Patents by Inventor Kazuo Yokoyama

Kazuo Yokoyama 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: 4752442
    Abstract: A bonding wire for use in semiconductor devices which consists essentially of 0.0003 to 0.01 wt. % of barium and the balance gold, the gold purity of said bonding wire being at least 99.99%. The bonding wire may further contain at least one element selected from the group consisting of 0.0005 to 0.005 wt. % of aluminum, 0.0001 to 0.003 wt. % of calcium, 0.0005 to 0.005 wt. % of silver and 0.0005 to 0.005 wt. % of palladium. The total content of the elements and barium in the bonding wire should not exceed 0.01 wt. % based on the weight of the bonding wire so that the gold purity of the bonding wire is at least 99.99%. The use of the additive elements improve the mechanical strength and wire-bondability, making the bonding wire highly suitable for use in wire bonding of semiconductor elements, especially for high-speed bonding.
    Type: Grant
    Filed: July 16, 1987
    Date of Patent: June 21, 1988
    Assignee: Shoei Chemical Inc.
    Inventors: Eiichi Asada, Kazuo Yokoyama, Masahiro Yata, Kenichi Hirano
  • Patent number: 4375899
    Abstract: A protector for a movable panel within a roof aperture is disclosed. In order to urge all of the rain drops and the like to drop into a water collecting channel fixed relative to the roof, the protector is formed with a downwardly extending lip which when the movable panel is in its closed position assumes a position above the center line of the water collecting channel.
    Type: Grant
    Filed: January 14, 1981
    Date of Patent: March 8, 1983
    Assignee: Nissan Motor Company, Ltd.
    Inventors: Yasuo Kajiyama, Kazuo Yokoyama, Yoshihiro Yamakami
  • Patent number: 4288307
    Abstract: In a method of making a magnetic gap by depositing a glass layer on a surface of magnetic head core materials by cathodic sputtering of a glass target and cementing a pair of the resulting glass-coated magnetic head core materials, the improvements constituted by monitoring the thickness of the sputtered glass layer by an interference of a light beam guided onto a surface of the magnetic head core materials during the deposition and using a sputtering apparatus having a sample holder beside the target for securing the magnetic core materials and a mask plate for achieving uniform thickness of the sputtered glass layer.The method makes possible production of magnetic heads having excellent electromagnetic conversion characteristics with high accuracy.
    Type: Grant
    Filed: February 19, 1980
    Date of Patent: September 8, 1981
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kiyotaka Wasa, Takao Tohda, Kazuo Yokoyama, Eiichi Hirota, Shigeru Hayakawa
  • Patent number: 4238215
    Abstract: A magnetic head having a sputter-deposited glass film of the gap forming area of the magnetic core, said glass film being made of borosilicate glass having the composition consisting of 65-85 mol % of SiO.sub.2, 8-30 mol % of B.sub.2 O.sub.3 and containing 2-15 mol % of alkali metal oxide Na.sub.2 O and K.sub.2 O and 0.1-5 mol % of Al.sub.2 O.sub.3, with the molar ratio of boron oxide to alkali metal oxides being defined by the following formula: ##EQU1## The magnetic head provides sharpness of the recording leakage flux, thus giving excellent electromagnetic conversion characteristics.
    Type: Grant
    Filed: March 30, 1979
    Date of Patent: December 9, 1980
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kazuo Yokoyama, Ryuji Nichiyama, Taketoshi Yonezawa
  • Patent number: 4170032
    Abstract: A magnetic head having a sputter-deposited glass film of the gap forming area of the magnetic core, said glass film being made of borosilicate glass having the composition consisting of 65-85 mol % of SiO.sub.2, 8-30 mol % of B.sub.2 O.sub.3 and containing 2-15 mol % of alkali metal oxide Na.sub.2 O and K.sub.2 O and 0.1-5 mol % of Al.sub.2 O.sub.3, with the molar ratio of boron oxide to alkali metal oxides being defined by the following formula: ##EQU1## The magnetic head provides sharpness of the recording leakage flux, thus giving excellent electromagnetic conversion characteristics.
    Type: Grant
    Filed: September 18, 1978
    Date of Patent: October 2, 1979
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Kazuo Yokoyama, Ryuji Nishiyama, Taketoshi Yonezawa