl vinyl ether; acid vinyl esters such as vinyl acetate, vinyl butyrate, vinyl laurate, vinyl stearate, etc. Classes: 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. Can be mentioned.

Examples of the crosslinkable monomer include tetramethylol methanetetra (meth) acrylate, tetramethylol methanetri (meth) acrylate, tetramethylol methanedi (meth) acrylate, trimethyl propanetri (meth) acrylate, and dipenta. Elythritol hexa (meth) acrylate, dipenta erythritol 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 acrylates, (poly) tetramethylene glycol di (meth) acrylates, 1,4-butanediol di (meth) acrylates; triallyl (iso) cyanurate, triallyl trimellitate, divinylbenzene, Examples thereof include silane-containing monomers such as diallyl phthalate, diallyl acrylamide, diallyl ether, γ- (meth) acryloxipropyltrimethoxysilane, trimethoxysilylstyrene, and vinyltrimethoxysilane.

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

When the base material particles are inorganic particles other than metal particles or organic-inorganic hybrid particles, examples of the inorganic material for forming the base material particles include silica and carbon black. It is preferable that the inorganic substance is not a metal. The particles formed of the silica are not particularly limited, but for example, after hydrolyzing a silicon compound having two or more hydrolyzable alkoxysilyl groups to form crosslinked polymer particles, firing is performed if necessary. Examples include particles obtained by doing so. Examples of the organic-inorganic hybrid particles include organic-inorganic hybrid particles formed of a crosslinked alkoxysilyl polymer and an acrylic resin.

When the base material particles are metal particles, examples of the metal as the material of the metal particles include silver, copper, nickel, silicon, gold, and titanium. However, the base material particles are preferably not metal particles and preferably not copper particles.

The particle size of the base particles is preferably 0.1 μm or more, more preferably 1.0 μm or more, still more 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, even more preferably 30 μm or less, even 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 size of the base material particles is equal to or larger than the above lower limit, the contact area between the conductive particles and the electrodes becomes large, so that the conduction reliability between the electrodes becomes even higher, and the conductive particles are connected via the conductive particles. The connection resistance between the electrodes becomes even lower. Further, when the conductive portion is formed on the surface of the base material particles by electroless plating, it becomes difficult to aggregate, and it becomes difficult to form the aggregated conductive particles. When the particle size of the base material particles is not more than the above upper limit, cracking of the conductive portion is more likely to occur, the conductive particles are easily sufficiently compressed, the connection resistance between the electrodes is further lowered, and the connection resistance between the electrodes is further reduced. The interval becomes smaller.

The particle size of the base material particles indicates the diameter when the base material particles are spherical, and indicates the maximum diameter when the base material particles are not spherical.

The particle size of the base particles is particularly preferably 2 μm or more and 5 μm or less. When the particle diameter of the base material particles is within the range of 2 to 5 μm, small conductive particles can be obtained even if the distance between the electrodes is small and the thickness of the conductive portion is increased.

Further, the particle size of the base particles is particularly preferably 1.0 μm or more and 4.0 μm or less. When the particle size of the base particles is satisfied, the conductive portion is less likely to be cracked, and the connection resistance is further effectively lowered.

[Conductive part]
The metal for forming the conductive portion 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, tarium, germanium, cadmium and silicon. And these alloys and the like. Examples of the metal include tin-doped indium oxide (ITO) and solder. Among them, an alloy containing tin, nickel, palladium, copper or gold is preferable, and nickel or palladium is preferable because the connection resistance between the electrodes can be further lowered.

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

Like the conductive particles 1 and 11, the conductive portion may be formed by one layer. Like the conductive particles 21, the conductive portion may be formed of a plurality of layers. That is, the conductive portion may have a laminated structure of two or more layers. When the conductive portion is formed by 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 preferably a gold layer. Is more preferable. When the outermost layer is these preferable conductive layers, the connection resistance between the electrodes becomes even lower. Further, when the outermost layer is a gold layer, the corrosion resistance is further improved.

The method of forming the conductive portion on the surface of the base particle is not particularly limited. Examples of the method for forming the conductive portion include a method by electroless plating, a method by electroplating, a method by physical vapor deposition, and a method of coating a metal powder or a paste containing the metal powder and a binder on the surface of the substrate particles. And so on. Among them, the method by electroless plating is preferable because the formation of the conductive portion is easy. Examples of the method by physical vapor deposition include methods such as vacuum vapor deposition, ion plating, and ion sputtering.

The particle size 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 equal to or greater than the above lower limit and equal to or less than the above upper limit, the contact area between the conductive particles and the electrodes becomes sufficiently large and the conductive portion is formed when the electrodes are connected using the conductive particles. It becomes difficult for agglomerated conductive particles to be formed when the particles are formed. In addition, the distance between the electrodes connected via the conductive particles does not become too large, and the conductive portion does not easily peel off from the surface of the substrate particles. 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 spherical, and means the maximum diameter when the conductive particles have a shape other than the spherical shape.

The thickness of the conductive portion (thickness of the entire conductive portion) is preferably 0.005 μm or more, more preferably 0.01 μm or more, preferably 10 μm or less, more preferably 1 μm or less, still more preferably 0.5 μm or less. Particularly preferably, it is 0.3 μm or less. The thickness of the conductive portion is the thickness of the entire conductive layer when the conductive portion has multiple layers. When the thickness of the conductive portion is at least the above lower limit and at least the above upper limit, sufficient conductivity is obtained, and the conductive particles are not too hard and the conductive particles are sufficiently deformed at the time of connection between the electrodes. ..

When the conductive portion 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 conductive layer of the outermost layer is not less than the above lower limit and not more than the above upper limit, the coating by the conductive layer of the outermost layer becomes uniform, the corrosion resistance becomes sufficiently high, and the connection resistance between the electrodes is further increased. It gets lower. Further, when the outermost layer is a gold layer, the thinner the gold layer, the lower the cost.

The thickness of the conductive portion can be measured by observing the cross section of the conductive particles using, for example, a field emission 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 conducting conductive particle inspection. A cross section of the conductive particles is cut out using an ion milling device (“IM4000” manufactured by Hitachi High-Technologies Corporation) so as to pass near the center of the conductive particles dispersed in the embedded resin for inspection.

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

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 portion containing nickel, the content of nickel 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, still more preferably. Is 80% by weight or more, particularly preferably 85% by weight or more, and most preferably 90% by weight or more. The nickel content is preferably 100% by weight (total amount) or less, 99% by weight or less, or 95% by weight or less in the 100% by weight of the conductive portion containing nickel. When the nickel content is at least the above lower limit, the connection resistance between the electrodes becomes even lower. Further, when the oxide film on the surface of the electrode or the conductive portion is small, the connection resistance between the electrodes tends to decrease as the nickel content increases.

The method for measuring the content of the metal contained in the conductive portion can use various known analytical methods and is not particularly limited. Examples of this measuring method include an absorption analysis method and a spectrum analysis method. In the above absorption analysis method, a frame absorptiometer, an electric heating furnace absorptiometer, or the like can be used. Examples of the spectrum analysis method include a plasma emission spectrometry method and a plasma ion source mass spectrometry method.

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

The conductive portion may contain phosphorus or boron in addition to nickel. Further, the conductive portion may contain a metal other than nickel. When a plurality of metals are contained in the conductive portion, the plurality of metals may be alloyed.

The content of phosphorus or boron in 100% by weight of the conductive portion containing nickel and 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 lowered, and the conductive portion contributes to the reduction of the 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 portion. It is preferable that the number of the protrusions is plurality. An oxide film is often formed on the surface of the electrode connected by the conductive particles. Further, an oxide film is often formed on the surface of the conductive portion of the conductive particles. By using the conductive particles having the protrusions, the conductive particles are arranged between the electrodes and then crimped, so that the oxide film is effectively removed by the protrusions. Therefore, the electrodes and the conductive particles can be brought into contact with each other more reliably, and the connection resistance between the electrodes can be lowered. Further, when the conductive particles have an insulating substance on the surface, or when the conductive particles are dispersed in the binder resin and used as a conductive material, the protrusions of the conductive particles cause the conductive particles to be connected to the electrode. The resin in between can be effectively eliminated. Therefore, the conduction reliability between the electrodes is further increased.

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

Examples of the method of forming the protrusions include a method of adhering a core substance to the surface of the base material particles and then forming a conductive portion by electroless plating, and a method of forming a conductive portion on the surface of the base material particles by electroless plating. , A method of adhering a core substance and further forming a conductive portion by electroless plating, and a method of adding a core substance in the middle of forming a conductive portion by electroless plating on the surface of base particle particles.

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

Specific examples of the material 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), and zirconia. (Mohs hardness 8 to 9), alumina (Mohs hardness 9), tungsten carbide (Mohs hardness 9), diamond (Mohs hardness 10) and the like can be mentioned. 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, and titanium oxide or zirconia. , Alumina, Tungsten Carbide or Diamond, and particularly preferably Zirconia, Alumina, Tungsten Carbide or Diamond. The Mohs hardness of the material 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 substance is not particularly limited. The shape of the core material is preferably lumpy. Examples of the core material include particulate lumps, agglomerates in which a plurality of fine particles are aggregated, and amorphous lumps.

The average diameter (average particle size) of the core substance is preferably 0.001 μm or more, more preferably 0.05 μm or more, preferably 0.9 μm or less, and more preferably 0.2 μm or less. When the average diameter of the core material is at least the above lower limit and at least the above upper limit, the connection resistance between the electrodes is effectively lowered.

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 above-mentioned protrusions per one of the above-mentioned conductive particles is preferably 3 or more, and more preferably 5 or more. The upper limit of the number of the protrusions is not particularly limited. The upper limit of the number of protrusions can be appropriately selected in consideration of the particle size of the conductive particles and the like.

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, and more preferably 0.2 μm or less. When the average height of the protrusions is at least the above lower limit and at least the above upper limit, the connection resistance between the electrodes is effectively lowered.

[Insulating substance]
It is preferable that the conductive particles include an insulating substance arranged on the surface of the conductive portion. In this case, if conductive particles are used for the connection between the electrodes, short circuits between adjacent electrodes can be further prevented. Specifically, when a plurality of conductive particles come into contact with each other, an insulating substance exists between the plurality of electrodes, so that it is possible to prevent a short circuit between the electrodes adjacent to each other in the lateral direction rather than between the upper and lower electrodes. By pressurizing the conductive particles with the two electrodes at the time of connection between the electrodes, the insulating substance between the conductive portion of the conductive particles and the electrodes can be easily removed. When the conductive particles have a plurality of protrusions on the outer surface of the conductive portion, the insulating substance between the conductive portion of the conductive particles and the electrodes can be more easily removed.

The insulating substance is preferably insulating particles because the insulating substance can be more easily removed during pressure bonding between the electrodes.

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

The average diameter (average particle diameter) of the insulating substance 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 size) of the insulating substance is preferably 0.005 μm or more, more preferably 0.01 μm or more, preferably 1 μm or less, and more preferably 0.5 μm or less. When the average diameter of the insulating substance is at least the above lower limit, it becomes difficult for the conductive portions of the plurality of conductive particles to come into contact with each other when the conductive particles are dispersed in the binder resin. 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 high 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 temperature.

The "average diameter (average particle diameter)" of the insulating substance indicates a number average diameter (number average particle diameter). The average diameter of the insulating substance is determined by using a particle size distribution measuring device or the like.

(Manufacturing method of conductive particles)
In the method for producing conductive particles according to the present invention, the conductive particles (conductive particles before annealing treatment) having a conductive portion arranged on the surface of the substrate particles are used. A step of annealing the particles to 200 ° C. or higher is provided. In the method for producing conductive particles according to the present invention, the above-mentioned annealing treatment obtains conductive particles in which the conductive portion does not contain hydrogen atoms or the conductive portion contains hydrogen atoms at 80 μg / g or less. In particular, it is preferable that the conductive portion having the crystal structure is annealed.

In order to reduce the content of hydrogen atoms in the conductive portion, the temperature of the annealing treatment is preferably 200 ° C. or higher, more preferably 300 ° C. or higher. The temperature of the annealing treatment is equal to or lower than the thermal decomposition temperature of the substrate particles and lower than the thermal decomposition temperature of the conductive portion. The temperature of the annealing treatment is preferably 30 ° C. or higher lower than the thermal decomposition temperature of the substrate particles. The temperature of the annealing treatment is preferably 800 ° C. or lower, more preferably 500 ° C. or lower.

Further, in order to reduce the content of hydrogen atoms in the conductive portion, the annealing treatment time is preferably 0.5 hours or more, more preferably 1 hour or more, still more preferably 3 hours or more.

Further, in order to reduce the content of hydrogen atoms in the conductive portion, it is preferable to perform the annealing treatment 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.

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

Further, 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, the plating surface area of the conductive particles is large, so that a high concentration reducing agent is required. Therefore, since hydrogen is generated by oxidative decomposition of a large amount of reducing agent, a relatively large amount of hydrogen atoms are contained in the conductive portion.

Examples of the method of controlling the hydrogen content in the conductive portion include a method of adjusting the reducing agent concentration to the minimum when forming the conductive portion by electroless nickel plating, and a method of 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. Can be mentioned.

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

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

Using a nickel plating solution prepared by adjusting the concentration of the reducing agent to 100 g / L or less, the content of hydrogen atoms in the conductive portion is reduced by slowly dropping the reducing agent onto a suspension in which resin particles are dispersed at 100 ml / min or less. can do.

Examples of the method for controlling the hydrogen content in the conductive portion include a method for controlling the pH of the nickel plating solution. When the pH of the nickel plating solution exceeds 8.0, a large amount of self-decomposition reaction of the reducing agent is involved, so that the amount of hydrogen generated increases and the content of hydrogen atoms in the conductive portion increases. 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 the precipitation of nickel plating is suppressed, so that hydrogen in the conductive part is suppressed. The content of atoms can be reduced.

Examples of the method for controlling the hydrogen content in the conductive portion include 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 self-decomposition reaction of the reducing agent is involved, so that the amount of hydrogen generated increases and the content of hydrogen atoms in the conductive portion 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 the precipitation of nickel plating is suppressed, so that hydrogen in the conductive part is suppressed. The content of atoms can be reduced.

(Conductive material)
The conductive material according to the present invention includes the above-mentioned conductive particles and a binder resin. It is preferable that the conductive particles are dispersed in the binder resin and used as a conductive material. The conductive material is preferably an anisotropic conductive material. It is preferable that the conductive particles and the conductive material are used for electrical connection between the electrodes, respectively. The conductive material is preferably a circuit connection material.

The binder resin is not particularly limited. As the binder resin, an insulating resin is generally used. Examples of the binder resin include vinyl resins, thermoplastic resins, curable resins, thermoplastic block copolymers, and elastomers. Only one kind of the binder resin may be used, or two or more kinds may be used in combination.

Examples of the vinyl resin include vinyl acetate resin, acrylic resin, styrene resin and the like. Examples of the thermoplastic resin include polyolefin resins, ethylene-vinyl acetate copolymers, and polyamide resins. Examples of the curable resin include epoxy resin, urethane resin, polyimide resin, unsaturated polyester resin and the like. 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 additive of a styrene-butadiene-styrene block copolymer, and a styrene-isoprene. -Hydrogen additives for styrene block copolymers and the like can be mentioned. 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 compounding ratio so that the binder resin is cured. When the binder resin contains a thermal cation curing initiator, an acid is likely to be contained in the cured product. However, by using the conductive particles according to the present invention, the connection resistance between the electrodes can be kept low.

In addition to the conductive particles and the binder resin, the conductive material includes, for example, a filler, a bulking agent, a softening agent, a plasticizer, a polymerization catalyst, a curing catalyst, a colorant, an antioxidant, a heat stabilizer, and a photostabilizer. It may contain various additives such as an agent, an ultraviolet absorber, a lubricant, an antistatic agent and a flame retardant.

The conductive material can be used as a conductive paste, a conductive film, or the like. When the conductive material is a conductive film, a film containing no conductive particles may be laminated on the conductive film containing the 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, and preferably 70% by weight or more. It is 99.99% by weight or less, more preferably 99.9% by weight or less. When the content of the binder resin is not less than the 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 connecting target member connected by the conductive material is further increased.

The content of the conductive particles in 100% by weight of the conductive material is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, preferably 80% by weight or less, and more preferably 60% by weight. Below, 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 increased.

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

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

FIG. 4 schematically shows a connection structure using conductive particles according to the first embodiment of the present invention in a front sectional view.

The connection structure 51 shown in FIG. 4 connects a first connection target member 52, a second connection target member 53, and a connection portion 54 connecting the first and second connection target members 52 and 53. Be prepared. The connecting portion 54 is formed by curing a conductive material containing the conductive particles 1. In FIG. 4, the conductive particles 1 are shown schematicly for convenience of illustration. Conductive particles 11, 21 and the like may be used instead of the conductive particles 1.

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 52a and the second electrode 53a are electrically connected by one or more conductive particles 1. Therefore, the first and second connection target members 52 and 53 are electrically connected by the conductive particles 1.

The method for manufacturing the connection structure is not particularly limited. As an example of the method for manufacturing the connection structure, the conductive material is arranged between the first connection target member and the second connection target member, and after obtaining a laminate, the laminate is heated. And the method of pressurizing and the like. The pressurizing pressure is about 9.8 × 10 ^{4 to} 4.9 × 10 ⁶ Pa. The heating temperature is about 120 to 220 ° C.

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

Examples of the electrodes provided on the connection target member include metal electrodes such as gold electrodes, nickel electrodes, tin electrodes, aluminum electrodes, copper electrodes, silver electrodes, SUS electrodes, molybdenum electrodes, and tungsten electrodes. When the connection target member is a flexible printed substrate, the electrode is preferably a gold electrode, a nickel electrode, a tin electrode, or a copper electrode. When the member to be connected is a glass substrate, the electrode is preferably an aluminum electrode, a copper electrode, a molybdenum electrode, or a tungsten electrode. When the electrode is an aluminum electrode, it may be an electrode formed only of aluminum, or an electrode in which an aluminum layer is laminated on the surface of a metal oxide layer. Examples of the material of the metal oxide layer include indium oxide doped with a trivalent metal element and zinc oxide doped with a trivalent metal element. Examples of the trivalent metal element include Sn, Al and Ga.

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

(Example 1)
(1) Preparation of Conductive Particles 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 solution of dimethylamine borane to activate the surface of the resin particles. The surface-activated resin particles were thoroughly 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 a nickel particle slurry (average particle diameter 150 nm) was added to the suspension (A) over 3 minutes to obtain base particles to which a core substance was attached. Further, 3 L of a nickel plating solution (pH 5.0) containing 50 g / L of nickel sulfate, 50 g / L of sodium hypophosphate and 20 g / L of sodium citrate was prepared.

While stirring the obtained suspension (A) at 45 ° C., the nickel plating solution was added dropwise to the suspension (A) at 50 ml / min to perform electroless nickel plating to form a nickel-phosphorus conductive layer. After the formation, the particles were taken out by filtering the plating solution, washed with water, and dried to obtain conductive particles. In this way, conductive particles having a conductive portion (thickness 102 nm) formed on the surface of the base particle A were obtained.

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

(2) Preparation of Anisotropic Conductive Paste 20 parts by weight of an epoxy compound (“EP-3300P” manufactured by Nagase ChemteX Corporation) which is a thermosetting compound and an epoxy compound (“EPICLON HP” manufactured by DIC) which is a thermosetting compound. -4032D ") 15 parts by weight and 5 parts by weight of a thermosetting agent (Sun Aid" SI-60 "manufactured by Sanshin Chemical Co., Ltd.) as a thermosetting agent, and the obtained conductive particles are further mixed with compound 100. An anisotropic conductive paste was obtained by adding the mixture so that the content in% by weight was 10% by weight, and then stirring the mixture at 2000 rpm for 5 minutes using a planetary stirrer.

(3) Preparation 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. Further, a semiconductor chip having a gold electrode pattern (gold electrode thickness 20 μm) having an L / S of 20 μm / 20 μm on the lower surface was prepared.

An anisotropic conductive paste immediately after production was applied to the upper surface of the glass substrate so as to have a thickness of 20 μm to form an anisotropic conductive material layer. Next, the semiconductor chips were laminated 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., the 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) Preparation of Connection Structure B Similar to Connection Structure A except that a pressure heating head is placed on the upper surface of the semiconductor chip and a pressure of 100 MPa is applied to cure the anisotropic conductive material layer at 100 ° C. The connection structure B was obtained.

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

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

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

While stirring the suspension (A) obtained in Example 1 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 phosphorus conductive layer, a plating solution for forming protrusions was added dropwise at 5 ml / min to form protrusions. During the dropping of the projection-forming plating solution, nickel plating was performed while the generated Ni protrusion nuclei were dispersed by ultrasonic stirring.

Next, the nickel plating solution was added dropwise at 25 ml / min to perform electroless nickel plating 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. In this way, conductive particles having a conductive portion (thickness 102 nm) formed on the surface of the base particle A were 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 hypophosphate and 20 g / L of sodium citrate was prepared.

0.5 L of a projection-forming plating solution (pH 10.0) 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 stirring the suspension (A) obtained in Example 1 at 45 ° C., the nickel plating solution was added dropwise to the suspension (A) at 20 ml / min, electroless nickel plating was performed, and nickel- After forming the phosphorus conductive layer, a plating solution for forming protrusions was added dropwise at 5 ml / min to form protrusions. During the dropping of the projection-forming plating solution, nickel plating was performed while the generated Ni protrusion nuclei were dispersed by ultrasonic stirring.

Next, the nickel plating solution was added dropwise at 20 ml / min to perform electroless nickel plating to form a nickel-phosphorus conductive layer on the surface of the base particle A.

Then, the suspension was filtered to take out the particles, and the suspension was washed with water to obtain particles on which a nickel-phosphorus conductive layer was formed. After thoroughly washing the particles with water, the particles were added to 500 parts by weight of distilled water and dispersed to obtain a suspension (B).

Then, while stirring the suspension (B) obtained above at 55 ° C., the gold plating solution was gradually added dropwise to the dispersed suspension (B) to perform gold plating. The dropping speed of the gold plating solution was 2 mL / min, and gold plating was performed.

The suspension was filtered to remove the particles, washed with water and dried to obtain conductive particles.

In this way, conductive particles in which a conductive portion (thickness 108 nm) plated with nickel-phosphorus and gold was formed on the surface of the base material particles A were 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 hypophosphate and 20 g / L of sodium citrate was prepared.

0.5 L of a projection-forming plating solution (pH 10.0) 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 stirring the suspension (A) obtained in Example 1 at 45 ° C., the nickel plating solution was added dropwise to the suspension (A) at 15 ml / min, electroless nickel plating was performed, and nickel- After forming the phosphorus conductive layer, a plating solution for forming protrusions was added dropwise at 5 ml / min to form protrusions. During the dropping of the projection-forming plating solution, nickel plating was performed while the generated Ni protrusion nuclei were dispersed by ultrasonic stirring.

Next, the nickel plating solution was added dropwise at 15 ml / min to perform electroless nickel plating to form a nickel-phosphorus conductive layer on the surface of the base particle A.

Then, the suspension was filtered to take out the particles, and the suspension was washed with water to obtain particles on which a nickel-phosphorus conductive layer was formed. After thoroughly washing the particles with water, the particles were added to 500 parts by weight of distilled water and dispersed to obtain a suspension (B).

Then, while stirring the suspension (B) obtained above at 50 ° C., the palladium plating solution was gradually added dropwise to the dispersed suspension (B) to perform palladium plating. The dropping rate of the palladium plating solution was 5 mL / min, and palladium plating was performed.

Next, the suspension was filtered to remove the particles, and the suspension was washed with water to obtain particles on which a nickel-phosphorus and palladium conductive layer was formed. After thoroughly washing the particles with water, the particles were added to 500 parts by weight of distilled water and dispersed to obtain a suspension (C).

Then, the gold plating solution was gradually added dropwise to the dispersed suspension (C) while stirring the suspension (C) obtained above at 55 ° C. to perform gold plating. The dropping speed of the gold plating solution was 2 mL / min, and gold plating was performed.

The suspension was filtered to remove the particles, washed with water and dried to obtain conductive particles.

In this way, conductive particles in which nickel-phosphorus, palladium, and a gold-plated conductive portion (thickness 106 nm) were formed on the surface of the base particle A were 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 a 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.

0.5 L of a projection-forming plating solution (pH 10.0) containing 120 g / L of dimethylamine borane 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 stirring the suspension (A) obtained in Example 1 at 45 ° C., the nickel plating solution was added dropwise to the suspension at 15 ml / min to perform electroless nickel plating, and a nickel-boron conductive layer was performed. After forming the above, the plating solution for forming the protrusion was added dropwise at 5 ml / min to form the protrusion. During the dropping of the projection-forming plating solution, nickel plating was performed while the generated Ni protrusion nuclei were dispersed by ultrasonic stirring.

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

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

Then, while stirring the suspension (B) obtained above at 50 ° C., the palladium plating solution was gradually added dropwise to the dispersed suspension (B) to perform palladium plating. The dropping rate of the palladium plating solution was 5 mL / min, and palladium plating was performed.

Next, the suspension was filtered to remove the particles, and the suspension was washed with water to obtain particles on which a nickel-phosphorus and palladium conductive layer was formed. After thoroughly washing the particles with water, the particles were added to 500 parts by weight of distilled water and dispersed to obtain a suspension (C).

Then, the gold plating solution was gradually added dropwise to the dispersed suspension (C) while stirring the suspension (C) obtained above at 55 ° C. to perform gold plating. The dropping speed of the gold plating solution was 2 mL / min, and gold plating was performed.

The suspension was filtered to remove the particles, washed with water and dried to obtain conductive particles.

In this way, conductive particles in which nickel-boron, palladium, and a gold-plated conductive portion (thickness 106 nm) were formed on the surface of the base particle A were 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)
Same as in Example 1 except that the annealing treatment 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 300 ° C. for 4 hours in an atmospheric pressure atmosphere of 10 KPa. The conductive particles, the anisotropic conductive paste, and the connecting structures A and B were obtained.

(Example 8)
Same as in Example 1 except that the annealing treatment 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 under a pressure atmosphere of 100 KPa. The conductive particles, the anisotropic conductive paste, and the connecting structures A and B were obtained.

(Example 9)
Conductive particles and anisotropic particles are the same as in Example 1 except that the base particle A is changed to the base particle B having a particle diameter of 2.5 μm, which is different from the base particle A only in the particle size. Conductive paste and connecting structures A and B were obtained.

(Example 10)
Conductive particles and anisotropic particles are the same as in Example 1 except that the base particle A is changed to the base particle C having a particle diameter of 3.5 μm, which is different from the base particle A only in the particle size. Conductive paste and connecting structures A and B were obtained.

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

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

(Example 12)
300 g of a 0.13 wt% ammonia aqueous solution was placed in a 500 mL reaction vessel equipped with a stirrer and a thermometer. Next, in the aqueous ammonia solution in the reaction vessel, 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.) The mixture with was added slowly. After advancing the hydrolysis and condensation reaction 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 obtained particles were subjected to an oxygen partial pressure of ^10-17 atm. , 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 was changed to the base particle E, and the conductive particle having the conductive portion formed on the surface of the base particle E was annealed at a temperature of 500 ° C. for 4 hours under a pressure atmosphere of 100 KPa. Conductive particles, anisotropic conductive paste, and connecting structures A and B were obtained in the same manner as in Example 1 except that the annealing treatment conditions were changed.

(Example 13)
Conductive particles and anisotropic particles are the same as in Example 5 except that the base particle A is changed to the base particle F having a particle diameter of 5.0 μm, which is different from the base particle A only in the particle size. Conductive paste and connecting structures A and B were obtained.

(Example 14)
Conductive particles and anisotropic particles are the same as in Example 5 except that the base particle A is changed to the base particle G having a particle size of 10.0 μm, which is different from the base particle A only in the particle size. Conductive paste and connecting structures A and B were obtained.

(Example 15)
100 mmol of methyl methacrylate and N, N, N-trimethyl-N-2-methacryloyloxyethyl in a 1000 mL separable flask equipped with a four-neck separable cover, stirring blade, three-way cock, cooling tube and temperature probe. 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 under a nitrogen atmosphere at a temperature of 70 ° C. for 24 hours. After completion of the reaction, the reaction was freeze-dried to obtain insulating particles having an ammonium group on the surface, having an average particle diameter of 220 nm and a CV value of 10%.

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

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

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

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

(Comparative Example 2)
The same as in Example 1 except that the annealing treatment 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 280 ° C. for 2 hours in a nitrogen atmosphere. , Conductive particles, anisotropic conductive paste, and connecting structures A and B were obtained.

(Evaluation)
(1) The content of hydrogen atoms in the conductive part The sample of the conductive part (metal film) to be measured was collected as follows.

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

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

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

(2) Crystalline size in cross-sectional observation of the conductive parts (first, second, and third conductive parts) "Technobit" manufactured by Kulzer Co., Ltd. so that the content of the obtained conductive particles is 30% by weight. It was added to "4000" and dispersed to prepare an embedded resin for conducting conductive particle inspection. 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 near 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 portion of the conductive particles. The crystallite size was determined by checking the particle size distribution chart of the crystallite size. It should be noted that the average value of the crystallite size (1) in the first conductive portion, the crystallite size (2) in the second conductive portion, and the crystallite size (3) in the third conductive portion is used as the crystallite. The size was calculated.

(3) Powder X-ray diffraction measurement was performed using a crystallite size X-ray diffractometer (“RINT2500VHF” manufactured by Rigaku Denki Co., Ltd.) based on the average value of crystallite sizes in each direction. The half width of the diffraction peak obtained by X-ray diffraction with CuKα rays and the crystallite size of the (111) plane, (200) plane, (220) plane, (311) plane, and (222) plane obtained from Scheller's equation. The crystallite size was calculated from the average value.

The XRD measurement conditions are 45 kV, 50 mA, and the scan rate is 4.0 deg / min. , The scan step was 0.02 deg, and the measurement range was 2 θ from 5.0 deg to 110.0 deg.

The crystallite size was calculated by the following Scheller's formula.

D = Kλ / βcosθ
D: Crystallite size K: Scheller constant λ: X-ray wavelength β: Half width [rad]
θ: diffraction angle

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

The XRD measurement conditions are 45 kV, 50 mA, and the scan rate is 4.0 deg / min. , The scan step was 0.02 deg, and the measurement range was 2 θ from 5.0 deg to 110.0 deg.

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

Δ2θ ・ cosθ / λ = 0.9 / D + 2ε ・ sinθ / λ
D: Crystallite size λ: X-ray wavelength Δ2θ: Half width [rad]
θ: Diffraction angle ε: Lattice strain

The crystallite size was plotted by plotting 2 sinθ / λ on the horizontal axis and Δ2θ · cosθ / λ on the vertical axis of the Williamson-Hall equation, and calculated the crystallite size from the value of the intercept of the straight line of the plot.

(5) Compressive modulus (10% K value) when conductive particles are compressed by 10%
The compressive elastic modulus (10% K value) of the obtained conductive particles was measured by the method described above using a microcompression tester (“Fisherscope H-100” manufactured by Fisher).

(6) Cracking of Conductive Part In the obtained connection structures A and B, the peeled surface was observed after peeling the semiconductor chip. It was evaluated whether or not the conductive portion was cracked in the 50 conductive particles. The cracks in the conductive part were judged according to the following criteria.

[Criteria for cracking conductive parts]
○○○: The ratio of the number of conductive particles having cracks in the conductive part out of 50 conductive particles is 0 or more and less than 10 ○○: Cracks occur in the conductive part out of 50 conductive particles. The ratio of the number of conductive particles is 10 or more and less than 20. ◯: The ratio of the number of conductive particles in which the conductive portion is cracked is 20 or more and less than 30 out of 50 conductive particles. : The ratio of the number of conductive particles having cracks in the conductive portion out of 50 conductive particles is 30 or more and less than 40. ×: Conductive with cracks in the conductive portion among 50 conductive particles. The ratio of the number of particles is 40 or more

(7) Initial connection resistance X
Measurement of connection resistance:
The connection resistance X between the opposite electrodes of the obtained connection structures A and B was measured by the 4-terminal method. Further, 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 is more than 2.0Ω and 3.0Ω or less ○: Connection resistance X is more than 3.0Ω and 5.0Ω or less △: Connection resistance X Exceeds 5.0Ω and 10Ω or less ×: Connection resistance X exceeds 10Ω

(8) Connection resistance Y (long-term reliability) after exposure to acid conditions
The obtained connection structures A and B were left in a high-temperature and high-humidity tank at 85 ° C. and 85% humidity for 100 hours. By leaving the connection structures A and B under the above conditions, the reaction between the water infiltrated into the binder resin and the acid contained in the binder resin causes the presence of acid in the connection portion between the electrodes in the connection structures A and B. It was exposed to the bottom for a certain period of time. In the connection structures A and B after being left to stand, the connection resistance Y between the opposing electrodes of the connection structure was measured by the 4-terminal method. In addition, the connection resistance Y after exposure to the presence of acid was determined according to the following criteria.

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

The results are shown in Table 1 below.

1 ... Conductive particles 2 ... Base material particles 3 ... Conductive parts 11 ... Conductive particles 11a ... Protrusions 12 ... Conductive parts 12a ... Protrusions 13 ... Core material 14 ... Insulating material 21 ... Conductive particles 21a ... Protrusions 22 ... Conductive parts 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 ... Second electrode 54 ... Connection

Claims (13)

A base material and a conductive portion arranged on the surface of the base material are provided.
Or the conductive portion does not include a hydrogen atom, or, the conductive portion is seen containing a hydrogen atom in the following 80 [mu] g / g,
The conductive portion includes a conductive portion having a crystal structure, and the conductive portion includes a conductive portion.
A conductive particle having a crystallite size of 50 nm or more in the conductive portion having a crystal structure in a cross-sectional observation of the conductive portion having the crystal structure . A base particle and a conductive portion arranged on the surface of the base particle are provided.
The conductive portion does not contain a hydrogen atom, or the conductive portion contains a hydrogen atom at 80 μg / g or less.
The conductive portion includes a conductive portion having a crystal structure, and the conductive portion includes a conductive portion.
In the conductive portion having the crystal structure, the half width of the diffraction peak obtained by X-ray diffraction and the (111) plane, (200) plane, (220) plane, (311) plane and (222) obtained from Scheller's equation. Conductive particles having a crystallite size of 50 nm or more based on the average value of the crystallite size of the surface. A base particle and a conductive portion arranged on the surface of the base particle are provided.
The conductive portion does not contain a hydrogen atom, or the conductive portion contains a hydrogen atom at 80 μg / g or less.
The conductive portion includes a conductive portion having a crystal structure, and the conductive portion includes a conductive portion.
In conducting portion having a crystal structure, the half width and Williamson of a diffraction peak obtained by X-ray diffraction - crystallite size determined from the Hall type is is 50nm or more, the conductive particles. A base particle and a conductive portion arranged on the surface of the base particle are provided.
The conductive portion does not contain a hydrogen atom, or the conductive portion contains a hydrogen atom at 80 μg / g or less.
Conductive particles having a compressive elastic modulus of 3000 N / mm ² or more when compressed by 10%. A base particle and a conductive portion arranged on the surface of the base particle are provided.
The conductive portion does not contain a hydrogen atom, or the conductive portion contains a hydrogen atom at 80 μg / g or less.
The conductive portion is a conductive particle containing at least nickel. The conductive particle according to any one of claims 1 to 4, wherein the conductive portion contains at least nickel, palladium, ruthenium, copper, tungsten, molybdenum, phosphorus, boron, gold, platinum or tin. The conductive particle according to any one of claims 1 to 6 , wherein the Vickers hardness of the conductive portion is 200 or more. The conductive particles according to any one of claims 1 to 7 , wherein the base particles are resin particles or organic-inorganic hybrid particles. The conductive particle according to any one of claims 1 to 8 , which has a plurality of protrusions on the outer surface of the conductive portion. The conductive particle according to any one of claims 1 to 9 , further comprising an insulating substance arranged on the outer surface of the conductive portion. Comprising a base particle, using conductive particles having a conductive portion disposed on the surface of the substrate particles, a step of annealing the conductive particles 200 ° C. or higher,
By the annealing treatment, the base material particles and the conductive portion arranged on the surface of the base material particles are provided, and the conductive portion does not contain hydrogen atoms, or the conductive portion contains hydrogen atoms at 80 μg / g or less. A method for producing conductive particles, which comprises obtaining conductive particles containing the particles. A conductive material containing the conductive particles according to any one of claims 1 to 10 and a binder resin. The first member to be connected and
The second connection target member and
A connecting portion connecting the first connection target member and the second connection target member is provided.
A connecting structure in which the material of the connecting portion is the conductive particles according to any one of claims 1 to 10 , or is a conductive material containing the conductive particles and a binder resin.

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