Patents by Inventor Kazuji Yamada

Kazuji Yamada has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4550612
    Abstract: In an integrated pressure sensor, a silicon chip for pressure detection and a substrate for supporting the silicon chip are made of the same material, the silicon chip has a thin diaphragm portion and a peripheral fixed portion thicker than the diaphragm portion, and the silicon chip is bonded to the substrate through a thin insulating film.
    Type: Grant
    Filed: May 31, 1984
    Date of Patent: November 5, 1985
    Assignee: Hitachi, Ltd.
    Inventors: Kazuji Yamada, Shigeyuki Kobori, Satoshi Shimada, Ryosaku Kanzawa, Ryoichi Kobayashi, Hideo Sato
  • Patent number: 4527428
    Abstract: A semiconductor pressure transducer including a measuring diaphragm of semiconductor material for sensing pressure supported by a support member of the same material. An oxide layer and a thin glass layer are interposed between the measuring diaphragm and the support member.
    Type: Grant
    Filed: December 30, 1982
    Date of Patent: July 9, 1985
    Assignee: Hitachi, Ltd.
    Inventors: Satoshi Shimada, Kazuji Yamada, Seikou Suzuki, Shigeyuki Kobori, Motohisa Nishihara
  • Patent number: 4495820
    Abstract: A capacitive pressure sensor and its manufacturing method are disclosed. An amplifier is formed on the main surface of a first semiconductor substrate by a diffusion process, and its surface is covered with an insulating film. An electrode is vapor-deposited on the surface of the amplifier and electrically connected to the amplifier through a through hole formed in the insulating film. For forming a diaphragm, the surface of a second semiconductor substrate disposed facing the electrode to form a capacitor, which is opposite to the surface of the second semiconductor substrate facing the electrode, is partially etched away to form a depression. The first and second semiconductor substrates are anodically bonded to each other using a glass layer.
    Type: Grant
    Filed: September 28, 1982
    Date of Patent: January 29, 1985
    Assignee: Hitachi, Ltd.
    Inventors: Satoshi Shimada, Kazuji Yamada, Seikou Suzuki, Motohisa Nishihara
  • Patent number: 4480478
    Abstract: Four semiconductor strain gauges constitute a bridge circuit. This bridge circuit and a sensitivity temperature compensation circuit are connected in series, and a constant voltage is applied to the series circuit. The sensitivity temperature compensation circuit varies a voltage across the bridge circuit, depending upon temperatures. The constant voltage is divided to produce a predetermined voltage. The predetermined voltage is selected to be equal to the voltage of one output side node of the bridge circuit at the time when the semiconductor strain gauges are unstrained and at a predetermined temperature. The point of this voltage and the output side node are connected through a resistor so as to perform zero-point temperature compensation.
    Type: Grant
    Filed: February 14, 1983
    Date of Patent: November 6, 1984
    Assignee: Hitachi, Ltd.
    Inventors: Hideo Sato, Motohisa Nishihara, Kazuji Yamada, Seikou Suzuki
  • Patent number: 4404539
    Abstract: A semiconductor strain gauge is arranged as a bridge having four piezoresistive elements which each include a low impurity concentration diffused portion and a heavily-doped diffused portion. The resistance values of the two low impurity concentration diffused portions opposite each other in the bridge are greater than the resistance values of the other two lower impurity concentration portions. The resistances of the heavily-doped diffused portion are selected so that the resistance of the piezoresistive elements are equal. However, by virtue of the fact that the resistance temperature coefficient of the low impurity portions are greater than the resistance temperature coefficients of the high impurity portions, the overall resistance temperature coefficients of the bridge arms will be different. This permits the zero-point voltage of the bridge to always increase with an increase in temperature.
    Type: Grant
    Filed: February 23, 1981
    Date of Patent: September 13, 1983
    Assignee: Hitachi, Ltd.
    Inventors: Kazuji Yamada, Motohisa Nishihara, Hideo Sato, Seiko Suzuki, Ryoichi Kobayashi
  • Patent number: 4291293
    Abstract: A semiconductor pressure transducer assembly comprising a silicon diaphragm assembly and a glass covering member. The silicon diaphragm assembly has a circular diaphragm portion of thin silicon which is formed using etching, and a thick supporting portion therearound. Piezoresistive elements of a piezoresistive bridge circuit and conducting paths for electrically connection thereof are formed on the silicon diaphragm assembly. On a surface of the silicon diaphragm assembly, a passivating layer of silicon dioxide are formed in uniform thickness, and further on a surface of the passivating layer is formed a layer of polysilicon on the supporting portion of the silicon diaphragm assembly. In the passivating layer, a contacting window is formed, through which the polysilicon layer is electrically connected to the silicon diaphragm assembly.
    Type: Grant
    Filed: September 19, 1979
    Date of Patent: September 22, 1981
    Assignee: Hitachi, Ltd.
    Inventors: Kazuji Yamada, Seiko Suzuki, Motohisa Nishihara, Kanji Kawakami, Hideo Sato, Shigeyuki Kobori, Ryosaku Kanzawa, Minoru Takahashi, Hitoshi Minorikawa
  • Patent number: 4173900
    Abstract: A semiconductor pressure transducer comprising a disc-shaped pressure-responsive diaphragm; a pair of radial strain gauge units having a piezoresistance effect, formed by injecting an impurity in the radial direction in the surface of the diaphragm; and a pair of tangential strain gauge units having a piezoresistance effect, formed by injecting an impurity in the tangential direction in the surface of the diaphragm, wherein the distance from the pair of the radial strain gauge units to the center of the circular diaphragm is greater than the distance from the pair of the tangential strain gauge units to the center of the circular diaphragm.
    Type: Grant
    Filed: March 6, 1978
    Date of Patent: November 13, 1979
    Assignee: Hitachi, Ltd.
    Inventors: Masanori Tanabe, Satoshi Shimada, Motohisa Nishihara, Kazuji Yamada, Yasumasa Matsuda, Michitaka Shimazoe, Yoshitaka Matsuoka, Yukio Takahashi, Katsuya Katohgi, Mitsuo Ai
  • Patent number: 4173148
    Abstract: A bridge circuit with four arms including semiconductor strain gauge elements has input terminals for coupling a DC power supply with a pair of diagonally opposite junctions of the bridge circuit per se and output terminals coupled with a pair of remaining diagonally opposite junctions. Initial zero-point temperature compensators each are connected in series and in parallel to each of semiconductor strain gauge elements on adjacent two arms of the bridge circuit. Temperature compensators for zero-point shift adjustment are each provided between the adjacent arms closer to each output terminal. A temperature compensator for span adjustment is provided between one of the input terminals and the DC power source. A constant current control unit for feeding a constant current to the bridge circuit is provided between the other input terminal and the DC power supply.
    Type: Grant
    Filed: October 5, 1978
    Date of Patent: November 6, 1979
    Assignee: Hitachi, Ltd
    Inventors: Kazuji Yamada, Hideo Sato, Tsutomu Okayama, Motohisa Nishihara, Yoshitaka Matsuoka, Katsuya Katohgi, Yasumasa Matsuda, Satoshi Shimada
  • Patent number: 4166384
    Abstract: 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.
    Type: Grant
    Filed: September 6, 1978
    Date of Patent: September 4, 1979
    Assignee: Hitachi, Ltd.
    Inventors: Yasumasa Matsuda, Kazuji Yamada, Satoshi Shimada, Motohisa Nishihara, Tomio Yasuda, Masatoshi Tsuchiya, Ko Soeno, Mitsuo Ai, Takeo Nagata, Yoshitaka Matsuoka
  • Patent number: 4151502
    Abstract: A semiconductor transducer comprises a semiconductor strain gauge composed of a mono-crystalline semiconducting material and a strain sensing region formed in a first main surface of the mono-crystalline semiconducting material, and a strain measuring member coupled to the semiconductor strain gauge through an alloy material. An electrical insulating layer is attached to a second main surface of the mono-crystalline semiconducting material which is coupled to the strain measuring member through the alloy material. The insulating layer is extended to a side surface of the mono-crystalline semiconducting material thereby to cover the same side.
    Type: Grant
    Filed: April 15, 1977
    Date of Patent: April 24, 1979
    Assignee: Hitachi, Ltd.
    Inventors: Yasutoshi Kurihara, Tetuo Kosugi, Teruyuki Kagami, Satoshi Shimada, Yasumasa Matsuda, Kazuji Yamada
  • Patent number: 4065971
    Abstract: A semiconductor pressure transducer includes a monocrystalline semiconductor diaphragm, the outer edges of which are fixed. When subjected to pressure, the transducer produces radial strains of opposite polarity in a central portion thereof and a portion surrounding the central portion close to the edge of the strain inducing region. The diaphragm contains a plurality of elongated resistances formed of semiconductor material of the same conductivity type which are electrically isolated from the diaphragm, per se. Resistances of an individual set which lie in proximity to one another are combined in the form of a bridge. The longitudinal direction of resistances forming one set of opposing arms of the bridge extend along axes of the same crystal system as the longitudinal direction of the elongated resistances forming the other set of opposing arms of the bridge.
    Type: Grant
    Filed: July 1, 1976
    Date of Patent: January 3, 1978
    Assignee: Hitachi, Ltd.
    Inventors: Michitaka Shimazoe, Kousuke Nakamura, Yasuo Matsushita, Satoshi Shimada, Kazuji Yamada, Yukio Takahashi
  • Patent number: 4050313
    Abstract: A semiconductor pressure transducer comprises a circular diaphragm formed of a single crystal semiconductor material, at least a first strain gauge element having a piezoresistance effect and formed by injecting an impurity into the diaphragm in a linear region extending in parallel with a predetermined axis which extends transversely of the surface of the diaphragm, at least a second strain gauge element having the piezoresistance effect and formed by injecting an impurity into the diaphragm in a linear region extending in the direction perpendicular to the axis, and means for securing the diaphragm at the outer peripheral portion thereof. The distance between the second strain gauge element and the center of the diaphragm is differed from the distance between the center of the first strain gauge element and the latter.
    Type: Grant
    Filed: June 3, 1976
    Date of Patent: September 27, 1977
    Assignee: Hitachi, Ltd.
    Inventors: Satoshi Shimada, Kazuji Yamada, Yasumasa Matsuda, Ichiro Kimura, Michitaka Shimazoe, Yukio Takahashi