Patents Assigned to Shoei Chemical Inc.
  • 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: 4574055
    Abstract: A resistor composition comprising conductive particles, a glass frit and a vehicle in which RuO.sub.2 particles coated with a polynary oxide of Bi and/or Pb and Ru are employed and, by using the surface-coated RuO.sub.2, the composition can provide readily a improved resistor having a advantageous combination of properties, particularly a very small absolute TCR and high voltage stability throughout a wide resistance range. The produced resistor can be successfully laser-trimmed without adversely affecting the properties thereof.
    Type: Grant
    Filed: December 12, 1984
    Date of Patent: March 4, 1986
    Assignee: Shoei Chemical Inc.
    Inventors: Eiichi Asada, Toshio Inokuma, Mikio Yamazoe
  • Patent number: 4439352
    Abstract: Resistor compositions are disclosed which comprise: (a) ruthenium oxide; (b) glass; (c) at least one metal oxide selected from the group consisting of lanthanum oxide, neodymium oxide, praseodymium oxide and samarium oxide; and (d) an organic vehicle. Resistors are produced using this composition by firing a resistor film comprising ruthenium oxide, glass and at least one metal oxide selected from the group consisting of lanthanum oxide, neodymium oxide, praseodymium oxide and samarium oxide onto an electrically insulating substrate. The use of the metal oxides in the resistor compositions surprisingly improve the TCR (temperature coefficient of resistance) particularly in high resistance ranges, and brings the TCR close to zero. In addition to the effect of improving the TCR, the metal oxides increase resistance and improve noise and VCR (voltage coefficient of resistance) properties.
    Type: Grant
    Filed: December 1, 1982
    Date of Patent: March 27, 1984
    Assignee: Shoei Chemical Inc.
    Inventors: Eiichi Asada, Toshio Inokuma, Hiroyuku Saito