Dowa Electronics Materials Co., Ltd.

Atsushi Ebara

Kenichi Inoue

Masahiro Yoshida

Yoshiyuki Michiaki

Kozo Ogi

Kyoso Masuda

Takahiro Yamada

Toshihiko Ueyama

Yoshihiro Okada

Yuki Kaneshiro

Shinichi Uchiyama

Akihiro Asano

Hideyuki Fujimoto

Yuto Hiyama

There are provided an inexpensive copper powder, which has a low content of oxygen even it has a small particle diameter and which has a high shrinkage starting temperature when it is heated, and a method for producing the same. While a molten metal of copper heated to a temperature, which is higher than the melting point of copper by 250 to 700° C. (preferably 350 to 650° C. and more preferably 450 to 600° C.), is allowed to drop, a high-pressure water is sprayed onto the heated molten metal of copper in a non-oxidizing atmosphere (such as an atmosphere of nitrogen, argon, hydrogen or carbon monoxide) to rapidly cool and solidify the heated molten metal of copper to produce a copper powder which has an average particle diameter of 1 to 10 μm and a crystallite diameter Dxof not less than 40 nm on (200) plane thereof, the content of oxygen in the copper powder being 0.7% by weight or less.

Copper powder and method for producing same

While a molten metal of copper heated to a temperature, which is higher than the melting point of copper by 250 to 700&#xb0; C. (preferably 350 to 650&#xb0; C. and more preferably 450 to 600&#xb0; C.), is allowed to drop, a high-pressure water is sprayed onto the heated molten metal of copper in a non-oxidizing atmosphere (such as an atmosphere of nitrogen, argon, hydrogen or carbon monoxide) to rapidly cool and solidify the heated molten metal of copper to produce a copper powder which has an average particle diameter of 1 to 10 &#x3bc;m and a crystallite diameter Dxof not less than 40 nm on (200) plane thereof, the content of oxygen in the copper powder being 0.7% by weight or less.

There is provided a silver powder which has a small average particle diameter and a small thermal shrinkage percentage, and a method for producing the same. While a molten metal of silver heated to a temperature (1292 to 1692&#xb0; C.), which is higher than the melting point (962&#xb0; C.) of silver by 330 to 730&#xb0; C., is allowed to drop, a high-pressure water is sprayed onto the molten metal of silver (preferably at a water pressure of 90 to 160 MPa) to rapidly cool and solidify the molten metal of silver to powderize silver to produce a silver powder which has an average particle diameter of 1 to 6 &#x3bc;m and a shrinkage percentage of not greater than 8% (preferably not greater than 7%) at 500&#xb0; C., the product of the average particle diameter by the shrinkage percentage at 500&#xb0; C. being 1 to 11 &#x3bc;m&#xb7;% (preferably 1.5 to 10.5 &#x3bc;m&#xb7;%).

Silver powder and method for producing same

An object of the present invention is to provide metal powder that can be used to form an external electrode, which is excellent in solder wettability and solder leach resistance while having a layer structure with fewer layers than in the related art and, furthermore, is excellent in electrical conductivity. This silver-coated alloy powder comprises a coating layer on a surface of an alloy core particle containing copper, nickel, zinc, and inevitable impurities, the coating layer containing silver.

Silver-coated alloy powder, electrically conductive paste, electronic part, and electric device

An object of the present invention is to provide a phosphorus-containing copper powder with good volume resistivity and a small carbon content by suppressing an oxygen content to a relatively low value even if a particle size is made small, and a method for producing the same. In the phosphorus-containing copper powder containing phosphorus, a ratio of an oxygen content (wt. %) to a BET specific surface area (m/g) (oxygen content/BET specific surface area) is 0.90 wt. %&#xb7;g/mor less, a divalent copper compound is present on a surface of particles constituting the phosphorus-containing copper powder, a carbon content is 0.10 wt. % or less, and D50 is 7.11 &#x3bc;m or less.

Phosphorus-containing copper powder and method for producing the same

To provide a silver-bismuth powder, which includes: silver; and bismuth, wherein a mass ratio (silver:bismuth) of the silver to the bismuth is 95:5 to 40:60, wherein a cumulative 50% point of particle diameter (D50) of the silver-bismuth powder in a volume-based particle size distribution thereof as measured by a laser diffraction particle size distribution analysis is 0.1 &#x3bc;m to 10 &#x3bc;m, and wherein an oxygen content of the silver-bismuth powder is 5.5% by mass or less.

Silver-bismuth powder, conductive paste and conductive film

A silver-coated copper alloy powder, which has a low volume resistivity and excellent storage stability (reliability), is produced by coating a copper alloy powder, which has a chemical composition comprising 1 to 50 wt % of at least one of nickel and zinc and the balance being copper and unavoidable impurities (preferably a copper alloy powder wherein a particle diameter (Ddiameter) corresponding to 50% of accumulation in cumulative distribution of the copper alloy powder, which is measured by a laser diffraction particle size analyzer, is 0.1 to 15 &#x3bc;m), with 7 to 50 wt % of a silver containing layer, preferably a layer of silver or an silver compound.

Silver-coated copper alloy powder and method for producing same

A highly oxidation-resistant copper powder for conductive paste, which is a copper powder containing not more than 5 wt % of Si, is characterized in that substantially all of the Si is adhered to the surfaces of the copper particles as SiO-system gel coating film.

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Tokyo, Japan

Atsushi Ebara