Hitachi, Ltd.

Masatoshi Tsuchiya

Ko Soeno

Hiroshi Ikeda

Satoshi Shimada

Moriaki Fuyama

Shinji Narishige

Takashi Kawabe

Makoto Morijiri

Motohisa Nishihara

Masanori Tanabe

Eiji Ashida

Yoshitaka Matsuoka

Mitsuo Ai

Hideyuki Nemoto

Makoto Saito

Hiroshi Fukui

Yutaka Sugita

Kazuji Yamada

Kanji Otsuka

Yasumasa Matsuda

Satoru Ogihara

Masanobu Hanazono

Akio Yasukawa

Masateru Suwa

Tomoji Oishi

Yokuo Saitoh

Yoshimi Yamamoto

Tadayuki Iwakura

Tetsuya Okai

Hiromi Kagohara

Makoto Aihara

Takeo Nagata

Shunichiro Kuwatsuka

Michitaka Shimazoe

Hideki Yamazaki

Tomio Yasuda

Shinichi Hara

Tomomasa Yoshida

Jin Onuke

Ataru Kobayashi

Akio Okayama

Hisakiti Onodera

Keiji Miyauchi

A magnetic disc apparatus includes a magnetic disc for recording information; a thin film magnetic head including a magnetic pole structure having an upper magnetic pole tip and a lower magnetic pole tip arranged to provide a magnetic gap at respective end portions thereof for writing and reading information in and from the magnetic disc; a device for rotating the magnetic disc; and a device for positioning the thin film magnetic head; the upper and lower magnetic pole tips having different contours at the respective end portions as viewed from a side confronting the magnetic disc wherein the difference (.DELTA.CW in .mu.m) in the width, along the magnetic gap, of the upper magnetic pole tip and the width, along the magnetic gap, of the lower magnetic pole tip satisfies the relation

Magnetic disc apparatus with thin film head suitable for high-density

A method of forming a thin film pattern on a base having a step portion. This method comprises a first step of forming a thin film of given material on the base, a second step of forming a predetermined pattern of a first photoresist film on said thin film at one of a first portion including a lower part of the step portion and a second portion including an upper part of the step portion, a third step of forming a predetermined pattern of a second photoresist film on said thin film at the other of the first and second portions and a fourth step of applying ion-milling to said thin film of given material using masks said first and second photoresist film patterns formed on said thin film at the first and second portions.

Method for forming thin film pattern and method for fabricating thin

An integrated circuit package in which semiconductor elements mounted on an insulating substrate, ends of lead pieces introduced from the outside and wires that electrically connect them, are accommodated in a cell that is air-tightly defined by the substrate, a cap and a sealing glass. The lead pieces are composed of an alloy having a coefficient of thermal expansion nearly equal to, or smaller than, the coefficient of thermal expansion of the substrate. The alloy is an iron alloy which contains nickel and cobalt, and having a martensite transformation temperture of lower than -55.degree. C.

Integrated circuit package with low-thermal expansion lead pieces

A semiconductor pressure transducer comprising a piezoresistive semiconductor diaphragm, a cylindrical stem made of a glass having a thermal expansion coefficient approximating that of the diaphragm and hermetically bonded by anodic bonding to the latter, and a cylindrical holder hermetically bonded by anodic bonding to the cylindrical stem is disclosed. The holder is made of a ferromagnetic alloy material containing Fe, Co and Ni and having a mean thermal expansion coefficient of 35.times.10.sup.-7 /.degree.C. or less within the temperature range between 30.degree. C. and 350.degree. C.

Semiconductor pressure transducer

A strain gauge is formed on one main surface of a semiconductor single crystal substrate while an insulating oxide film is formed on the other main surface of the substrate. A metal junction layer including several layers inclusive of eutectic alloy layers is formed on the surface of the insulating oxide film and the thus prepared structure is mounted on a metal strain generator. By heating this assembly to temperatures approximating to the eutectic point of the eutectic alloy layer, the semiconductor substrate and the metal strain generator are joined together.

Method of producing semiconductor displacement transducer

A pressure transducer comprising a silicon diaphragm on which a semiconductor strain gauge is formed and which has a diaphragm portion deformable in response to a pressure, an insulating support which is made of borosilicate glass having the silicon diaphragm rigidly mounted thereon and which is provided with a pressure introducing hole in its central part, a metallic support which is cylindrical, which is made of an iron-nickel alloy similar in the thermal expansion coefficient to the borosilicate glass and on which the glass insulating support is rigidly mounted, and a metallic housing within which the integrated structure consisting of the silicon diaphragm, the glass insulating support and the metallic support is arranged; the silicon diaphragm, the insulating support and the metallic support being joined by the anodic bonding, the metallic support being rigidly welded to the metallic housing at its lower end part.

Pressure sensitive apparatus

A method of producing a sintered material having a high wearing resistance and damping capacity by mixing 5-30 wt. % of a powdery metal selected from the group consisting of lead, magnesium and graphite with the remainder of a powdery metal selected from the group consisting of iron, copper, aluminum, cast iron and alloys thereof, compression-molding the mixture, subjecting the same to plastic treatment and sintering the same by heating to a temperature above a recrystallization point of the matrix metal, and the sintered material thus produced.

Method of producing sintered material having high damping capacity and

A semiconductor transducer comprising an improved strain-yielding body yielding a strain in response to the impartation of a force or displacement, and a semiconductor strain gauge bonded to the strain-yielding body. The improved strain-yielding body is made of an iron-nickel-cobalt alloy containing 28.2 to 31.0% by weight of nickel and 15.0 to 19.5% by weight of cobalt. This iron-nickel-cobalt alloy is initially heated up to a temperature above 600.degree. C. for the purpose of standard heat treatment for removing its internal strain. After the standard heat treatment, the iron-nickel-cobalt alloy is subjected to cold working at a working rate of more than and including 60%, and is then subjected to heat treatment at a temperature between 350.degree. C. and 600.degree. C. The heat-treated iron-nickel-cobalt alloy is shaped into the predetermined form of the strain-yielding body.

Semiconductor transducer

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Hitachi, Japan

Masatoshi Tsuchiya