JP2016115560A - Pasty metal particle composition, bonding method and electronic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pasty metal particle composition that is excellent in shape retention after coating while suppressing separation of sinterable metal particles and a volatile dispersion medium, to provide a bonding method capable of easily forming a strong and stable bond between metallic members and to provide an electronic device in which a semiconductor element and a lead frame or a circuit board are stably bonded.SOLUTION: The pasty metal particle composition 2 is a pasty product comprising heat-sinterable metal particles having an average particle size of 0.01 to 10 μm, a low-viscosity volatile dispersion medium and a high-viscosity volatile dispersion medium, forms a non-fluid substance having plasticity by volatilizing the low-viscosity volatile dispersion medium upon drying at 25 to 125°C and allows the metal particles to be sintered upon heating at 150 to 400°C. The method for bonding metallic members comprises heating and sintering the pasty metal particle composition 2 between the metallic members. The electronic device is produced by bonding a semiconductor element 3 to a lead frame or a circuit board 1 using the pasty metal particle composition 2.SELECTED DRAWING: Figure 2

Description

The present invention comprises sinterable metal particles, a low-viscosity volatile dispersion medium, and a high-viscosity volatile dispersion medium, and the low-viscosity volatile dispersion medium is volatilized by drying to form a non-fluid having plasticity, and then heated. The high-viscosity volatile dispersion medium is volatilized and the sinterable metal particles are sintered to form a solid metal, and the paste-like metal particle composition and the metal using the paste-like metal particle composition The present invention relates to a method for joining manufactured members and an electronic device in which a semiconductor element and a lead frame or a wiring substrate are joined by the paste-like metal particle composition.

Conductive pastes and heat conductive pastes prepared by dispersing fine particles of metal such as silver, copper and nickel in a curable resin composition are cured by heating to form conductive films and heat conductive films. Since it is formed, the formation of conductive circuits on printed circuit boards, the formation of various electronic components such as resistors and capacitors and the electrodes of various display elements, the formation of conductive films for electromagnetic wave shielding, capacitors, resistors, diodes, and memories Bonding and adhesion of chip components such as arithmetic elements (CPU) to substrates, formation of solar cell electrodes, especially solar cell electrodes that cannot be processed at high temperature using amorphous silicon semiconductors, multilayer ceramic capacitors, multilayer ceramic inductors, multilayers Application to the formation of external electrodes of chip-type ceramic electronic components such as ceramic actuators is known (Patent Document 1: Japanese Patent Laid-Open No. 2004-260688). 003-55701).
However, since it is in the form of a paste, it is not easy to obtain a predetermined shape, size, or thickness during the forming operation or the joining operation. In addition, the conductive film and the heat conductive film are composed of metal particles and a cured resin, and since the cured resin is electrically insulating and has low thermal conductivity, there is a limit to the size of the conductivity and thermal conductivity. .
In recent years, due to higher performance of chip parts, the amount of heat generated from the chip parts has increased, and improvement in thermal conductivity as well as electrical conductivity is required.

On the other hand, as a conductive / thermal conductive paste that does not contain a curable resin, it consists of noble metal (for example, silver) flakes and an organic solvent and is sintered by heating, and the noble metal paste is heated and sintered between the electronic device and the substrate. Thus, a method of fixing an electronic device to a substrate is disclosed (Patent Document 2: Japanese Patent Publication No. 7-111981).

However, the paste-like metal particle composition is a mixture of sinterable metal particles having a large specific gravity and a volatile dispersion medium having a small specific gravity, and there is a problem that they are easily separated due to the difference in specific gravity between them. In addition, since it is in the form of a paste, it is not easy to ensure a predetermined shape, size, and thickness at the time of application, and there is a problem that the shape, size, thickness, etc. are likely to change with time after application.

Therefore, the present inventors do not separate the sinterable metal particles from the volatile dispersion medium, easily obtain a predetermined shape, size, and thickness, and also have a sinterable metal particle composition excellent in shape retention. Although proposed, since the sinterable metal particle composition is in a solid state, when the sinterable metal particle composition is disposed in a die pad portion for use as a bonding agent between a semiconductor element and a lead frame or a circuit board. It has been found that there is a problem that the sinterable metal particle composition moves due to vibration or inclination of the lead frame or circuit board, and the bonding position is not stable (Patent Document 3: WO2008 / 065728).

JP 2003-55701 A Japanese Patent Publication No. 7-111981 WO2008 / 065728

As a result of intensive research to develop a paste-like metal particle composition free from the above problems, the present inventors have found that when a sinterable metal particle is pasted with a volatile dispersion medium, a plurality of low and high viscosity Inventing a paste-like metal particle composition having excellent shape retention after coating while suppressing separation of the sinterable metal particles and the volatile dispersion medium by using the volatile dispersion medium of Successful. An object of the present invention is to provide a paste-like metal particle composition having excellent shape retention after coating while suppressing the separation of the sinterable metal particles and the volatile dispersion medium, and between metal members. Provided is a joining method that facilitates strong and stable joining of metal members by heating and sintering the paste-like metal particle composition, and an electronic device in which a semiconductor element and a lead frame or a circuit board are stably joined. There is to do.

This purpose is
[1] (A) Sinterable metal particles produced by a reduction method and having an average particle diameter of 0.01 to 10 μm and having a surface coated with an organic substance, (B1) having a viscosity at 25 ° C. of 0.1 A paste-like material comprising a low-viscosity volatile dispersion medium having a viscosity of ˜500 mPa · s and (B2) a high-viscosity volatile dispersion medium having a viscosity of 10 to 200 Pa · s at 25 ° C. A paste-like metal particle characterized by being a non-fluid having plasticity when dried at a temperature of 125 ° C. or lower and a sintered product of the metal particles (A) when heated at 150 ° C. or higher and 400 ° C. or lower. Composition.
[2] More than half of the low-viscosity volatile dispersion medium (B1) contained in the paste is volatilized by drying, and more than half of the high-viscosity volatile dispersion medium (B2) remains. The paste-like metal particle composition according to [1].
[2-1] The paste-like metal particle composition according to [1] or [2], wherein the non-fluid plasticity has a Williams plasticity of 10 to 500 at 25 ° C.
[3] The paste-like metal particle composition according to [1] or [2], wherein the material of the sinterable metal particles is gold, silver, copper, platinum, palladium, or an alloy thereof. .
[4] The volume resistivity of the sintered product is 1 × 10 ⁻⁵ Ω · cm or less, and the thermal conductivity is 100 W / m · K or more, [1], [2] Or the paste-like metal particle composition according to [3].

[5] (A) Sinterable metal particles produced by a reduction method and having an average particle diameter of 0.01 to 10 μm and having a surface coated with an organic substance, (B1) having a viscosity of 0.1 at 25 ° C. A paste-like metal particle composition comprising a low-viscosity volatile dispersion medium having a viscosity of ˜500 mPa · s and (B2) a high-viscosity volatile dispersion medium having a viscosity of 10 to 200 Pa · s at 25 ° C. is made into a metal member (C1) After the coating, and drying at a temperature of 25 ° C. to 125 ° C. to make the paste-like metal particle composition a plastic non-fluid, the metal member (C2) is mounted on the non-fluid The metallic member (C1) and the metallic member (C2) are joined as a sintered product of the metallic particles (A) by heating at 150 ° C or higher and 400 ° C or lower. Joining of metal member (C1) and metal member (C2) Method.
[6] It is characterized by volatilizing more than half of the low-viscosity volatile dispersion medium (B1) contained in the paste-like material and leaving more than half of the high-viscosity volatile dispersion medium (B2) by drying. The joining method according to [5].
[6-1] The joining method according to [5] or [6], wherein the Williams plasticity of the non-fluid having plasticity is 10 to 500 at 25 ° C.
[7] The joining method according to [5] or [6], wherein the material of the sinterable metal particles is gold, silver, copper, platinum, palladium, or an alloy thereof.
[8] The material of the metal member (C1) and the metal member (C2) is gold, silver, copper, platinum, palladium, or an alloy thereof, [5], [6] or The joining method according to [7].
[9] The metal member (C1) is a metal part of a lead frame or a circuit board, and the metal member (C2) is a metal part of a semiconductor element, [5], [6], The joining method according to [7] or [8].
[10] From [5] to [9], wherein the sintered product has a volume resistivity of 1 × 10 −5 Ω · cm or less and a thermal conductivity of 100 W / m · K or more. The joining method according to any one of the above.

[11] (A) Sinterable metal particles produced by a reduction method and having an average particle diameter of 0.01 to 10 μm and having a surface coated with an organic substance, and (B1) a viscosity at 25 ° C. of 0.1. A paste-like metal particle composition comprising a low-viscosity volatile dispersion medium having a viscosity of ˜500 mPa · s and (B2) a high-viscosity volatile dispersion medium having a viscosity of 10 to 200 Pa · s at 25 ° C. After being applied to a circuit board having the structure, it is dried at a temperature of 25 ° C. or more and 125 ° C. or less to make the paste-like metal particle composition a plastic non-fluid, and then a semiconductor element having a metal portion is formed on the non-fluid. And is heated at 150 ° C. or more and 400 ° C. or less to bond the metal part of the semiconductor element and the metal part of the lead frame or circuit board as a sintered product of the metal particles (A). Apparatus.
[12] It is characterized by volatilizing more than half of the low-viscosity volatile dispersion medium (B1) contained in the paste-like material and leaving more than half of the high-viscosity volatile dispersion medium (B2) by drying. The electronic device according to [11].
[12-1] The electronic device according to [11] or [12], wherein the non-fluid plasticity has a Williams plasticity of 10 to 500 at 25 ° C.
[13] The electronic device according to [11] or [12], wherein the material of the sinterable metal particles is gold, silver, copper, platinum, palladium, or an alloy thereof.
[14] The electronic device according to [11], [12] or [13], wherein the metal part is made of gold, silver, copper, platinum, palladium, or an alloy thereof.
[15] From [11] to [14], wherein the sintered product has a volume resistivity of 1 × 10 ⁻⁵ Ω · cm or less and a thermal conductivity of 100 W / m · K or more. An electronic device according to any one of the above. Achieved by;

In the paste-like metal particle composition defined in claim 1 of the present invention, the low-viscosity volatile dispersion medium (B1) is first volatilized by drying to become a non-fluid having plasticity, and then heated to sinterable metal. Since the particles (A) are sintered together, the shape and thickness of the sintered product are stable. In addition, a thick metal particle sintered product, that is, a solid metal can be obtained.

In the joining method using the paste-like metal particle composition defined in claim 5 of the present invention, the paste-like metal particle composition is applied onto the metal member (C1) and then dried to reduce the low-viscosity volatile dispersion medium (B1). ) Is volatilized into a non-fluid material having plasticity, so that the paste-like metal particle composition spreads on the metal member (C1) and does not protrude to the periphery, and the metal member ( When mounting C2), the non-fluid is not crushed or deformed, and does not creep up and contaminate the side and top surfaces of the metal member (C2). In addition, since the non-fluid having plasticity has a high viscosity volatile dispersion medium (B2) remaining in a large amount, the non-fluid has adhesiveness without being dried, so that the adhesion to the metal member (C2) is improved. Are better. Further, when the sintered metal particles (A) are sintered, the metal member (C1) and the metal member (C2) are firmly joined, and the metal member ( The thickness and position of the bonding layer between C1) and the metal member (C2) are stable.

According to an eleventh aspect of the present invention, a semiconductor element and a lead frame or a circuit board are firmly bonded, the appearance is good, and the dimensions of the bonding layer between the semiconductor element and the lead frame or the circuit board are Since the shape is stable, the performance of the electronic device is stable and excellent.

It is a top view about the test body for shape retentivity measurement in an Example. It is sectional drawing in X of the test body shown in FIG.

The paste-like metal particle composition of the present invention comprises (A) a sinterable metal particle produced by a reduction method, having an average particle diameter of 0.01 to 10 μm and having a surface coated with an organic substance, and (B1 A paste form comprising a low-viscosity volatile dispersion medium having a viscosity at 25 ° C. of 0.1 to 500 mPa · s, and (B2) a high-viscosity volatile dispersion medium having a viscosity of 10 to 200 Pa · s at 25 ° C. When it is dried at a temperature of 25 ° C. or more and 125 ° C. or less, it becomes a non-fluid having plasticity, and when heated at 150 ° C. or more and 400 ° C. or less, the remaining low-viscosity volatile dispersion medium (B1) and the high viscosity The volatile dispersion medium (B2) is volatilized and becomes a sintered product of the metal particles (A), that is, a solid metal.

The sinterable metal particles (A) are not limited as long as they are metal particles having heat sinterability, but are preferably selected from silver, gold, copper, platinum, and palladium particles in terms of heat sinterability. Silver particles are preferred. These metal alloy particles or other metal particles whose surfaces are coated with these metals may be used, or two or more kinds of these metal particles may be used in combination.

The sinterable metal particles (A) are produced by a reduction method of a metal salt (wherein the metal is preferably selected from the group consisting of silver, copper, gold, platinum and palladium). For example, in the case of silver particles, the reduction method usually involves mixing and reacting an aqueous silver nitrate solution and aqueous ammonia to obtain an aqueous silver ammine complex solution, which is then contacted with an aqueous solution of hydroquinone, anhydrous potassium sulfite or ammonium and gelatin. An example is a method in which silver powder is reduced and precipitated, filtered, the residue is washed with water, and dried by heating. Alternatively, silver nitrate aqueous solution and aqueous ammonia are mixed and reacted to obtain a silver ammine complex aqueous solution, which is contacted with an organic reducing agent (hydroquinone, ascorbic acid, glucose, etc.), particularly hydroquinone aqueous solution, to reduce silver powder. Examples are methods of 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 sinterable silver particles (A) thus produced are usually spherical or granular. Moreover, when the metal of the metal particles is selected from the group consisting of copper, gold, platinum and palladium, it can be produced by a similar method using a metal nitrate, a metal sulfate, or the like.

The average particle diameter of the sinterable metal particles (A) is a weight-based integrated fraction 50% value of the particle size distribution measured using a laser diffraction scattering type particle size distribution measuring apparatus, that is, the median diameter (D50 value). .
If the average particle size of the sinterable metal particles exceeds 10 μm, the sinterability between the sinterable metal particles (A) may be lowered, and therefore it is 10 μm or less, and preferably 5 μm or less. In addition, if it is less than 0.01 μm, the surface activity is too strong and the storage stability of the paste-like metal particle composition may be lowered, so that it is 0.01 μm or more, preferably 0.02 μm or more, More preferably, it is 0.1 μm or more.

The shape of the sinterable metal particles in the paste-like metal particle composition of the present invention is not limited, and is spherical, granular, flakes (pieces), needles, squares, dendritics, irregular shapes, teardrops, Examples include plate, ultrathin plate, hexagonal plate, columnar, rod, porous, fiber, lump, sponge, kernel, round, etc., but spherical, granular, flaky (scale-like) Preferably there is. In addition, you may use together the sinterable metal particle of these shapes. In addition, the classification of JIS Z 2500 can be used for the shape of a sinterable metal particle, for example.

The sinterable metal particles (A) have a surface coated with an organic material in order to prevent aggregation between the sinterable metal particles and obtain excellent sinterability. As the organic material, (a) a fatty acid or its alkali Examples include metal salts or esters, (b) polymer dispersants having acidic functional groups and / or basic functional groups, and (c) nitrogen-containing organic compounds, wherein (a) fatty acids or alkali metal salts or esters thereof, Alternatively, (b) a polymer dispersant having an acidic functional group and / or a basic functional group is preferable. Note that the organic material covering the surface of the sinterable metal particles may be associated with the sinterable metal particles.
A small amount of an organic substance such as a reducing agent used in the step of producing the sinterable metal particles by the reduction method may remain in the sinterable metal particles, but is not included in the organic substance in the present invention.

(A) Fatty acid or fatty acid in its alkali metal salt or ester, pentanoic acid (valeric acid), hexanoic acid (caproic acid), heptanoic acid (enanthic acid), octanoic acid (caprylic acid) having 5 or more carbon atoms , 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) Acid), 12-hydroxyoctadecanoic acid (12-hydroxyoleic acid), eicosanoic acid (arachidic acid), docosanoic acid (behenic acid), tetracosanoic acid (lignoceric acid), hexacosanoic acid (serotic acid), octacosanoic acid (montanic acid) Monovalent linear saturated fatty acid such as 14 carbon atoms Monovalent branched saturated fatty acids such as 2-pentylnonanoic acid, 2-hexyldecanoic acid, 2-heptyldodecanoic acid and isooleic acid; sorbic acid, maleic acid, palmitoleic acid, oleic acid, isooleic acid, elaidic acid, linol Examples thereof include monovalent unsaturated fatty acids such as acid, linolenic acid, ricinoleic acid, gadrenic acid, erucic acid, and ceracoleic acid.

Such fatty acids include oxalic acid, malonic acid, succinic acid, maleic acid, fumaric acid, oxydiacetic acid (diglycolic acid), glutaric acid, adipic acid, pimelic acid and speric acid having 2 or more carbon atoms. And polyvalent aliphatic carboxylic acids such as azelaic acid, sebacic acid and diglycolic acid, and polyvalent aromatic carboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid.

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 usually has a weight average molecular weight of 1,000 or more. The weight average molecular weight (Mw) is a polystyrene equivalent weight average molecular weight measured by gel permeation chromatography (carrier: tetrahydrofuran).

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

In the polymer 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 alkali metal and alkaline earth metal hydroxides, ammonia, alkylamines, amide amines, alkanolamines, and N-alkylmorpholines. Can be mentioned. 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 ・Products sold by Japan Co., Ltd.] (BYK and ANTI-TERRA are registered trademarks of Beik-Hemmy 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.].

Examples of (c) nitrogen-containing organic compounds include primary, secondary or tertiary alkylamines, alkylamidoamines, N-alkylethanolamines, N-alkylmorpholines, and other organic amine compounds.

The paste-like metal particle composition of the present invention comprises at least a sinterable metal particle (A), a low-viscosity volatile dispersion medium (B1), and a high-viscosity volatile dispersion medium (B2), and is a mixture thereof. The sinterable metal particles (A) are pasted by the action of the volatile dispersion medium (B1) and the volatile dispersion medium (B2). By making it into a paste, it can be easily discharged from a cylinder or nozzle, and is particularly suitable for screen printing and printing application using a metal mask. The thickness of the paste-like metal particle composition after printing is not limited, but is, for example, 2 mm or less, preferably 1 mm or less, more preferably 5 to 500 μm, and particularly preferably 20 to 200 μm. . The reason why the volatile dispersion medium (B1) and the volatile dispersion medium (B2) are used instead of the non-volatile dispersion medium is that the dispersion medium is preliminarily formed when the sinterable metal particles (A) are sintered by heating. This is because, when volatilized, the sinterable metal particles (A) are easily sintered, and as a result, the electrical conductivity, thermal conductivity, and adhesiveness of the sintered product are improved.

Such a low-viscosity volatile dispersion medium (B1) is preferably one that does not alter the surface of the sinterable metal particles, and the viscosity is preferably from 0.1 to 500 mP · s, and from 0.2 to 400 mP · s. It is more preferable that When the viscosity is less than 0.1 mP · s, the volatility becomes extremely high, and it is difficult to prepare a paste-like metal particle composition. Moreover, when the viscosity exceeds 500 mP · s, it is difficult to volatilize by drying at 25 ° C. or more and 125 ° C. or less, and it becomes difficult to obtain a non-fluid having plasticity.

Low viscosity volatile dispersion medium (B1): water; volatilization of ethyl alcohol, propyl alcohol, butyl alcohol, pentyl alcohol, hexyl alcohol, heptyl alcohol, octyl alcohol, nonyl alcohol, decyl alcohol, benzyl alcohol, cyclohexanol, terpineol, etc. Volatile polyhydric alcohols such as ethylene glycol, propylene glycol, hexanediol and octanediol; volatile aliphatic hydrocarbons such as lower n-paraffins and lower isoparaffins; volatile aromatic carbonization such as toluene and xylene Hydrogen; acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, diacetone alcohol (4-hydroxy-4-methyl-2-pentanone), 2-octanone, isophorone Volatile ketones such as 3,5,5-trimethyl-2-cyclohexen-1-one) and dibutyl ketone (2,6-dimethyl-4-heptanone); volatilization such as ethyl acetate and butyl acetate Volatile aliphatic carboxylic acid esters such as methyl butyrate, methyl hexanoate, methyl octoate and methyl decanoate; Volatilization of tetrahydrofuran, methyl cellosolve, propylene bricol monomethyl ether, methyl methoxybutanol, butyl carbitol, etc. Volatile ethers; low molecular weight volatile silicone oils and volatile organic modified silicone oils. Two or more kinds of volatile dispersion media (B1) may be used in combination, and the compatibility of the volatile dispersion media is not limited.

The high-viscosity volatile dispersion medium (B2) preferably does not alter the surface of the sinterable metal particles, and the viscosity is 10 to 200 P · s at 25 ° C., preferably 30 to 150 P · s, more preferably. Is 50 to 100 P · s. When the viscosity is less than 10 P · s, the dried product obtained by drying the paste-like metal particle composition of the present invention at 25 ° C. or more and 125 ° C. or less may not be able to obtain plasticity and tackiness, and the viscosity is 200 P · s. If it exceeds 1, the dried product is hardly volatilized and decomposed even when heated at 150 ° C. or higher and 400 ° C. or lower, and may remain in the formed sintered product.

Examples of such a high-viscosity volatile dispersion medium (B2) include polybutene, polyvinyl alcohol, polyethylene glycol, cyclohexanedimethanol (a mixture of cis and trans), bornylcyclohexanol, isobornylcyclohexanol, bornylphenol, isobornol. Nylphenol is exemplified, but isobornylcyclohexanol and isobornylphenol are preferable.

The paste-like metal particle composition of the present invention includes a volatile dispersion medium that is solid at room temperature, such as pyrogallol, p-methylbenzyl alcohol, o-methylbenzyl, as long as the effect of the present invention is not adversely affected and the effect is not impaired. Alcohols such as alcohol, sil-3,3,5-trimethylcyclohexanol, 1,4-cyclohexanedimethanol, 1,4-cyclohexanediol, pinacol; hydrocarbons such as biphenyl, naphthalene, durene; dibenzoylmethane, A small amount of ketones such as chalcone and acetylcyclohexane; fatty acids such as lauric acid and capric acid may be added.

The total amount of the low-viscosity volatile dispersion medium (B1) and the high-viscosity volatile dispersion medium (B2) may be sufficient to make the sinterable metal particles (A) into a paste, The amount is 5 to 40 parts by mass, more preferably 10 to 25 parts by mass, per 100 parts by mass of the binding metal particles (A). The ratio of the low-viscosity volatile dispersion medium (B1) and the high-viscosity volatile dispersion medium (B2) varies depending on the respective viscosities. For example, the low-viscosity volatile dispersion medium (B1) is a high-viscosity volatile dispersion by mass ratio. Medium (B2) = 30-70: 70-30.
The paste-like metal particle composition of the present invention includes metal particles other than the sinterable metal particles (A) or non-metallic powders, metal oxides as long as the effects of the present invention are not adversely affected. Additives such as metal compounds, metal complexes, thixotropic agents, stabilizers and sintering accelerators may be added in small or trace amounts.

When the paste-like metal particle composition of the present invention is first dried at 25 ° C. or more and 125 ° C. or less, it is more than half of the low-viscosity volatile dispersion medium (B1) contained in the paste-like metal particle composition, preferably 70 to When the amount corresponding to 100% by mass, more preferably 80-100% by mass is volatilized to form a non-fluid having plasticity and heated at 150 ° C. or higher and 400 ° C. or lower, preferably 200 ° C. or higher and 350 ° C. or lower, The low-viscosity volatile dispersion medium (B1) and the high-viscosity volatile dispersion medium (B2), or the remaining high-viscosity volatile dispersion medium (B2) is volatilized and the sinterable metal particles (A) are sintered together. It is characterized by that. At the end of the drying, the Williams plasticity of the plastic non-fluid is preferably 10 to 500, more preferably 30 to 400 at 25 ° C. Moreover, more than half of the high-viscosity volatile dispersion medium (B2) contained in the paste-like metal particle composition, preferably 70 to 100% by mass, more preferably 90 to 100% by mass remains. .

The paste-like metal particle composition of the present invention is preferably used as a bonding agent between a plurality of metal members. After applying the paste-like metal particle composition to the metal member (C1) by screen printing, stencil printing or the like, it is dried at a temperature of 25 ° C. or more and 125 ° C. or less to form a non-fluid having plasticity, The metal member (C2) is mounted on the dried paste-like metal particle composition, and heated at 150 ° C. or higher and 400 ° C. or lower, preferably 200 ° C. or higher and 350 ° C. or lower, thereby remaining low-viscosity volatile dispersion. The medium (B1) and the high-viscosity volatile dispersion medium (B2), or the remaining high-viscosity volatile dispersion medium (B2) are volatilized to form a sintered product of the sinterable metal particles (A). C1) and the metal member (C2) can be firmly joined. When the sinterable metal particles (A) are sintered, the organic matter covering the surface of the sinterable metal particles is also removed by volatilization, decomposition, or the like. At the end of the drying, the Williams plasticity of the plastic non-fluid is preferably 10 to 500, more preferably 30 to 400 at 25 ° C. Further, the high-viscosity volatile dispersion medium (B2) may be volatilized in a trace amount or a small amount, but preferably an amount corresponding to 70 to 100% by mass remains, and more preferably corresponds to 90 to 100% by mass. The amount remains.

Plasticity (also referred to as plasticity) is a property that deforms when a force is applied, and a non-fluid having plasticity after drying the paste-like metal particle composition of the present invention is deformed when a force is applied. To do. The plasticity indicating the degree of plasticity can be measured, for example, with a Williams plastometer defined in JIS K 6249. The Williams plasticity is preferably 10-500 at 25 ° C., more preferably 30-400.
Since the paste-like metal particle composition of the present invention is easy to control the thickness of the coating film without flowing out, it has shape retention and can easily form a thick film. Moreover, since at least half of the high-viscosity volatile dispersion medium (B2) remains after drying, the surface of the dried product has adhesiveness. Thereby, the adhesiveness of the metal member (C1) and the metal member (C2) is excellent, and thus the adhesion and bonding between the two after heating are excellent.
The paste-like metal particle composition of the present invention was sintered after removing at least half of the dried product obtained by drying at a temperature of 25 ° C. or more and 125 ° C. or less, that is, the low-viscosity volatile dispersion medium (B1). The conductive metal particles (A) may be partially sintered, but must not be sintered before they lose their plasticity and tackiness.
The amount of the low-viscosity volatile dispersion medium (B1) remaining after drying the paste-like metal particle composition of the present invention, the amount of the high-viscosity volatile dispersion medium (B2), and the sinterable metal particles (A) are coated. The amount of the organic substance that can be measured can be easily measured by thermogravimetric analysis (TGA), and many thermogravimetric analyzers are commercially available.

When the metal member (C2) is mounted on the dried product of the paste-like metal particle composition of the present invention, if the dried product is a non-fluid having plasticity, the dried product will not flow and move. Therefore, the metal member (C1) spreads in the plane direction and does not contaminate the periphery, and the high-viscosity volatile dispersion medium (B2) remains in the dried product and has a sticky surface. The adhesiveness with the metal member (C2) is excellent, so that the metal member (C1) after heating and the metal member (C2) can be firmly joined, and the metal member (C2) is formed on the dried product. ) Can be prevented from being crushed and deformed by its own weight and an artificial load applied when mounting), and the dried product can creep up and contaminate the side and top surfaces of the metal member (C2). Without the metal member (C1) and the metal member (C ) Can be kept constant thickness as the bonding agent, stable dimensional accuracy of the bonded body becomes particularly possible to secure a stable thickness.

The metal member (C1) and the metal member (C2) may be the same or different in material, shape, size, surface treatment and the like. Similar to the sinterable metal particles (A), the material of the metal member (C1) and the metal member (C2) is preferably gold, silver, copper, platinum, palladium, or an alloy thereof.

When the metal member (C1) is a metal part of a lead frame or a circuit board and the metal member (C2) is a metal part of a semiconductor element, the electronic device joined in this way is a lead frame or a circuit. The thickness of the bonding layer (die bond agent) between the metal part of the substrate and the metal part of the semiconductor element is uniform, and the dimensions (particularly the thickness) as an electronic device, particularly a semiconductor device, can be made constant. Since the semiconductor element does not crawl on the side surface and the upper surface, there is an effect that the current of the semiconductor element is not short-circuited, and the electronic device, in particular, the stability of the characteristics of the semiconductor device is excellent.

Examples of the atmosphere when heating the paste-like metal particle composition of the present invention include air or an oxidizing gas containing oxygen, a reducing gas containing hydrogen gas, and an inert gas such as nitrogen. In the case of containing easily oxidized copper particles or the like, a reducing gas containing hydrogen gas or an inert gas such as nitrogen is preferable. However, after sintering in an oxidizing gas, it may be reduced in a reducing gas.

A sintered product obtained by sintering the sinterable metal particles (A), that is, a solid metal, is excellent in conductivity and thermal conductivity. Specifically, the volume resistivity is preferably 1 × 10 ⁻⁵ Ω · cm or less, and the thermal conductivity is preferably 100 W / m · K or more. As described above, the paste-like metal particle composition of the present invention has excellent conductivity and heat conductivity (heat dissipation) in the sintered product, and is excellent in the metal member that was in contact during sintering. Therefore, it can be suitably used as a bonding agent or coating agent for metal parts such as metal parts of semiconductor elements, metal parts of chip parts, lead frames, and electrodes on circuit boards. Therefore, it is useful for manufacturing electronic components, electronic devices, electrical components, electrical devices, etc., and bonding of chip components such as capacitors and resistors to circuit boards; semiconductor devices such as light emitting diodes, laser diodes, memories, IGBTs, and CPUs It is useful for joining a metal part and a metal part of a lead frame or a circuit board; joining a high heat generating CPU chip and a cooling plate.

A light-emitting diode element is also referred to as an LED chip, and a light-emitting diode device, which is a kind of electronic device, has an LED chip bonded (bonded) to a lead frame or a circuit board, and the paste-like metal particle composition of the present invention is a bonding material. It can be used as (bonding agent). The material of the metal part of the light emitting diode element, the lead frame, and the metal part of the circuit board to be joined by the paste-like metal particle composition of the present invention has light resistance, heat resistance, etc., and has high connection reliability, gold, Silver, copper, palladium, platinum, and alloys of these metals are preferable, or plating with these metals or alloys of these metals is preferable. The form of the light emitting diode device is not limited, and examples thereof include a shell type, a flat type, a chip type, and an array.

As a compound semiconductor constituting the light emitting diode element, GaAlAs, GaInP, GaAsP, AlGaInP, GaP, InGaN, GaN, AlN, or the like can be used, depending on the target emission peak wavelength. Note that the wavelength of light emitted from the light emitting diode element usually has a certain range, and the emission peak wavelength is a wavelength showing the highest emission intensity among them. The emission peak wavelength can be easily known by measuring the emission spectrum with a spectrophotometer. Moreover, the light emission amount and the light emission peak wavelength can be changed by selecting the ratio of each component.

Light-emitting diode elements generate a large amount of heat with light emission, and may emit ultraviolet rays that have the property of decomposing organic substances, so the use of adhesives containing organic substances such as epoxy resins that are easily degraded by heat and ultraviolet rays It is not preferred, and the paste-like metal particle composition of the present invention which does not substantially contain an organic substance in the sintered product of the paste-like metal particle composition can be suitably used.

Further, the sintered product of the paste-like metal particle composition of the present invention is preferably silver, gold, copper, platinum, palladium, or an alloy thereof, and has excellent adhesion to a metal member that was in contact during sintering. In addition to a CPU that operates at a high frequency and generates a large amount of heat, it operates at a high voltage of several hundred to several thousand volts and has a large amount of heat generated. Power semiconductor elements (power semiconductor elements) whose operating temperature also becomes high, for example, transistors such as MOSFET (field effect transistor), IGBT (insulated gate bipolar transistor), LTT (light trigger thyristor), GTO (gate turn-off thyristor), It can be suitably used for joining a thyristor such as a triac and a lead frame or a circuit board.
The power semiconductor element is generally preferably a nitride semiconductor element such as aluminum nitride, gallium nitride, or indium nitride that can operate at a high temperature.

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 is 50% of the weight-based cumulative fraction of the particle size distribution measured using a laser diffraction / scattering particle size distribution analyzer. Mean the median diameter (D50 value). The heating and drying in the examples and comparative examples are heating and drying in a forced circulation oven, and the atmosphere in the forced circulation oven is air unless otherwise noted.
Coating amount of sinterable metal particles (A); viscosity of low-viscosity volatile dispersion medium (B1) and high-viscosity volatile dispersion medium (B2); plasticity after drying paste-like metal particle composition, Williams plasticity Degree, fluidity, adhesiveness; the removal rate of the low-viscosity volatile dispersion medium (B1), the removal rate of the volatile dispersion medium (2) and the surface of the sinterable metal particles by drying the paste-like metal particle composition Removal rate of coated organic matter: Volume resistivity and thermal conductivity of sintered product produced by heating, and shape stability and adhesive strength of joined product joined by heating were measured by the following methods. did. The measurement is a measurement at room temperature (about 25 ° C.) in the atmosphere unless otherwise specified.

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

[Viscosity of low-viscosity volatile dispersion medium (B1) and high-viscosity volatile dispersion medium (B2)]
Using a rotor type viscometer (RB80 type manufactured by Toki Sangyo Co., Ltd.), measurement was performed at a rotational speed of 0.3 to 60 rpm using rotor No. 10 or rotor No. 14. The rotor and the number of rotations were appropriately selected so as to be in a measurable range according to the viscosity of the dispersion medium in the paste-like metal particle compositions of this example and the comparative example.

[Plasticity, plasticity, fluidity, and adhesiveness of a dried product obtained by drying a paste-like metal particle composition]
A paste-like metal particle composition was applied on a glass plate having a width of 50 mm × length of 50 mm × thickness of 2.0 mm using a metal mask having a thickness of 10 mm × length of 10 mm and having an opening of 10 mm in width and a predetermined thickness. It was heated for a predetermined time in a forced circulation oven at a temperature to obtain a plate-like dried product. When the sinterable metal particles were copper particles, they were heated in nitrogen gas instead of in the air.

[Plasticity of the dried product]
A metal cylinder having a diameter of 5 mm and a weight of 20 g is placed on the dried product for 10 seconds and then removed, and when the trace of the stainless bar remains on the dried product visually, it is considered plastic and no trace remains. In the case, it was assumed that there was no plasticity. Although the shape was maintained, a state where the powder was clearly dried and solidified (having no adhesiveness on the surface) was regarded as having no plasticity.

[William plasticity of the dried product]
Measured according to the method specified in JIS K 6249 “Testing method for uncured and cured silicone rubber”. That is, 2 cm ³ of the dried product was used as a spherical test piece, which was sandwiched between cellophane papers, set on a parallel plate plasticity meter (Williams Plastometer) with a dial gauge, applied with a load of 5 kg and left for 3 minutes. After that, the scale of the dial gauge was read to 1/100 of a millimeter, and the thickness of the test specimen was multiplied by 100 to obtain the plasticity. A Williams Plastometer manufactured by Ueshima Seisakusho Co., Ltd. was used. In the table, it was indicated as plasticity.

[Flowability of the dried product]
From the range of 10 mm in width and 10 mm in length as applied, when there was no protrusion on the outside after visual observation, no fluidity was assumed, and when there was an overflow, fluidity was assumed.

[Adhesiveness of the dried product]
A transparent polyethylene film having a thickness of 20 μm is placed on the surface of the dried product, and a metal cylinder having a diameter of 5 mm and a weight of 20 g is placed thereon for 10 seconds and then removed. When the polyethylene film was in close contact with the dried product, it was considered to be tacky, and when it was peeled off from the dried product or floated, there was no tackiness.

[The removal rate of the low-viscosity volatile dispersion medium (B1), the removal ratio of the volatile dispersion medium (2), and the surface of the sinterable metal particles (A) are coated by drying the paste-like metal particle composition. Organic removal rate]
A paste-like metal particle composition was applied on a glass plate having a width of 50 mm × length of 50 mm × thickness of 2.0 mm using a metal mask having a thickness of 10 mm × length of 10 mm and having an opening of 10 mm in width and a predetermined thickness. It was heated for a predetermined time in a forced circulation oven at a temperature to obtain a plate-like dried product. When the sinterable metal particles (A) were copper particles, they were heated in nitrogen gas instead of in the air.

The removal rate of the volatile dispersion medium (B1) was calculated by the following method.
The dried product is taken out into an aluminum cup for thermogravimetric analysis (TGA), and then the mass of the dried product is precisely weighed, and is measured at room temperature (DTG-60AH type manufactured by Shimadzu Corporation) using a simultaneous differential thermothermal gravimetric measuring device. Thermogravimetry was performed by heating from about 25 ° C. to 500 ° C., and the masses of the low-viscosity volatile dispersion medium (B1) and the sinterable metal particles contained in the dried product were measured. When the sinterable metal particles were copper particles, nitrogen gas was used instead of the air.
Similarly, the paste-like metal particle composition before drying was subjected to thermogravimetric analysis, and the respective masses of the low-viscosity volatile dispersion medium (B1) and the sinterable metal particles contained therein were measured.

Since the sinterable metal particles do not volatilize at the drying temperature of the present invention and the mass is unchanged, the mass of the low-viscosity volatile dispersion medium (B1) per unit mass of the sinterable metal particles before and after drying is compared. By doing so, the ratio can be calculated as the reduced amount is removed. That is, the mass (1) and the low-viscosity volatile dispersion medium (B1) after drying relative to the mass (1) of the low-viscosity volatile dispersion medium (B1) before drying per unit mass of the sinterable metal particles As the mass of the low-viscosity volatile dispersion medium (B1) from which the difference in mass (2) was removed, the removal rate was calculated by the following equation.
Removal rate of low-viscosity volatile dispersion medium (B1) (%) = {mass (1) -mass (2)} / mass (1) × 100
Similarly, the removal rate of the volatile dispersion medium (2) and the removal rate of organic substances covering the surface of the sinterable metal particles were determined. The remaining rate (%) can be calculated by 100-removal rate (%).

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

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

[Shape stability 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. Using a thick metal mask, the paste-like metal particle composition was applied and heated in a forced circulation oven at a predetermined temperature for a predetermined time to obtain a dry product of the paste-like metal particle composition. When the sinterable metal particles were copper particles, they were heated in nitrogen gas instead of in the air.

A silver chip (silver purity 99.99%) each having a width of 2.5 mm, a length of 2.5 mm, and a thickness of 0.5 mm is mounted on each of the four dried products, and further, a width of 25 mm and a length. The plastic plate having a thickness of 70 mm and a weight of 20 g is pressed for 10 seconds, and then the plastic plate is removed. The plastic plate is heated in a forced circulation oven at a predetermined temperature for 1 hour, and the paste-like metal particle composition Sinterable metal particles were sintered to join the silver substrate and the silver chip. When the sinterable metal particles were copper particles, they were further heated at a predetermined temperature for 10 minutes in a forming gas that was a mixed gas of 10% by volume of hydrogen gas and 90% by volume of nitrogen gas.

The thickness (the total thickness of the sintered body of the silver substrate, the silver chip, and the paste-like metal particle composition) of the shape stability measurement specimen thus obtained was measured and measured in advance. The value obtained by subtracting the thickness of the silver substrate and the silver chip was taken as the thickness of the sintered product in the joined body, and the average thickness and standard deviation of the four were calculated. As the average thickness increases, the paste-like metal particle composition is not crushed due to the mounting of the silver chip, and the smaller the standard deviation value, the greater the shape stability of the joined body.

[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. Using a thick metal mask, the paste-like metal particle composition was applied and heated in a forced circulation oven at a predetermined temperature for a predetermined time to obtain a dry product of the paste-like metal particle composition. When the sinterable metal particles were copper particles, they were heated in nitrogen gas instead of in the air.

A silver chip (silver purity 99.99%) each having a width of 2.5 mm, a length of 2.5 mm, and a thickness of 0.5 mm is mounted on each of the four dried products, and further, a width of 25 mm and a length. The plastic plate having a thickness of 70 mm and a weight of 20 g was pressed for 10 seconds, then the plastic plate was removed, and the plastic plate was heated in a forced circulation oven at a predetermined temperature for 1 hour. Sinterable metal particles were sintered to join the silver substrate and the silver chip. When the sinterable metal particles were copper particles, they were further heated at a predetermined temperature for 10 minutes in a forming gas that was a mixed gas of 10% by volume of hydrogen gas and 90% by volume of nitrogen gas.

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

[Example 1]
In a mixer, 100 parts of granular silver particles produced by the silver nitrate reduction method, having an average particle diameter of 1.0 μm and coated with oleic acid (the amount of oleic acid is 0.5% by mass) , Α-Terpineol (reagent sold by Wako Pure Chemical Industries, Ltd .; viscosity 36 mPa · s at 25 ° C.) as low-viscosity volatile dispersion medium (B1) and isobornyl as high-viscosity volatile dispersion medium (B2) 8 parts of cyclohexanol (Nippon Terpene Chemical Co., Ltd., abbreviation MTPH, viscosity 80 Pa · s at 25 ° C.) was added and mixed uniformly to prepare a paste-like silver particle composition.
The dried product obtained by drying this pasty silver particle composition at 60 ° C. for 1 hour was measured for plasticity, plasticity, fluidity, tackiness, and α-terpineol removal rate. There was no fluidity and there was stickiness, and the removal rate of α-terpineol was 95%.

Next, when the volume resistivity and the thermal conductivity of the sintered silver particles produced by heating at 250 ° C. for 1 hour were measured, the volume resistivity was low and the thermal conductivity was high. Moreover, when shape stability and adhesiveness were measured about the joined body manufactured by mounting a silver chip in this dried material and heating at 250 degreeC for 1 hour, shape stability was good and adhesiveness was high.
The above results are summarized in Table 1. This paste-like silver particle composition has high conductivity and thermal conductivity of the sintered product, strongly joins the metal member (C1) and the metal member (C2), and contributes to the shape stability of the joined body. I understand that.

[Example 2]
In a mixer, 100 parts of spherical silver particles produced by a silver nitrate reduction method, having an average particle size of 0.08 μm, and coated with octanoic acid on the surface (the amount of octanoic acid is 1.5% by mass) 14 parts of α-terpineol (a reagent sold by Wako Pure Chemical Industries, Ltd., viscosity 36 mPa · s at 25 ° C.) as a low-viscosity volatile dispersion medium (B1) and isobornyl as a high-viscosity volatile dispersion medium (B2) 8 parts of cyclohexanol (Nippon Terpene Chemical Co., Ltd., abbreviation MTPH, viscosity 80 Pa · s at 25 ° C.) was added and mixed uniformly to prepare a paste-like silver particle composition.
The dried product obtained by drying the pasty silver particle composition at 60 ° C. for 15 minutes was measured for plasticity, plasticity, fluidity, adhesiveness, and α-terpineol removal rate. There was no fluidity, there was stickiness, and the removal rate of α-terpineol was 85%.

Next, when the volume resistivity and the thermal conductivity of the sintered silver particles produced by heating at 250 ° C. for 1 hour were measured, the volume resistivity was low and the thermal conductivity was high. Moreover, when shape stability and adhesiveness were measured about the joined body manufactured by mounting a silver chip in this dried material and heating at 250 degreeC for 1 hour, shape stability was good and adhesiveness was high.
The above results are summarized in Table 1. This paste-like silver particle composition has high conductivity and thermal conductivity of the sintered product, strongly joins the metal member (C1) and the metal member (C2), and contributes to the shape stability of the joined body. I understand that.

[Example 3]
In a mixer, the silver particles produced by the silver nitrate reduction method were flaked, the average particle size was 3.5 μm, and the surface was coated with stearic acid (the amount of stearic acid was 0.8% by mass) To 100 parts of flaky silver particles, 11 parts of α-terpineol (a reagent sold by Wako Pure Chemical Industries, Ltd., a viscosity of 36 mPa · s at 25 ° C.) as a low-viscosity volatile dispersion medium (B1), and a high-viscosity volatile dispersion As a medium (B2), 7 parts of isobornylcyclohexanol (manufactured by Nippon Terpene Chemical Co., Ltd., abbreviation MTPH, viscosity 80 Pa · s at 25 ° C.) was added and mixed uniformly to prepare a paste-like silver particle composition.
The dried product obtained by drying the pasty silver particle composition at 100 ° C. for 5 minutes was measured for plasticity, plasticity, fluidity, adhesiveness, and α-terpineol removal rate. There was no fluidity and there was stickiness, and the removal rate of α-terpineol was 98%.

Next, when the volume resistivity and the thermal conductivity of the sintered silver particles produced by heating at 250 ° C. for 1 hour were measured, the volume resistivity was low and the thermal conductivity was high. Moreover, when shape stability and adhesiveness were measured about the joined body manufactured by mounting a silver chip in this dried material and heating at 250 degreeC for 1 hour, shape stability was good and adhesiveness was high.
The above results are summarized in Table 1. This paste-like silver particle composition has high conductivity and thermal conductivity of the sintered product, strongly joins the metal member (C1) and the metal member (C2), and contributes to the shape stability of the joined body. I understand that.

[Example 4]
In a mixer, granular silver particles 100 produced by a silver nitrate reduction method, having an average particle diameter of 1.0 μm, and coated with potassium oleate (the amount of potassium oleate is 0.9% by mass) 100 11 parts of n-hexane (a reagent sold by Wako Pure Chemical Industries, Ltd., viscosity 0.3 mPa · s at 25 ° C.) as a low-viscosity volatile dispersion medium (B1), and a high-viscosity volatile dispersion medium (B2) 8 parts of isobornylcyclohexanol (Nippon Terpene Chemical Co., Ltd., abbreviation MTPH, viscosity 80 Pa · s at 25 ° C.) was added and mixed uniformly to prepare a paste-like silver particle composition.
The dried product obtained by drying this pasty silver particle composition at 30 ° C. for 2 hours was measured for plasticity, plasticity, fluidity, tackiness, and removal rate of n-hexane. There was no fluidity, there was stickiness, and the removal rate of n-hexane was 100%.

Next, when the volume resistivity and the thermal conductivity of the sintered silver particles produced by heating at 250 ° C. for 1 hour were measured, the volume resistivity was low and the thermal conductivity was high. Moreover, when shape stability and adhesiveness were measured about the joined body manufactured by mounting a silver chip in this dried material and heating at 250 degreeC for 1 hour, shape stability was good and adhesiveness was high.
The above results are summarized in Table 2. This paste-like silver particle composition has high conductivity and thermal conductivity of the sintered product, strongly joins the metal member (C1) and the metal member (C2), and contributes to the shape stability of the joined body. I understand that.

[Example 5]
In a mixer, 100 parts of granular silver particles produced by the reduction method of silver nitrate, having an average particle diameter of 1.0 μm and coated with oleic acid (oleic acid is 0.5% by mass) Octanediol (a reagent sold by Wako Pure Chemical Industries, Ltd. as a low-viscosity volatile dispersion medium (B1), 12 parts of viscosity at 25 ° C.) and isobornylcyclohexanol as a high-viscosity volatile dispersion medium (B2) (Nihon Terpene Chemical Co., Ltd., abbreviation MTPH, viscosity 80 Pa · s at 25 ° C.) was added in an amount of 8 parts and mixed uniformly to prepare a paste-like silver particle composition.
The dried product obtained by drying the pasty silver particle composition at 100 ° C. for 10 minutes was measured for plasticity, plasticity, fluidity, adhesiveness, and octanediol removal rate. There was no fluidity and there was stickiness, and the removal rate of octanediol was 99%.

Next, when the volume resistivity and the thermal conductivity of the sintered silver particles produced by heating at 250 ° C. for 1 hour were measured, the volume resistivity was low and the thermal conductivity was high. Moreover, when shape stability and adhesiveness were measured about the joined body manufactured by mounting a silver chip in this dried material and heating at 250 degreeC for 1 hour, shape stability was good and adhesiveness was high.
The above results are summarized in Table 2. This paste-like silver particle composition has high conductivity and thermal conductivity of the sintered product, strongly joins the metal member (C1) and the metal member (C2), and contributes to the shape stability of the joined body. I understand that.

[Example 6]
In the mixer, manufactured by the reduction method of silver nitrate, the average particle diameter is 1.0 μm, the surface is DISPERBYK-2020 (acid value: 37 mgKOH / g, amine value: 36 mgKOH / g) manufactured by BYK Japan Coated (DISPERBYK-2020 amount is 0.5 mass%) granular silver particles 100 parts, α-terpineol as a low-viscosity volatile dispersion medium (B1) (a reagent sold by Wako Pure Chemical Industries, Ltd. 25) 8 parts at a viscosity of 36 mPa · s) and isobornylphenol as a high-viscosity volatile dispersion medium (B2) (prepared according to the production method described in Japanese Patent No. 5150054. Viscosity at 25 ° C. 62 Pa · s ) Was added and mixed uniformly to prepare a paste-like silver particle composition.
The dried product obtained by drying this pasty silver particle composition at 60 ° C. for 1 hour was measured for plasticity, plasticity, fluidity, tackiness, and α-terpineol removal rate. There was no fluidity and there was stickiness, and the removal rate of α-terpineol was 95%.

Next, when the volume resistivity and thermal conductivity of the sintered silver particles produced by heating at 300 ° C. for 1 hour were measured, the volume resistivity was low and the thermal conductivity was high. Moreover, when shape stability and adhesiveness were measured about the joined body manufactured by mounting a silver chip on this dry substance and heating at 300 degreeC for 1 hour, shape stability was good and adhesiveness was high.
The above results are summarized in Table 2. This paste-like silver particle composition has high conductivity and thermal conductivity of the sintered product, strongly joins the metal member (C1) and the metal member (C2), and contributes to the shape stability of the joined body. I understand that.

[Example 7]
100 parts of spherical copper particles produced by a copper sulfate reduction method in a mixer, having an average particle diameter of 1.0 μm and coated with stearic acid on the surface (the amount of stearic acid is 0.7% by mass) In addition, 12 parts of α-terpineol (a reagent sold by Wako Pure Chemical Industries, Ltd., a viscosity of 36 mPa · s at 25 ° C.) as a low-viscosity volatile dispersion medium (B1), and isovol as a high-viscosity volatile dispersion medium (B2). 8 parts of Nylcyclohexanol (Nippon Terpene Chemical Co., Ltd., abbreviation MTPH, viscosity 80 Pa · s at 25 ° C.) was added and mixed uniformly to prepare a paste-like copper particle composition.
The dried product obtained by drying the paste-like copper particle composition at 60 ° C. for 1 hour was measured for plasticity, plasticity, fluidity, adhesiveness, and α-terpineol removal rate. There was no fluidity and there was stickiness, and the removal rate of α-terpineol was 95%.

Next, a sintered product of copper particles produced by heating at 300 ° C. for 1 hour and further heating at 300 ° C. for 10 minutes in a forming gas which is a mixed gas of 10% by volume of hydrogen gas and 90% by volume of nitrogen gas. When the volume resistivity and thermal conductivity were measured, the volume resistivity was low and the thermal conductivity was high. The dried product is mounted with a silver chip and heated at 300 ° C. for 1 hour, and further heated at 300 ° C. for 10 minutes in a forming gas that is a mixed gas of 10% by volume of hydrogen gas and 90% by volume of nitrogen gas. As a result of measuring the shape stability and the adhesiveness of the joined body produced in this manner, the shape stability was good and the adhesiveness was high.
The above results are summarized in Table 3. This paste-like copper particle composition has high electrical conductivity and thermal conductivity of the sintered product, strongly joins the metal member (C1) and the metal member (C2), and contributes to the shape stability of the joined body. I understand that.

[Comparative Example 1]
In a mixer, 100 parts of granular silver particles produced by the silver nitrate reduction method, having an average particle diameter of 1.0 μm and coated with oleic acid (the amount of oleic acid is 0.5% by mass) , Α-Terpineol (reagent sold by Wako Pure Chemical Industries, Ltd .; viscosity 36 mPa · s at 25 ° C.) as low-viscosity volatile dispersion medium (B1) and isobornyl as high-viscosity volatile dispersion medium (B2) 8 parts of cyclohexanol (Nippon Terpene Chemical Co., Ltd., abbreviation MTPH, viscosity 80 Pa · s at 25 ° C.) was added and mixed uniformly to prepare a paste-like silver particle composition.
About the undried material which does not dry this paste-like silver particle composition, when plasticity, plasticity, fluidity, adhesiveness, and removal rate of α-terpineol were measured, the undried material had fluidity. The removal rate of α-terpineol was 0%. The plasticity was not measurable due to the fluidity.

The sintered product produced by heating the undried material at 250 ° C. for 1 hour was measured for volume resistivity and thermal conductivity. As a result, the volume resistivity was low and the thermal conductivity was high. The joined body produced by mounting the silver chip and heating at 250 ° C. for 1 hour had low shape stability.
The above results are summarized in Table 4. Since this paste-like silver particle composition is not dried, the entire amount of the low-viscosity volatile dispersion medium (B1) remains, and when the metal member (C2) is mounted, the undried material is crushed into a shape. Since stability falls, it turns out that it cannot contribute to the shape stability of the joined body of metal members (C1) and metal members (C2).

[Comparative Example 2]
In a mixer, 100 parts of granular silver particles produced by the silver nitrate reduction method, having an average particle diameter of 1.0 μm and coated with oleic acid (the amount of oleic acid is 0.5% by mass) 12 parts of glycerin (a reagent sold by Wako Pure Chemical Industries, Ltd., viscosity 1400 mPa · s at 25 ° C.) as a low-viscosity volatile dispersion medium, and isobornylcyclohexanol (Nippon Terpene as a high-viscosity volatile dispersion medium (B2)) Chemical Co., Ltd., abbreviation MTPH, 8 parts of a viscosity of 80 Pa · s at 25 ° C. were added and mixed uniformly to prepare a paste-like silver particle composition.
The dried product obtained by drying the pasty silver particle composition at 40 ° C. for 30 minutes was measured for plasticity, plasticity, fluidity, adhesiveness, and glycerin removal rate. The dried product had fluidity. The removal rate of glycerin was 2%. The plasticity was not measurable due to the fluidity.

The sintered product produced by heating the dried product at 250 ° C. for 1 hour was measured for volume resistivity and thermal conductivity. As a result, the volume resistivity was low and the thermal conductivity was high. The joined body manufactured by mounting the chip and heating at 250 ° C. for 1 hour had low shape stability.
The above results are summarized in Table 4. Since this paste-like silver particle composition is difficult to remove the low-viscosity volatile dispersion medium in drying and remains in a large amount, when the metal member (C2) is mounted, the undried material is crushed and shape stability is obtained. Therefore, it can be seen that it cannot contribute to the shape stability of the joined body of the metal member (C1) and the metal member (C2).

[Comparative Example 3]
In a mixer, 100 parts of granular silver particles produced by the silver nitrate reduction method, having an average particle diameter of 1.0 μm and coated with oleic acid (the amount of oleic acid is 0.5% by mass) , 11 parts of n-hexane (a reagent sold by Wako Pure Chemical Industries, Ltd. as a low-viscosity volatile dispersion medium (B1) and a viscosity of 0.3 mPa · s at 25 ° C.) and octanediol (a sum of high-viscosity volatile dispersion medium) A reagent sold by Kojun Pharmaceutical Co., Ltd. 8 parts of a viscosity of 0.3 Pa · s at 25 ° C. was added and mixed uniformly to prepare a paste-like silver particle composition.
The dried product obtained by drying the pasty silver particle composition at 60 ° C. for 1 hour was measured for plasticity, plasticity, fluidity, adhesiveness, and removal rate of n-hexane. The removal rate of n-hexane was 100%. It was dry and brittle and the plasticity was not measurable.

The sintered product produced by heating the dried product at 250 ° C. for 1 hour was measured for volume resistivity and thermal conductivity. As a result, the volume resistivity was low and the thermal conductivity was high. The bonded body manufactured by mounting the chip and heating at 250 ° C. for 1 hour was measured for adhesion, and was not bonded.
The above results are summarized in Table 4. In this pasty silver particle composition, since the high-viscosity volatile dispersion medium (B2) is not sufficiently present in the dried product, the dried product loses its plasticity and adhesiveness, and the metallic member (C1) and the metallic product It can be seen that the member (C2) cannot be joined.

[Comparative Example 4]
In a mixer, 100 parts of granular silver particles produced by the silver nitrate reduction method, having an average particle diameter of 1.0 μm and coated with oleic acid (the amount of oleic acid is 0.5% by mass) , Α-Terpineol (reagent sold by Wako Pure Chemical Industries, Ltd .; viscosity 36 mPa · s at 25 ° C.) as low-viscosity volatile dispersion medium (B1) and isobornyl as high-viscosity volatile dispersion medium (B2) 8 parts of cyclohexanol (Nippon Terpene Chemical Co., Ltd., abbreviation MTPH, viscosity 80 Pa · s at 25 ° C.) was added and mixed uniformly to prepare a paste-like silver particle composition.
The dried product obtained by drying the pasty silver particle composition at 150 ° C. for 30 minutes was measured for plasticity, plasticity, fluidity, adhesiveness, and α-terpineol removal rate. The removal rate of α-terpineol was 100%.

The sintered product produced by heating the dried product at 250 ° C. for 1 hour was measured for volume resistivity and thermal conductivity. As a result, the volume resistivity was low and the thermal conductivity was high. When the adhesiveness was measured for the joined body manufactured by mounting the chip and heating at 250 ° C. for 1 hour, it was not adhered.
The above results are summarized in Table 5. In the pasty silver particle composition, if the drying temperature is higher than 125 ° C., the sintering progresses during drying and loses plasticity and adhesiveness, and the metal member (C1) and the metal member (C2) are sufficiently obtained. It can be seen that they cannot be joined to each other.

[Comparative Example 5]
In a mixer, 100 parts of granular silver particles produced by the silver nitrate reduction method, having an average particle diameter of 1.0 μm and coated with oleic acid (the amount of oleic acid is 0.5% by mass) , Α-Terpineol (reagent sold by Wako Pure Chemical Industries, Ltd .; viscosity 36 mPa · s at 25 ° C.) as low-viscosity volatile dispersion medium (B1) and isobornyl as high-viscosity volatile dispersion medium (B2) 8 parts of cyclohexanol (Nippon Terpene Chemical Co., Ltd., abbreviation MTPH, viscosity 80 Pa · s at 25 ° C.) was added and mixed uniformly to prepare a paste-like silver particle composition.
The dried product obtained by drying this pasty silver particle composition at 60 ° C. for 1 hour was measured for plasticity, plasticity, fluidity, tackiness, and α-terpineol removal rate. There was no fluidity and there was stickiness, and the removal rate of α-terpineol was 95%.

Since the dried product was not sintered even when heated at 100 ° C. for 1 hour, a sintered product was not obtained, and volume resistivity and thermal conductivity could not be measured. Moreover, when adhesiveness was measured about the joined body manufactured by mounting a silver chip in this dried material and heating at 100 degreeC for 1 hour, it was not adhere | attaching.
The above results are summarized in Table 5. In the paste-like silver particle composition, when the heating temperature after drying is less than 150 ° C., the silver does not sinter enough, so the metal member (C1) and the metal member (C2) are joined. I can't understand.

[Comparative Example 6]
In a mixer, 100 parts of granular silver particles produced by the silver nitrate reduction method, having an average particle diameter of 1.0 μm and coated with oleic acid (the amount of oleic acid is 0.5% by mass) , 14 parts of α-terpineol (a reagent sold by Wako Pure Chemical Industries, Ltd., a viscosity of 36 mPa · s at 25 ° C.) as a low-viscosity volatile dispersion medium (B1), and dimethyl silicone oil as a high-viscosity volatile dispersion medium (B2) (Toray Dow Corning Co., Ltd., abbreviation SH200 oil, viscosity 300 Pa · s at 25 ° C.) was added 8 parts and mixed uniformly to prepare a paste-like silver particle composition.
The dried product obtained by drying this pasty silver particle composition at 60 ° C. for 1 hour was measured for plasticity, plasticity, fluidity, tackiness, and α-terpineol removal rate. There was no fluidity and there was stickiness, and the removal rate of α-terpineol was 95%.

Since the dried product was not sintered even when heated at 250 ° C. for 1 hour, a sintered product could not be obtained, and the volume resistivity and thermal conductivity could not be measured. Moreover, when adhesiveness was measured about the joined body manufactured by mounting a silver chip in this dried material and heating at 100 degreeC for 1 hour, it was not adhere | attaching.
The above results are summarized in Table 5. In the paste-like silver particle composition, when the heating temperature after drying is less than 150 ° C., the silver particles do not sinter sufficiently, so the metal member (C1) and the metal member (C2) are joined. I can't understand.

[Comparative Example 7]
In a mixer, 100 parts of granular silver particles produced by the silver nitrate reduction method, having an average particle diameter of 1.0 μm and coated with oleic acid (the amount of oleic acid is 0.5% by mass) As a low-viscosity volatile dispersion medium (B1), only 20 parts of α-terpineol (a reagent sold by Wako Pure Chemical Industries, Ltd., a viscosity of 36 mPa · s at 25 ° C.) is added and mixed uniformly to form a paste-like silver particle composition A product was prepared.
The dried product obtained by drying the pasty silver particle composition at 60 ° C. for 1 hour was measured for plasticity, plasticity, fluidity, adhesiveness, and α-terpineol removal rate. The removal rate of α-terpineol was 100%. It was dry and brittle and the plasticity was not measurable.

The sintered product produced by heating the dried product at 250 ° C. for 1 hour was measured for volume resistivity and thermal conductivity. As a result, the volume resistivity was low and the thermal conductivity was high. The bonded body manufactured by mounting the chip and heating at 250 ° C. for 1 hour was measured for adhesion, and was not bonded.
The above results are summarized in Table 6. In this paste-like silver particle composition, since the high-viscosity volatile dispersion medium (B2) does not exist in the dried product, the dried product loses plasticity and adhesiveness, and the metal member (C1) and the metal member ( It can be seen that C2) cannot be joined.

[Comparative Example 8]
In a mixer, 100 parts of granular silver particles produced by the silver nitrate reduction method, having an average particle diameter of 1.0 μm and coated with oleic acid (the amount of oleic acid is 0.5% by mass) As a high-viscosity volatile dispersion medium (B2), 25 parts of isobornylcyclohexanol (released by Nippon Terpene Chemical Co., Ltd., abbreviation MTPH, viscosity 80 Pa · s at 25 ° C.) were added and mixed, but the paste did not form a paste. A silver particle composition could not be prepared.
The above results are summarized in Table 6. It can be seen that the low-viscosity volatile dispersion medium (B1) is a necessary component for preparing a uniform paste-like silver particle composition.

Since the pasty metal particle composition of the present invention is dried, more than half of the low-viscosity volatile dispersion medium (B1) is volatilized and becomes a non-fluid having plasticity, so that the shape stability after coating is excellent and high. When more than half of the viscosity volatile dispersion medium (B2) remains, the adhesiveness is excellent because it has adhesiveness. When heated, the remaining low-viscosity volatile dispersion medium (B1) and high Since the viscosity volatile dispersion medium (B2) is volatilized and the sinterable metal particles (A) are sintered together, the metal member (C1) and the metal member (C2) are firmly joined, so that a plurality of metal Useful for joining between members. In particular, it is useful for joining a metal part of a semiconductor element and a metal part of a lead frame or a circuit board. Since the thickness of the bonding agent layer between the semiconductor element and the lead frame is stable, it is useful for manufacturing electronic parts and electronic devices having excellent shape stability.

A Test specimen for measuring adhesive strength 1 Silver substrate 2 Paste-like metal particle composition (solid metal after heating and sintering)
3 Silver chip

Such a low-viscosity volatile dispersion medium (B1) is preferably one that does not alter the surface of the sinterable metal particles, and the viscosity is preferably from 0.1 to 500 mP · s, and from 0.2 to 400 mP · s. It is more preferable that Viscosity volatile becomes extremely high is less than 0.1 MPa · s, is difficult ing preparation of the pasty metal particle composition. Moreover, when the viscosity exceeds 500 mP · s, it is difficult to volatilize by drying at 25 ° C. or more and 125 ° C. or less, and it becomes difficult to obtain a plastic non-fluid.

[Plasticity of dried product was dried pasty metal particle composition, Williams plasticity, flowability, tackiness]
A paste-like metal particle composition was applied on a glass plate having a width of 50 mm × length of 50 mm × thickness of 2.0 mm using a metal mask having a thickness of 10 mm × length of 10 mm and having an opening of 10 mm in width and a predetermined thickness. It was heated for a predetermined time in a forced circulation oven at a temperature to obtain a plate-like dried product. When the sinterable metal particles were copper particles, they were heated in nitrogen gas instead of in the air.

[William plasticity of the dried product]
Measured according to the method specified in JIS K 6249 “Testing method for uncured and cured silicone rubber”. That is, 2 cm ³ of the dried product was used as a spherical test piece, which was sandwiched between cellophane papers, set on a parallel plate plasticity meter (Williams Plastometer) with a dial gauge, applied with a load of 5 kg and left for 3 minutes. After that, the scale of the dial gauge was read to 1/100 of a millimeter, and the thickness of the test specimen was multiplied by 100 to obtain the plasticity. A Williams Plastometer manufactured by Ueshima Seisakusho Co., Ltd. was used. In each example, each comparative example, and the table | surface, it displayed as a plasticity.

The sintered product produced by heating the dried product at 250 ° C. for 1 hour was measured for volume resistivity and thermal conductivity. As a result, the volume resistivity was low and the thermal conductivity was high. The bonded body manufactured by mounting the chip and heating at 250 ° C. for 1 hour was measured for adhesion, and was not bonded.
The above results are summarized in Table 4. The paste Jogin particle composition, since the high viscosity volatile dispersion medium in dry matter (B2) is not exist, the dried product is thermoplastic, it loses tack, metallic member (C1) and the metal member It can be seen that (C2) cannot be joined.

[Comparative Example 6]
In a mixer, 100 parts of granular silver particles produced by the silver nitrate reduction method, having an average particle diameter of 1.0 μm and coated with oleic acid (the amount of oleic acid is 0.5% by mass) , low viscosity volatile dispersion medium (B1) as α- terpineol (manufactured by Wako Pure Chemical Industries, viscosity 36 MPa · s in the reagent .25 ° C. Ltd. Release) 14 parts of dimethyl silicone oil with a high viscosity volatile dispersion medium ( Toray Dow Corning Co., Ltd., abbreviated SH200 oil (viscosity 300 Pa · s at 25 ° C.) 8 parts was added and mixed uniformly to prepare a pasty silver particle composition.
The dried product obtained by drying this pasty silver particle composition at 60 ° C. for 1 hour was measured for plasticity, plasticity, fluidity, tackiness, and α-terpineol removal rate. There was no fluidity and there was stickiness, and the removal rate of α-terpineol was 95%.

The average particle size of the sinterable metal particles (A) is a volume- based integrated fraction 50% value of the particle size distribution measured using a laser diffraction / scattering particle size distribution measuring device, that is, the median diameter (D50 value). .
If the average particle size of the sinterable metal particles exceeds 10 μm, the sinterability between the sinterable metal particles (A) may be lowered, and therefore it is 10 μm or less, and preferably 5 μm or less. In addition, if it is less than 0.01 μm, the surface activity is too strong and the storage stability of the paste-like metal particle composition may be lowered, so that it is 0.01 μm or more, preferably 0.02 μm or more, More preferably, it is 0.1 μm or more.

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 size is a volume- based integrated fraction 50% value of particle size distribution measured using a laser diffraction scattering type particle size distribution measuring device, that is, Mean the median diameter (D50 value). The heating and drying in the examples and comparative examples are heating and drying in a forced circulation oven, and the atmosphere in the forced circulation oven is air unless otherwise noted.
Coating amount of sinterable metal particles (A); viscosity of low-viscosity volatile dispersion medium (B1) and high-viscosity volatile dispersion medium (B2); plasticity after drying paste-like metal particle composition, Williams plasticity Degree, fluidity, adhesiveness; the removal rate of the low-viscosity volatile dispersion medium (B1), the removal rate of the volatile dispersion medium (2) and the surface of the sinterable metal particles by drying the paste-like metal particle composition Removal rate of coated organic matter: Volume resistivity and thermal conductivity of sintered product produced by heating, and shape stability and adhesive strength of joined product joined by heating were measured by the following methods. did. The measurement is a measurement at room temperature (about 25 ° C.) in the atmosphere unless otherwise specified.

Such as a high viscosity volatile dispersion medium (B2), cyclo hexane dimethanol (cis, mixture of trans), isobornyl cyclohexanol, isobornylcyclohexanol, bornyl phenol, isobornyl phenol is exemplified However, isobornylcyclohexanol and isobornylphenol are preferable.

Claims (15)

(A) Sinterable metal particles produced by a reduction method and having an average particle diameter of 0.01 to 10 μm and having a surface coated with an organic substance, (B1) having a viscosity at 25 ° C. of 0.1 to 500 mPa · s. s is a low-viscosity volatile dispersion medium, and (B2) is a paste-like material composed of a high-viscosity volatile dispersion medium having a viscosity at 25 ° C. of 10 to 200 Pa · s. A paste-like metal particle composition, which is a non-fluid having plasticity when dried at a temperature of 1, and becomes a sintered product of the metal particles (A) when heated at 150 ° C to 400 ° C. By drying, more than half of the low-viscosity volatile dispersion medium (B1) contained in the paste is volatilized and more than half of the high-viscosity volatile dispersion medium (B2) remains. Item 2. The paste-like metal particle composition according to Item 1. The paste-like metal particle composition according to claim 1 or 2, wherein a material of the sinterable metal particles is gold, silver, copper, platinum, palladium, or an alloy thereof. The volume resistivity of the sintered product is 1 × 10 ⁻⁵ Ω · cm or less, and the thermal conductivity is 100 W / m · K or more. 4. The paste-like metal particle composition according to 3. (A) Sinterable metal particles produced by a reduction method and having an average particle diameter of 0.01 to 10 μm and having a surface coated with an organic substance, (B1) having a viscosity at 25 ° C. of 0.1 to 500 mPa · s. A paste-like metal particle composition composed of a low-viscosity volatile dispersion medium that is s and (B2) a high-viscosity volatile dispersion medium that has a viscosity at 25 ° C. of 10 to 200 Pa · s was applied to the metal member (C1). Then, after drying at a temperature of 25 ° C. or more and 125 ° C. or less to make the paste-like metal particle composition a plastic non-fluid, a metal member (C2) is mounted on the non-fluid, A metal member characterized by joining the metal member (C1) and the metal member (C2) as a sintered product of the metal particles (A) by heating at a temperature of not less than 400 ° C and not more than 400 ° C. How to join (C1) and metal member (C2) . By drying, more than half of the low-viscosity volatile dispersion medium (B1) contained in the paste is volatilized, and more than half of the high-viscosity volatile dispersion medium (B2) remains. Item 6. The joining method according to Item 5. The joining method according to claim 5 or 6, wherein a material of the sinterable metal particles is gold, silver, copper, platinum, palladium, or an alloy thereof. The material of the metal member (C1) and the metal member (C2) is gold, silver, copper, platinum, palladium, or an alloy thereof. The joining method described in 1. The metal member (C1) is a metal portion of a lead frame or a circuit board, and the metal member (C2) is a metal portion of a semiconductor element. The joining method according to item. 10. The volume resistivity of the sintered product is 1 × 10 ⁻⁵ Ω · cm or less, and the thermal conductivity is 100 W / m · K or more. 2. The joining method according to item 1. (A) Sinterable metal particles produced by a reduction method and having an average particle size of 0.01 to 10 μm and having a surface coated with an organic substance, and (B1) a viscosity at 25 ° C. of 0.1 to 500 mPa · a circuit board having a lead frame or a metal part, a paste-like metal particle composition comprising a low-viscosity volatile dispersion medium s and (B2) a high-viscosity volatile dispersion medium having a viscosity at 25 ° C. of 10 to 200 Pa · s After the coating, the paste-like metal particle composition is dried at a temperature of 25 ° C. or more and 125 ° C. or less to make a plastic non-fluid, and then a semiconductor element having a metal portion is mounted on the non-fluid. By heating at 150 ° C. or more and 400 ° C. or less, an electronic device formed by joining a metal part of a semiconductor element and a metal part of a lead frame or a circuit board as a sintered product of the metal particles (A). . By drying, more than half of the low-viscosity volatile dispersion medium (B1) contained in the paste is volatilized, and more than half of the high-viscosity volatile dispersion medium (B2) remains. Item 12. The electronic device according to Item 11. The electronic device according to claim 11 or 12, wherein a material of the sinterable metal particles is gold, silver, copper, platinum, palladium, or an alloy thereof. 14. The electronic device according to claim 11, 12, or 13, wherein a material of the metal portion is gold, silver, copper, platinum, palladium, or an alloy thereof. 15. The volume resistivity of the sintered product is 1 × 10 ⁻⁵ Ω · cm or less, and the thermal conductivity is 100 W / m · K or more. The electronic device according to item 1.

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