Patents by Inventor Shigeru Ohtawa

Shigeru Ohtawa 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).

  • Photopolymerizable compositions
    Patent number: 5922510
    Abstract: A photopolymerizable composition composed principally of an acrylic linear copolymer, an ethylenically-unsaturated compound and a photoinitiator and adapted to fabricate printed circuit boards. The ethylenically-unsaturated compound contains a specific acrylic ester. The photopolymerizable composition can be developed with an aqueous mild alkaline solution.
    Type: Grant
    Filed: March 2, 1994
    Date of Patent: July 13, 1999
    Assignee: Tokyo Ohka Kogyo Co., Ltd.
    Inventors: Shigeru Ohtawa, Junichi Onodera, Kouji Harada
  • Photopolymerizable compositions
    Patent number: 5344747
    Abstract: A photopolymerizable composition composed principally of an acrylic linear copolymer, an ethylenically-unsaturated compound and a photoinitiator and adapted to fabricate printed circuit boards. The ethylenically-unsaturated compound contains a specific acrylic ester. The photopolymerizable composition can be developed with an aqueous mild alkaline solution.
    Type: Grant
    Filed: April 20, 1992
    Date of Patent: September 6, 1994
    Assignee: Tokyo Ohka Kogyo Co., Ltd.
    Inventors: Shigeru Ohtawa, Junichi Onodera, Kouji Harada
  • Photopolymerizable compositions
    Patent number: 5147759
    Abstract: A photopolymerizable composition composed principally of an acrylic linear copolymer, an ethylenically-unsaturated compound and a photoinitiator and adapted to fabricate printed circuit boards. The ethylenically-unsaturated compound contains a specific acrylic ester. The photopolymerizable composition can be developed with an aqueous mild alkaline solution.
    Type: Grant
    Filed: December 6, 1990
    Date of Patent: September 15, 1992
    Assignee: Tokyo Ohka Kogyo Co., Ltd.
    Inventors: Shigeru Ohtawa, Junichi Onodera, Kouji Harada
  • Remover solution for photoresist
    Patent number: 4904571
    Abstract: A remover solution for photoresist comprising (a) a solvent which is typically water, (b) an inorganic or organic alkaline compound such as sodium and potassium hydroxides, and (c) a borohydride compound such as sodium and lithium borohydrides and organic amine borane compounds. When used for removing patterned photoresist layer in the manufacturing process of, for example, electronic circuit board substrates. The method gives quite satisfactory results without discoloration or denaturation of the copper surface and solder surface, consequently leading to the production of high-quality products.
    Type: Grant
    Filed: July 15, 1988
    Date of Patent: February 27, 1990
    Assignee: Tokyo Ohka Kogyo Co., Ltd.
    Inventors: Tsuyoshi Miyashita, Shigeru Ohtawa, Hiroyuki Tohda, Shozo Toda, Hisashi Nakane