Dowa Electronics Materials Co., Ltd.

Dowa Mining Co., Ltd.

Pchem Associates, Inc.

Hiromasa Miyoshi

Keiichi Endoh

Satoru Kurita

Kazushi Sano

Yoshihiro Okada

Yoshiomi Takada

Takashi Hinotsu

Minami Nagaoka

Yoshiko Kohno

Kimitaka Sato

Tatsuro Hori

Gregory A Jablonski

Hidefumi Fujita

Akihiro Miyazawa

Michael A Mastropietro

Kimikazu Motomura

Tomonori Shibayama

Koichi Yuzaki

There are provided a bonding material, which can prevent voids from being generated in a silver bonding layer by preventing the entrainment of bubbles during the formation of a coating film even if the coating film is thickened, and a bonding method using the same. The bonding material of a silver paste includes fine silver particles, a solvent and an addition agent, wherein the solvent contains a first solvent of a diol, such as octanediol, and a second solvent which is a polar solvent (preferably one or more selected from the group consisting of dibutyl diglycol, hexyl diglycol, decanol and dodecanol) having a lower surface tension than that of the first solvent and wherein the addition agent is a triol.

Joining material and joining method using same

A bonding material includes: fine silver particles having an average primary particle diameter of 1 to 50 nm, each of the fine silver particles being coated with an organic compound having a carbon number of not greater than 8, such as hexanoic acid; silver particles having an average primary particle diameter of 0.5 to 4 &#x3bc;m each of the silver particles being coated with an organic compound, such as oleic acid; a solvent containing a primary alcohol solvent and a terpene alcohol solvent; and a dispersant containing a phosphoric acid ester dispersant (or a phosphoric acid ester dispersant and an acrylic resin dispersant), wherein the content of the fine silver particles is in the range of from 5 wt % to 30 wt %, and the content of the silver particles is in the range of from 60 wt % to 90 wt %, the total content of the fine silver particles and the silver particles being not less than 90 wt %, and wherein the bonding material further includes a sintering aid of a monocarboxylic acid having an ether bond.

Bonding material and bonding method using same

There is provided an inexpensive bonding material, which can be easily printed on articles to be bonded to each other and which can suppress the generation of voids in the bonded portions of the articles to be bonded to each other, and a bonding method using the same. In a bonding material of a copper paste which contains a copper powder containing 0.3% by weight or less of carbon and having an average particle diameter of 0.1 to 1 &#x3bc;m, and an alcohol solvent, such as a monoalcohol, a diol, a triol or a terpene alcohol, the content of the copper powder is in the range of from 80% by weight to 95% by weight, and the content of the alcohol solvent is in the range of from 5% by weight to 20% by weight.

A bonding material of a silver paste contains: fine silver particles having an average primary particle diameter of 1 to 200 nm, each of the fine silver particles being coated with an organic compound having a carbon number of not greater than 8, such as sorbic acid; and a solvent mixed with the fine silver particles, wherein a diol, such as an octanediol, is used as the solvent and wherein a triol having a boiling point of 200 to 300&#xb0; C., a viscosity of 2,000 to 10,000 mPa&#xb7;s at 20&#xb0; C. and at least one methyl group, such as 3-methylbutane-1,2,3-triol or 2-methylbutane-1,2,4-triol, is mixed with the solvent as an addition agent.

A bonding material of a silver paste includes: fine silver particles having an average primary particle diameter of 1 to 50 nanometers, each of the fine silver particles being coated with an organic compound having a carbon number of not greater than 8, such as hexanoic acid; silver particles having an average primary particle diameter of 0.5 to 4 micrometers, each of the silver particles being coated with an organic compound, such as oleic acid; a solvent containing 3 to 7% by weight of an alcohol and 0.3 to 1% by weight of a triol; a dispersant containing 0.5 to 2% by weight of an acid dispersant and 0.01 to 0.1% by weight of phosphate ester dispersant; and 0.01 to 0.1% by weight of a sintering aid, such as diglycolic acid, wherein the content of the fine silver particles is in the range of from 5% by weight to 30% by weight, and the content of the silver particles is in the range of from 60% by weight to 90% by weight, the content of the total of the fine silver particles and the silver particles being not less than 90% by weight.

There is produced a fine silver particle dispersing solution which contains: fine silver particles (the content of silver in the fine silver particle dispersing solution is 30 to 90% by weight), which have an average primary particle diameter of 1 to 100 nm and which are coated with an amine having a carbon number of 8 to 12, such as octylamine, serving as an organic protective material; a polar solvent (5 to 70% by weight) having a boiling point of 150 to 300&#xb0; C.; and an acrylic dispersing agent (1.5 to 5% by weight with respect to the fine silver particles), such as a dispersing agent of at least one of acrylic acid ester and methacrylic acid ester.

Fine silver particle dispersing solution

There is provided a metal nanoparticle dispersion which can be bonded at a lower temperature (for example, 200&#xb0; C. or less), and enabling to obtain excellent mechanical properties and electric properties of the bonded portion, the metal nanoparticle dispersion, including: metal nanoparticles, with at least a part of a surface of each particle coated with amine A having 8 or more carbon atoms; and a dispersion medium for dispersing the metal nanoparticles, wherein the dispersion medium contains amine B which is primary, secondary, or tertiary amine having 7 or less carbon atoms, and which is linear alkyl amine or alkanol amine.

Metal nanoparticle dispersion, method for producing metal nanoparticle dispersion, and bonding method

A silver nanoparticle composition is provided which is possible to be sintered through sintering at a low temperature in a short time and to form silver electro conductive film and wiring which is favorable for adhesion to a substrate and low in resistance, and articles using the same are provided. The silver nanoparticle composition is provided, wherein a main component of a solvent is water, a pH of the composition is within a range of 5.3 to 8.0, a silver nanoparticle included in the composition is protected by an organic acid or a derivative thereof, and the content of the organic acid or the derivative thereof with respect to silver is 2 to 20% by mass.

Low-temperature sintered silver nanoparticle composition and electronic articles formed using the same

Copper particle clusters constituting a powder suitable for making a conductive paste are provided that are individually composed of not fewer than two and not more than 20 unit particles joined through neck portions. A conductive paste made from the powder is excellent in conductivity. A conductive filler for conductive paste is provided that consists essentially of a mixture of copper particle clusters A individually composed of two or more unit particles joined through neck portions and spherical metallic particles B of smaller diameter than the particles A. A conductive paste made from the filler is low in viscosity and excellent in conductivity.

Copper particle clusters and powder containing the same suitable as conductive filler of conductive paste

When copper powder manufactured by a wet reduction method is kneaded with resin in a high filling rate, it is difficult to maintain a low viscosity. The invention is to solve the problem of high viscosity without changing the characteristics such as particle size and specific surface area of the copper powder obtained by a wet reduction method. This invention relates to copper powder for an electrically conductive paste wherein copper powder manufactured by a wet reduction method is subjected to a surface-flattening treatment in which the particles are mechanically collided each other.

Copper powder for electrically conductive paste

A copper powder is provided that has an average particle diameter in the range of from not less than 0.1 &#x3bc;m to less than 1.5 &#x3bc;m, that has a narrow particle size distribution width whose value A defined by Equation (1) below in terms of X25, X50 and X75 defined below is not greater than 1.2, and that forms a pseudo-fused sintered product when held at a temperature of 800&#xb0; C. under an atmosphere of inert gas at one atmosphere pressure:=(75&#x2212;25)/50&#x2003;&#x2003;(1),where X25, X50 and X75 are values of particle diameter X corresponding to Q %=25%, 50% and 75% on a cumulative particle-size curve plotted in an orthogonal coordinate system whose abcissa represents particle diameter X (&#x3bc;m) and ordinate represents Q % (ratio of particles present of a diameter not greater than the corresponding value of X; expressed in units of vol % of particles). The copper powder is produced by conducting wet reduction of cuprous oxide into metallic copper powder in the presence of ammonia or an ammonium salt. When used to form the terminal electrodes of multi-layer capacitor, it enables the electrodes to form into solid sintered bodies with few pores by sintering at a low temperature.

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Okayama, Japan

Hiromasa Miyoshi