JP2016148104A - Paste-like metal particle composition, method for producing metallic member-joined body, and method for producing porous metal particle sintered substance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paste-like metal particle composition which is formed into a porous metal particle sintered substance having excellent conductivity by heating and can firmly join a plurality of metallic members; and a method for producing a metallic member member-joined body in which the plurality of metallic members are firmly joined to each other.SOLUTION: A paste-like metal particle composition is formed of (A) heat-sinterable metal particles which are heat-sinterable metal particles that have an average particle diameter of 0.7 μm or more and 6 μm or less and have a spherical form, a teardrop form or a granular form, and have a coating amount of an organic substance that covers the surface of the heat-sinterable metal particles and has a polar group of 0.1-2.0 mass%; (B) a volatile dispersion medium; and (C) a thermosetting resin composition. A mass ratio of the metal particles and the resin composition is 98.5:1.5 to 99.9:0.1. A method for producing a metallic member-joined body includes: interposing the paste-like metal particle composition between the plurality of metallic members; volatilizing the volatile dispersion medium by heating the metal particle composition at 70 to 300°C; sintering the heat-sinterable metal particles (A) and curing the thermosetting resin composition (C); and thereby producing a porous metal particle sintered substance.SELECTED DRAWING: Figure 4

Description

The present invention relates to a paste-like metal particle composition, a method for producing a metal member assembly, and a method for producing a sintered porous metal particle. Specifically, a paste-like metal particle composition comprising a heat-sinterable metal particle, a volatile dispersion medium, and a thermosetting resin composition, and the paste-like metal particle composition interposed between a plurality of metal members are heated. A method for producing a metal member assembly in which the volatile dispersion medium is volatilized, the heat-sinterable metal particles (A) are sintered together, and the thermosetting resin composition (C) is cured, and the paste A porous metal particle composition that is heated to volatilize the volatile dispersion medium, sinter the heat-sinterable metal particles (A) to cure the thermosetting resin composition (C) The present invention relates to a method for producing a sintered particle.

A conductive / thermal conductive paste obtained by dispersing a metal powder such as silver, copper, or nickel in a liquid thermosetting resin composition is cured by heating to form a conductive / thermal conductive film. Therefore, formation of conductive circuits on printed circuit boards, formation of various electronic components such as resistors and capacitors, and electrodes of various display elements, formation of conductive films for electromagnetic wave shielding, capacitors, resistors, diodes, memories, arithmetic elements (CPU) and other chip components to substrates, formation of solar cell electrodes, especially formation of solar cell electrodes that cannot be processed at high temperatures due to the use of amorphous silicon semiconductors, multilayer ceramic capacitors, multilayer ceramic inductors It is used for forming external electrodes of chip-type ceramic electronic components such as multilayer ceramic actuators.

In recent years, with higher performance of chip components, the amount of heat generated from the chip components has increased, and improvement in thermal conductivity as well as conductivity (electrical conductivity) is required. Therefore, it tries to improve conductivity and thermal conductivity by increasing the content of metal particles as much as possible. However, when it does so, there exists a problem that the viscosity of a paste rises and workability | operativity falls remarkably.

In order to solve such a problem, in Patent Document 1 (Japanese Patent Application Laid-Open No. 2014-51590), “(A) a silver particle that is a spherical open communicating porous body, (B) a resin and / or (C) a dispersant, A silver paste composition and a method for producing the same, which preferably includes at least one selected from (D) a curing agent, (E) a fluxing agent, and (F) a curing accelerator.
However, since (A) silver particles, which are spherical open communicating porous bodies, have innumerable pores communicating from the surface to the inside, (B) when the amount of the resin is a very small amount or a small amount, Since the resin penetrates and the amount remaining on the surface of the silver particles is small, there is a problem that there is no effect of dramatically improving the adhesion to the member in contact with the thermosetting resin.

In Patent Document 2 (Japanese Patent Laid-Open No. 2014-194013), “(A) plate-type silver fine particles, (B) silver powder, and (C) a thermosetting resin, and the silver fine particles of the component (A) and the (B) When the total amount of the component silver powder is 100 parts by mass, the thermosetting resin composition containing 1 to 20 parts by mass of the component (C), and the resin composition as a die attach paste or a heat radiation member bonding material Semiconductor devices and electric / electronic components manufactured by using as a device have been proposed.
However, since (A) the plate-like silver fine particles are an essential component, when the thermosetting resin composition is continuously discharged from the storage container, the plate-like silver fine particles gradually accumulate in front of the discharge port and clogging occurs. There is a problem.

In Patent Document 3 (Japanese Patent Laid-Open No. 2010-65277), “a paste-like metal particle composition comprising (A) a heat-sinterable metal particle having an average particle diameter of 0.1 μm to 50 μm and (B) a volatile dispersion medium is disclosed. , Interposing between a plurality of metal members, heating at 70 ° C. or more and 400 ° C. or less, volatilizing the volatile dispersion medium, joining the metal members with a sintered product of the metal particles, and then curable "A method for producing a metal member assembly" in which a porous resin is impregnated with a liquid resin composition and cured.
However, in this method, after the paste-like metal particle composition containing the heat-sinterable metal particles is heated to sinter the metal particles, the liquid curable resin composition is impregnated by capillary action. Therefore, there is a problem that work efficiency is low.

In Patent Document 4 (Japanese Patent Laid-Open No. 2013-214733), low-temperature sinterable silver fine particles, in particular, low-temperature sinterable silver fine particles include silver fine particles having an average particle diameter of 1 to 500 nm; and a thermosetting binder, and silver fine particles A heat conductive paste having a thermosetting binder of 2 to 7 parts by mass with respect to 100 parts by mass has been proposed.
However, this thermally conductive paste has high surface activity because the low-temperature sinterable silver particles are so-called nano-sized ultrafine particles, and a large amount of surface coating agent is required to prevent aggregation between the silver particles. For this reason, the sintered body of the silver particles necessarily has a high porosity, and if the ratio of the thermosetting binder is small, the durability against thermal shock is lowered. In order to prevent this, a large amount of thermosetting binder is used, and in that case, a large amount of thermosetting binder is included in the sintered body. However, since thermosetting binders such as epoxy resins are organic, they have low heat resistance, and when the sintered body is placed at a high temperature, a large amount of pyrolysis gas is generated and contaminates surrounding members. There is a problem.

JP 2014-51590 A JP 2014-194013 A JP 2010-65277 A JP 2013-214733 A

As a result of intensive research to solve the above problems, the present inventors have found that a paste-like metal particle composition comprising a heat-sinterable metal particle having an average particle size of micrometer size and a volatile dispersion medium has a small amount or When a paste-like metal particle composition containing a small amount of a thermosetting resin composition is heated, the heat-sinterable metal particles are sintered with each other and the thermosetting resin composition is cured to be conductive and thermally conductive. A porous metal particle sintered product with excellent properties, and when heated by interposing the paste-like metal particle composition between a plurality of metal members, a plurality of metals while maintaining high conductivity and thermal conductivity It was found that the manufactured member was strongly bonded, and the bonded body thus obtained was excellent in durability against thermal shock, and the present invention was achieved.

The object of the present invention is to sinter porous metal particles that are excellent in electrical conductivity, thermal conductivity, and durability against thermal shock by sintering heat-sinterable metal particles when heated and curing the thermosetting resin composition. Paste metal particle composition to be a product, a method for manufacturing a metal member assembly in which a plurality of metal members are firmly bonded and have excellent durability against thermal shock, and conductivity, thermal conductivity, and thermal shock Another object of the present invention is to provide a method for producing a sintered product of porous metal particles having excellent durability against the above.

This purpose is
“[1] (A) Spherical, teardrop-shaped or granular heat-sinterable metal particles having an average particle diameter of 0.7 μm or more and 6 μm or less, and the polarity covering the surface of the heat-sinterable metal particles A heat-sinterable metal particle having a coating amount of the organic substance having a group of 0.1 to 2.0% by mass, (B) a volatile dispersion medium, and (C) a thermosetting resin composition, Is a paste-like material in which the mass ratio of the conductive metal particles (A) and the thermosetting resin composition (C) is 98.5: 1.5 to 99.9: 0.1, and is 70 ° C. or higher and 300 ° C. or lower. By heating at, the volatile dispersion medium is volatilized, the heat-sinterable metal particles (A) are sintered together, the thermosetting resin composition (C) is cured, and the porous metal particles are sintered. A paste-like metal particle composition, characterized in that it becomes a product.
[1-1] The organic substance having a polar group is (a) a fatty acid or an alkali metal salt or ester thereof, (b) a polymer dispersant having an acidic functional group and / or a basic functional group, or (c) a nitrogen-containing compound The paste-like metal particle composition according to [1], which is an organic compound.
[2] The material according to [1] or [1-1], wherein the material of the heat-sinterable metal particles (A) is gold, silver, copper, platinum, palladium, or an alloy thereof. Paste metal particle composition.
[3] The paste according to [1], [1-1] or [2], wherein the thermosetting resin composition is a thermosetting epoxy resin composition containing an inclusion type curing agent. Metal particle composition.
[4] The paste-like metal particle composition according to any one of [1] to [3], wherein the porous metal particle sintered product has a porosity of 5 to 38%.
[5] The volume resistivity of the sintered porous metal particles is 1 × 10 ⁻⁵ Ω · cm or less, and the thermal conductivity is 100 W / m · K or more, [1] The paste-like metal particle composition according to any one of to [4].

[6] (A) Spherical, teardrop-shaped, or granular heat-sinterable metal particles having an average particle diameter of 0.7 μm or more and 6 μm or less, the polar group covering the surface of the heat-sinterable metal particles The heat-sinterable metal particles having an organic coating amount of 0.1 to 2.0% by mass, (B) a volatile dispersion medium, and (C) a thermosetting resin composition, A paste-like metal particle composition in which the mass ratio of the metal particles (A) to the thermosetting resin composition (C) is 98.5: 1.5 to 99.9: 0.1 is converted into a plurality of metal members. The thermosetting resin composition (C) is heated between 70 ° C. and 300 ° C. to volatilize the volatile dispersion medium and sinter the heat-sinterable metal particles (A) together. A metal member joined body characterized by joining a plurality of metal members by curing to form a sintered porous metal particle. Manufacturing method.
[6-1] The organic substance having a polar group is (a) a fatty acid or an alkali metal salt or ester thereof, (b) a polymer dispersant having an acidic functional group and / or a basic functional group, or (c) a nitrogen-containing compound The method for producing a metal member assembly according to [6], which is an organic compound.
[7] The material according to [6] or [6-1], wherein the material of the heat-sinterable metal particles (A) is gold, silver, copper, platinum, palladium, or an alloy thereof. Manufacturing method of metal member assembly.
[8] The thermosetting resin composition according to [6], [6-1], or [7], wherein the thermosetting epoxy resin composition includes an inclusion type curing agent. Manufacturing method of metal member assembly.
[9] The metal member according to any one of [6] to [8], wherein the metal of the metal member is copper, silver, gold, platinum, palladium, or an alloy of these metals Manufacturing method of joined body.
[10] The method for producing a metal member assembly according to any one of [6] to [9], wherein the porous metal particle sintered product has a porosity of 5 to 38%.
[11] The volume resistivity of the sintered porous metal particles is 1 × 10 ⁻⁵ Ω · cm or less, and the thermal conductivity is 100 W / m · K or more, [6] To [10] A method for producing a metal member assembly according to any one of [10]
[12] The method for producing a metal member assembly according to any one of [6] to [11], wherein the metal member is a lead frame, a circuit board, or an electronic component having a metal part. .

[13] (A) Spherical, teardrop-shaped or granular heat-sinterable metal particles having an average particle diameter of 0.7 μm or more and 6 μm or less, the polar group covering the surface of the heat-sinterable metal particles The heat-sinterable metal particles having an organic coating amount of 0.1 to 2.0% by mass, (B) a volatile dispersion medium, and (C) a thermosetting resin composition, A paste-like material having a mass ratio of the metal particles (A) to the thermosetting resin composition (C) of 98.5: 1.5 to 99.9: 0.1 is heated at 70 ° C. or higher and 300 ° C. or lower. Then, the volatile dispersion medium is volatilized, the heat-sinterable metal particles (A) are sintered together, and the thermosetting resin composition (C) is cured to form a porous metal particle sintered product. A method for producing a sintered product of porous metal particles, characterized in that
[13-1] The organic substance having a polar group is (a) a fatty acid or an alkali metal salt or ester thereof, (b) a polymer dispersant having an acidic functional group and / or a basic functional group, or (c) a nitrogen-containing compound The method for producing a sintered product of porous metal particles according to [13], which is an organic compound.
[14] The material according to [13] or [13-1], wherein the material of the heat-sinterable metal particles (A) is gold, silver, copper, platinum, palladium, or an alloy thereof. A method for producing a sintered porous metal particle.
[15] The porous material according to [13], [13-1] or [14], wherein the thermosetting resin composition is a thermosetting epoxy resin composition containing an inclusion type curing agent. Of producing sintered metal particles.
[16] The porous metal according to any one of [13] to [15], wherein the metal of the metal member is copper, silver, gold, platinum, palladium, or an alloy of these metals A method for producing a sintered particle.
[17] The method for producing a sintered product of porous metal particles according to any one of [13] to [16], wherein the porosity of the sintered product of porous metal particles is 5 to 38%.
[18] The volume resistivity of the sintered porous metal particles is 1 × 10 ⁻⁵ Ω · cm or less, and the thermal conductivity is 100 W / m · K or more. [13] To [17] A method for producing a sintered porous metal particle according to any one of [17]. Is achieved.

The paste-like metal particle composition of the present invention has excellent micro-discharge properties and heat-sinterability, and heat-sinterable metal particles (A) are sintered together by heating to produce a thermosetting resin composition (C). Curing results in a porous metal particle sintered product having excellent electrical conductivity and thermal conductivity, and the porous metal particle sintered product is excellent in durability against thermal shock.

According to the method for producing a metal member assembly of the present invention, metal members are extremely firmly joined to each other, and a metal member assembly having excellent durability against thermal shock can be reliably produced. This metal member joined body is useful as a metal member in an electronic component, electronic device, electric component, electric device or the like having a metal substrate or a metal part.

According to the method for producing a sintered porous metal particle of the present invention, a sintered porous metal particle having excellent conductivity, thermal conductivity, and durability against thermal shock can be reliably produced.

It is a top view of the test body A for shear bond strength measurement in an Example. The silver substrate 1 and the silver chip 3 are joined by porous silver or porous copper which is a heat-sintered product of silver particles or copper particles. It is the XX sectional view taken on the line in FIG. It is an electron micrograph of what removed the octanediol by heating the paste-form silver particle composition in Example 1 at 40 degreeC under 133 Pa of pressure reduction. 2 is an electron micrograph of a cross-sectional view of a porous silver particle sintered product (before a cooling cycle test) generated by heating the paste-like silver particle composition in Example 1. FIG. 3 is an electron micrograph of a cross-sectional view of a porous silver particle sintered product (before a cooling cycle test) generated by heating the paste-like silver particle composition in Comparative Example 1. FIG. 2 is an electron micrograph of a cross-sectional view of a sintered porous silver particle after a cooling cycle test in Example 1. FIG. 4 is an electron micrograph of a cross-sectional view of a porous silver particle sintered product after a cooling / heating cycle test in Comparative Example 1. FIG. FIG. 4 is the same photo size as FIG. FIG. 6 is the same photo size as FIG. FIG. 7 is the same photo size as FIG.

The paste-like metal particle composition of the present invention comprises (A) spherical, teardrop-shaped or granular heat-sinterable metal particles having an average particle size of 0.7 μm or more and 6 μm or less, the heat-sinterable metal Heat-sinterable metal particles in which the coating amount of the organic substance having a polar group covering the surface of the particles is 0.1 to 2.0% by mass, (B) a volatile dispersion medium, and (C) a thermosetting resin composition A paste-like material having a mass ratio of 98.5: 1.5 to 99.9: 0.1 of the heat-sinterable metal particles (A) and the thermosetting resin composition (C). The heating at 70 ° C. to 300 ° C. volatilizes the volatile dispersion medium, sinters the heat-sinterable metal particles (A), and cures the thermosetting resin composition (C). It becomes a porous metal particle sintered product.

The heat-sinterable metal particles (A) are produced by a wet reduction method of a metal salt (where the metal is selected from silver, copper, gold, platinum, palladium), that is, heated by a wet reduction method. Sinterable metal particles are preferred. For example, when the metal particles are silver particles, in the wet reduction method, an aqueous silver ammine complex solution is usually obtained by mixing and reacting an aqueous silver nitrate solution and aqueous ammonia, and this is combined with hydroquinone, anhydrous potassium sulfite or ammonium, and gelatin. Examples include a method in which an aqueous solution is contact-reacted to reduce and precipitate silver powder, which is filtered, and the residue is washed with water and dried by heating. Alternatively, silver nitrate aqueous solution and aqueous ammonia are mixed and reacted to obtain a silver ammine complex aqueous solution, which is contacted with an organic reducing agent (hydroquinone, ascorbic acid, glucose, etc.), particularly hydroquinone aqueous solution, to reduce silver powder. Prepared by precipitation, filtration, washing and drying. The filtration residue contains ammonia, hydroquinone, anhydrous potassium sulfite or ammonium, and gelatin. Since ammonia, hydroquinone, anhydrous potassium sulfite, ammonium, and gelatin adhere to the silver particle surface, it is usually washed repeatedly with clean water. doing. Alternatively, the filtration residue contains ammonia and an organic reducing agent, particularly hydroquinone, and ammonia and an organic reducing agent, particularly hydroquinone, are attached to the surface of the silver particles, so it is usually repeatedly washed with clean water and methanol. Can be obtained. The silver particles (A) thus produced are usually spherical, teardrop-shaped or granular. When the metal particles are copper, copper nitrate, copper sulfate or the like can be used, and other metal particles can be produced by the same method.
As described above, the heat-sinterable metal particles obtained by the metal salt wet reduction method are not porous having a large number of pores penetrating or communicating from the surface to the inside.

The average particle diameter of the heat-sinterable metal particles (A) is 0.7 μm or more and 6 μm or less. This average particle diameter is a cumulative 50% particle diameter in a volume-based particle size distribution obtained by a laser diffraction / scattering particle size distribution measuring method, that is, a median diameter. When the average particle diameter exceeds 6 μm, the sinterability of the metal particles is lowered, so that the smaller one is preferable, and particularly, 3 μm or less is preferable. However, if the average particle size is less than 0.7 μm, the surface activity is strong, so a large amount of coating agent is required to prevent aggregation between the metal particles, and when the metal particles are heated and sintered , The porosity in the sintered product inevitably increases, the durability of the porous sintered product between the metal particles decreases with respect to the thermal shock, and in the porous metal particle sintered product in the thermal shock test There is a problem that cracks are likely to occur. Moreover, since the storage stability of a paste-like metal particle composition falls and the joining strength at the time of heat sintering tends to become non-uniform | heterogenous, it is especially preferable that it is 0.8 micrometer or more. That is, the more preferable average particle diameter of the metal particles (A) is 0.8 to 3 μm. In addition, within a range that does not contradict the purpose and effect of the present invention, a small amount or a small amount of heat-sinterable metal particles having an average particle size of less than 0.7 μm and more than 6 μm may be used.

The material of the heat-sinterable metal particles (A) may be sintered by heating, and the surface is made of silver, copper, gold, platinum, palladium, an alloy or a mixture of each of these metals, and further each of these metals. It may be plated metal (eg, nickel, iron, aluminum, tin) particles or resin (eg, epoxy resin, polyethersulfone resin) particles. When the metal particles (A) are silver particles, a part of the surface or inside may be silver oxide or silver peroxide, and in the case of copper particles, a part of the surface or inside is copper oxide. Also good.

The shape of the heat-sinterable metal particles (A) is spherical, teardrop-shaped or granular, which is easily dispersed uniformly in the paste-like metal particle composition of the present invention and has excellent micro-discharge properties and sinterability. It is preferable. For these shapes, for example, the classification described in JIS Z 2500 can be used.
As long as the object and effect of the present invention are not adversely affected, flakes (flakes), needles, squares, dendrites, irregular shapes, plates, ultrathin plates, hexagons, columns, rods, and porous shapes・ Metallic particles such as fiber, lump, sponge, square, round, etc. (however, the metal is selected from the group consisting of silver, copper, gold, platinum, and palladium) may be used in small or trace amounts. .
The heat-sinterable metal particles (A) do not have a large number of pores penetrating or communicating from the surface to the inside. When there are a large number of pores and the pores penetrate or communicate with the interior, the thermosetting resin composition (C) which remains in a small amount or a small amount of the compound in the paste-like metal particle composition of the present application is heated. This is because it penetrates into the sinterable metal particles (A) and the effect of blending the thermosetting resin composition (C) cannot be exhibited.

The heat-sinterable metal particles (A) prevent aggregation of the heat-sinterable metal particles (A), improve dispersibility in the volatile dispersion medium (B), and obtain excellent sinterability. Therefore, an organic substance having a polar group on its surface, preferably (a) a fatty acid or an alkali metal salt or ester thereof, (b) a polymer dispersant having an acidic functional group and / or a basic functional group, or (c ) Coated with nitrogen-containing organic compound. The organic substance having a polar group is particularly preferably (a) a fatty acid or an alkali metal salt or ester thereof, or (b) a polymer dispersant having an acidic functional group and / or a basic functional group. In addition, although organic substances, such as a reducing agent used in the process of manufacturing metal particles by a reduction method, may remain in the metal particles (A), they are included in the organic substances in the present invention. The organic substance having a polar group in the present invention may be associated, bonded or adsorbed to metal particles such as silver particles, but is included in the coating. The organic substance having a polar group may be solid, semi-solid, or liquid at room temperature as long as the heat-sinterable metal particles (A) can be coated.

Examples of the polar group include a carboxyl group, a carboxylic anhydride group, a carboxylic acid group, a carboxylic ester group, a hydroxyl group, an alkoxy group, an alkyl ether group, a sulfo group (sometimes referred to as a sulfonic acid group), a thiol group, Examples of the phosphoric acid group, acidic phosphoric acid ester group, and phosphonic acid group include a carboxyl group, a carboxylic acid group, a carboxylic acid ester group, and a hydroxyl group.
Further, examples include an amino group, an imino group (= NH), an ammonium base, and a heterocyclic group having a basic nitrogen atom, and an amino group is preferable.
The number of carbon atoms of the carbon atom-containing polar group is preferably 1 to 54, more preferably 1 to 18.

(A) As fatty acids in fatty acids or alkali metal salts or esters thereof, propanoic acid (propionic acid) having 3 or more carbon atoms, butanoic acid (butyric acid), pentanoic acid (valeric acid), hexanoic acid (caproic acid), Heptanoic acid (enanthic acid), octanoic acid (caprylic acid), nonanoic acid (pelargonic acid), decanoic acid (capric acid), dodecanoic acid (lauric acid), tetradecanoic acid (myristic acid), pentadecanoic acid, hexadecanoic acid (palmitic acid) ), Heptadecanoic acid (margaric acid), octadecanoic acid (stearic acid), 12-hydroxyoctadecanoic acid (12-hydroxyoleic acid), eicosanoic acid (arachidic acid), docosanoic acid (behenic acid), tetracosanoic acid (lignoceric acid), Hexacosanoic acid (serotinic acid), octacosanoic acid (montan) Monovalent linear saturated fatty acids such as 2-pentylnonanoic acid, 2-hexyldecanoic acid, 2-heptyldodecanoic acid and isooleic acid having 14 or more carbon atoms; sorbic acid, Examples thereof include monovalent unsaturated fatty acids such as maleic acid, palmitoleic acid, oleic acid, isooleic acid, elaidic acid, linoleic acid, linolenic acid, ricinoleic acid, gadrenic acid, erucic acid, and ceracoleic acid. The number of carbon atoms of these exemplified fatty acids is 24 at the maximum, but is not limited thereto, and may be 54, for example.

Such fatty acids include oxalic acid, malonic acid, succinic acid, maleic acid, fumaric acid, oxydiacetic acid (diglycolic acid), glutaric acid, adipic acid, pimelic acid and speric acid having 2 or more carbon atoms. And polyvalent aliphatic carboxylic acids such as azelaic acid, sebacic acid and diglycolic acid, and polyvalent aromatic carboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid. The maximum value of the number of carbon atoms of these fatty acids is not particularly limited, and may be 54, for example.

Examples of the alkali metal salt of the fatty acid include sodium salt, potassium salt, and lithium salt, and sodium salt and potassium salt are preferable.
Examples of fatty acid esters include alkyl esters (for example, methyl esters and ethyl esters) and phenyl esters. The alkyl group of these alkyl esters preferably has 1 to 6 carbon atoms.

(B) The polymer dispersant having an acidic functional group and / or a basic functional group is a dispersant composed of a polymer, and the weight average molecular weight is usually 1,000 or more. The weight average molecular weight (Mw) is a polystyrene equivalent weight average molecular weight measured by gel permeation chromatography (carrier: tetrahydrofuran).

Examples of the acidic functional group include a carboxyl group, an acid anhydride group, a sulfo group (sometimes referred to as a sulfonic acid group), a thiol group, a phosphoric acid group, an acidic phosphoric acid ester group, and a phosphonic acid group. A carboxyl group, a phosphate group or an acidic phosphate group is preferred. The acidic phosphate group is one in which a part of the phosphorus-bonded hydroxyl group is alkoxylated. Examples of the alkoxy group include lower alkoxy groups such as a methoxy group, an ethoxy group, and a propoxy group. The number of carbon atoms of the lower alkoxy group is preferably 1-8.
Examples of the basic functional group include an amino group, an imino group (= NH), an ammonium base, and a heterocyclic group having a basic nitrogen atom, but an amino group, an ammonium base (for example, a tertiary ammonium base, A quaternary ammonium base). The amino group may be any of a primary amino group (—NH ₂ ), a secondary amino group (—NHR), and a tertiary amino group (—NRR ′). R and R ′ are an alkyl group, a phenyl group, an aralkyl group and the like, and preferably have 1 to 8 carbon atoms.

In the polymer dispersant having an acidic functional group and a basic functional group, a part of the acidic functional group in the molecule may be neutralized or chlorinated with a basic compound. Examples of basic compounds used for neutralization or chlorination include nitrogen-containing organic compounds such as hydroxides of alkali metals and alkaline earth metals, ammonia, alkylamines, amide amines, alkanolamines, and morpholine. Examples of the alkali metal or alkaline earth metal hydroxide include sodium hydroxide, potassium hydroxide, magnesium hydroxide and the like. Specific examples of alkylamines include methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine. And ethylenediamine. The alkyl group and alkylene group preferably have 1 to 8 carbon atoms.

Further, a part of the basic functional group in the molecule may be neutralized or salified with an acidic compound. Examples of the acidic compound used for neutralization or chlorination include phosphoric acid, partially alkyl esterified phosphoric acid (acidic phosphoric acid ester), and carboxylic acid (for example, lower aliphatic monocarboxylic acid and lower aliphatic dicarboxylic acid). These carboxylic acids preferably have 1 to 8 carbon atoms. A part of the acidic functional group may form a salt with the basic functional group.

The acid value of the polymer dispersant having an acidic functional group and / or a basic functional group is preferably 5 to 300 mgKOH / g, and more preferably 10 to 200 mgKOH / g. Further, the amine value of the polymer dispersant is preferably 5 to 300 mgKOH / g, more preferably 10 to 200 mgKOH / g.
The acid value represents the acid value per 1 g of the solid content of the polymer dispersant, and can be determined by potentiometric titration according to JIS K 0070. The amine value represents the amine value per gram of the polymer dispersant solid content, and is a value converted to an equivalent of potassium hydroxide after being obtained by potentiometric titration using a 0.1N hydrochloric acid aqueous solution.

In the polymer dispersant, the bonding position of the acidic functional group and the basic functional group to the polymer main body is not particularly limited, and may be a main chain, a side chain, a main chain and a side chain. May be located. The acidic functional group and the basic functional group may be directly bonded to the polymer main body or may be bonded via a linking group. As a linking group, a lower alkylene group such as an ethylene group to an octylene group, a phenylene group, a low intermediate alkylene group having an ether bond in the chain, a low intermediate alkylene group having a carboxylic acid ester bond in the chain, a carboxylic acid amide in the chain Examples are low and intermediate alkylene groups having a bond. The lower alkylene group preferably has 1 to 8 carbon atoms, and the lower intermediate alkylene group having an ether bond in the chain preferably has 2 to 12 carbon atoms in total.

As a polymer dispersant having a commercially available acidic functional group and / or basic functional group, SOLSPERSE24000 (acid value: 24 mgKOH / g, amine value: 47 mgKOH / g), SOLSPERSE32000 (acid value: 15 mgKOH / g, amine value: 180 mgKOH) / G) (manufactured by Lubrizol, Ltd.) (SOLSPERSE is a registered trademark of Lyubrizol Limited).

DISPERBYK-106 (acid value: 132 mgKOH / g, amine value: 74 mgKOH / g), DISPERBYK-130 (acid value: 2 mgKOH / g, amine value: 190 mgKOH / g), DISPERBYK-140 (acid value: 73 mgKOH / g) , Amine value: 76 mgKOH / g), DISPERBYK-142 (acid value: 46 mgKOH / g, amine value: 43 mgKOH / g), DISPERBYK-145 (acid value: 76 mgKOH / g, amine value: 71 mgKOH / g), DISPERBYK-180 (Acid value: 94 mgKOH / g, amine value: 94 mgKOH / g), DISPERBYK-187 (acid value: 35 mgKOH / g, amine value: 35 mgKOH / g), DISPERBYK-191 (acid value: 30 mgKOH / g, amine value: 20 mgKOH) / G), DISPERBYK-2001 (acid value: 19 mgKOH / g, amine value: 29 mgKOH / g), DISPERBYK-2010 (acid value: 20 mgKOH / g, a DISPERBYK-2020 (acid value: 37 mgKOH / g, amine value: 36 mgKOH / g), DISPERBYK-2020N (acid value: 36 mgKOH / g, amine value: 36 mgKOH / g), DISPERBYK-2025 ( Acid value: 38 mgKOH / g, amine value: 37 mgKOH / g), DISPERBYK-102 (acid value: 101 mgKOH / g), DISPERBYK-174 (acid value: 22 mgKOH / g), DISPERBYK-2096 (acid value: 40 mgKOH / g) , DISPERBYK-2150 (amine value: 57 mgKOH / g), etc. Disperbic series products [BIC Chemie Japan Co., Ltd. sales] (DISPERBYK is a registered trademark of Bik-Hemi Geselsyaft Mitto Beschlenktel Huffung) .

Further, BYK-9076 (acid value: 38 mgKOH / g, amine value: 44 mgKOH / g), BYK-9077 (amine value: 48 mgKOH / g), ANTI-TERRA-U (acid value: 24 mgKOH / g, amine value: 19 mgKOH) / G), ANTI-TERRA-U100 (acid value: 50 mgKOH / g, amine value: 35 mgKOH / g), ANTI-TERRA-204 (acid value: 41 mgKOH / g, amine value: 37 mgKOH / g), ANTI-TERRA- Bic series products such as 205 (acid value: 40 mg KOH / g, amine value: 37 mg KOH / g), ANTI-TERRA-250 (acid value: 46 mg KOH / g, amine value: 41 mg KOH / g), anti-terra series products [Bic Chemie ・Japan Co., Ltd. Sales] (BYK and ANTI-TERRA are registered trademarks of Beik-Hemi Geselsyaft Mits Beschlenktel Huffung).

Disparon series products such as Dispalon DA-234 (acid value: 16 mg KOH / g, amine value: 20 mg KOH / g), Disparon DA-325 (acid value: 14 mg KOH / g, amine value: 20 mg KOH / g) [Enomoto Kasei Disparon is a registered trademark of Enomoto Kasei Co., Ltd.); Azisper PB-821 (acid value: 17 mg KOH / g, amine value: 10 mg KOH / g), Azisper PB-822 (acid value: 14 mg KOH / g, Amine value: 17 mg KOH / g), Azisper PB-881 (acid value: 17 mg KOH / g, amine value: 17 mg KOH / g), Azisper PN-411 (acid value: 6 mg KOH / g, Azisper PA-111 (acid value: 35 mg KOH / g) g) Ajisper series products such as [Ajinomoto Fine Techno [Ajispur is a registered trademark of Ajinomoto Co., Inc.].

(C) Examples of the nitrogen-containing organic compound include primary, secondary or tertiary alkylamines, alkylamidoamines, N-alkylethanolamines, N-alkylmorpholines, and other organic amine compounds. The number of carbon atoms in the nitrogen-containing organic compound is preferably 1 to 54.

The coating amount of the organic substance having a polar group for coating the heat-sinterable metal particles (A) is 0.1 to 2.0% by mass of these heat-sinterable metal particles, and more preferably 0.2 to 1.5% by mass. If the amount is too small, the metal particles (A) tend to aggregate and storage stability is lowered. As a result, the bonding strength at the time of heat sintering becomes non-uniform, and if too large, the heat sinterable metal particles (A) The heat sinterability is lowered, and the porosity of the sintered product is increased, and the durability of the sintered product against thermal shock is reduced.

The coating amount of the organic substance having a polar group can be measured by a usual method. For example, a method of measuring the weight loss by heating the metal particles (A) in nitrogen gas to a temperature equal to or higher than the boiling point or thermal decomposition temperature of the organic substance, and heating the metal particles (A) in an oxygen stream An example is a method in which carbon in the organic matter adhering to (A) is changed to carbon dioxide and quantitative analysis is performed by infrared absorption spectroscopy.

The paste-like metal particle composition of the present invention is composed of the heat-sinterable metal particles (A), the volatile dispersion medium (B), and the thermosetting resin composition (C), The binder metal particles (A) and the thermosetting resin composition (C) are pasted by the action of the volatile dispersion medium (B). The thermosetting resin composition (C) is liquid or solid at room temperature, but is preferably dissolved in the volatile dispersion medium (B). By making a paste in this way, a small amount can be discharged from a cylinder or a nozzle or a thin line can be discharged, and printing can be easily applied with a metal mask, and even a small area can be applied with good workability.
Further, the volatile dispersion medium (B) is not a non-volatile dispersion medium, and the volatile dispersion medium is used because the dispersion medium is not heated when the heat-sinterable metal particles (A) are sintered by heating. This is because, when volatilized in advance, the heat-sinterable metal particles (A) are easily sintered, and as a result, conductivity, thermal conductivity, and adhesion to a metal member are improved. The volatile dispersion medium (B) does not alter the surface of the metal particles, and has a boiling point of 60 ° C. or higher and preferably 300 ° C. or lower. When the boiling point is less than 60 ° C, the volatile dispersion medium (B) is easily volatilized during the operation of preparing the paste-like metal particle composition, and when the boiling point is higher than 300 ° C, the heat-sinterable metal particles This is because the volatile dispersion medium (B) may remain even after (A) is sintered.

As such a volatile dispersion medium (B), water; ethyl alcohol, propyl alcohol, butyl alcohol, pentyl alcohol, hexyl alcohol, heptyl alcohol, octyl alcohol, nonyl alcohol, decyl alcohol, benzyl alcohol, cyclohexanol, terpineol, etc. Volatile monohydric alcohols; volatile polyhydric alcohols such as ethylene glycol, propylene glycol, hexanediol and octanediol; volatile aliphatic hydrocarbons such as lower n-paraffins and lower isoparaffins; volatile aromatics such as toluene and xylene Hydrocarbon: acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, diacetone alcohol (4-hydroxy-4-methyl-2-pentanone), 2-octanone, isophoro Volatile ketones such as (3,5,5-trimethyl-2-cyclohexen-1-one) and dibutyl ketone (2,6-dimethyl-4-heptanone); such as ethyl acetate (ethyl acetate) and butyl acetate Volatile acetic acid ester; Volatile aliphatic carboxylic acid ester such as methyl butyrate, methyl hexanoate, methyl octoate, methyl decanoate; tetrahydrofuran, methyl cellosolve, propylene bricol monomethyl ether, methyl methoxybutanol, butyl carbitol, etc. Examples include volatile ethers; low molecular weight volatile silicone oils and volatile organic modified silicone oils. Two or more kinds of volatile dispersion media (B) may be used in combination, and the compatibility of the volatile dispersion media is not limited. In addition, since the paste-like metal particle composition of the present invention may be in the form of a paste when used, the volatile dispersion medium (B) is solid at room temperature, for example, pyrogallol, p-methylbenzyl alcohol, o- Alcohols such as methylbenzyl alcohol, sil-3,3,5-trimethylcyclohexanol, 1,4-cyclohexanedimethanol, 1,4-cyclohexanediol, pinacol; hydrocarbons such as biphenyl, naphthalene, durene; dibenzoyl It may contain ketones such as methane, chalcone and acetylcyclohexane; fatty acids such as lauric acid and capric acid. At this time, a plurality of volatile dispersion media having different melting points, boiling points, vapor pressures, viscosities, dielectric constants, refractive indexes, and the like may be used in combination.

The blending amount of the volatile dispersion medium (B) may be an amount sufficient to make the heat-sinterable metal particles (A) and the thermosetting resin composition (C) into a paste form. The amount is usually 3 to 20 parts by mass, preferably 5 to 15 parts by mass per 100 parts by mass in total of the binding metal particles (A) and the thermosetting resin composition (C). The paste-like metal particle composition of the present invention includes metal particles other than the heat-sinterable metal particles (A) or non-metallic powders, metal oxides, and metals unless the object / effect of the present invention is violated. Additives such as compounds, metal complexes, thixotropic agents, stabilizers, and sintering accelerators may be added in small or trace amounts.

The thermosetting resin composition (C) in the present invention is cured when the paste-like metal particle crude composition of the present invention is heated, and the heat-sinterable metal particles (A) are produced by heating. There is an effect of reinforcing the brittleness (mechanical strength) of the sintered porous metal particles. In addition, when the metal member is joined by the porous metal particle sintered product produced by interposing the paste-like metal particle composition of the present invention between a plurality of metal members and heating the porous metal particle composition, This has the effect of reinforcing the bonding between the metal particle sintered product and the metal member to greatly increase the bonding strength, and further improving the durability of the porous sintered body against thermal shock. For this reason, the curing mechanism of the thermosetting resin composition (C) is thermosetting.

Such a thermosetting resin composition (C) is composed of at least a thermosetting resin and a curing agent, unless the thermosetting resin itself is thermosetting. The amount of curing agent is an amount sufficient to heat cure the thermosetting resin. The thermosetting resin composition (C) further contains a small amount, for example, a curing accelerator having a mass of 5% or less, a reactive diluent, a reaction inhibitor, a heat stabilizer, an antioxidant, a colorant and the like. May be. The thermosetting resin composition (C) is not particularly limited as long as it is thermosetting, and is a thermosetting epoxy resin composition, a thermosetting phenol resin composition, a thermosetting polyurethane resin composition, and a thermosetting resin. Examples include alkyd resin compositions, thermosetting polyester resin compositions, thermosetting silicone resin compositions, thermosetting polyamideimide resin compositions, thermosetting polyamic acid type polyimide resin compositions, and the like. Among these, the thermosetting epoxy resin composition, the thermosetting polyimide resin itself, and the thermosetting in terms of the solubility in the volatile dispersion medium (B) and the bonding strength of the porous metal particle sintered product. A curable polyimide resin composition is preferable, and a thermosetting epoxy resin composition is particularly preferable. The thermosetting resin composition (C) may be solid, semi-solid, or liquid at room temperature.

The thermosetting resin composition (C) is a powdery filler, for example, non-heat-sinterable metal particles, metal oxide particles, organic resin particles, etc. However, if it is contained in a large amount, the sintering of the heat-sinterable metal particles (A) of the present invention is inhibited, so the filler in the thermosetting resin composition (C) is 2 It is preferable that it is below mass%.

The thermosetting epoxy resin composition is usually composed of a main agent such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolac type epoxy resin, and alicyclic epoxy resin, and a curing agent such as amine, imidazole, and acid anhydride. Furthermore, a curing accelerator, a monofunctional or polyfunctional reactive diluent, a reaction inhibitor, a heat stabilizer, an antioxidant, a colorant and the like may be contained.

The main component of the thermosetting epoxy resin composition in the present invention needs to have at least two epoxy groups (glycidyl ether groups) in one molecule, and more preferably three or more. Many such polyfunctional epoxy resins are commercially available, and examples include phenol novolac type epoxy resins, cresol novolac type epoxy resins, naphthalene type epoxy resins, N, N, N ′, N′-tetraglycidyldiaminodiphenylmethane, and the like. Is done.

The curing agent of the thermosetting epoxy resin composition in the present invention is an amine compound, aliphatic polyamine, polyaminoamide (polyamide resin), alicyclic diamine, aromatic diamine, imidazole, tertiary amine), acid anhydride compound. And mercaptan compounds, phenol resins, amino resins, dicyandiamide, Lewis acid complex compounds and the like. In addition, these hardening | curing agents may have the effect which accelerates | stimulates hardening of an epoxy resin. The amount of the curing agent is sufficient to heat cure the thermosetting epoxy resin. The amount sufficient for heat-curing the thermosetting epoxy resin differs depending on the kind of the curing agent, so it is difficult to uniformly define, but it is 2 to 15% by mass of the thermosetting epoxy resin.

Since the main agent and the curing agent in the thermosetting epoxy resin composition are present in a state diluted with the volatile dispersion medium (B) in the paste-like metal particle composition of the present invention, the main agent and the curing agent are present. Although the curing reaction of the curing agent is suppressed, a latent curing agent should be used as the curing agent for the thermosetting epoxy resin composition in order to further suppress the curing reaction during storage of the paste-like metal particle composition of the present invention. Is preferred. As a latent curing agent, a solid curing agent that is difficult to dissolve in the volatile dispersion medium (B), a capsule curing agent in which the curing agent is confined in a capsule such as a resin that melts by heat, and a curing agent as a part of the main agent Or an adduct type curing agent that has been pre-addition-reacted with a compound having an epoxy group, an inclusion type curing agent in which a curing agent is incorporated in a molecule or in a molecular assembly, and the like are exemplified. An inclusion type curing agent having a high reaction suppressing effect in (B) is particularly preferred.

Examples of the inclusion type curing agent include 2-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 1-benzyl-2-methylimidazole, 2-phenyl-4- Imidazoles such as methyl-5-hydroxymethylimidazole, 2-phenyl4,5-dihydroxymethylimidazole, 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane, 5-nitroisophthalic acid, 5-hydroxyisophthalate Examples of the curing agent are clathrated with an acid or the like.

The glass transition temperature (Tg) of the cured product obtained by heating and curing the thermosetting epoxy resin composition in the present invention is preferably 120 ° C. or higher, and more preferably 150 ° C. or higher.

In the paste-like metal particle composition of the present invention, the mass ratio of the heat-sinterable metal particles (A) and the thermosetting resin composition (C) is 98.5: 1.5 to 99.9: 0. .1 and preferably 98.8: 1.3 to 99.5: 0.4, particularly preferably 98.8: 1.2 to 99.5: 0.5. . In the said ratio, when the numerical value of this thermosetting resin composition (C) exceeds 1.5, when this heat-sinterable metal particle (A) sinters, this thermosetting resin composition ( C) inhibits the sintering of the heat-sinterable metal particles (A), and the resulting porous metal particle sintered product has decreased conductivity, thermal conductivity, and durability against thermal shock, and the porous The joining strength when joining a plurality of metal members with a metal particle sintered product cannot be extremely increased (see Comparative Examples 7 and 8). Moreover, in the said ratio, when the numerical value of this thermosetting resin composition (C) is less than 0.1, although the electrical conductivity and thermal conductivity of this porous metal particle sintered product are high, it is durable against thermal shock. The joining strength when joining a plurality of metal members with the porous metal particle sintered product cannot be extremely increased (see Comparative Examples 1 and 2).

In the paste-like metal particle composition of the present invention, the heat-sinterable metal particles (A), the volatile dispersion medium (B), and the thermosetting resin composition (C) are uniformly pasted with a mixer. It can manufacture easily by stirring and mixing until it becomes. At this time, the heat-sinterable metal particles (A), the volatile dispersion medium (B), and the curable resin composition (C) may be simultaneously put into a mixer and mixed. The dispersion medium (B) and the thermosetting resin composition (C) may be put into a mixer and mixed, and then the heat-sinterable metal particles (A) may be put into a mixer and mixed.

The method for producing a metal member assembly according to the present invention comprises (A) spherical, teardrop-shaped or granular heat-sinterable metal particles having an average particle size of 0.7 μm or more and 6 μm or less, wherein the heat-sintering Heat-sinterable metal particles having a coating amount of an organic substance having a polar group for coating the surface of the conductive metal particles being 0.1 to 2.0% by mass, (B) a volatile dispersion medium, and (C) a thermosetting resin A paste comprising a composition, the mass ratio of the heat-sinterable metal particles (A) to the thermosetting resin composition (C) being 98.5: 1.5 to: 99.9: 0.1 The metal particle composition is interposed between a plurality of metal members, heated at 70 ° C. or more and 300 ° C. or less to volatilize the volatile dispersion medium, and the heat-sinterable metal particles (A) are sintered together. By curing the thermosetting resin composition (C) to form a sintered porous metal particle, a plurality of metal members are joined together. It is characterized in.
At this time, heating may be performed while applying pressure or ultrasonic vibration.

The method for producing a sintered porous metal particle according to the present invention comprises (A) spherical, teardrop-shaped or granular heat-sinterable metal particles having an average particle diameter of 0.7 μm or more and 6 μm or less, Heat-sinterable metal particles having a coating amount of an organic substance having a polar group covering the surface of the sinterable metal particles is 0.1 to 2.0% by mass, (B) a volatile dispersion medium, and (C) thermosetting. A mass ratio of the heat-sinterable metal particles (A) to the thermosetting resin composition (C) is 98.5: 1.5 to: 99.9: 0.1. The paste-like material is heated at 70 ° C. or more and 300 ° C. or less to volatilize the volatile dispersion medium, and the heat-sinterable metal particles (A) are sintered together to form the thermosetting resin composition (C). It is hardened to form a sintered porous metal particle.

The metal member used in the manufacturing method of the metal member bonded body is a bonded body bonded by a sintered porous metal particle formed by heating the paste-like metal particle composition of the present invention. Examples of the material of the metal member include gold, silver, copper, platinum, palladium, nickel, tin, aluminum, and alloys of these metals. However, in terms of conductivity and bondability, gold, silver, copper Platinum, palladium or an alloy of each of these metals is preferable, and may be plated with these metals. Specific examples of the metal member include metal substrates such as lead frames, printed boards, and heat sinks, and electronic parts such as semiconductor elements and chip parts, all or part of which are made of metal.

In both the above production methods, the atmosphere gas during heating is not particularly limited as long as it does not inhibit the sintering of the heat-sinterable metal particles (A), but the heat-sinterable metal particles (A) and the metal When the member made of silver or a silver alloy is used, an oxidizing gas such as air containing oxygen gas is preferable. When the heat-sinterable metal particles (A) and the metal member are made of a material that is easily oxidized, such as copper or a copper alloy, it contains an inert gas such as nitrogen gas that does not contain oxygen gas, or hydrogen gas. A reducing gas is preferred. Of these, a reducing gas called a forming gas comprising 5 to 25% by volume of hydrogen gas and 95 to 75% by volume of nitrogen gas is particularly preferable.

The paste-like metal particle composition interposed between a plurality of metal members is heated to a temperature equal to or higher than the sintering temperature of the heat-sinterable metal particles (A), whereby the volatile dispersion medium (B) Volatilization, sintering of the heat-sinterable metal particles (A), sintering of the thermosetting resin composition (C), and sintering of porous metal particles excellent in conductivity and thermal conductivity It becomes a thing and joins metal members firmly. At this time, since the thermosetting resin composition (C) has a remarkably small blending amount as compared with the heat-sinterable metal particles (A), the conductivity and thermal conductivity of the porous metal particle-sintered product. The joint strength between metal members is remarkably improved.

When the paste-like metal particle composition is heated to a temperature equal to or higher than the sintering temperature of the heat-sinterable metal particles (A), the volatile dispersion medium (B) is volatilized and the heat-sinterable The metal particles (A) are sintered together, and the thermosetting resin composition (C) is cured, so that a porous metal particle sintered product having excellent conductivity and thermal conductivity is obtained. At this time, since the thermosetting resin composition (C) has a remarkably small blending amount as compared with the heat-sinterable metal particles (A), the conductivity and thermal conductivity of the porous metal particle-sintered product. Will not be damaged.

The heating temperature in these cases is a temperature at which the volatile dispersion medium (B) is volatilized, the heat-sinterable metal particles (A) are sintered, and the thermosetting resin composition (C) is cured. What is necessary is just 70 degreeC or more normally, and 150 degreeC or more is more preferable. However, when the temperature exceeds 400 ° C., the volatile dispersion medium (B) evaporates suddenly, and the shape of the sintered porous metal particles formed by sintering the heat-sinterable metal particles (A) together. Therefore, it is necessary that the temperature be 300 ° C. or lower, and preferably 250 ° C. or lower.

A sintered product produced by sintering the heat-sinterable metal particles (A) and curing the thermosetting resin composition (C), and a plurality of metal members produced as described above The sintered product produced by sintering the heat-sinterable metal particles (A) between them and curing the thermosetting resin composition (C) is a series of fine pores and voids. It has voids or pores and is porous. The porosity is preferably 5 to 38%, more preferably 10 to 35%. When pressure is applied when sintering the heat-sinterable metal particles (A), the porosity can be reduced. In this case, the porosity may be less than 10%.

As a method for measuring the porosity, a normal measuring method can be used. A cross section of the sintered porous metal particles is photographed with an electron microscope, the area ratio between the solid part and the space part is obtained with image analysis software, and the photograph taken with the electron microscope is printed on homogeneous paper, etc. And the space part is cut with scissors or the like to measure each mass, and the mass ratio is used as the area ratio.
Note that the cured product of the thermosetting resin composition is usually transparent, and even if it exists in the pores of the sintered porous metal particles, it is not visible and does not appear in the scanning electron micrograph. The cured product of the resin composition is contained in the space portion.

The cross-sectional shape and size of the pores in the sintered porous metal particles are various (see FIGS. 4 and 8). The cross-sectional shape is a substantially circular shape, a substantially oval shape, a substantially rectangular shape, a substantially triangular shape, an irregular shape, or the like.
Since the gaps between the heat-sinterable metal particles (A) before sintering mainly become pores, the longest diameter of each pore is usually about 0.1 to 4 μm.

Although the thermosetting resin composition (C) has a significantly lower bonding amount than the heat-sinterable metal particles (A), the thermosetting resin composition (C) has a high bonding strength, so It is presumed that the conductive resin composition (C) is cured in a state where it is thinly penetrated into the pores of the sintered porous metal particles.

Further, since the heat-sinterable metal particles (A) in the paste-like metal particle composition of the present invention have high conductivity and thermal conductivity, the heat-sinterable metal particles (A) are porously sintered. The product is also excellent in electrical conductivity and thermal conductivity. Specifically, the volume resistivity indicating the degree of electrical conductivity is preferably 1 × 10 ⁻⁶ Ω · cm or less, and the thermal conductivity indicating the degree of thermal conductivity is 100 W / m · K or more. Preferably there is.

When the paste-like metal particle composition of the present invention is used for joining between a plurality of metal members, the sintered product of the heat-sinterable metal particles (A) is in contact with the metal member at the time of sintering. For example, gold plated substrate, gold alloy plated substrate, silver substrate, silver plated metal substrate, silver alloy substrate, silver alloy plated substrate, copper substrate, copper plated substrate, copper alloy substrate, copper alloy plated substrate, platinum plated substrate, platinum alloy substrate It adheres firmly to metal parts such as electrodes on metal substrates such as platinum alloy plated substrates, palladium plated substrates, palladium alloy substrates, palladium alloy plated substrates and the like, and electrical insulating substrates. Furthermore, since the thermosetting resin composition (C) has an effect of improving the bonding strength, the adhesive strength is remarkably increased, and the sintered product between the metal members is excellent in durability against thermal shock. For this reason, the metal member assembly by the manufacturing method of the present invention is useful as a metal member assembly in an electronic component, an electronic device, an electric component, an electric device or the like having a metal substrate or a metal part.

As such a junction, it has a metal part, a chip part such as a capacitor, a resistor, a light emitting diode, a laser diode, a memory, an IC, an IGBT, a CPU etc. and a lead frame or a circuit board, a metal part, The joining of a highly heat-generating semiconductor element and a cooling plate is exemplified.

Examples and comparative examples of the present invention will be given. In Examples and Comparative Examples, “part” means “part by mass”, and “average particle diameter” means the median diameter described above. The heating in Examples and Comparative Examples is heating in a forced circulation oven, and the atmosphere in the forced circulation oven is air unless otherwise noted. Fine discharge property of paste-like metal particle composition, coating amount of heat-sinterable metal particles, porosity, volume resistivity, thermal conductivity of heated porous metal particle sintered product, heating and bonding The adhesion strength measurement and the cooling / heating cycle test of the joined body were performed by the following methods. The measurement is a measurement at room temperature (about 25 ° C.) in the atmosphere unless otherwise specified.

[Coating amount of heat-sinterable metal particles]
Using a differential thermothermal gravimetric simultaneous measurement device (DTG-60AH type, manufactured by Shimadzu Corporation), the temperature of the heat-sinterable metal particles was increased from room temperature (about 25 ° C.) to 500 ° C. at a temperature increase rate of 10 ° C./min. Thus, the weight loss rate of the heat-sinterable metal particles was calculated as the coating amount. When the heat-sinterable metal particles were heat-sinterable copper particles, the temperature was measured in nitrogen gas instead of in the air.

[Micro discharge property of paste-like metal particle composition]
A 5 ml syringe (EFD, Inc.) is filled with 3 ml of a paste-like metal particle composition, and a metal needle (made by Musashi Engineering Co., Ltd.) having an inner diameter of 0.14 mm and a length of 15 mm is attached, and pressure is applied at intervals of 1 second. The presence or absence of clogging was observed by repeating discharge with and without pressurization of 200 kPa.

[Porosity of sintered porous metal particles]
A 1 mm thick stainless steel mask having a 15 mm square opening was placed on the polytetrafluoroethylene resin plate, and the paste-like metal particle composition was applied by printing.

When the heat-sinterable metal particles in the paste-like metal particle composition are heat-sinterable silver particles, the heat-sinterable silver particles are taken out by heating at a predetermined temperature for 1 hour in a hot-air circulating oven, and the paste-like metal particle composition The heat-sinterable metal particles (A) therein were sintered. When the heat-sinterable metal particles were heat-sinterable copper particles, they were further heated at a predetermined temperature for 10 minutes in a forming gas that is a mixed gas of 10% by volume of hydrogen gas and 90% by volume of nitrogen gas.

The obtained porous metal particle sintered product was removed from the polyimide resin plate to obtain a test piece for measuring porosity.
The obtained plate-shaped specimen is cut out with an automatic precision cutting device (trade name isomet, manufactured by JEOL Ltd.), and the resulting cross section is photographed with a scanning electron microscope, and the image is printed on a homogeneous printing paper. Then, the solid portion and the space portion of the porous metal particle sintered product were separated, the respective masses were measured, and the ratio of the space portion was expressed as% as the porosity.
The cured product of the thermosetting resin composition is transparent, and even if it exists in the pores of the sintered porous metal particles, it is not visible and does not appear in the photograph. An object is included in the space portion.

[Volume resistivity of sintered porous metal particles]
A paste-like metal particle composition was applied onto a glass plate having a width of 50 mm × length of 50 mm × thickness of 2.0 mm using a 2 mm thick metal mask having an opening of width 10 mm × length 10 mm. A plate-shaped porous metal particle sintered product was obtained by heating in a forced circulation oven at a predetermined temperature for 1 hour. When the heat-sinterable metal particles were heat-sinterable copper particles, they were further heated at a predetermined temperature for 10 minutes in a forming gas that is a mixed gas of 10% by volume of hydrogen gas and 90% by volume of nitrogen gas.
The volume resistivity (unit: Ω · cm) of the sintered metal particle peeled from the glass plate was measured by a method according to JIS K 7194.

[Thermal conductivity of sintered porous metal particles]
A paste-like metal particle composition was applied onto a glass plate having a width of 50 mm × length of 50 mm × thickness of 2.0 mm using a 2 mm thick metal mask having an opening of width 10 mm × length 10 mm. A plate-shaped porous metal particle sintered product was obtained by heating in a forced circulation oven at a predetermined temperature for 1 hour. When the metal particles were copper particles, the metal particles were further heated at a predetermined temperature for 10 minutes in a forming gas which is a mixed gas of 10% by volume of hydrogen gas and 90% by volume of nitrogen gas.
The porous metal particle sintered product peeled from the glass plate was measured for thermal conductivity (unit: W / m · K) by a laser flash method.

[Adhesive strength of joined body]
On a silver substrate (silver purity 99.99%) 25 mm wide × 70 mm long × 1.0 mm thick, 100 μm having four 2.5 mm wide × 2.5 mm long openings at 10 mm intervals. After applying a paste-like metal particle composition using a thick metal mask, and mounting a silver chip (silver purity 99.99%) of width 2.5 mm × length 2.5 mm × thickness 0.5 mm thereon Then, they were joined by heating in a forced circulation oven at a predetermined temperature for 1 hour. In the case of containing copper particles, it was further heated for 10 minutes at a predetermined temperature in a forming gas which is a mixed gas of 10 vol% hydrogen gas and 90 vol% nitrogen gas.

The side surface of the silver chip having a width of 2.5 mm, a length of 2.5 mm, and a thickness of 0.5 mm of the test specimen for measuring the adhesive strength thus obtained was pressed at a speed of 23 mm / min with an adhesive strength tester, The adhesive strength (unit: MPa) was defined as the load at the time of shear fracture.

[Cold thermal cycle test]
Using a 100 μm-thick metal mask having an opening of 2.5 mm in width and 2.5 mm in length on a silver-plated copper substrate (silver purity 99.9%) of 25 mm × 25 mm × thickness 1.0 mm A metal particle composition is applied, and a silver chip (silver purity 99.99%) having a width of 2.5 mm, a length of 2.5 mm, and a thickness of 0.5 mm is mounted thereon, and then a forced circulation oven at a predetermined temperature. It was heated and joined for 1 hour. In the case of containing copper particles, it was further heated for 10 minutes at a predetermined temperature in a forming gas which is a mixed gas of 10 vol% hydrogen gas and 90 vol% nitrogen gas.

The thus obtained specimen for a cold cycle test was subjected to 1000 cycles of a cold cycle test in which a cycle of standing at −55 ° C. for 30 minutes and leaving at + 125 ° C. for 30 minutes was performed for 1 cycle, and then a scanning electron microscope Using JSM-7500F manufactured by JSM-7500), the specimen was shaved by an automatic precision cutting device (trade name isomet, manufactured by JEOL Ltd.), and the resulting cross-section was observed to cause cracks in porous sintered metal particles. The presence or absence was confirmed. A very elongated void having a length of 25 μm or more and a maximum width of 2 μm or more, or an elongated void having a length of 4 μm or more and less than 25 μm and a maximum width of 2 μm or more is a crack (FIG. 7). Bottom, see FIG. 10).

[Reference Example 1]
[Preparation of thermosetting epoxy resin composition (1), curing agent is clathrate type curing agent]
In a mixer, a tetrafunctional epoxy resin (trade name: jER604, viscosity 7.5 Pa · s (25 ° C.), epoxy equivalent 120 g) 93 parts manufactured by Mitsubishi Chemical Corporation, clathrate type manufactured by Nippon Soda Co., Ltd. as a curing agent A thermosetting epoxy resin composition (1) was prepared by uniformly mixing 7 parts of a curing material (trade name: TEP-2P4MHZ). The glass transition temperature of the cured product produced by heating this epoxy resin composition at 200 ° C. for 1 hour is 190 ° C. In addition, TEP-2P4MHZ includes 2-phenyl-4-methyl-5-hydroxymethylimidazole in 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane, and the imidazole is 46%. contains.

[Reference Example 2]
[Preparation of thermosetting epoxy resin composition (2), curing agent is non-inclusion curing agent]
In a mixer, polyfunctional type epoxy resin manufactured by Mitsubishi Chemical Corporation (trade name: jER152, viscosity 1.5 Pa · s (52 ° C.), epoxy equivalent 177 g) 97 parts, 2-phenyl manufactured by Mitsubishi Chemical Corporation as a curing agent A thermosetting epoxy resin composition (2) was prepared by uniformly mixing 3 parts of -4-methyl-5-hydroxymethylimidazole. The glass transition temperature of the cured product produced by heating this epoxy resin composition at 200 ° C. for 1 hour is 178 ° C.

[Reference Example 3]
[Non-thermosetting epoxy resin]
A tetrafunctional epoxy resin (trade name: jER604, viscosity 7.5 Pa · s (25 ° C.), epoxy equivalent 120 g) manufactured by Mitsubishi Chemical Corporation was used as it was. This epoxy resin did not cure even when heated at 200 ° C. for 1 hour.

[Example 1]
Manufactured by a wet reduction method of silver nitrate in a mixer, the average particle diameter is 0.8 μm, and the surface is coated with oleic acid (the amount of oleic acid is 0.5% by mass). 91.2 parts of the binding silver particles, 7.7 parts of octanediol (manufactured by Kyowa Hakko Chemical Co., Ltd., boiling point 244 ° C. (hereinafter the same)) as the volatile dispersion medium, and the thermosetting epoxy resin prepared in Reference Example 1 A paste-like silver particle composition was prepared by uniformly mixing 1.1 parts of the composition (1). The mass ratio of the heat-sinterable silver particles and the thermosetting epoxy resin composition is 98.8: 1.2.

The fine discharge property of the paste-like silver particle composition, and the porous sintered product of the heat-sinterable silver particles produced by heating the paste-like silver particle composition at 200 ° C. for 1 hour, the porosity, volume When the adhesion strength was measured for the resistivity, thermal conductivity, and joined body, and the cold cycle test of the joined body was performed, the micro-discharge property was good, the volume resistivity of the porous silver particle sintered product was low, and the heat The conductivity was high. Moreover, the adhesive strength of the joined body was large, and no cracks were generated in the porous silver particle sintered product after the thermal cycle test (see FIG. 6).
The above results are summarized in Table 1. This paste-like silver particle composition is capable of minute discharge, has high conductivity and thermal conductivity of porous silver particle sintered material, and bonds a plurality of silver members extremely firmly, and is also resistant to thermal shock. It turns out that the nature is high.

[Example 2]
In a mixer, it was manufactured by a wet reduction method of silver nitrate, the average particle diameter was 0.7 μm, and the surface was coated with octanoic acid (octanoic acid content was 1.4% by mass). 90.9 parts of binding silver particles, n-hexane (a reagent manufactured by Wako Pure Chemical Industries, Ltd., boiling point 69 ° C.) 8.1 parts as a volatile dispersion medium, and the thermosetting epoxy prepared in Reference Example 1 A paste-like silver particle composition was prepared by uniformly mixing 1.0 part of the resin composition (1). The mass ratio of the heat-sinterable silver particles and the thermosetting epoxy resin composition is 98.9: 1.1.

The fine discharge property of the paste-like silver particle composition, and the porous sintered product of the heat-sinterable silver particles produced by heating the paste-like silver particle composition at 200 ° C. for 1 hour, the porosity, volume When the adhesion strength was measured for the resistivity, thermal conductivity, and joined body, and the cold cycle test of the joined body was performed, the micro-discharge property was good, the volume resistivity of the porous silver particle sintered product was low, and the heat The conductivity was high. Moreover, the bonding strength of the joined body was large, and no cracks were generated in the sintered product of the porous silver particles after the thermal cycle test.
The above results are summarized in Table 1. This paste-like silver particle composition is capable of minute discharge, has high conductivity and thermal conductivity of porous silver particle sintered material, and bonds a plurality of silver members extremely firmly, and is also resistant to thermal shock. It turns out that the nature is high.

[Example 3]
Spherical heat sinterability produced by wet reduction method of silver nitrate in a mixer, average particle diameter of 6.0 μm, and surface coated with stearic acid (the amount of stearic acid is 0.2 mass%) 92.3 parts of silver particles, 7.0 parts of octanediol (manufactured by Kyowa Hakko Chemical Co., Ltd.) as a volatile dispersion medium, and 0.7 part of the thermosetting epoxy resin composition (1) prepared in Reference Example 1 The paste-like silver particle composition was prepared by mixing uniformly. The mass ratio of the heat-sinterable silver particles and the thermosetting epoxy resin composition is 99.2: 0.8.

The fine discharge property of the paste-like silver particle composition, and the porous sintered product of the heat-sinterable silver particles produced by heating the paste-like silver particle composition at 200 ° C. for 1 hour, the porosity, volume When the adhesion strength was measured for the resistivity, thermal conductivity, and joined body, and the cold cycle test of the joined body was performed, the micro-discharge property was good, the volume resistivity of the porous silver particle sintered product was low, and the heat The conductivity was high. Moreover, the bonding strength of the joined body was large, and no cracks were generated in the sintered product of the porous silver particles after the thermal cycle test.
The above results are summarized in Table 1. This paste-like silver particle composition is capable of minute discharge, has high conductivity and thermal conductivity of porous silver particle sintered material, and bonds a plurality of silver members extremely firmly, and is also resistant to thermal shock. It turns out that the nature is high.

[Example 4]
In a mixer, a spherical heat-firing method manufactured by a wet reduction method of silver nitrate, having an average particle size of 3.0 μm, and coated with potassium oleate (the amount of potassium oleate is 0.3% by mass). 91.3 parts of binding silver particles, 7.7 parts of α-terpineol (manufactured by Kanto Chemical Co., Inc.) as a volatile dispersion medium, and 1.0 of the thermosetting epoxy resin composition (1) prepared in Reference Example 1 Parts were uniformly mixed to prepare a paste-like silver particle composition. The mass ratio of the heat-sinterable silver particles and the thermosetting epoxy resin composition is 98.9: 1.1.

The fine discharge property of the paste-like silver particle composition, and the porous sintered product of the heat-sinterable silver particles produced by heating the paste-like silver particle composition at 250 ° C. for 1 hour, the porosity, volume When the adhesion strength was measured for the resistivity, thermal conductivity, and joined body, and the cold cycle test of the joined body was performed, the micro-discharge property was good, the volume resistivity of the porous silver particle sintered product was low, and the heat The conductivity was high. Moreover, the bonding strength of the joined body was large, and no cracks were generated in the sintered product of the porous silver particles after the thermal cycle test.
The above results are summarized in Table 2. This paste-like silver particle composition is capable of minute discharge, has high conductivity and thermal conductivity of porous silver particle sintered material, and bonds a plurality of silver members extremely firmly, and is also resistant to thermal shock. It turns out that the nature is high.

[Example 5]
DISPERBYK- manufactured by Big Chemie Japan Co., Ltd., which is an amphoteric polymer dispersant produced by a wet reduction method of silver nitrate in a mixer, having an average particle size of 1.0 μm, and having a phosphate group and an amino group on the surface. 92.1 parts of granular heat-sinterable silver particles coated with 2020 (acid value: 37 mg KOH / g, amine value: 36 mg KOH / g) (DISPERBYK-2020 amount is 0.3% by weight), volatile dispersion 7.4 parts octanediol (manufactured by Kyowa Hakko Chemical Co., Ltd.) as a medium, and thermosetting polyimide resin (product number CT4112 manufactured by Kyocera Chemical Co., Ltd., solid content is 17.5% by mass, and the rest is a volatile solvent. 2.9 parts of N, N-dimethylacetamide (boiling point 166 ° C.) was uniformly mixed to prepare a pasty silver particle composition. The mass ratio of the heat-sinterable silver particles and the thermosetting polyimide resin composition is 99.5: 0.5.

The fine discharge property of the paste-like silver particle composition, and the porous sintered product of the heat-sinterable silver particles produced by heating the paste-like silver particle composition at 250 ° C. for 1 hour, the porosity, volume When the adhesion strength was measured for the resistivity, thermal conductivity, and joined body, and the cold cycle test of the joined body was performed, the micro-discharge property was good, the volume resistivity of the porous silver particle sintered product was low, and the heat The conductivity was high. Moreover, the bonding strength of the joined body was large, and no cracks were generated in the sintered product of the porous silver particles after the thermal cycle test.
The above results are summarized in Table 2. This paste-like silver particle composition is capable of minute discharge, has high conductivity and thermal conductivity of porous silver particle sintered material, and bonds a plurality of silver members extremely firmly, and is also resistant to thermal shock. It turns out that the nature is high.

[Example 6]
In a mixer, manufactured by the wet reduction method of silver nitrate, the average particle size is 1.0μm, and the surface is coated with oleic acid (the amount of oleic acid is 0.3% by mass). 92.9 parts of silver particles, 7.0 parts of octanediol (manufactured by Kyowa Hakko Chemical Co., Ltd.) as a volatile dispersion medium, and 0.093 parts of the thermosetting epoxy resin composition (1) prepared in Reference Example 1 The paste-like silver particle composition was prepared by mixing uniformly. The mass ratio of the heat-sinterable silver particles and the thermosetting epoxy resin composition is 99.9: 0.1.

The fine discharge property of the paste-like silver particle composition, and the porous sintered product of the heat-sinterable silver particles produced by heating the paste-like silver particle composition at 200 ° C. for 1 hour, the porosity, volume When the adhesion strength was measured for the resistivity, thermal conductivity, and joined body, and the cold cycle test of the joined body was performed, the micro-discharge property was good, the volume resistivity of the porous silver particle sintered product was low, and the heat The conductivity was high. Further, the bonding strength of the joined body was large, and no cracks were generated in the sintered product of the porous silver particles after the thermal cycle test.
The above results are summarized in Table 2. This paste-like silver particle composition is capable of minute discharge, has high conductivity and thermal conductivity of porous silver particle sintered material, and bonds a plurality of silver members extremely firmly, and is also resistant to thermal shock. It turns out that the nature is high.

[Example 7]
Spherical heat-sintered manufactured by a wet reduction method of copper sulfate in a mixer, with an average particle size of 1.0 μm and coated with stearic acid on the surface (the amount of stearic acid is 0.3% by mass) 90.9 parts of conductive copper particles, 7.7 parts of octanediol (manufactured by Kyowa Hakko Chemical Co., Ltd.) as a volatile dispersion medium, and 1.4 parts of the thermosetting epoxy resin composition (2) prepared in Reference Example 2 Were uniformly mixed to prepare a paste-like copper particle composition. The mass ratio of the heat-sinterable copper particles and the thermosetting epoxy resin composition is 98.5: 1.5.

The fine discharge property of the paste-like copper particle composition and the paste-like copper particle composition are heated at 300 ° C. for 1 hour, and further in a forming gas which is a mixed gas of 10% by volume of hydrogen gas and 90% by volume of nitrogen gas The porous sintered product of the heat-sinterable copper particles produced by heating at 300 ° C. for 10 minutes, the porosity, volume resistivity, thermal conductivity and adhesive strength of the joined body were measured, and the joined body When the thermal cycle test was conducted, the micro-discharge property was good, the volume resistivity of the sintered porous copper particles was low, and the thermal conductivity was high. Moreover, the bonding strength of the joined body was large, and no cracks were generated in the porous copper particle sintered product after the thermal cycle test.
The above results are summarized in Table 3. This paste-like copper particle composition is capable of micro-ejection, has high conductivity and thermal conductivity of the sintered porous copper particles, and is extremely strong in joining a plurality of silver members, and is also resistant to thermal shock. It turns out that the nature is high.

[Comparative Example 1]
In a mixer, manufactured by the wet reduction method of silver nitrate, the average particle size is 1.0μm, and the surface is coated with oleic acid (the amount of oleic acid is 0.3% by mass). 92.3 parts of silver particles and 7.7 parts of octanediol (manufactured by Kyowa Hakko Chemical Co., Ltd.) as a volatile dispersion medium were uniformly mixed to prepare a paste-like silver particle composition. The mass ratio of the silver particles to the thermosetting epoxy resin composition is 100.0: 0.0.

The fine discharge property of the paste-like silver particle composition, and the porous sintered product of the heat-sinterable silver particles produced by heating the paste-like silver particle composition at 200 ° C. for 1 hour, the porosity, volume When the adhesion strength was measured for the resistivity, thermal conductivity, and joined body, and the thermal cycle test of the joined body was performed, the micro-discharge property was good, and the volume resistivity of the sintered porous silver particles was low, and the thermal conductivity Although the rate was high, the bonding strength of the joined body was small, and cracks were generated in the porous silver particle sintered product after the thermal cycle test (see FIG. 7).
The above results are summarized in Table 4. This paste-like silver particle composition is capable of micro-discharge, and the porous silver particle sintered product has high conductivity and thermal conductivity, but it cannot bond a plurality of silver members very firmly and is resistant to thermal shock. It is clear that there are few.

[Comparative Example 2]
In a mixer, manufactured by the wet reduction method of silver nitrate, the average particle size is 1.0μm, and the surface is coated with oleic acid (the amount of oleic acid is 0.3% by mass). 92.25 parts of silver particles, 7.7 parts of octanediol (manufactured by Kyowa Hakko Chemical Co., Ltd.) as a volatile dispersion medium, and 0.05 part of the thermosetting epoxy resin composition (1) prepared in Reference Example 1 The paste-like silver particle composition was prepared by mixing uniformly. The mass ratio of the heat-sinterable silver particles and the thermosetting epoxy resin composition is 99.95: 0.05.

The fine discharge property of the paste-like silver particle composition, and the porous sintered product of the heat-sinterable silver particles produced by heating the paste-like silver particle composition at 200 ° C. for 1 hour, the porosity, volume When the adhesion strength was measured for the resistivity, thermal conductivity, and joined body, and the thermal cycle test of the joined body was performed, the micro-discharge property was good, and the volume resistivity of the sintered porous silver particles was low, and the thermal conductivity Although the rate was high, the bonding strength of the joined body was small, and cracks similar to those in FIG. 7 were generated in the sintered product of the porous silver particles after the thermal cycle test.
The above results are summarized in Table 4. This paste-like silver particle composition is capable of micro-discharge, and the porous silver particle sintered product has high conductivity and thermal conductivity, but it cannot bond a plurality of silver members very firmly and is resistant to thermal shock. It is clear that there are few.

[Comparative Example 3]
Spherical heat sinterability produced by wet reduction method of silver nitrate in a mixer, average particle diameter of 0.5 μm, surface coated with oleic acid (the amount of oleic acid is 2.1% by mass) 87.0 parts of silver particles, 12.0 parts of octanediol (manufactured by Kyowa Hakko Chemical Co., Ltd.) as a volatile dispersion medium, and 1.0 part of the thermosetting epoxy resin composition (1) prepared in Reference Example 1 The paste-like silver particle composition was prepared by mixing uniformly. The mass ratio of the heat-sinterable silver particles and the thermosetting epoxy resin composition is 98.9: 1.1.

The fine discharge property of the paste-like silver particle composition, and the porous sintered product of the heat-sinterable silver particles produced by heating the paste-like silver particle composition at 200 ° C. for 1 hour, the porosity, volume When the adhesion strength was measured for the resistivity, thermal conductivity, and joined body, and the thermal cycle test of the joined body was performed, the micro-discharge property was good, and the volume resistivity of the sintered porous silver particles was low, and the thermal conductivity Although the rate was high, the bonding strength of the joined body was small, and cracks similar to those in FIG. 7 were generated in the sintered product of the porous silver particles after the thermal cycle test.
The above results are summarized in Table 4. This paste-like silver particle composition is capable of micro-discharge, and the porous silver particle sintered product has high conductivity and thermal conductivity, but it cannot bond a plurality of silver members very firmly and is resistant to thermal shock. It is clear that there are few.

[Comparative Example 4]
In a mixer, manufactured by the wet reduction method of silver nitrate, the average particle size is 1.0μm, and the surface is coated with oleic acid (the amount of oleic acid is 0.3% by mass). 91.3 parts of silver particles, 7.7 parts of octanediol (manufactured by Kyowa Hakko Chemical Co., Ltd.) as a volatile dispersion medium, and 1.0 part of a non-thermosetting epoxy resin described in Reference Example 3 were uniformly mixed. A pasty silver particle composition was prepared. The mass ratio of the heat-sinterable silver particles and the non-thermosetting epoxy resin is 98.9: 1.1.

The fine discharge property of the paste-like silver particle composition, and the porous sintered product of the heat-sinterable silver particles produced by heating the paste-like silver particle composition at 200 ° C. for 1 hour, the porosity, volume When the adhesion strength was measured for the resistivity, thermal conductivity, and joined body, and the thermal cycle test of the joined body was performed, the micro-discharge property was good, and the volume resistivity of the sintered porous silver particles was low, and the thermal conductivity Although the rate was high, the bonding strength of the joined body was small, and cracks similar to those in FIG. 7 were generated in the sintered product of the porous silver particles after the thermal cycle test.
The above results are summarized in Table 5. This paste-like silver particle composition is capable of micro-discharge, and the porous silver particle sintered product has high conductivity and thermal conductivity, but it cannot bond a plurality of silver members very firmly and is resistant to thermal shock. It is clear that there are few.

[Comparative Example 5]
In a mixer, granular silver particles produced by a wet reduction method of silver nitrate were flaked by a rolling ball mill, the average particle diameter was 7.0 μm, and the surface was coated with stearic acid (the amount of stearic acid was 0 (4 mass%) 92.3 parts of flaky heat-sinterable silver particles, 7.0 parts of octanediol (manufactured by Kyowa Hakko Chemical Co., Ltd.) as the volatile dispersion medium, and the heat prepared in Reference Example 1 A paste-like silver particle composition was prepared by uniformly mixing 0.7 part of a curable epoxy resin. The mass ratio of the heat-sinterable silver particles and the thermosetting epoxy resin is 99.2: 0.8.

The fine discharge property of the paste-like silver particle composition, and the porous sintered product of the heat-sinterable silver particles produced by heating the paste-like silver particle composition at 200 ° C. for 1 hour, the porosity, volume When the adhesion strength was measured for the resistivity, thermal conductivity, and bonded body, and the cold cycle test of the bonded body was performed, the micro-discharge property was poor, the volume resistivity of the sintered porous silver particles was low, and the thermal conductivity Although the bond strength of the joined body was small, cracks similar to those in FIG. 7 were generated in the sintered product of the porous silver particles after the thermal cycle test.
The above results are summarized in Table 5. Although this paste-like silver particle composition cannot be micro-discharged and the porous silver particle sintered product has high conductivity and thermal conductivity, it cannot bond a plurality of silver members very firmly and is resistant to thermal shock. It turns out that the durability is poor.

[Comparative Example 6]
According to the description in JP-A-2014-51590, porous silver particles having a large number of pores penetrating or communicating from the surface to the inside were produced by the following method.
After weighing 10 kg of silver nitrate aqueous solution (concentration: 10 mol% / L), 4 kg of citric acid aqueous solution (concentration: 10 mol% / L), and 20 kg of pure water at 25 ° C., each was put into a 50 liter (L) stainless steel tank and room temperature ( The mixture was stirred at 25 ° C. ± 10 ° C. for 30 minutes using a stirrer (manufactured by Shimazaki Seisakusho, trade name: jet agitator) to prepare a mixed solution of silver nitrate and citric acid.
Next, 17 kg of an ascorbic acid aqueous solution (L-ascorbic acid aqueous solution; concentration 5 mol% / L) and 300 kg of pure water at 25 ° C. were weighed respectively, and then charged into a 450 liter stainless steel reaction tank, and room temperature (25 ° C. ± 10 ° C. ) And stirred for 30 minutes using a stirrer (manufactured by Shimazaki Seisakusho, trade name: jet agitator). The addition ratio of silver nitrate, citric acid and ascorbic acid was 1: 0.4: 0.85 in molar ratio (silver nitrate: citric acid: ascorbic acid).

Next, using a stirrer (500 rpm) having four 600 mm diameter stainless steel blades, a mixed solution of silver nitrate and citric acid is put into the prepared ascorbic acid aqueous solution, and the mixed solution of silver nitrate and citric acid and ascorbine are mixed. The acid aqueous solution was mixed.
After adding an aqueous solution of ascorbic acid to the mixed solution of silver nitrate and citric acid, the reduction reaction starts several seconds later, and after the foaming phenomenon accompanying the reduction reaction is completed, the stirring is continued at 15 to 25 ° C. for 30 minutes. Stopped. The pH of the mixed solution of silver nitrate, citric acid and ascorbic acid after the reduction reaction was 2.
After allowing the reaction solution to stand, the supernatant is removed, the precipitated silver particles are filtered using a Nutsche, and the filtered silver particles A are spread on a stainless steel pad and kept in a dryer maintained at 60 ° C. for 15 hours. Dried.
The silver particles thus produced have an average particle diameter of 2.5 μm and have a low cohesiveness, so the surface is not coated with organic matter. The surface of the silver particles has a large number of penetrating or communicating to the inside. The pores are exposed.

In a mixer, 91.3 parts of the silver particles, 8.0 parts of octanediol (manufactured by Kyowa Hakko Chemical Co., Ltd.) as a volatile dispersion medium, and 0.7 part of the thermosetting epoxy resin prepared in Reference Example 1 The paste-like silver particle composition was prepared by mixing uniformly. The mass ratio of the silver particles to the thermosetting epoxy resin is 99.2: 0.8.

The fine discharge property of the paste-like silver particle composition, and the porous sintered product of the heat-sinterable silver particles produced by heating the paste-like silver particle composition at 200 ° C. for 1 hour, the porosity, volume When the adhesion strength was measured for the resistivity, thermal conductivity, and joined body, and the thermal cycle test of the joined body was performed, the micro-discharge property was good, and the volume resistivity of the sintered porous silver particles was low, and the thermal conductivity Although the rate was high, the bonding strength of the joined body was small, and cracks similar to those in FIG. 7 were generated in the sintered product of the porous silver particles after the thermal cycle test.
The above results are summarized in Table 6. This paste-like silver particle composition is capable of micro-discharge, and the porous silver particle sintered product has high conductivity and thermal conductivity, but it cannot bond a plurality of silver members very firmly and is resistant to thermal shock. It is clear that there are few.

[Comparative Example 7]
In a mixer, manufactured by the wet reduction method of silver nitrate, the average particle size is 1.0μm, and the surface is coated with oleic acid (the amount of oleic acid is 0.3% by mass). 90.8 parts of silver particles, 7.7 parts of octanediol (manufactured by Kyowa Hakko Chemical Co., Ltd.) as a volatile dispersion medium, and 1.5 parts of the thermosetting epoxy resin composition (1) prepared in Reference Example 1 The paste-like silver particle composition was prepared by mixing uniformly. The mass ratio of the heat-sinterable silver particles and the thermosetting epoxy resin composition is 98.4: 1.6.

The fine discharge property of the paste-like silver particle composition, and the porous sintered product of the heat-sinterable silver particles produced by heating the paste-like silver particle composition at 200 ° C. for 1 hour, the porosity, volume When the adhesion strength was measured for the resistivity, thermal conductivity, and joined body, and the thermal cycle test of the joined body was performed, the micro-discharge property was good, but the volume resistivity of the porous silver particle sintered product was large, The thermal conductivity and the bond strength of the joined body were small, and cracks similar to those in FIG. 7 were generated in the sintered porous silver particles after the thermal cycle test.
The above results are summarized in Table 6. This paste-like silver particle composition is capable of micro-discharge, and although the porous silver particle sintered product has high conductivity and thermal conductivity, it cannot bond a plurality of silver members very firmly and is resistant to thermal shock. It turns out that the durability is poor.

[Comparative Example 8]
Manufactured by a wet reduction method of silver acetate in a mixer, the average particle size is 0.06 μm, and the surface is coated with 3-methoxypropylamine (the amount of 3-methoxypropylamine is 5.5% by mass) ) 85.3 parts of spherical heat-sinterable silver particles, 13.0 parts of benzyl alcohol (manufactured by Kanto Chemical Co., Inc.) as a volatile dispersion medium, and the thermosetting epoxy resin composition prepared in Reference Example 1 (1 ) 1.7 parts was uniformly mixed to prepare a paste-like silver particle composition. The mass ratio of the heat-sinterable silver particles and the thermosetting epoxy resin composition is 98.0: 2.0 (that is, 100: 2.0).

The fine dischargeability of the paste-like silver particle composition, and the porosity and volume resistivity of the porous sintered product of the porous silver particles produced by heating the paste-like silver particle composition at 200 ° C. for 1 hour When the thermal conductivity and bonding strength of the bonded body were measured and the bonded body was subjected to a thermal cycle test, the micro-discharge property was good, but the volume resistivity of the sintered porous silver particles was large, and the heat conduction The bonding strength of the bonded body was small, and cracks similar to those in FIG. 7 were generated in the sintered porous silver particles after the thermal cycle test.
The above results are summarized in Table 6. This paste-like silver particle composition is one that can be micro-discharged, and the porous silver particle sintered product has low conductivity and thermal conductivity, and it cannot bond a plurality of silver members very firmly, and it also has a thermal shock. It can be seen that the durability against is poor.

[Comparative Example 9]
Manufactured by a wet reduction method of silver acetate in a mixer, the average particle size is 0.06 μm, and the surface is coated with 3-methoxypropylamine (the amount of 3-methoxypropylamine is 5.5% by mass) ) 83.6 parts of spherical heat-sinterable silver particles, 13.0 parts of benzyl alcohol (manufactured by Kanto Chemical Co., Inc.) as a volatile dispersion medium, and the thermosetting epoxy resin composition prepared in Reference Example 1 (1 ) 3.4 parts was mixed uniformly to prepare a paste-like silver particle composition. The mass ratio of the heat-sinterable silver particles and the thermosetting epoxy resin composition is 96.1: 3.9 (ie, 100: 4.1).

The fine dischargeability of the paste-like silver particle composition, and the porosity and volume resistivity of the porous sintered product of the porous silver particles produced by heating the paste-like silver particle composition at 200 ° C. for 1 hour When the thermal conductivity and bonding strength of the bonded body were measured and the bonded body was subjected to a thermal cycle test, the micro-discharge property was good, but the volume resistivity of the sintered porous silver particles was large, and the heat conduction The rate and bond strength of the joints were small. In addition, the crack was not generate | occur | produced in this porous silver particle sintered compact after a thermal cycle test.
The above results are summarized in Table 7. This paste-like silver particle organism can be micro-discharged and has good thermal shock, but the porous silver particle sintered product has low electrical conductivity and thermal conductivity, and it can bond multiple silver members very firmly. I understand that I can't.

[Comparative Example 10]
In a mixer, a granular heat-sinterability produced by a wet reduction method of silver acetate, having an average particle size of 0.3 μm, and coated with oleic acid on the surface (oleic acid is 2.4% by mass) Uniformly, 87.7 parts of silver particles, 10.5 parts of benzyl alcohol (manufactured by Kanto Chemical Co., Inc.) as a volatile dispersion medium, and 1.8 parts of the thermosetting epoxy resin composition (1) prepared in Reference Example 1 And a paste-like silver particle composition was prepared. The mass ratio of the heat-sinterable silver particles and the thermosetting epoxy resin composition is 98.0: 2.0 (that is, 100: 2.0).

The fine dischargeability of the paste-like silver particle composition, and the porosity and volume resistivity of the porous sintered product of the porous silver particles produced by heating the paste-like silver particle composition at 200 ° C. for 1 hour When the thermal conductivity and bonding strength of the bonded body were measured and the bonded body was subjected to a thermal cycle test, the micro-discharge property was good, but the volume resistivity of the sintered porous silver particles was large, and the heat conduction Although the rate was good, the bonding strength of the joined body was small, and cracks similar to those in FIG. 7 were generated in the sintered product of the porous silver particles after the thermal cycle test.
The above results are summarized in Table 7. Although this paste-like silver particle composition is capable of micro-discharge and the thermal conductivity of the porous silver particle sintered product is good, the conductivity is low, and a plurality of silver members cannot be joined very firmly, and heat It can be seen that the durability against impact is poor.

The paste-like metal particle composition of the present invention has good micro-discharge properties, heat-sinterable metal particles are sintered by heating, and the thermosetting resin composition is cured to have high conductivity and heat conductivity. Porous metal particle sintered product having high performance, and can be bonded extremely strongly between metal members, and is useful as a bonding material between a plurality of metal members, in particular, chips such as capacitors and resistors. Useful for joining components and circuit boards, joining light-emitting diodes, laser diodes, memory elements, ICs, IGBTs, CPUs and other semiconductor elements and lead frames or circuit boards, and joining high-heat generation CPU chips and cooling plates. is there.
The metal member assembly by the method for producing a metal member assembly of the present invention is useful as a metal member in an electronic component, an electronic device, an electrical component, an electrical device or the like having a metal substrate or a metal part.
The porous metal particle sintered product according to the method for producing a sintered porous metal particle of the present invention is useful as a bonding layer between a plurality of metal members, and is a conductive wiring circuit formed on a circuit board. It is useful for the formation of

A Test specimen for measuring shear bond strength 1 Silver substrate 2 Paste-like silver particle composition or paste-like copper particle composition (porous silver or porous copper after heat sintering)
3 Silver chip

Further, since the heat-sinterable metal particles (A) in the paste-like metal particle composition of the present invention have high conductivity and thermal conductivity, the heat-sinterable metal particles (A) are porously sintered. The product is also excellent in electrical conductivity and thermal conductivity. Specifically, the volume resistivity indicating the degree of electrical conductivity is preferably 1 × 10 ⁻⁵ Ω · cm or less, and the thermal conductivity indicating the degree of thermal conductivity is 100 W / m · K or more. Preferably

Claims (13)

(A) Spherical, teardrop-shaped or granular heat-sinterable metal particles having an average particle diameter of 0.7 μm or more and 6 μm or less, and having an organic group having a polar group covering the surface of the heat-sinterable metal particles The heat-sinterable metal particles having a coating amount of 0.1 to 2.0% by mass, (B) a volatile dispersion medium, and (C) a thermosetting resin composition, A paste having a mass ratio of 98.5: 1.5 to 99.9: 0.1 between A) and the thermosetting resin composition (C), and heating at 70 ° C. to 300 ° C. The volatile dispersion medium is volatilized, the heat-sinterable metal particles (A) are sintered together, and the thermosetting resin composition (C) is cured to form a porous metal particle sintered product. A paste-like metal particle composition characterized by the above. The paste-like metal particle composition according to claim 1, wherein the material of the heat-sinterable metal particles (A) is gold, silver, copper, platinum, palladium, or an alloy thereof. The paste-like metal particle composition according to claim 1 or 2, wherein the thermosetting resin composition is a thermosetting epoxy resin composition containing an inclusion type curing agent. The paste-like metal particle composition according to any one of claims 1 to 3, wherein the porous metal particle sintered product has a porosity of 5 to 38%. The volume resistivity of the porous metal particle sintered product is 1 × 10 ⁻⁵ Ω · cm or less, and the thermal conductivity is 100 W / m · K or more. 4. The paste-like metal particle composition according to any one of 4 above. (A) Spherical, teardrop-shaped or granular heat-sinterable metal particles having an average particle diameter of 0.7 μm or more and 6 μm or less, and having an organic group having a polar group covering the surface of the heat-sinterable metal particles The heat-sinterable metal particles having a coating amount of 0.1 to 2.0% by mass, (B) a volatile dispersion medium, and (C) a thermosetting resin composition, A paste-like metal particle composition having a mass ratio of A) to the thermosetting resin composition (C) of 98.5: 1.5 to 99.9: 0.1 is interposed between a plurality of metal members. And heating at 70 ° C. to 300 ° C. to volatilize the volatile dispersion medium, sinter the heat-sinterable metal particles (A) to cure the thermosetting resin composition (C). By producing a porous metal particle sintered product, a plurality of metal members are bonded to each other. Method. The method for producing a metal member assembly according to claim 6, wherein the heat-sinterable metal particles (A) are made of gold, silver, copper, platinum, palladium, or an alloy thereof. The method for producing a metal member assembly according to claim 6 or 7, wherein the thermosetting resin composition is a thermosetting epoxy resin composition containing an inclusion type curing agent. The metal member assembly according to any one of claims 6 to 8, wherein the metal of the metal member is copper, silver, gold, platinum, palladium, or an alloy of these metals. Production method. The method for producing a metal member assembly according to any one of claims 6 to 9, wherein the porous metal particle sintered product has a porosity of 5 to 38%. The volume resistivity of the sintered porous metal particles is 1 × 10 ⁻⁵ Ω · cm or less, and the thermal conductivity is 100 W / m · K or more. The manufacturing method of the metal member assembly in any one of 10. The method of manufacturing a metal member assembly according to any one of claims 6 to 11, wherein the metal member is a lead frame, a circuit board, or an electronic component having a metal part. (A) Spherical, teardrop-shaped or granular heat-sinterable metal particles having an average particle diameter of 0.7 μm or more and 6 μm or less, and having an organic group having a polar group covering the surface of the heat-sinterable metal particles The heat-sinterable metal particles having a coating amount of 0.1 to 2.0% by mass, (B) a volatile dispersion medium, and (C) a thermosetting resin composition, A paste-like product having a mass ratio of A) to the thermosetting resin composition (C) of 98.5: 1.5 to 99.9: 0.1 is heated at 70 ° C. or higher and 300 ° C. or lower to obtain the paste. Volatile dispersion medium is volatilized, the heat-sinterable metal particles (A) are sintered together, and the thermosetting resin composition (C) is cured to form a porous metal particle sintered product. A method for producing a sintered product of porous metal particles.