Patents by Inventor Seigo Oka

Seigo Oka 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: 6303230
    Abstract: This invention relates to laminates in which a layer of polyimide precursors and a layer of photosensitive resins are formed one on top of another on an electric conductor such as a stainless steel foil and also to laminates consisting of a stainless steel foil and successive layers of polyimide precursors and photosensitive resins useful for the manufacture of HDD suspensions. In particular, the use of resins containing a repeating unit derivable from specific aromatic diamines and aromatic carboxylic acid dianhydrides as polyimide precursors makes it possible to fabricate an insulator of high fabrication accuracy and reliability on an electric conductor and, in addition, the laminates are useful as materials for the manufacture of HDD suspensions of an integrated circuit/wiring structure with high accuracy.
    Type: Grant
    Filed: October 22, 1997
    Date of Patent: October 16, 2001
    Assignee: Nippon Steel Chemical Co., Ltd.
    Inventors: Hisashi Watanabe, Takashi Tanaka, Hiroyuki Chinju, Seigo Oka, Soichiro Kawamura, Taeko Hayama
  • Patent number: 6203918
    Abstract: This invention relates to laminates for use in HDD suspensions which are composed of a stainless steel base material and successive layers formed thereon of polyimides and an electrical conductor and in which the linear expansion coefficient of the polyimide layer is controlled in the range of 1×10−5/° C. to 3×10−5/° C. and the adhesive strength between stainless steel and polyimide and that between polyimide and electrical conductor are controlled at 0.5 kg/cm or more. This invention also relates to a process for preparing laminates for use in HDD suspensions comprising applying a solution of polyimide precursors or polyimides to a stainless steel base material with a thickness of 10 to 70 &mgr;m in one layer or more, drying, performing heat treatment at 250° C. or more to form a layer of polyimides with a thickness of 3 to 20 &mgr;m and a linear expansion coefficient of 1×10−5/° C. to 3×10−5/° C.
    Type: Grant
    Filed: February 19, 1999
    Date of Patent: March 20, 2001
    Assignee: Nippon Steel Chemical Co., Ltd.
    Inventors: Makoto Shimose, Hisashi Watanabe, Seigo Oka, Yuji Matsushita, Eri Kabemura