Fujitsu Corporation

Fijitsu Limited

Suzuki, Hitoshi

Niwa, Koichi

Ogawa, Hiromi

Kamehara, Nobuo

Yokoyama, Hiromitsu

Tsukada, Mineharu

Koichi Niwa

Nobuo Kamehara

Kishio Yokouchi

Hiromitsu Yokoyama

Kazunori Yamanaka

Hitoshi Suzuki

Yoshihiko Imanaka

Atsushi Tanaka

Takuya Uzumaki

Kyohei Murakawa

Hiromi Ogawa

Kazuaki Kurihara

Kaoru Hashimoto

Mitsutaka Yamada

Takato Machi

Masato Wakamura

Mineharu Tsukada

Hiroshi Kamezaki

Yuichi Suzuki

Koji Omote

Wataru Yamagishi

Teruo Murase

Seiichi Yamada

Masatoshi Fujimori

A coolant for cooling a semiconductor element by direct immersion, cooling, which has an improved cooling capability, is disclosed. The coolant comprises a low boiling point fluorocarbon having a boiling point of 30&deg; C. to 100&deg; C. and a high boiling point fluorocarbon having a boiling point higher than that of the low boiling point fluorocarbon by at least 100&deg; C.; an amount of the high boiling point fluorocarbon being less than 20% by volume, based on the volume of the low boiling point fluorocarbon.

Immersion cooling coolant

Disclosed is a process for forming a super-conducting film, which a multi-layer metal film (buffer film) is formed at a specific temperature on a ceramic substrate and a superconducting film is formed at a specific temperature on the multi-layer metal film. According to this process, a superconducting film having a high critical temperature can be formed over the ceramic substrate while controlling or suppressing the occurrence of a chemical reaction between the substrate and the superconducting film, and required superconducting performances can be manifested or exhibited.

Process for forming oxide superconducting films with a plurality of

A process for producing a multi-layer wiring board having alternate layers of a glass ceramic material and conductor patterns. The glass ceramic layers are made up of a glass ceramic material including a glass matrix and ceramic particles dispersed in the matrix. The glass ceramic layers are caused to contain hollow or porous silica glass spheres dispersed in the glass ceramic material. The hollow or porous silica glass spheres are covered with a ceramic coating layer containing alumina as a constituent element. Such a structure prevents crystallization of the silica spheres and avoids the resultant rapid increase in the the thermal expansion coefficient of the glass ceramic layers. The structure provided by the process of the invention also precudes the formation of pores in the surfaces of the glass ceramic layers.

Process for preparing a multi-layer wiring board

A perovskite type superconductor film having a high content, almost a single phase, of the high Tc phase is formed by the steps of: depositing at least one first film of a first material (e.g., a composite oxide of Bi-Sr-Ca-Cu-O system or Tl-Ba-Ca-Cu-O system) constituting a perovskite type superconductor over a substrate; depositing at least one second film of a second material containing an oxide or element (Bi.sub.2 O.sub.3, Tl.sub.2 O.sub.3, PbO.sub.x, etc., particularly PbO.sub.x) having a vapor pressure of more than 10.sup.-4 Pa at 800.degree. C. at least as a main component over the substrate; to thereby form a stack of the first and second films; and heat treating the stack of the first and second films to form the perovskite type superconductor film on the substrate. Further, preferred compositions of the as-deposited films or stack are determined.

Process for preparing a perovskite Bi-containing superconductor film

Composition for the formation of ceramic vias

A coolant for cooling a semiconductor element by direct immersion, cooling, which has an improved cooling capability, is disclosed. The coolant comprises a low boiling point fluorocarbon having a boiling point of 30.degree. C. to 100.degree. C. and a high boiling point fluorocarbon having a boiling point higher than that of the low boiling point fluorocarbon by at least 100.degree. C.; an amount of the high boiling point fluorocarbon being less than 20% by volume, based on the volume of the low boiling point fluorocarbon.

Immersion cooling coolant and electronic device using this coolant

Process for producing Bi- and Pb-containing oxide superconducting wiring

Process for producing Bi-Pb-Sr-Ca-Cu-O superconducting films

A process of producing a multiple-layer glass-ceramic circuit board having a copper conductor, comprising the steps of: forming throughholes in a glass-ceramic green sheet at sites where via-contacts will be formed; filling the throughholes with a powder mixture of a copper powder blended with a ceramic powder, the copper powder and the ceramic powder having a powder particle size providing a packing density comparable with or greater than that of the glass-ceramic green sheet when filled in the throughholes; printing a conductor paste on the green sheet having the throughholes filled with the powder mixture, to form a circuit conductor pattern on the green sheet; laminating a plurality of the green sheets having the conductor pattern formed thereon, to form a laminate body; heating the laminate body to thereby remove a binder therefrom and preliminary-fire the laminate body; and firing the preliminary-fired body.

Process of producing multiple-layer glass-ceramic circuit board

A superconducting circuit board is provided comprising a sintered alumina board containing more than 99% by weight of alumina and an interconnection pattern of an superconducting ceramics formed on the alumina board. Adhesion of the interconnection pattern to the alumina board is improved by an addition of Ti or Si coupling agent to a paste for forming the interconnection pattern. The use of copper powder in place of copper oxide powder as an ingredient forming a superconducting ceramics in the paste is advantageous for printing and obtaining a uniform superconducting ceramic pattern.

Method for manufacturing an oxide superconducting circuit board by

A laminated multi-layer wiring board comprising alternate layers of a glass ceramic material and conductor pattern. The glass ceramic layers are made of a glass ceramic comprising glass and dispersed ceramic particles. The glass ceramic layers further contain hollow or porous silica glass spheres dispersed in the glass ceramic. The hollow or porous silica glass spheres are covered with a ceramic coating layer containing aluminum as a constituent element. Such a structure prevents crystallization of the silica spheres and the resultant rapid increase in the thermal expansion coefficient of the glass ceramic layer. The structure also procludes the formation of pores in the surfaces of the spheres.

Multi-layer wiring board

A perovskite type superconductor film having a high content, almost a single phase, of the high Tc phase is formed by the steps of: depositing at least one first film of a first material (e.g., a composite oxide of Bi-Sr-Ca-Cu-O system or Tl-Ba-Ca-Cu-O system) constituting a perovskite type superconductor over a substrate; depositing at least one second film of a second material containing an oxide or element (Bi.sub.2 O.sub.3, Tl.sub.2 O.sub.3, PbO.sub.x, etc., particularly PbO.sub.x) having a vapor pressure of more than 10 .sup.-4 Pa at 800.degree. C. at least as a main component over the substrate; to thereby form a stack of the first and second films; and heat treating the stack of the first and second films to form the perovskite type superconductor film on the substrate. Further, preferred compositions of the as-deposited films or stack are determined.

Multilayer deposition method for forming Pb-doped Bi-Sr-Ca-Cu-O

Superconducting circuit board and paste adopted therefor

Superconductors of the Bi-Pb-Sr-Ca-Cu-O system and Tl-Pb-Ba-Ca-Cu-O system having a high Tc phase (about 110K and about 125K, respectively, or more) at a high proportion are obtained by adding a calcium compound which forms CaO and a liquid phase at a temperature for firing the superconductors, e.g., Ca.sub.2 PbO.sub.x (x=3 or 4); or by starting form a composition represented by the formula: Bi.sub.2 Pb.sub.(n-1)/2 Sr.sub.2 Ca.sub.n Cu.sub.n+1 O.sub.b, or Tl.sub.2 Pb.sub.(n-1)/2 Ba.sub.2 Ca.sub.n Cu.sub.n+1 Ob where 2.ltoreq.n.ltoreq.10, 5.ltoreq.b.ltoreq.40.5, i.e., at a ratio of Ca:Pb=2:1.

Process for preparing superconductor

A coolant for use in cryogenic devices of closed cycle system which comprises a mixture of a liquid nitrogen and a fluorocarbon of the formula: C.sub.n F.sub.2n+2, wherein n is an integer of 2 to 4. The coolant, when used to cool heat generating semiconductor devices and other devices to a cryogenic temperature, exhibits an increased heat flux and thus an increased cooling capability, in addition to a simple and small structure of the cooling system, and a prevention of environmental pollution.

Production and use of coolant in cryogenic devices

Growing community of inventors

Tama, Japan

Koichi Niwa