JP6556302B1 - Paste-like silver particle composition, method for producing metal member assembly, and method for producing composite of sintered porous silver particle and cured resin - Google Patents

Abstract

Disclosed is a paste-like silver particle composition that has a good storage stability and is a composite of a porous sintered silver particle and a cured resin upon heating, and can firmly bond a plurality of metal members. , A method for producing a metal member assembly, and a method for producing a composite of a porous sintered silver particle and a cured resin. (A) Heat sinterability having an average particle diameter of 0.01 μm or more and 10 μm or less, spherical, teardrop-shaped or granular, and an organic substance having a polar group in an amount of 0.05 to 5.0% by mass. A paste-like silver particle composition comprising silver particles, (B) a volatile dispersion medium, and (C) a thermosetting resin powder having a melting point of 40 to 300 ° C. The paste-like silver particle composition is interposed between a plurality of metal members and heated to volatilize the volatile dispersion medium, thereby obtaining a composite of a porous silver particle sintered product and a cured resin product. The paste-like silver particle composition is heated to volatilize the volatile dispersion medium, the heat-sinterable silver particles (A) are sintered together, and the thermosetting resin powder (C) is cured. [Selection] Figure 3

Description

The present invention relates to a paste-like silver particle composition, a method for producing a metal member assembly, and a method for producing a composite of a porous silver particle sintered product and a cured resin product. Specifically, a paste-like silver particle composition comprising a heat-sinterable silver particle, a volatile dispersion medium, and a thermosetting resin powder having a melting point of 40 to 300 ° C., and the paste-like silver particle composition between a plurality of metal members A method for producing a metal member assembly, in which the volatile dispersion medium is volatilized by interposing and heating the product, the heat-sinterable silver particles are sintered together, and the thermosetting resin powder is cured, and A porous silver particle sintered product that heats a paste-like silver particle composition to volatilize the volatile dispersion medium, sinters the heat-sinterable silver particles and cures the thermosetting resin powder; The present invention relates to a method for producing a composite of cured resin.

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 the metal particles in the conductive / thermally conductive paste as much as possible. However, when it does so, there exists a problem that the viscosity of this paste rises and workability | operativity falls remarkably.
For example, in the column of the prior art of Japanese Patent Application Laid-Open No. 2003-309352, “As this type of conductive adhesive, generally, a flaky silver particle is mixed with a binder resin, a solvent, and other additives to form a paste. The conductive adhesive is applied on a conductor circuit, and an electronic component is mounted on the conductive circuit, and then the conductive adhesive is cured by heating or the like. However, the conventional conductive adhesives have a problem that the connection resistance is relatively large and the connection reliability is low, because additives such as a binder remain in the conductive adhesive after heat curing. It is thought that the contact between the flaky silver particles is hindered. "

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 Application Laid-Open No. 2014-194013), “(A) plate-type silver fine particles, (B) silver powder, and (C) thermosetting resin, (A) silver fine particles and (B) component When the total amount of silver powder is 100 parts by mass, the thermosetting resin composition containing 1 to 20 parts by mass of component (C), and the resin composition are used as a die attach paste or a material for adhering heat dissipation members. Semiconductor devices and electrical / electronic components manufactured in this manner 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 (Unexamined-Japanese-Patent No. 2013-214733), it contains low-temperature-sinterable silver fine particles and a thermosetting binder, and the thermosetting binder is 2 to 7 parts by mass with respect to 100 parts by mass of the silver fine particles. Thermally conductive pastes have been proposed.
However, since the thermosetting binder is an organic resin having extremely low conductivity and thermal conductivity, the particle size of the silver fine particles is large and the ratio of the thermosetting binder to the silver fine particles is high, There is a problem that the conductivity and heat conductivity of the silver particle sintered product of the heat conductive paste are low.

In patent document 5 (Unexamined-Japanese-Patent No. 2016-148104), it consists of a heat-sinterable metal particle, a volatile dispersion medium, and a small amount of thermosetting resin compositions, and this heat-sinterable metal particle and this thermosetting resin composition Mass ratio of 98.5: 1.5 to 99.9: 0.1, the volatile dispersion medium is volatilized by heating, and the heat-sinterable metal particles are sintered together. A paste-like metal particle composition has been proposed in which the thermosetting resin composition is cured to form a porous metal particle sintered product excellent in conductivity and thermal conductivity.
However, when the thermosetting resin composition to be used is in a liquid state (for example, in the case of a liquid composed of a liquid epoxy resin and a liquid curing agent), since the curing reactivity is high, it is long time at room temperature (for example, 25 ° C.). When stored, the epoxy resin and the curing agent react in the paste-like metal particle composition, and the viscosity increases with time and gels. The adhesive strength of the paste-like metal particle composition over time There is a problem that decreases. Therefore, there is a problem that an expensive inclusion curing agent must be used. When the thermosetting resin composition used is solid or semi-solid, there is a problem that the paste-like metal particle composition becomes non-uniform due to poor dispersibility.

JP 2014-51590 A JP 2014-194013 A JP 2010-65277 A JP 2013-214733 A JP 2016-148104 A

As a result of intensive studies to solve the above problems, the inventors of the present invention have a small amount of a melting point of 40 to 300 ° C. in a paste-like silver particle composition composed of heat-sinterable silver particles and a volatile dispersion medium. The paste-like silver particle composition containing the thermosetting resin powder has good needle dischargeability and storage stability before heating, and when heated, the heat-sinterable silver particles are sintered together. The thermosetting resin powder is cured to form a composite of porous silver particle sintered material and resin cured material having excellent conductivity and thermal conductivity, and the paste-like structure between a plurality of metal members. When heated by interposing a silver particle composition, a plurality of metal members are firmly bonded while maintaining high conductivity and thermal conductivity, and the bonded body thus obtained has excellent durability against thermal shock. As a result, the present invention has been reached.

The object of the present invention is that the needle dischargeability and storage stability are good before heating, and when heated, the heat-sinterable silver particles sinter and the thermosetting resin powder hardens to become conductive and thermally conductive. Paste silver particle composition that is a composite of porous silver particle sintered product and cured resin, excellent in durability and durability against thermal shock, and multiple metal members are firmly bonded, and durability against thermal shock Provides a method for producing a metal member assembly having excellent resistance, and a method for producing a composite of a sintered porous silver particle and a cured resin having excellent conductivity, thermal conductivity and durability against thermal shock. There is to do.

[1] (A) Spherical, teardrop-shaped, or granular heat-sinterable silver particles having an average particle diameter of 0.01 μm or more and 10 μm or less, the polar group covering the surface of the heat-sinterable silver particles Heat-sinterable silver particles having an organic coating amount of 0.05 to 5.0% by mass, (B) a volatile dispersion medium, and (C) a thermosetting epoxy having a melting point of 40 to 300 ° C. The thermosetting epoxy resin powder (C) has an average particle size of 0.1 to 100 μm and is 100 parts by mass of the sinterable silver particles (A). , 0.01 parts by mass or more and less than 5.0 parts by mass, and by heating at 100 ° C. or more and 300 ° C. or less, the volatile dispersion medium is volatilized, and the heat-sinterable silver particles (A) are sintered together. As a result, the thermosetting epoxy resin powder (C) is cured, and a composite of a porous sintered silver particle and a cured epoxy resin is obtained. A paste-like silver particle composition, which is a compound.
[2] The volume resistivity of the composite of the sintered porous silver particles and the cured epoxy resin is 1 × 10 ⁻⁵ Ω · cm or less and the thermal conductivity is 100 W / m · K or more. The paste-like silver particle composition according to [1], wherein

[3] (A) Spherical, teardrop-shaped or granular heat-sinterable silver particles having an average particle diameter of 0.01 μm or more and 10 μm or less, the polar group covering the surface of the heat-sinterable silver particles Heat-sinterable silver particles having an organic coating amount of 0.05 to 5.0% by mass, (B) a volatile dispersion medium, and (C) a thermosetting epoxy having a melting point of 40 to 300 ° C. Resin powder, the thermosetting epoxy resin powder (C) has an average particle size of 0.1 to 100 μm, and 0.01 mass with respect to 100 parts by mass of the sinterable silver particles (A). The paste-like silver particle composition that is at least part and less than 5.0 parts by weight is interposed between a plurality of metal members and heated at 100 ° C. or higher and 300 ° C. or lower to volatilize the volatile dispersion medium, silver particles sintered silver particles (a) with each other by sintering to cure the thermosetting epoxy resin powder (C) and porous With composite sintered material and the epoxy resin cured product, characterized by bonding the plurality of metal members to each other, the manufacturing method of the metal member assembly.
[4] The method for producing a metal member assembly according to [3] , wherein the metal of the metal member is copper, silver, gold, platinum, palladium, or an alloy of these metals.
[5] The volume resistivity of the composite of the sintered porous silver particles and the cured epoxy resin is 1 × 10 ⁻⁵ Ω · cm or less and the thermal conductivity is 100 W / m · K or more. The method for producing a metal member assembly according to [3] or [4] , wherein:
[6] The method for producing a metal member assembly according to any one of [3] to [5] , wherein the metal member is a lead frame, a circuit board, or an electronic component having a metal part .

[7] (A) Spherical, teardrop-shaped or granular heat-sinterable silver particles having an average particle diameter of 0.01 μm or more and 10 μm or less, the polar group covering the surface of the heat-sinterable silver particles Heat-sinterable silver particles having an organic coating amount of 0.05 to 5.0% by mass, (B) a volatile dispersion medium, and (C) a thermosetting epoxy having a melting point of 40 to 300 ° C. Resin powder, the thermosetting epoxy resin powder (C) has an average particle size of 0.1 to 100 μm, and 0.01 mass with respect to 100 parts by mass of the sinterable silver particles (A). The paste-like silver particle composition that is at least part and less than 5.0 parts by mass is heated at 100 ° C. or more and 300 ° C. or less to volatilize the volatile dispersion medium, and the heat-sinterable silver particles (A) are sintered together. is sintered, the thermosetting epoxy resin powder (C) a cured silver particles sinter porous and the cured epoxy resin Characterized by a compound, method for producing a composite of porous silver particles sinter and epoxy resin cured product.
[8] The volume resistivity of the composite of the sintered porous silver particles and the cured epoxy resin is 1 × 10 ⁻⁵ Ω · cm or less and the thermal conductivity is 100 W / m · K or more. [7] The method for producing a composite of a sintered porous silver particle and a cured epoxy resin according to [7] .

The paste-like silver particle composition of the present invention has good storage stability and needle dischargeability, is excellent in heat-sinterability, and heat-sinterable silver particles (A) are sintered together by heating to have a melting point. The thermosetting resin powder (C) having a temperature of 40 to 300 ° C. is cured to form a composite of a porous silver particle sintered product and a cured resin product having excellent conductivity and thermal conductivity. A metal member joined body made of a composite of a silver particle sintered product and a cured resin product has excellent 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 composite of porous silver particle sintered product and resin cured product of the present invention, porous silver particle sintered product and resin having excellent conductivity, thermal conductivity and durability against thermal shock A composite of cured product 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 a composite of a porous silver particle sintered product and a cured resin product. It is the XX sectional view taken on the line in FIG. It is a cross-sectional photograph of the composite of a porous silver particle sintered product and a cured resin product produced by heating the pasty silver particle composition at 200 ° C. for 1 hour in Example 4. The three peripheral portions that are black in the peripheral portion and white and large in the central portion are cured epoxy resin particles, and about 10 portions that are black and medium in size and many small black portions are voids or cured epoxy resin particles. 6 is a cross-sectional photograph of a composite of a porous sintered silver particle product and a cured resin product produced by heating the pasty silver particle composition at 200 ° C. for 1 hour in Example 5. FIG. Medium to large black portions are cured epoxy resin particles, and many minute black portions are voids or cured epoxy resin particles. It is a cross-sectional photograph of the composite of the porous silver particle sintered product and the cured resin product produced by heating the pasty silver particle composition at 200 ° C. for 1 hour in Example 6. Medium to large black portions are cured epoxy resin particles, and many minute black portions are voids or cured epoxy resin particles.

The paste-like silver particle composition of the present invention is (A) spherical, teardrop-shaped or granular heat-sinterable silver particles having an average particle diameter of 0.01 μm or more and 10 μm or less, the heat-sinterable silver Heat-sinterable silver particles in which the coating amount of the organic substance having a polar group covering the surface of the particles is 0.05 to 5.0% by mass, (B) a volatile dispersion medium, and (C) a melting point of 40 to 40%. It is a paste-like product comprising a thermosetting epoxy resin powder at 300 ° C., and the thermosetting epoxy resin powder (C) has an average particle size of 0.1 to 100 μm, and the sinterable silver particles (A) It is 0.01 mass part or more and less than 5.0 mass part with respect to 100 mass parts, Comprising: The heating at 100 degreeC or more and 300 degrees C or less volatilizes this volatile dispersion medium, and this heat-sinterability silver particles (a) with each other and sintering, thermosetting epoxy resin powder (C) is cured, the porous silver grains Characterized by comprising a composite of sinter and cured epoxy resin.

The heat-sinterable silver particles (A) are preferably those produced by a silver salt wet reduction method, that is, heat-sinterable silver particles by a wet reduction method.
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 contacted with an aqueous solution of hydroquinone, anhydrous potassium sulfite or ammonium and gelatin to reduce and precipitate silver powder. A method of preparing by filtering, washing the residue with water and drying under heating is exemplified. 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 heat-sinterable silver particles (A) thus produced are usually spherical, granular or teardrop-like, but in the case of a granular form which is an aggregate of fine silver particles of nanometer size or smaller There are many. Usually, in this reduction step, in order to prevent aggregation of the generated silver particles, an organic substance having a polar group is added to cover the generated silver particle surface. In that case, the organic substance covering the surface of the silver particles is strongly bonded to the surface of the silver particles by association, adsorption, ionic bonding, or the like, and is not easily removed by subsequent washing.
In addition, although organic substances, such as a reducing agent used in the process of producing silver particles by the reduction method, may remain in the heat-sinterable silver particles (A) in a small amount, they have polar groups, so in the present invention. Included in organic substances having polar groups.

The average particle diameter of the heat-sinterable silver particles (A) is 0.01 μm or more and 10 μm or less. The average particle size is a cumulative 50% particle size in a volume-based particle size distribution obtained by a laser diffraction / scattering particle size distribution measurement method, that is, a median diameter. In addition, when this measuring method cannot be used, the median diameter calculated from the particle diameter by an electron micrograph or a simple average value may be sufficient. When the average particle diameter exceeds 10 μm, the sinterability of the silver particles is lowered, so that the smaller one is preferable, and in particular, 5 μm or less is preferable. However, if the average particle size is less than 0.01 μm, the surface activity is strong, so a large amount of coating agent is required to prevent aggregation between the silver particles, and when the silver particles are heated and sintered There is a problem that the porosity in the sintered product is inevitably increased, and the durability against thermal shock of the composite of the porous silver particle sintered product and the cured resin product is lowered. Moreover, since the storage stability of the paste-like silver particle composition is lowered and the bonding strength during heat sintering tends to be non-uniform, it is preferably 0.1 μm or more, more preferably 0.7 μm or more. preferable. 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 silver particles having an average particle size of less than 0.01 μm and more than 10 μm may be used.

The heat-sinterable silver particles (A) may be sintered by heating in the air or in the air. Metal (for example, nickel, iron, aluminum, tin) particles or resin (for example, surfaces plated with silver) For example, epoxy resin particles may be used. Further, a part of the surface or inside may be silver oxide or silver peroxide. The silver in the heat-sinterable silver particles (A) is preferably pure silver, but may be a silver alloy (however, the silver content is preferably 90% by mass or more).

The shape of the heat-sinterable silver particles (A) is spherical, granular, or teardrop-shaped, easily dispersed uniformly in the paste-like silver particle composition of the present invention, and excellent in fine dischargeability and sinterability. It is preferable. These shapes can be confirmed by objective classification described in official documents such as JIS Z 2500 and ISO / DIS 3252. The teardrop-like silver particles may be classified as granular or spherical depending on the shape.
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 -Silver particles such as fibrous, lump-like, sponge-like, square-like, round-like shapes may be used in combination, and metal particles selected from the group consisting of copper, gold, platinum and palladium may be used in combination. .

The heat-sinterable silver particles (A) may have fine pores (however, 1% or less of the average particle diameter) penetrating or communicating from the surface to the inside. Even if there are such fine pores, the thermosetting resin powder having a melting point of 40 to 300 ° C. is blended in a small amount or in a trace amount in the paste-like silver particle composition of the present application with respect to the diameter of the pores. Since the average particle diameter of (C) is as large as 0.1 to 100 μm as described later, it penetrates into the fine pores penetrating or communicating from the surface to the inside of the heat-sinterable silver particles (A). This is because there is almost nothing, and even if it enters the interior, the amount is very small.

The heat-sinterable silver particles (A) prevent aggregation of the heat-sinterable silver particles (A), improve dispersibility in the volatile dispersion medium (B), and have excellent heat-sinterability. In order to obtain an organic substance having a polar group on the 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) It is coated with a nitrogen-containing organic compound. Note that a small amount of an organic substance having a polar group such as a reducing agent used in the step of producing silver particles by the reduction method may remain in the silver particles (A), but is included in the organic substance in the present invention. In addition, the organic substance having a polar group in the present invention may be associated with, bonded to, or adsorbed to the silver particles. The organic substance having a polar group may be solid, semi-solid, or liquid at room temperature as long as the heat-sinterable silver particles (A) can be coated.

Examples of the polar group include a carboxyl group, a carboxylic acid anhydride group, a carboxylic acid group, a carboxylic acid ester group, a hydroxyl group, an alkoxy group, an alkyl ether group, a phosphoric acid group, an acidic phosphoric acid ester group, and a phosphonic acid group. A carboxyl group, a carboxylate group, a carboxylate 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 are not limited to fatty acids in a narrow sense, but are fatty acids in a broad sense, such as oxalic acid, malonic acid, succinic acid, maleic acid, fumaric acid, oxydiacetic acid (diglycolic acid) having 2 or more carbon atoms. ), Polyvalent aliphatic carboxylic acids such as glutaric acid, adipic acid, pimelic acid, speric acid, azelaic acid, sebacic acid and diglycolic acid, and polyvalent aromatic carboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid Is exemplified. 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 phosphoric acid group, an acidic phosphate group, and a phosphonic acid group, and a carboxyl group, a phosphate group, or an acidic phosphate group is preferable. 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) Nitrogen-containing organic compounds include primary, secondary or tertiary alkylamines, diamines, triamines, alkylamidoamines, N-alkylethanolamines, N-alkylmorpholines, and other organic amine compounds. Illustrated. The number of carbon atoms in the nitrogen-containing organic compound is preferably 1 to 54.

Alkylamines, diamines, triamines such as dipropylamine, dibutylamine, hexylamine, cyclohexylamine, heptylamine, octylamine, nonylamine, alkylamines such as decylamine, dodecylamine, tripropylamine, tributylamine; ethylenediamine N, N-dimethylethylenediamine, N, N′-dimethylethylenediamine, N, N-diethylethylenediamine, N, N′-diethylethylenediamine, 1,2-propanediamine, 1,3-propanediamine, 2,2-dimethyl -1,3-propanediamine, N, N-dimethyl-1,3-diaminopropane, N, N-diethyl-1,3-diaminopropane, 1,4-diaminobutane, 1,5-diamino-2-methyl Pentane, 1,6- Diamines such as diaminohexane, N, N′-dimethyl-1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane; diethylenetriamine, dipropylenetriamine, dibutylenetriamine, N-aminoethylpiperazine And the like.

The coating amount of the organic substance having a polar group for coating the heat-sinterable silver particles (A) is 0.05 to 5.0% by mass of these heat-sinterable silver particles, and more preferably 0.1 to 0.1%. 2% by mass. If the amount is too small, the silver 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 silver particles (A) The heat sinterability is lowered, and further, the voids in the sintered product are 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, thermogravimetric analysis in which the silver particles (A) are heated above the boiling point, volatilization temperature or thermal decomposition temperature of the organic substance to measure weight loss, and the silver particles (A) are heated in an oxygen stream to An example is a method in which carbon in the organic matter adhering to the particles (A) is changed to carbon dioxide and quantitative analysis is performed by infrared absorption spectroscopy. In the latter case, the carbon content in the organic substance is measured. However, since the structure and components of the organic substance can be confirmed by infrared analysis, mass spectrometry, etc., the amount of the organic substance can be easily calculated from the carbon amount. .

The paste-like silver particle composition of the present invention comprises a heat-sinterable silver particle (A), a volatile dispersion medium (B), and a thermosetting resin powder (C). (A) and the thermosetting resin powder (C) are pasted by the action of 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.
In addition, 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 silver particles (A) are sintered by heating. This is because, when volatilized in advance, the heat-sinterable silver 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 silver 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 silver particle composition, and when the boiling point is higher than 300 ° C., the heat-sinterable silver 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 pasty silver particle composition of the present invention may be pasty 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. In addition, water is not preferable when the coating agent having a polar group that covers the surface of the heat-sinterable silver particles (A) of the present invention is water-repellent.

The blending amount of the volatile dispersion medium (B) is sufficient to paste the heat-sinterable silver particles (A) and the thermosetting resin powder (C), and the heat-sintering The amount is usually 5 to 25 parts by mass, preferably 8 to 15 parts by mass, per 100 parts by mass in total of the conductive silver particles (A) and the thermosetting resin powder (C).

In the paste-like silver particle composition of the present invention, base metal metal particles other than the heat-sinterable silver particles (A), non-metal particles, metal oxide, Additives such as metal compounds, metal complexes, thixotropic agents, stabilizers, and sintering accelerators may be added in a small amount to a trace amount (for example, 10% by mass or less).

In the present invention, the thermosetting resin powder (C) having a melting point of 40 to 300 ° C. is melted and cured when the paste-like silver particle composition of the present invention is heated, and the heat-sinterable silver particles (A) There is an effect of improving mechanical strength by reinforcing brittle porous silver particle sintered products produced by heating each other. In addition, the thermosetting resin powder (C) is produced by interposing the paste-like silver particle composition of the present invention between a plurality of metal members and heating the porous silver particle sintered product. It functions as an adhesive when joining the manufactured members, reinforces the connection between the porous silver particle sintered product and the metal member, and increases the bonding strength. There is an effect of improving the durability against thermal shock of a sintered silver particle.
In the case where the thermosetting resin powder (C) suppresses the growth of voids in the porous body by suppressing silver crystal growth in the high-temperature aging test of the porous silver particle sintered product. There is an effect of suppressing a decrease in the bonding strength after the high temperature aging test.

Since the thermosetting resin powder (C) has a melting point of 40 to 300 ° C., it is powdery at a temperature lower than the melting point. However, since it may soften if kept at a temperature slightly lower than the melting point, it is preferably powdery at a temperature at least 15 ° C. lower than each melting point. For example, when the melting point is 40 ° C., it is powdery at least at 25 ° C. The melting point is preferably 40 to 200 ° C., more preferably 40 to 100 ° C., and particularly preferably 40 to 80 ° C. in terms of ease of procurement and ease of manufacture.
Moreover, since the heating temperature of the paste-form silver particle composition of this invention is 100 degreeC or more and 300 degrees C or less, it is preferable that this thermosetting resin powder (C) fuse | melts at the heating temperature at that time. The time from the melting of the thermosetting resin powder (C) to the curing is not limited, but it is preferable to cure by the time the heating of the pasty silver particle composition of the present invention is completed.

The thermosetting resin powder (C) has an average particle diameter of 0.1 to 100 μm, and in terms of dischargeability from a fine discharge port such as a needle or nozzle of the paste-like silver particle composition of the present invention, It is preferably 50 μm or less, and more preferably 20 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. In addition, when this measuring method cannot be used, the median diameter calculated from the particle diameter by an electron micrograph or a simple average value may be sufficient.
The adjustment of the average particle diameter can be easily performed with a wire mesh having a predetermined opening diameter, a mechanical classifier or the like. In the case of a wire mesh, for example, coarse particles of about 50 μm or more can be excluded by passing through a 300 mesh wire mesh, and coarse particles of about 15 μm or more can be excluded by passing through a 1000 mesh wire mesh. Many types of classifiers are commercially available, including the jet type. The shape of the thermosetting resin powder (C) is not limited. Examples include crushed, granular, spherical, and irregular shapes.

As such thermosetting resin powder (C) having a melting point of 40 to 300 ° C., thermosetting epoxy resin powder, thermosetting phenol resin powder, thermosetting novolac resin powder, thermosetting polyurethane resin powder, heat Curable alkyd resin powder, thermosetting acrylic resin powder, thermosetting polyester resin powder, thermosetting silicone resin powder, thermosetting polyamic acid type polyimide resin powder, thermosetting bismaleimide resin powder, and those resins A modified resin powder is exemplified. These thermosetting resin powders are preferably thermosetting aromatic resin powders in terms of heat resistance.
These thermosetting resin powders (C) usually contain a curing agent, but when the thermosetting resin powder (C) itself is thermosetting, it does not need to contain a curing agent.
The thermosetting resin powder (C) has a low solubility in the volatile dispersion medium (B), is melted by heating, and has a good adhesive property. A resin powder is preferred.
Examples of the thermosetting epoxy resin powder having such a melting point include a thermosetting epoxy resin powder coating. Many thermosetting epoxy resin powder coatings are commercially available, and are characterized by excellent storage stability at room temperature (for example, 25 ° C.), which is difficult with a liquid curable epoxy resin composition.

The thermosetting epoxy resin powder coating contains an epoxy resin, a curing agent, a stabilizer, an inorganic filler such as silica, a pigment, and the like, but the epoxy resin and the curing agent are essential components, and the others are optional components.
The epoxy resin is usually a polyfunctional epoxy resin having at least two epoxy groups in one molecule, and the epoxy group is a part of glycidyl group or 2- (3,4-epoxycyclohexyl) ethyl group. included.
The curing agent is an amine, imidazole, acid anhydride or the like, the stabilizer is a reaction inhibitor, a heat resistance stabilizer, an antioxidant, or the like, and the inorganic filler is silica, alumina, aluminum hydroxide, or the like. The pigment is a fine powder, and the pigment is a colorant such as bengara or titanium oxide. In addition, you may contain a monofunctional or polyfunctional reactive diluent.

Many such polyfunctional epoxy resins are commercially available, such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolac type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, naphthalene type epoxy resin, etc. Examples include aromatic epoxy resins, alicyclic epoxy resins, N, N, N ′, N′-tetraglycidyldiaminodiphenylmethane, and the like. An aromatic epoxy resin is preferable in terms of heat resistance.

Such curing agents include aliphatic polyamines, polyaminoamides (polyamide resins), alicyclic diamines, aromatic diamines, imidazoles, tertiary amines), acid anhydride compounds, phenol resins, amino resins, dicyandiamide, Lewis Examples include acid complex compounds. 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 an amount sufficient to heat cure the thermosetting epoxy resin powder. The amount sufficient to heat and cure the thermosetting epoxy resin powder varies 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 powder.

In order to suppress the curing reaction of the thermosetting epoxy resin powder during storage of the pasty silver particle composition of the present invention, it is preferable to use a latent curing agent as the curing agent. As a latent curing agent, a capsule-type curing agent that is hard to dissolve in the volatile dispersion medium (B), is a powdery curing agent at room temperature, a capsule that is impregnated or confined in a capsule such as a resin that melts by heat, and curing Examples include adduct type hardeners that have been pre-addition-reacted with a part of the main agent or a compound having an epoxy group, and inclusion type hardeners that contain a hardener inside the molecule or inside the molecular assembly. The

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.

As for the thermosetting resin powder (C) in this invention, it is preferable that the glass transition temperature (Tg) of the hardened | cured material hardened | cured by heating is 80 degreeC or more.

In the paste-like silver particle composition of the present invention, the ratio of the thermosetting resin powder (C) is 0.01 parts by mass or more and 5.0 parts by mass with respect to 100 parts by mass of the heat-sinterable silver particles (A). Less than 0.1 parts by weight, more preferably 0.1 parts by weight or more and 3 parts by weight or less, and particularly preferably 0.1 parts by weight or more and 1.5 parts by weight or less. When the ratio of the thermosetting resin powder (C) is less than 0.01 parts by mass, the effect of adding the thermosetting resin powder (C) is poor, and when it is 5.0 parts by mass or more, The conductivity and thermal conductivity of a composite of a porous silver particle sintered product and a cured resin product, which are heating products of the pasty silver particle composition, are lowered.

The paste-like silver particle composition of the present invention is obtained by mixing the heat-sinterable silver particles (A), the volatile dispersion medium (B), and the thermosetting resin powder (C) with, for example, a planetary mixer. It can be easily produced by stirring and mixing until a paste is obtained. At this time, the heat-sinterable silver particles (A), the volatile dispersion medium (B), and the curable resin powder (C) may be simultaneously put into a planetary mixer and mixed. The dispersible dispersion medium (B) and the thermosetting resin powder (C) may be put into a planetary mixer and mixed, and then the heat-sinterable silver particles (A) may be put into a planetary mixer and mixed. Good. The pasty silver particle composition is preferably filtered through a 100 to 1000 mesh filter in order to remove the mixed coarse foreign matter.

The method for producing a metal member assembly according to the present invention comprises (A) spherical, teardrop-shaped or granular heat-sinterable silver particles having an average particle diameter of 0.01 μm or more and 10 μm or less, the heat-sintering silver particles Heat-sinterable silver particles having a coating amount of an organic substance having a polar group covering the surface of the diffusible silver particles of 0.05 to 5.0% by mass, (B) a volatile dispersion medium, and (C) a melting point Ri Do and a thermosetting epoxy resin powder is 40 to 300 ° C., thermosetting epoxy resin powder (C) is a mean particle diameter of 0.1 to 100 [mu] m, and the sintered silver particles (a ) The paste-like silver particle composition that is 0.01 parts by mass or more and less than 5.0 parts by mass with respect to 100 parts by mass is interposed between a plurality of metal members, and heated at 100 ° C. or more and 300 ° C. or less. Volatile dispersion medium is volatilized, the heat-sinterable silver particles (A) are sintered together, and the thermosetting epoxy resin powder A plurality of metal members are bonded to each other by curing the powder (C) to form a composite of a porous sintered silver particle and a cured epoxy resin.

The method for producing a composite of a sintered porous silver particle and an epoxy resin cured product according to the present invention is as follows: (A) Spherical, teardrop-shaped, or granular heat-sintered having an average particle size of 0.01 μm to 10 μm Heat-sinterable silver particles having a polar group covering the surface of the heat-sinterable silver particles and having a coating amount of 0.05 to 5.0% by mass, (B) a volatile dispersion medium, the (C) melting point Ri Do and a thermosetting epoxy resin powder is 40 to 300 ° C., thermosetting epoxy resin powder (C), is the mean particle diameter 0.1~100μm And the paste-like silver particle composition which is 0.01 mass part or more and less than 5.0 mass parts is heated at 100 degreeC or more and 300 degrees C or less with respect to 100 mass parts of this sinterable silver particle (A). The volatile dispersion medium is volatilized, the heat-sinterable silver particles (A) are sintered together, and the thermosetting epoxy resin The fat powder (C) is cured to form a composite of a porous sintered silver particle and a cured epoxy resin.

The metal member used in the method for producing a metal member joined body is joined by a composite of a sintered porous silver particle and a cured resin product produced by heating the paste-like silver particle composition of the present invention. It is an object to be joined. 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 the method for producing a metal member assembly, the atmosphere when heating the paste-like silver particle composition is air or air containing a sufficient amount of oxygen gas in terms of the sinterability of the heat-sinterable silver particles. An oxidizing gas such as is preferable. When the metal member is made of a material that is easily oxidized, such as copper or a copper alloy, a reducing gas containing hydrogen gas is preferable, and a forming gas composed of 5 to 25% by volume of hydrogen gas and 95 to 75% by volume of nitrogen gas. A reducing gas referred to as is particularly preferred. Alternatively, the reduction may be performed by heating in an oxidizing gas such as air or air containing a sufficient amount of oxygen and then heating in a gas containing hydrogen.

The paste-like silver particle composition interposed between the plurality of metal members is heated to a temperature equal to or higher than the sintering temperature of the heat-sinterable silver particles (A), whereby the volatile dispersion medium (B) is volatilized. The heat-sinterable silver particles (A) are sintered with each other, the thermosetting resin powder (C) is cured, and a porous silver particle sintered product having excellent conductivity and thermal conductivity is obtained. It becomes a composite of cured resin and firmly joins metal members. At this time, since the thermosetting resin powder (C) has a smaller blending amount than the heat-sinterable silver particles (A), the conductivity of the composite of the silver particle sintered product and the resin cured product can be reduced. Without impairing the thermal conductivity, the bonding strength between the metallic members is remarkably improved.

The heating temperature in these cases is a temperature at which the volatile dispersion medium (B) is volatilized, the heat-sinterable silver particles (A) are sintered, and the thermosetting resin powder (C) is cured. What is necessary is just 100 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 sintered sintered silver particles (A) are produced by sintering the heat-sinterable silver particles (A). Since it may adversely affect the shape of the composite resin cured product, it is 300 ° C. or lower, preferably 250 ° C. or lower.

The composite of the silver particle sintered product and the resin cured product produced by sintering the heat-sinterable silver particles (A) thus produced and curing the thermosetting resin powder (C). And sintered silver particles produced by sintering the heat-sinterable silver particles (A) between a plurality of metal members and the thermosetting resin powder (C). The composite of the object has a large number of fine pores and voids, continuous voids, that is, pores, and is porous.
In addition, when the cured product of the thermosetting resin powder (C) is transparent or thinly or finely dispersed, an electron micrograph is present even if it exists in the pores of the porous silver particle sintered product. Therefore, it is impossible to measure and calculate the porosity.

The cross-sectional shape and size of the pores in the composite of the porous silver particle sintered product and the cured resin product are various, and the cross-sectional shape is approximately circular, approximately elliptical, approximately rectangular, approximately triangular, Such as irregular shapes.
In addition, since the gaps between the heat-sinterable silver particles (A) before sintering are mainly pores, the longest diameter of each pore is usually about 0.1 to 5 μm.

The thermosetting resin powder (C) has a high bonding strength in spite of a small amount compared to the heat-sinterable silver particles (A). It is assumed that most of the powder (C) is thinly cured in the pores of the composite of the porous silver particle sintered product and the resin cured product or at the interface with the metal member. The specific gravity (density) of the heat-sinterable silver particles (A) is 10.53, which is about 6 to 10 times the specific gravity (density) of the thermosetting resin powder (C). Even if the blending amount of the thermosetting resin powder (C) is small in units, the blending amount of the thermosetting resin powder (C) is small in terms of the volume ratio that substantially determines the characteristics of the composite. I can't say that. For this reason, the paste-like silver particle composition of the present invention is heated to produce a composite of a porous silver particle sintered product and a cured resin product, not just a porous silver particle sintered product. .

Further, since the heat-sinterable silver particles (A) in the paste-like silver particle composition of the present invention have high conductivity and thermal conductivity, the heat-sinterable silver 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 there is.

When the paste-like silver particle composition of the present invention is used for bonding between a plurality of metal members, the composite of the sintered product of the heat-sinterable silver particles (A) and the cured resin product is obtained during sintering. Metal parts that were in contact, such as 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, It adheres firmly to a metal part such as a platinum-plated substrate, a platinum alloy substrate, a platinum alloy-plated substrate, a palladium-plated substrate, a palladium alloy substrate, a palladium alloy-plated substrate, or the like on an electrically insulating substrate. Furthermore, since the thermosetting resin powder (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, “parts” means “parts by mass”, and the average particle diameter means the median diameter as described above. The heating in the examples and comparative examples is heating in a forced circulation oven installed in a laboratory, and the atmosphere in the forced circulation oven is air unless otherwise noted. Specific gravity and melting point of thermosetting resin powder (C), confirmation of powder and measurement of glass transition temperature of cured product, coating amount of heat-sinterable silver particles, needle dischargeability of paste-like silver particle composition Storage stability, porosity of sintered porous silver particles, volume resistivity, thermal conductivity, composite of sintered porous silver particles and cured resin produced by heating, 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.
The heat-sinterable silver particles and the thermosetting resin powder in Examples and Comparative Examples are silver particle manufacturer products and resin powder manufacturer products. The thermosetting resin powder was appropriately classified with a mesh-like wire netting to adjust the average particle size. The spherical silver particles having an average particle diameter of 0.7 μm in Example 2 were prepared by themselves according to the example of Japanese Patent Application No. 53-29716 (Japanese Patent Application Laid-Open No. 54-121270). The granular silver particles having an average particle diameter of 1.2 μm in Example 3 and Example 4 were produced by themselves according to the example of Japanese Patent Application No. 2012-201391 (Japanese Patent Application Laid-Open No. 2014-55332), which is an in-house application. It is.

[Specific gravity and melting point of thermosetting resin powder (C)]
The specific gravity and melting point of the thermosetting resin powder (C) are measured values of the resin powder manufacturer or characteristic values described in the product data. The specific gravity of the cured product of the thermosetting liquid epoxy resin composition of the reference example was measured with an electronic hydrometer (EW-300SG manufactured by Nippon Keiki Co., Ltd.).
[Confirmation that thermosetting resin powder (C) is powder]
It was performed by visually observing the powder form.
[Glass transition temperature (Tg) of cured product of thermosetting resin powder (C)]
The glass transition temperature of the thermosetting resin powder (C) is a measured value of the resin powder manufacturer or a characteristic value described in a product document. The glass transition temperature of the cured product of the thermosetting liquid epoxy resin composition of the reference example was measured by the following method. Expansion obtained by heating the cured product from room temperature (about 25 ° C.) to 400 ° C. at a heating rate of 10 ° C./min in an air atmosphere using a thermomechanical analyzer (TMA-60 manufactured by Shimadzu Corporation) In the curve, the temperature showing the inflection point was defined as the glass transition temperature.

[Coating amount of heat-sinterable silver particles]
Using a differential thermothermal gravimetric simultaneous measurement apparatus (DTG-60AH type, manufactured by Shimadzu Corporation), heat-sinterable silver particles are heated from room temperature (about 25 ° C.) to 500 ° C. at a heating rate of 10 ° C./min in the air atmosphere. The temperature was raised, and the weight loss rate of the heat-sinterable silver particles was calculated as the coating amount.

[Needle ejection and storage stability of paste-like silver particle composition]
A 3 ml syringe (manufactured by EFD, Inc.) was filled with 1 ml of the pasty silver particle composition and allowed to stand at 25 ° C. for 3 days. Next, a metal needle (made by Musashi Engineering Co., Ltd.) with an inner diameter of 0.14 mm and a length of 13 mm is attached to the tip of the syringe, and discharge is performed with and without pressurization at a pressure of 200 kPa at 1 second intervals. Then, it was examined whether or not clogging occurred in the metal needle before the entire amount was discharged. When clogging did not occur even when the entire amount was discharged, it was judged that there was no clogging (needle dischargeability was good) and storage stability was good. When clogging occurred before the entire amount was discharged, it was determined that clogging occurred (needle dischargeability was poor) and storage stability was poor.

[Porosity of porous sintered silver 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 silver particle composition was applied by printing.

This was heated and taken out at a predetermined temperature for 1 hour in a hot air circulation oven in the laboratory, and the heat-sinterable silver particles (A) in the paste-like silver particle composition were sintered.

The obtained porous silver particle sintered product was removed from the polytetrafluoroethylene 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 part and the space part of the porous silver particle sintered product were separated, the respective masses were measured, and the proportion of the space part was shown as% as the porosity.

[Volume resistivity of composite of porous silver particle sintered product and cured resin]
A paste-like silver particle composition was applied onto a glass plate having a width of 50 mm, a length of 50 mm, and a thickness of 2.0 mm using a 2 mm thick metal mask having an opening having a width of 10 mm and a length of 10 mm. Was heated in a forced circulation oven at a predetermined temperature for a predetermined hour to obtain a composite of a plate-like porous silver particle sintered product and a cured resin product.
The volume resistivity (unit: Ω · cm) of the composite of the silver particle sintered product and the cured resin product peeled from the glass plate was measured by a method according to JIS K 7194.

[Thermal conductivity of a composite of sintered porous silver particles and cured resin]
A paste-like silver particle composition was applied onto a glass plate having a width of 50 mm, a length of 50 mm, and a thickness of 2.0 mm using a 2 mm thick metal mask having an opening having a width of 10 mm and a length of 10 mm. Was heated in a forced circulation oven at a predetermined temperature for a predetermined hour to obtain a composite of a plate-like porous silver particle sintered product and a cured resin product.
Thermal conductivity (unit: W / m · K) was measured by a laser flash method for the composite of the sintered porous silver particles and the cured resin, peeled from the glass plate.

[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 silver particle composition using a thick metal mask, and mounting 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. The samples were joined by heating for 1 hour in a forced circulation oven at a predetermined temperature in the laboratory.

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.
In addition, the adhesive strength of the joined body was measured for a paste-like silver particle composition immediately after preparation and for a paste after standing at 25 ° C. for 3 days.

[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 After applying a silver particle composition, and mounting a silver chip (silver purity 99.99%) of 2.5 mm width × 2.5 mm length × thickness 0.5 mm on it, forced to a predetermined temperature in the laboratory It joined by heating for 1 hour in a circulation type oven.

The thus obtained specimen for a cold cycle test was subjected to 500 cycles of a cold cycle test in which an air atmosphere was left at -55 ° C for 30 minutes and left at + 125 ° C for 30 minutes, and then joined in the same manner. The adhesive strength of was measured.
In addition, the adhesive strength of the joined body was measured for a paste-like silver particle composition immediately after preparation and for a paste after standing at 25 ° C. for 3 days.

[Reference example]
[Preparation of thermosetting liquid epoxy resin composition]
In a planetary mixer, 97 parts of a polyfunctional epoxy resin (trade name: jER152, viscosity 1.5 Pa · s (52 ° C.), epoxy equivalent 177 g) manufactured by Mitsubishi Chemical Corporation, 2 manufactured by Mitsubishi Chemical Corporation as a curing agent -A thermosetting epoxy resin composition which was liquid at 25 ° C was prepared by uniformly mixing 3 parts of phenyl-4-methyl-5-hydroxymethylimidazole. The specific gravity of the cured product produced by heating this epoxy resin composition at 200 ° C. for 1 hour is 1.12 and the glass transition temperature is 178 ° C.

[Example 1]
In a planetary mixer, manufactured by the wet reduction method of silver nitrate, the average particle diameter is 1.2 μm, and the surface is coated with oleic acid (the amount of oleic acid is 0.5% by mass). 100.0 parts of binding silver particles, 12.0 parts of octanediol (manufactured by Kyowa Hakko Chemical Co., Ltd.) as a volatile dispersion medium, and thermosetting epoxy resin powder having a melting point of 45 ° C. (PCE- manufactured by Pernox Corporation) 300, average particle size 18 μm, specific gravity 1.62 after curing, Tg 90 ° C.) 1.0 part was uniformly mixed to prepare a pasty silver particle composition.

The paste-like silver particle composition was tested for needle ejection, and the paste-like silver particle composition was heated at 200 ° C. for 1 hour to produce a composite of a sintered porous silver particle and a cured resin. When the cold cycle test of the joined body created immediately after preparation of the resistivity, thermal conductivity and pasty silver particle composition and the joined body prepared after standing at 25 ° C. for 3 days after preparation,
Needle ejection properties and storage stability were good, and the volume resistivity and the thermal conductivity of the composite of the sintered porous silver particles and the cured resin were low. Moreover, the adhesive strength of the joined body immediately after the preparation of the pasty silver particle composition and after standing for 3 days at 25 ° C. was large, and the adhesive strength of the joined body after the thermal cycle test was also large. The composite of the porous silver particle sintered product and the resin cured product is composed of 99.5 parts (specific gravity 10.53) of the heat-sinterable silver particle sintered product and the thermosetting epoxy resin powder. It consists of 1.0 part of a cured product (specific gravity 1.62), and the volume ratio is a composite of 93.9%: 6.1%.
The above results are summarized in Table 1. This pasty silver particle composition has good storage stability, good needle ejection properties, and high conductivity and thermal conductivity of a composite of porous silver particle sintered product and resin cured product, It can be seen that a plurality of silver members are joined extremely firmly and yet have high durability against thermal shock.

[Example 2]
In a planetary mixer, manufactured by the wet reduction method of silver nitrate, the average particle diameter is 0.7 μm, and the surface is coated with stearic acid (the amount of stearic acid is 1.0 mass%). 100.0 parts of binding silver particles, 16.0 parts of octanediol (manufactured by Kyowa Hakko Chemical Co., Ltd.) as a volatile dispersion medium, and thermosetting epoxy resin powder having a melting point of 50 ° C. (PCE- manufactured by Pernox Corporation) 60, average particle size 18 μm, specific gravity after curing 1.65, Tg is 100 ° C.) 1.5 parts) was uniformly mixed to prepare a paste-like silver particle composition.

The paste-like silver particle composition was tested for needle ejection, and the paste-like silver particle composition was heated at 200 ° C. for 1 hour to produce a composite of a sintered porous silver particle and a cured resin. When the cold cycle test of the joined body created immediately after preparation of the resistivity, thermal conductivity and pasty silver particle composition and the joined body prepared after standing at 25 ° C. for 3 days after preparation,
Needle ejection properties and storage stability were good, and the volume resistivity and the thermal conductivity of the composite of the sintered porous silver particles and the cured resin were low. Moreover, the adhesive strength of the joined body immediately after the preparation of the pasty silver particle composition and after standing for 3 days at 25 ° C. was large, and the adhesive strength of the joined body after the thermal cycle test was also large. In addition, the composite of the porous silver particle sintered product and the resin cured product is composed of 99.0 parts (specific gravity 10.53) of the heat-sinterable silver particle sintered product and the thermosetting epoxy resin powder. It consists of 1.5 parts of cured product (specific gravity 1.65), and its volume ratio is 91.2%: 8.8%.
The above results are summarized in Table 1. This pasty silver particle composition has good storage stability, good needle ejection properties, and high conductivity and thermal conductivity of a composite of porous silver particle sintered product and resin cured product, It can be seen that a plurality of silver members are joined extremely firmly and yet have high durability against thermal shock.

[Example 3]
In a planetary mixer, produced by a wet reduction method of silver nitrate, the average particle size is 1.2 μm, the surface is coated with DISPERBYK-2020 (the amount of DISPERBYK-2020 is 0.3% by mass) Heat-sinterable silver particles 100.0 parts, α-terpineol (manufactured by Kanto Chemical Co., Inc.) 12.0 parts as a volatile dispersion medium, and thermosetting epoxy resin powder (manufactured by Pernox Co., Ltd.) having a melting point of 42 ° C. PCE-330, average particle diameter 18 μm, specific gravity after curing 1.68, Tg 94 ° C.) 0.8 parts was uniformly mixed to prepare a paste-like silver particle composition.

The paste-like silver particle composition was tested for needle ejection, and the paste-like silver particle composition was heated at 200 ° C. for 1 hour to produce a composite of a sintered porous silver particle and a cured resin. When the cold cycle test of the joined body created immediately after preparation of the resistivity, thermal conductivity and pasty silver particle composition and the joined body prepared after standing at 25 ° C. for 3 days after preparation,
Needle ejection properties and storage stability were good, and the volume resistivity and the thermal conductivity of the composite of the sintered porous silver particles and the cured resin were low. Moreover, the adhesive strength of the joined body immediately after the preparation of the pasty silver particle composition and after standing for 3 days at 25 ° C. was large, and the adhesive strength of the joined body after the thermal cycle test was also large. In addition, the composite of the porous silver particle sintered product and the resin cured product is composed of 99.7 parts (specific gravity 10.53) of the heat-sinterable silver particle sintered product and the thermosetting epoxy resin powder. It consists of 0.8 parts of cured product (specific gravity 1.68), and its volume ratio is a composite of 95.2%: 4.8%.
The above results are summarized in Table 1. This pasty silver particle composition has good storage stability, good needle ejection properties, and high conductivity and thermal conductivity of a composite of porous silver particle sintered product and resin cured product, It can be seen that a plurality of silver members are joined extremely firmly and yet have high durability against thermal shock.

[Example 4]
In a planetary mixer, produced by a wet reduction method of silver nitrate, the average particle size is 1.2 μm, and the surface is coated with 1,2-propanediamine (the amount of 1,2-propanediamine is 0.2 mass) 100.0 parts of granular heat-sinterable silver particles, 12.0 parts of α-terpineol (manufactured by Kanto Chemical Co., Inc.) as a volatile dispersion medium, and a thermosetting epoxy resin having a melting point of 42 ° C. A paste-like silver particle composition was prepared by uniformly mixing 0.8 parts of powder (PCE-330, manufactured by Pernox Co., Ltd., average particle diameter 9 μm, specific gravity 1.68 after curing, Tg 94 ° C.).

The paste-like silver particle composition was tested for needle dischargeability, and the paste-like silver particle composition was heated at 200 ° C. for 1 hour to produce a composite of a sintered porous silver particle and a cured resin. When the cold cycle test of the joined body created immediately after preparation of the volume resistivity, thermal conductivity and pasty silver particle composition and the joined body prepared after standing at 25 ° C. for 3 days after preparation,
Needle ejection properties and storage stability were good, and the volume resistivity and the thermal conductivity of the composite of the sintered porous silver particles and the cured resin were low. Moreover, the adhesive strength of the joined body immediately after the preparation of the pasty silver particle composition and after standing for 3 days at 25 ° C. was large, and the adhesive strength of the joined body after the thermal cycle test was also large. The composite of the porous silver particle sintered product and the cured resin product is composed of 99.8 parts (specific gravity 10.53) of the sintered product of heat-sinterable silver particles and the thermosetting epoxy resin powder. It consists of 0.8 parts of cured product (specific gravity 1.68), and its volume ratio is a composite of 95.2%: 4.8%.
The above results are summarized in Table 2. This pasty silver particle composition has good storage stability, good needle ejection properties, and high conductivity and thermal conductivity of a composite of porous silver particle sintered product and resin cured product, It can be seen that a plurality of silver members are joined extremely firmly and yet have high durability against thermal shock.

[Example 5]
In a planetary mixer, manufactured by the wet reduction method of silver nitrate, the average particle diameter is 1.2 μm, and the surface is coated with oleic acid (the amount of oleic acid is 0.5% by mass). 100.0 parts of binding silver particles, 12.0 parts of octanediol (manufactured by Kyowa Hakko Chemical Co., Ltd.) as a volatile dispersion medium, and thermosetting epoxy resin powder having a melting point of 45 ° C. (PCE- manufactured by Pernox Corporation) 300, average particle diameter 18 μm, specific gravity 1.62 after curing, Tg 90 ° C.) 0.2 part was uniformly mixed to prepare a paste-like silver particle composition.

The paste-like silver particle composition was tested for needle ejection, and the paste-like silver particle composition was heated at 200 ° C. for 1 hour to produce a composite of a sintered porous silver particle and a cured resin. When the cold cycle test of the joined body created immediately after preparation of the resistivity, thermal conductivity and pasty silver particle composition and the joined body prepared after standing at 25 ° C. for 3 days after preparation,
Needle ejection properties and storage stability were good, and the volume resistivity and the thermal conductivity of the composite of the sintered porous silver particles and the cured resin were low. Moreover, the adhesive strength of the joined body immediately after the preparation of the pasty silver particle composition and after standing for 3 days at 25 ° C. was large, and the adhesive strength of the joined body after the thermal cycle test was also large. The composite of the porous silver particle sintered product and the resin cured product is composed of 99.5 parts (specific gravity 10.53) of the heat-sinterable silver particle sintered product and the thermosetting epoxy resin powder. It consists of 0.2 part of a cured product (specific gravity 1.62), and its volume ratio is 98.7%: 1.3% composite.
The above results are summarized in Table 2. This pasty silver particle composition has good storage stability, good needle ejection properties, and high conductivity and thermal conductivity of a composite of porous silver particle sintered product and resin cured product, It can be seen that a plurality of silver members are joined extremely firmly and yet have high durability against thermal shock.

[Example 6]
In a planetary mixer, manufactured by the wet reduction method of silver nitrate, the average particle diameter is 1.2 μm, and the surface is coated with oleic acid (the amount of oleic acid is 0.5% by mass). 100.0 parts of binding silver particles, 12.0 parts of octanediol (manufactured by Kyowa Hakko Chemical Co., Ltd.) as a volatile dispersion medium, and thermosetting epoxy resin powder having a melting point of 45 ° C. (PCE- manufactured by Pernox Corporation) 300, average particle size 18 μm, specific gravity 1.62 after curing, Tg 90 ° C.) 2.5 parts was uniformly mixed to prepare a pasty silver particle composition.

The paste-like silver particle composition was tested for needle ejection, and the paste-like silver particle composition was heated at 200 ° C. for 1 hour to produce a composite of a sintered porous silver particle and a cured resin. When the cold cycle test of the joined body created immediately after preparation of the resistivity, thermal conductivity and pasty silver particle composition and the joined body prepared after standing at 25 ° C. for 3 days after preparation,
Needle ejection properties and storage stability were good, and the volume resistivity and the thermal conductivity of the composite of the sintered porous silver particles and the cured resin were low. Moreover, the adhesive strength of the joined body immediately after the preparation of the pasty silver particle composition and after standing for 3 days at 25 ° C. was large, and the adhesive strength of the joined body after the thermal cycle test was also large. The composite of the porous silver particle sintered product and the resin cured product is composed of 99.5 parts (specific gravity 10.53) of the heat-sinterable silver particle sintered product and the thermosetting epoxy resin powder. It consists of 2.5 parts of cured product (specific gravity 1.62), and its volume ratio is a composite of 86.0%: 14.0%.
The above results are summarized in Table 2. This pasty silver particle composition has good storage stability, good needle ejection properties, and high conductivity and thermal conductivity of a composite of porous silver particle sintered product and resin cured product, It can be seen that a plurality of silver members are joined very firmly and yet highly resistant to thermal shock.

[Comparative Example 1]
In Example 1, a thermosetting epoxy resin powder having a melting point of 45 ° C. (Pernox Co., Ltd., PCE-300, average particle size 18 μm, specific gravity 1.62 after curing, Tg 90 ° C.) was not mixed. A pasty silver particle composition was prepared.

The paste-like silver particle composition was tested for needle ejection, and the paste-like silver particle composition was heated at 200 ° C. for 1 hour to produce a porous sintered product of the heat-sinterable silver particles. The adhesive strength was measured for the bonded body prepared immediately after the preparation of the resistivity, thermal conductivity, and paste-like silver particle composition, and the bonded body prepared after standing at 25 ° C. for 3 days after the preparation. After testing,
Needle ejection properties and storage stability are good, and the volume resistivity of the sintered porous silver particles is low and the thermal conductivity is high, but the bonding strength of the bonded body is small, and the bonding after the thermal cycle test The bond strength of the body was also small.
The above results are summarized in Table 3. This paste-like silver particle composition has good storage stability, good needle ejection properties, and the porous silver particle sintered product has high conductivity and thermal conductivity, but a plurality of silver members are extremely strong. It can be seen that the material cannot be bonded to the film, and the durability against thermal shock is poor.

[Comparative Example 2]
In Example 1, instead of 1.0 part of thermosetting epoxy resin powder having a melting point of 45 ° C. (PCE-300 manufactured by Pernox Corporation, average particle size 18 μm, specific gravity 1.62 after curing, Tg 90 ° C.), A pasty silver particle composition was prepared in the same manner except that 1.0 part of a liquid thermosetting liquid epoxy resin composition (specific gravity after curing 1.12) prepared at 25 ° C. prepared in Reference Example was used.

The paste-like silver particle composition was tested for needle ejection, and the paste-like silver particle composition was heated at 200 ° C. for 1 hour to produce a composite of a sintered porous silver particle and a cured resin. The adhesive strength was measured for the bonded body prepared immediately after the preparation of the resistivity, thermal conductivity, and paste-like silver particle composition, and the bonded body prepared after standing at 25 ° C. for 3 days after the preparation. When tested, clogging occurred in the needle discharge, and the storage stability was poor. The composite of the porous silver particle sintered product and the cured resin product has low volume resistivity, high thermal conductivity, and high bond strength immediately after preparation of the paste-like silver particle composition. Thereafter, the bonding strength of the joined body prepared after standing at 25 ° C. for 3 days was small. The composite of sintered porous silver particles and cured resin is composed of 99.5 parts (specific gravity 10.53) of the sintered material of heat-sinterable silver particles and the thermosetting epoxy resin composition. This is a composite having a volume ratio of 91.4%: 8.6%.
The above results are summarized in Table 3. This pasty silver particle composition was incapable of needle ejection and had poor storage stability. The composite of porous silver particle sintered product and resin cured product has high conductivity and thermal conductivity, but after preparing the paste-like silver particle composition, the adhesive strength decreases over time, and a plurality of silver members It can be seen that the material cannot be bonded extremely firmly and has poor durability against thermal shock.

[Comparative Example 3]
In Example 1, instead of 1.0 part of thermosetting epoxy resin powder having a melting point of 45 ° C. (PCE-300 manufactured by Pernox Corporation, average particle size of 18 μm, Tg after curing is 90 ° C.) A pasty silver particle composition was prepared in the same manner except that 5.5 parts of the liquid thermosetting liquid epoxy resin composition (specific gravity after curing 1.12) prepared at 25 ° C. was used.

The paste-like silver particle composition was tested for needle ejection, and the paste-like silver particle composition was heated at 200 ° C. for 1 hour to produce a composite of a sintered porous silver particle and a cured resin. The adhesive strength was measured for the bonded body prepared immediately after the preparation of the resistivity, thermal conductivity, and paste-like silver particle composition, and the bonded body prepared after standing at 25 ° C. for 3 days after the preparation. After testing,
Clogging occurred in needle ejection and storage stability was poor. Bond strength immediately after preparation of the paste-like silver particle composition was high, and the joint was prepared after standing at 25 ° C. for 3 days. The bond strength of the body was also high, but the volume resistivity of the composite of the sintered porous silver particles and the cured resin was high and the thermal conductivity was low. The composite of sintered porous silver particles and cured resin is composed of 99.5 parts (specific gravity 10.53) of the sintered material of heat-sinterable silver particles and the thermosetting epoxy resin composition. This is a composite having a volume ratio of 65.8%: 34.2%.
The above results are summarized in Table 3. This paste-like silver particle composition cannot be ejected by needles, has poor storage stability, and has a high adhesive strength between a composite of a sintered silver particle and a cured resin, but is conductive. It can be seen that the thermal conductivity is low.

[Comparative Example 4]
In a planetary mixer, manufactured by the wet reduction method of silver nitrate, the average particle diameter is 1.2 μm, and the surface is coated with oleic acid (the amount of oleic acid is 0.5% by mass). 100.0 parts of binding silver particles, 20.0 parts of octanediol (manufactured by Kyowa Hakko Chemical Co., Ltd.) as a volatile dispersion medium, and thermosetting epoxy resin powder having a melting point of 42 ° C. (PCE- manufactured by Pernox Corporation) 330, average particle size 110 μm, specific gravity after curing 1.68, Tg 94 ° C.) 5.5 parts were uniformly mixed to prepare a paste-like silver particle composition.

The paste-like silver particle composition was tested for needle ejection, and the paste-like silver particle composition was heated at 200 ° C. for 1 hour to produce a composite of a sintered porous silver particle and a cured resin. The adhesive strength was measured for the bonded body prepared immediately after the preparation of the resistivity, thermal conductivity, and paste-like silver particle composition, and the bonded body prepared after standing at 25 ° C. for 3 days after the preparation. After testing,
Needle discharge caused clogging and storage stability was poor. Further, the bonding strength of the bonded body immediately after preparation of the paste-like silver particle composition was large, and the bonded body prepared after standing at 25 ° C. for 3 days was also large, but the porous silver particles The composite of the sintered product and the cured resin product had a high volume resistivity and a low thermal conductivity. The composite of the porous silver particle sintered product and the resin cured product is composed of 99.5 parts (specific gravity 10.53) of the heat-sinterable silver particle sintered product and the thermosetting epoxy resin powder. It consists of 5.5 parts of cured product (specific gravity 1.68), and its volume ratio is a composite of 74.3%: 25.7%.
The above results are summarized in Table 4. This paste-like silver particle composition cannot be ejected by needles, has poor storage stability, and has a high adhesive strength between a composite of a sintered silver particle and a cured resin, but is conductive. It can be seen that the thermal conductivity is low.

Note: The porosity of Comparative Example 1 is the porosity of the sintered product.

The paste-like silver particle composition of the present invention has good storage stability and needle dischargeability, heat-sinterable silver particles are sintered by heating, and has a melting point of 40 to 300 ° C. Since the assembled powder melts and cures, it becomes a composite of porous silver particle sintered product and resin cured product having high conductivity and thermal conductivity, and metal members can be joined extremely firmly, It is useful as a bonding material between a plurality of metal members, and in particular, bonding between chip components such as capacitors and resistors and circuit boards, light emitting diodes, laser diodes, memories, ICs, IGBTs, CPUs and other semiconductor elements and leads It is useful for joining a frame or a circuit board, joining a high heat generating CPU chip and a cooling plate, and the like.
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 composite produced by the method for producing a composite of a sintered porous silver particle and a cured resin according to the present invention is useful as a bonding layer between a plurality of metal members, and is formed on a circuit board. This is useful for forming a wiring circuit of the same nature.

A Specimen 1 for measuring shear bond strength 1 Silver substrate 2 Pasty silver particle composition (composite of sintered silver particle and cured resin after heat sintering)
3 Silver chip

Claims (8)

(A) Spherical, teardrop-shaped, or granular heat-sinterable silver particles having an average particle diameter of 0.01 μm or more and 10 μm or less, and an organic substance having a polar group that covers the surface of the heat-sinterable silver particles Heat-sinterable silver particles having a coating amount of 0.05 to 5.0% by mass, (B) a volatile dispersion medium, and (C) a thermosetting epoxy resin powder having a melting point of 40 to 300 ° C. The thermosetting epoxy resin powder (C) has an average particle size of 0.1 to 100 μm, and is 0.1% with respect to 100 parts by mass of the sinterable silver particles (A). 01 parts by mass or more and less than 5.0 parts by mass, by heating at 100 ° C. or more and 300 ° C. or less, the volatile dispersion medium is volatilized, and the heat-sinterable silver particles (A) are sintered together, and curing the thermosetting epoxy resin powder (C) is a composite of the porous silver particles sinter and epoxy resin cured product of Characterized in that the paste Jogin particle composition. The volume resistivity of the composite of the porous silver particle sintered product and the cured epoxy resin is 1 × 10 ⁻⁵ Ω · cm or less, and the thermal conductivity is 100 W / m · K or more. The paste-like silver particle composition according to claim 1. (A) Spherical, teardrop-shaped or granular heat-sinterable silver particles having an average particle diameter of 0.01 μm or more and 10 μm or less, and an organic substance having a polar group covering the surface of the heat-sinterable silver particles Heat-sinterable silver particles having a coating amount of 0.05 to 5.0% by mass, (B) a volatile dispersion medium, and (C) a thermosetting epoxy resin powder having a melting point of 40 to 300 ° C. The thermosetting epoxy resin powder (C) has an average particle diameter of 0.1 to 100 μm, and 0.01 parts by mass or more and 5 parts by mass with respect to 100 parts by mass of the sinterable silver particles (A). The paste-like silver particle composition that is less than 0.0 part by mass is interposed between a plurality of metal members and heated at 100 ° C. or more and 300 ° C. or less to volatilize the volatile dispersion medium, and the heat-sinterable silver Sintering particles (A) and curing the thermosetting epoxy resin powder (C) to sinter porous silver particles A method for producing a metal member joined body, wherein a plurality of metal members are joined to each other by using a composite of a cured product and an epoxy resin cured product. The method for producing a metal member assembly according to claim 3 , wherein the metal of the metal member is copper, silver, gold, platinum, palladium, or an alloy of these metals. The volume resistivity of the composite of the porous silver particle sintered product and the cured epoxy resin 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 according to claim 3 or 4 . The method for manufacturing a metal member assembly according to any one of claims 3 to 5 , 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 silver particles having an average particle diameter of 0.01 μm or more and 10 μm or less, and an organic substance having a polar group covering the surface of the heat-sinterable silver particles Heat-sinterable silver particles having a coating amount of 0.05 to 5.0% by mass, (B) a volatile dispersion medium, and (C) a thermosetting epoxy resin powder having a melting point of 40 to 300 ° C. The thermosetting epoxy resin powder (C) has an average particle diameter of 0.1 to 100 μm, and 0.01 parts by mass or more and 5 parts by mass with respect to 100 parts by mass of the sinterable silver particles (A). The paste-like silver particle composition that is less than 0.0 parts by mass is heated at 100 ° C. or more and 300 ° C. or less to volatilize the volatile dispersion medium, and the heat-sinterable silver particles (A) are sintered together. composite of thermosetting epoxy resin powder (C) a cured porous silver particles sinter and epoxy resin cured product of A method for producing a composite of a porous sintered silver particle and a cured epoxy resin, wherein the composite is a product. The volume resistivity of the composite of the porous silver particle sintered product and the cured epoxy resin is 1 × 10 ⁻⁵ Ω · cm or less, and the thermal conductivity is 100 W / m · K or more. A method for producing a composite of a sintered porous silver particle and a cured epoxy resin according to claim 7 .