Patents by Inventor Yoshiji Ohtsu

Yoshiji Ohtsu 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: 9553063
    Abstract: The semiconductor element has an electrode including: a Ni-inclusion metal layer containing nickel formed on a side of at least one surface of the semiconductor-element constituting part; a Ni-barrier metal layer formed outwardly on a side of the Ni-inclusion metal layer opposite to the side toward the semiconductor-element constituting part; and a surface metal layer outwardly formed on a side of the Ni-barrier metal layer opposite to the side toward the semiconductor-element constituting part, to be connected to the metal nanoparticles sintered layer; wherein the Ni-barrier metal layer contains a metal for suppressing diffusion of nickel toward the surface metal layer.
    Type: Grant
    Filed: April 18, 2011
    Date of Patent: January 24, 2017
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Yoshiji Ohtsu, Taku Kusunoki, Akira Yamada, Takeharu Kuroiwa, Masayoshi Tarutani
  • Patent number: 9224665
    Abstract: A semiconductor device includes a circuit substrate which is configured with an insulative substrate formed of a ceramic material and provided on its one surface with an electrode formed of a copper material, and a power semiconductor element bonded with the electrode using a sinterable silver-particle bonding material, wherein the electrode has a Vickers hardness of 70 HV or more in its portion from the bonding face with the power semiconductor element toward the insulative substrate to a depth of 50 ?m, and has a Vickers hardness of 50 HV or less in its portion at the side toward the insulative substrate.
    Type: Grant
    Filed: July 6, 2012
    Date of Patent: December 29, 2015
    Assignee: Mitsubishi Electric Corporation
    Inventors: Kenji Ohtsu, Yoshiji Ohtsu, Taku Kusunoki, Takeshi Araki, Hiroaki Tatsumi
  • Publication number: 20140312361
    Abstract: The semiconductor element has an electrode including: a Ni-inclusion metal layer containing nickel formed on a side of at least one surface of the semiconductor-element constituting part; a Ni-barrier metal layer formed outwardly on a side of the Ni-inclusion metal layer opposite to the side toward the semiconductor-element constituting part; and a surface metal layer outwardly formed on a side of the Ni-barrier metal layer opposite to the side toward the semiconductor-element constituting part, to be connected to the metal nanoparticles sintered layer; wherein the Ni-barrier metal layer contains a metal for suppressing diffusion of nickel toward the surface metal layer.
    Type: Application
    Filed: April 18, 2011
    Publication date: October 23, 2014
    Applicant: Mitsubishi Electric Corporation
    Inventor: Yoshiji Ohtsu
  • Publication number: 20140138710
    Abstract: A semiconductor device includes a circuit substrate which is configured with an insulative substrate formed of a ceramic material and provided on its one surface with an electrode formed of a copper material, and a power semiconductor element bonded with the electrode using a sinterable silver-particle bonding material, wherein the electrode has a Vickers hardness of 70 HV or more in its portion from the bonding face with the power semiconductor element toward the insulative substrate to a depth of 50 ?m, and has a Vickers hardness of 50 HV or less in its portion at the side toward the insulative substrate.
    Type: Application
    Filed: July 6, 2012
    Publication date: May 22, 2014
    Applicant: Mitsubishi Electric Corporation
    Inventor: Yoshiji Ohtsu