Hitachi, Ltd.

Teruyoshi Abe

Ryuichi Saito

Yasuhisa Aono

Yoshihiko Koike

Junya Kaneda

Yasuo Kondo

Kazutaka Okamoto

Tadashi Fujieda

Masahisa Inagaki

Hideo Arakawa

Sai Ogawa

Shinzou Ikeda

Tasuhisa Aono

Fumio Tajima

Motoya Ito

Yoshihisa Ishikawa

Kiyomi Nakamura

Toshio Uchida

Teruo Hirane

A rotating electrical machine having an RF-IC chip for detecting a rotation and also having a stator and a rotor. When a compact RF-IC chip is used as the RF-IC chip, the chip can detect the rotation of the rotating electrical machine.

Rotating electrical machine

A rotating electrical machine comprises a stator and a rotor; the stator comprising a stator core having teeth and slots, and stator windings disposed in the slots, wherein the stator core is made of laminated steel sheets, teeth and slots of the steel sheet are made by etching, and the thickness of the steel sheet is between 0.05 mm and 0.30 mm. Specifically, it is preferable that the steel sheet used herein be a silicon steel sheet containing crystalline particles.

An electromagnetic wave absorber for use in the high frequency range above 1 Ghz and a composite member are characterized by the fact that magnetic metal grains are covered with ceramic above 20 volume %. Further, a method of manufacturing the electromagnetic absorber and the composite member is characterized by the fact that composite magnetic particles, in which a plurality of magnetic metal grains and ceramic are unified, are formed through a mechanical alloying method applied to a composite powder composed of magnetic metal powder and ceramic powder. The electromagnetic wave absorber can be used in a semiconductor device, an optical sending module, an optical receiving module, an optical sending and receiving module, an automatic tollgate in which erroneous operation due to electromagnetic wave disturbance is provided by use of the electromagnetic wave absorber.

Electromagnetic wave absorber, method of manufacturing the same and appliance using the same

A composite material is provided, which has a low thermal expansivity, a high thermal conductivity, and a good plastic workability, which composite material may be applied to semiconductor devices and many other uses. The composite material is composed of metal and inorganic particles having a smaller coefficient of thermal expansion than the metal. It is characterized in that the inorganic particles are dispersed in such a way that 95% or more of them (in terms of their area in cross-section) form aggregates of complex configuration joined together. The composite material contains 20-80 vol % of copper oxide, with the remainder being copper. It has a coefficient of thermal expansion of 5&#xd7;10to 14&#xd7;10/&#xb0; C. and thermal conductivity of 30-325 W/m&#xb7;K in the range of room temperature to 300&#xb0; C. It is suitable for the radiator plate of semiconductor devices and the dielectric plate of electrostatic attractors.

Composite material including copper and cuprous oxide and application thereof

An object of the present invention is to provide a high strength Mg based alloy and a Mg based casting alloy having a good fluidity and a good mechanical property, and a molded article using the alloy. A high strength Mg based alloy, which contains, by weight, 12 to 20% of Al, 0.1 to 10% of Zn; 0.1 to 15% of Sn; and 0.05 to 1.5% of Mn.

High strength Mg based alloy and Mg based casting alloy and article made of the alloy

Composite material, and manufacturing method and uses of same

Provided are a composite material excellent in plastic workability, a method of producing the composite material, a heat-radiating board of a semiconductor equipment, and a semiconductor equipment to which this heat-radiating board is applied. This composite material comprises a metal and an inorganic compound formed to have a dendritic shape or a bar shape. In particular, this composite material is a copper composite material, which comprises 10 to 55 vol. % cuprous oxide (Cu O) and the balance of copper (Cu) and incidental impurities and has a coefficient of thermal expansion in a temperature range from a room temperature to 300&deg; C. of from 5&times;10 to 17&times;10 /&deg; C. and a thermal conductivity of 100 to 380 W/m&middot;k. This composite material can be produced by a process comprising the steps of melting, casting and working and is applied to a heat-radiating board of a semiconductor article.

Growing community of inventors

Hitachi, Japan

Teruyoshi Abe