Patents by Inventor Mitsugu Shirai

Mitsugu Shirai 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 for forming conductive bumps
    Patent number: 5551148
    Abstract: A flexible film-like member having conductive metals filled in tapered holes extending through the thickness is positioned such that the holes of the member face to respective pad patterns on a circuit board on which bumps are to be formed, the conductive metals are then heated and fused so that they are joined and transferred to the pad patterns on the circuit board, and the film-like member is then removed by heating or cleaning liquid.
    Type: Grant
    Filed: October 28, 1994
    Date of Patent: September 3, 1996
    Assignee: Hitachi, Ltd.
    Inventors: Shinichi Kazui, Makoto Matsuoka, Hideyuki Fukasawa, Mitsunori Tamura, Mitsugu Shirai, Hideaki Sasaki
  • Soldering method and apparatus for use in connecting electronic circuit devices
    Patent number: 5516031
    Abstract: In order to remove oxide film and contamination film on members to be bonded by soldering and solder material therefor corresponding to variation of thickness thereof by sputter-etching in a fluxless bonding method and apparatus therefor, substance emitted from the solder material under sputter-etching using atom or ion is detected and determined whether it is from the solder material or from the oxide film thereon. The sputter-etching is controlled on the basis of the determination to remove the oxide film. Then, the members are aligned in oxidizing atmosphere and soldered in non-oxidizing atmosphere.
    Type: Grant
    Filed: May 2, 1994
    Date of Patent: May 14, 1996
    Assignee: Hitachi, Ltd.
    Inventors: Toru Nishikawa, Masahito Ijuin, Ryohei Sato, Mitsugu Shirai
  • Semiconductor package with metalized portions
    Patent number: 5329160
    Abstract: In a semiconductor package in which a cover and a substrate are combined with each other in a sealed state, metallized portions consisting of a material of a high solder wettability are provided on the joint surface, which is opposed to the substrate, of the cover, outer side surfaces of the cover, and the portions of the inner side surfaces of the cover which are in the vicinity of the joint surface. These metallized portions are formed so that the height thereof on the outer side surfaces of the cover is larger than that on the inner side surfaces thereof. The metallized portions on the outer side surfaces are formed so that the height thereof at the corner portions of the cover is larger than that at the intermediate portions of the four sides thereof, and the metallized portions on the inner side surfaces are formed so that the height thereof at the intermediate portions of the four sides of the cover is larger than that at the corner portions thereof.
    Type: Grant
    Filed: February 11, 1992
    Date of Patent: July 12, 1994
    Assignee: Hitachi, Ltd.
    Inventors: Shinya Miura, Kouzou Kanda, Mitsugu Shirai