Hitachi, Ltd.

Yukio Takeda

Kunihiro Maeda

Satoru Ogihara

Kousuke Nakamura

Yasuo Matsushita

Mitsuru Ura

Tokio Ohkoshi

Takaaki Suzuki

Ken Takahashi

Tadahiko Miyoshi

Masaki Ohura

Shinsuke Higuchi

Sadanori Nagaike

Takeo Yamazaki

Tadamichi Asai

Atsuko Soeta

Masatoshi Nakazawa

Shiro Iijima

Kie Nakamura

Choushiro Kitazawa

Osamu Asai

Katsuhisa Usami

Tokio Okoshi

A superconducting oxide wire and a method of manufacturing the same are disclosed. The wire comprises a pipe made of a metal and a superconducting oxide material filling the interior of the pipe and comprising superconducting oxide grains which are bonded to each other and which have a perovskite crystal structure having a C face and a C axis. The superconducting oxide grains contain more than 50 vol % of plate-shaped grains of which the length in the direction of the C face is greater than the length in the direction of the C axis. The C faces of most the plate-shaped grains are arranged to be directed toward longitudinal axis of the pipe.

Superconducting wire and method of manufacturing the same

The present invention provides a highly thermal conductive, electrical insulating ceramic body having at least 90% of theoretical density and comprising 20 to 40% by weight of silicon carbide, the balance being substantially aluminum nitride, the silicon carbide containing not more than 0.1 by weight of sum total of boron, aluminum and nitrogen and not more than 0.2% by weight of sum total of iron, titanium, vanadium, chromium and nickel, and the aluminum nitride containing not more than 1% by weight of oxygen and not more than 0.5% by weight of sum total of silicon, iron and magnesium, the sintered body having a thermal conductivity at 20.degree. C. of at least 250 W/m..degree.K, an electrical resistivity at 20.degree. C. of at least 10.sup.10 .OMEGA.. cm, a dielectric strength at 20.degree. C. of at least 20 kV/cm, a dielectric constant at 1 MHz of not more than 10, a bending strength at 20.degree. C. of at least 400 MPa and a fracture toughness at 20.degree. C. of at least 5MN/m.sup.3/2. The present sintered body can be used as a substrate for a semi-conductor device, and a semi-conductor device using the present sintered body has good heat radiation. The present sintered body can be used as a substrate for a semi-conductor device, and a semi-conductor device using the present sintered body has a good heat radiation characteristic.

Electrical insulating, sintered aluminum nitride body having a high

A film magnetic slider which comprises a slider performing contact-start-stop actions on a recording medium and being provided with a film magnetic head device on the side end of the slider, at least the recording-medium-contacting part of the slider being made from a sintered material having a thermal conductivity of not more than 0.02 cal/cm.sec..degree.C. and an average crystal grain size of not more than 5 .mu.m has a good slidability on the recording medium and a good machinability and can improve the life of the recording medium.

Film magnetic head slider having a contacting portion containing

A thin film magnetic head slider is formed of a sintered material made of a mixture of AlN and TiN. The ratio of volume % AlN to TiN in the mixture is in the range of 50:50 to 99:1. The thin film magnetic head slider has improved lubricant property as shown by its high contact-start-stop (C.S.S.) life.

Thin film magnetic head slider

A semi-conductor device comprising sintered aluminum nitride having a high thermal conductivity, which comprises at least 65% by weight of aluminum nitride, and at least one of beryllium, a beryllium compound, lithium and a lithium compound.

Sintered aluminum nitride semi-conductor device

Disclosed are semiconductor devices in which an electrical insulating substrate is made of a sintered silicon carbide body having thermal conductivity of at least 0.4 cal/cm.multidot.sec.multidot..degree.C. at 25.degree. C., electrical resistivity of at least 10.sup.7 ohm.multidot.cm at 25.degree. C. and coefficient of thermal expansion of 3.3.about.4.times.10.sup.-6 /.degree.C. at 25.degree. C. to 300.degree. C.

Semiconductor device having electrically insulating substrate of SiC

A sintered silicon carbide body having a high thermal conductivity and a high electrical insulation without any drop substantially throughout the sintered body is produced from a powdery silicon carbide composition comprising at least 90% by weight of silicon carbide powders having an average particle size of not more than 10 .mu.m and 0.01 to 4% by weight of powders of beryllium or its compound having a particle size of not more than 30 .mu.m in terms of beryllium atom, a nitrogen content of the composition being not more than 500 ppm.

Powdery silicon carbide composition for sintering

A silicon carbide sintered body comprising silicon carbide as principal constituent, a first component for providing electrical insulating properties to said silicon carbide, said first component comprising at least one of metallic beryllium, beryllium compounds, boron and boron compounds and contained in a total amount of 0.01 to 3.5% by weight calculated as metal, and a second component which can further promote said silicon carbide sinterability provided by said first component and which does not diffuse easily in the particles of said silicon carbide, said second component comprising at least one substance selected from the Group I elements exclusive of hydrogen and francium, Group II elements exclusive of beryllium, radium and mercury, Group III elements exclusive of boron and aluminum, Group IV elements exclusive of carbon, Group V elements, Group VIa elements, Group VIIa elements Group VIII elements exclusive of iron, and compounds thereof, and contained in a total amount of 0.01 to 10% by weight, with the remainder substantially comprising silicon carbide. This silicon carbide sintered body has an electrical resistivity of 10.sup.7 .OMEGA..cm or above at room temperature and is also excellent in electrical insulating properties and can be advantageously used as substrates for semiconductor devices, etc.

Electrically insulating silicon carbide sintered body

Sintered aluminum nitride having a high thermal conductivity, which comprises at least 65% by weight of aluminum nitride, and at least one of beryllium, a beryllium compound, lithium and a lithium compound, and a semi-conductor device using the same.

Sintered aluminum nitride and semi-conductor device using the same

From 0.1 to 3.5% by weight of beryllium oxide powder, calculated as beryllium, is added to silicon carbide powder containing up to 0.1% by weight of aluminum, up to 0.1% by weight of boron and up to 0.4% by weight of free carbon, and the mixed powder is pressure-molded. The resulting molded article is heated to a temperature of 1,850.degree. C. to 2,500.degree. C. till there is obtained a sintered body having at least 90% relative density of silicon carbide. Thus, the sintered body having thermal conductivity of at least 0.4 cal/cm.sec..degree. C. at 25.degree. C., electrical resistivity of at least 10.sup.7 Ohm.cm at 25.degree. C. and coefficient of thermal expansion of 3.3.about.4.times.10.sup.-6 /.degree.C. at 25.degree. C. to 300.degree. C. can be obtained.

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Hitachi, Japan

Yukio Takeda