Hitachi Chemical Company, Ltd.

Technopolis Hakodata Industrial Technology Promotion Organization

Technopolis Hakodate Industrial Technology

Hideji Kuwajima

Shozo Yamana

Junichi Kikuchi

Hiroshi Wada

Takeyoshi Watanabe

Toranosuke Ashizawa

Keiji Sumiya

Akihiro Sasaki

Keizo Hirai

Minoru Ishihara

Shuichiro Shimoda

Hisashi Kaga

Yoshikatsu Mikami

Kuniaki Sato

Kuniaki Satou

Kazuyoshi Shike

Hisashi Dokochi

Toshikazu Ono

Jun-ichi Kikuchi

Hirofumi Mizoguchi

Juichi Sakurada

There are disclosed a highly packed, mixed conductive powder with a relative packing density of at least 68%, a process for producing the same, a conductive paste using the mixed conductive powder and a process for producing the same, as well as a sheet and a sheet with attached film using the mixed conductive powder. This mixed conductive powder comprises substantially monodispersed conductive scale-like particles (A1) and conductive substantially spherical particles (B1). Or, this mixed conductive powder comprises substantially monodispersed, conductive, substantially spherical particles (A2) and conductive substantially spherical particles (B2) with a smaller particle diameter than that of the substantially spherical particles (A2).

Mixed conductive powder and use thereof

Mixed conductive power and use thereof

The present invention provides an electroconductive paste that can contain a high proportion of an electroconductive powder, has excellent electroconductivity reliability and migration resistance, has a highly competitive price due to a reduced amount of silver plating, and is suitable for use in solder electrode formation, an electroconductive adhesive, etc. The electroconductive paste of the present invention comprises a binder and an electroconductive powder containing 80 to 97 wt % of a substantially spherical silver-coated copper powder in which the surface of a copper powder is coated with silver and the surface thereof is further coated with 0.02 to 0.5 wt % relative to the copper powder of a fatty acid, and 3 to 20 wt % of a flat-shaped silver-coated copper powder in which the surface of a copper powder is coated with silver and the surface thereof is further coated with 0.02 to 1.2 wt % relative to the copper powder of a fatty acid.

Conductive paste

Disclosed are conductive powder having a packing density of 68% by volume or more with a relative value preferably comprising 60 to 92% by weight of roughly spherical and silver-plated copper powder part of the surface of which has been coated with 3 to 30% by weight of silver based on an amount of roughly spherical copper powder with exposing at least a surface of a portion of an alloy of copper with silver, and the surface of which is coated with 0.02 to 1.0% by weight of an aliphatic acid based on an amount of the roughly spherical and silver-plated copper powder, and 8 to 40% by weight of silver powder, and a method for preparing the same.

Conductive powder and method for preparing the same

A through-hole wiring board comprising through-holes passing through a substrate and filled with an electroconductive material; copper toil lands and copper foil circuits formed on surfaces of the substrate; insulating layers formed on the copper toil circuits and between necessary portions of the copper foil lands and the copper foil circuits; and printed circuits (jumper circuits) formed by another electroconductive material having a different composition from that filling the through-holes on a part of the copper foil circuits, and the copper foil lands and the insulating layers except for unnecessary portions for electroconductivity; wherein the printed circuits and ends of the through-holes are electrically connected with an electroconductive material having a different composition from that filling the through-holes, permits easy formation of an electrical connection of the through-holes, has a high reliability on connection and is suitable for industrial production.

Through-hole wiring board

Electroconductive composite metal powders comprising flat non-noble metal powders, each covered with a noble metal in an amount of 2 to 30% by weight in average based on the weight of the non-noble metal powders, on 50% or more in average of the whole surface area of the non-noble metal powders, interposing a layer of a mixture of the non-noble metal and noble metal between each non-noble metal powder and a noble metal covering layer, are suitable for providing an electroconductive paste after mixing with a binder, said paste showing excellent electroconductivity and prevention of migration.

Electric circuit device having circuit conductors using an

Composite electroconductive powder, electroconductive paste, process for

Electroconductive paste

The present invention provides an oxide superconductor which is mainly composed of bismuth, lead, strontium, calcium, magnesium, and copper and has the composition represented by the formula:

Bi-Pb-Sr-Mg-Ba-Ca-Cu-O oxide superconductors and production thereof

A superconducting thick film circuit board or thick film superconductor obtained by forming a rod-like crystal superconducting composite layer comprising a superconductor made of a compound of M-Ba-Cu-O, M being Y and/or a lanthanide element, and a composite of Ag and Pt on a stabilized zirconia substrate has a high Jc value and good superconducting properties.

Superconducting thick film circuit board, production thereof, thick film

A reconstituted mica material produced by sheet forming a slurry containing mica flakes prepared by disintegrating unfired mica and comprising (i) mica flakes having a particle size of 1.7 mm or more and an aspect ratio of 150 or more, (ii) mica flakes having a particle size of 1.0 mm or more and less than 1.7 mm and an aspect ratio of 150 or more, (iii) mica flakes having a particle size of 0.25 mm or more and less than 1.0 mm and an aspect ratio of 100 or more, and (iv) mica flakes having a particle size of less than 0.25 mm and an aspect ratio of 100 or more, in definite ranges, gives reconstituted mica prepreg materials, reconstituted mica products and insulated coils having excellent mechanical and electrical properties.

Reconstituted mica materials, reconstituted mica prepreg materials,

A reconstituted mica material produced by sheet forming a slurry containing mica flakes prepared by disintegrating unfired mica and comprising (i) mica flakes having a particle size of 1.0 mm or more and an aspect ratio of 150 or more, (ii) mica flakes having a particle size of 0.25 mm or more and less than 1.0 mm and (iii) mica flakes having a particle size of less than 0.25 mm, in definite ranges, gives reconstituted mica prepreg materials, reconstituted mica products and insulated coils having excellent mechanical and electrical properties.

Mica flakes are disintegrated to mica scales having a diameter of 10 mm or less and a ratio of diameter/thickness of 100-1000 by using an apparatus and a method comprising bringing about coarse size reduction followed by size reduction of the mica flakes by high-pressure jets of water, if desired together with high-pressure jets of gas, separating mica scales from mica flakes by vertical classification followed by horizontal classification, and taking out the mica scales as a slurry while recycling nondisintegrated mica flakes to size reduction. The slurry of mica scales is used for making mica paper.

Growing community of inventors

Hitachinaka, Japan

Hideji Kuwajima