Patents by Inventor Hiroyoshi Yokoyama

Hiroyoshi 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).

  • Method of manufacturing multilayer printed wiring board
    Patent number: 5826330
    Abstract: In a method of manufacturing a multilayer printed wiring board including an internal wiring circuit formed on a board, an insulating resin layer formed on the internal wiring circuit, a blind hole formed in the insulating resin layer and communicating with the internal wiring circuit, and a conductive portion formed on an inner wall of the blind hole and connected to the internal wiring circuit, the blind hole is formed by using a short-pulse CO.sub.2 laser.
    Type: Grant
    Filed: December 18, 1996
    Date of Patent: October 27, 1998
    Assignee: Hitachi AIC Inc.
    Inventors: Satoshi Isoda, Yasuhiro Iwasaki, Kenshirou Fukuzato, Tsutomu Zama, Koichi Noguchi, Toshiro Okamura, Hiroyoshi Yokoyama, Youiti Matuda
  • Process for producing printed wiring boards
    Patent number: 5153987
    Abstract: By using a composite film comprising an additive layer and an insulating layer containing an epoxy resin and a synthetic rubber as major components, printed wiring boards having a higher circuit density and higher reliability can be produced simply and effectively.
    Type: Grant
    Filed: April 10, 1989
    Date of Patent: October 13, 1992
    Assignees: Hitachi Chemical Company, Ltd., Hitachi, Condenser Co., Ltd., Yokohama Rubber Company Limited
    Inventors: Hiroshi Takahashi, Shin Takanezawa, Masao Kanno, Toshiro Okamura, Naoki Fukutomi, Hiroyoshi Yokoyama, Hideo Watanabe, Hajime Yamazaki, Hiroyuki Wakamatsu, Toshinobu Takahashi
  • Adhesive composition for printed wiring boards with acrylonitrile-butadiene rubber having carboxyl groups and 20 PPM or less metal ionic impurities; an alkyl phenol resin; an epoxy resin; palladium catalyst, and coupling agent
    Patent number: 5053280
    Abstract: An adhesive composition for producing printed wiring boards comprising (A) acrylonitrile-butadiene rubber having carboxyl groups in the molecule and containing 20 ppm or less of metal ionic impurities, (B) an alkyl phenol resin, (C) an epoxy resin, (D) a catalyst for electroless plating, and (E) a coupling agent having an ethylene or vinyl group, is useful in a so-called additive process.
    Type: Grant
    Filed: September 18, 1989
    Date of Patent: October 1, 1991
    Assignee: Hitachi-Chemical Co., Ltd.
    Inventors: Shin Takanezawa, Yorio Iwasaki, Hiroshi Takaahashi, Toshiro Okamura, Saburo Amano, Hiroyoshi Yokoyama, Noriyoshi Fukuoka, Tatsuya Amano
  • Process for producing printed circuit board
    Patent number: 4585502
    Abstract: A process for producing a printed circuit board characterized by forming a thermosetting resin layer on internal walls of through holes before an electroless plating treatment can produce printed circuit boards having high reliability without causing blow-holes on the through hole walls.
    Type: Grant
    Filed: February 14, 1985
    Date of Patent: April 29, 1986
    Assignee: Hitachi Condenser Co., Ltd.
    Inventors: Nobuo Uozu, Hiroyoshi Yokoyama, Yoichi Matsuda