Patents by Inventor Ritsuko Obata

Ritsuko Obata 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).

  • Photosensitive resin composition and application of its photosensitivity
    Patent number: 6060215
    Abstract: A photosensitive resin composition comprising (A) a resin having an amide bond, an oxyalkylene group and a carboxyl group, (B) a photopolymerizable compound having an ethylenically unsaturated group and (C) a photopolymerization initiator has an alkali developability, good sensitivity and photocurability, an efficient pattern formability by photolithography, a good application workability to a film and is capable of producing cured products having good folding endurance, solder reflow heat resistance, solvent resistance, bondability and nonflammability and suitable for producing a photosensitive element, a photosensitive laminate and a flexible printed circuit board.
    Type: Grant
    Filed: March 27, 1998
    Date of Patent: May 9, 2000
    Assignee: Hitachi, Ltd.
    Inventors: Jin Amanokura, Fumihiko Ota, Ritsuko Obata, Toshihiko Akahori, Kenji Suzuki, Hiroshi Nishizawa, Katsunori Tsuchiya, Takao Hirayama, Hiroaki Hirakura
  • Photolithographically viahole-forming photosensitive element comprising two photosensitive layers for the fabrication process of multilayer wiring board
    Patent number: 5532105
    Abstract: A photolithographically viahole-forming photosensitive element is formed of a light-transmitting base material and a photosensitive resin composition laminated as a layer on the light-transmitting base material. The photosensitive resin composition comprises:(a) 100 parts by weight of a mixture comprising:(a-1) 10 to 90 parts by weight of a rubber,(a-2) 5 to 40 parts by weight of a phenol resin, and(a-3) 10 to 80 parts by weight of an epoxy resin;(b) 1 to 10 parts by weight of an epoxy resin photoinitiator; and(c) 1 to 10 parts by weight of an aromatic polyazide compound.
    Type: Grant
    Filed: August 9, 1993
    Date of Patent: July 2, 1996
    Assignee: Hitachi Chemical Company, Ltd.
    Inventors: Takashi Yamadera, Kazumasa Takeuchi, Ritsuko Obata, Naoki Fukutomi, Kazuko Suzuki