Patents by Inventor Hosei Hirano

Hosei Hirano 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: 8901569
    Abstract: Provided is a power semiconductor device comprising a bonding joint that, even under a temperature environment of 150° C. or greater enabling operation of a wide bandgap semiconductor, reduces cracking-destruction occurring owing to thermal cycle while conductively connecting an electrode, connection terminal, and semiconductor device substrate. It is a power semiconductor device capable of operating under a temperature of 150° C. or greater having an electrode laminated on a wide bandgap semiconductor substrate and a connection terminal joined to the electrode for connection to external wiring, which power semiconductor device is characterized in that difference among the three coefficients of linear expansion of the electrode, a core of the connection terminal, and the semiconductor device substrate is 5.2×10?6/K at maximum, and that it comprises a joint that directly joins the connection terminal and the electrode.
    Type: Grant
    Filed: February 18, 2011
    Date of Patent: December 2, 2014
    Assignee: Nippon Steel & Sumitomo Metal Corporation
    Inventor: Hosei Hirano
  • Publication number: 20120305945
    Abstract: Provided is a power semiconductor device comprising a bonding joint that, even under a temperature environment of 150° C. or greater enabling operation of a wide bandgap semiconductor, reduces cracking-destruction occurring owing to thermal cycle while conductively connecting an electrode, connection terminal, and semiconductor device substrate. It is a power semiconductor device capable of operating under a temperature of 150° C. or greater having an electrode laminated on a wide bandgap semiconductor substrate and a connection terminal joined to the electrode for connection to external wiring, which power semiconductor device is characterized in that difference among the three coefficients of linear expansion of the electrode, a core of the connection terminal, and the semiconductor device substrate is 5.2×10?6/K at maximum, and that it comprises a joint that directly joins the connection terminal and the electrode.
    Type: Application
    Filed: February 18, 2011
    Publication date: December 6, 2012
    Inventor: Hosei Hirano
  • Patent number: 5640315
    Abstract: A switching regulator including: a switching element connected to an input DC signal and operating for turning-on and -off the input DC signal to produce an AC signal such as a rectangular wave signal; a rectifier for rectifying the AC signal thereby generating an output voltage; a circuit for producing a frequency-variable triangular wave signal having a constant amplitude; a comparator for comparing the triangular wave signal with the output voltage of the rectifier thereby obtaining a pulse-width modulated signal used for controlling the operation of the switching element; a modulation signal generator for generating a modulation signal having an amplitude variable in asynchronism with the frequency of the triangular wave signal; a sampling and holding circuit for sampling the modulation signal at a timing in synchronism with the frequency of the triangular wave signal or preferably at the timing of a maximum or minimum value of the triangular wave signal and holding the sampled modulation signal; and a ci
    Type: Grant
    Filed: March 17, 1995
    Date of Patent: June 17, 1997
    Assignee: Nippon Steel Corporation
    Inventors: Hosei Hirano, Tetsuro Tanaka
  • Patent number: 5621649
    Abstract: Analysis of an electromagnetic field in a region including an electric conductor having an arbitrary shape is efficiently and accurately performed with a computer. A value of electric potential at a predetermined portion of the electric conductor or a value of the normal component of an electric current density vector to the cross section of a predetermined portion of the electric conductor is used as an initial condition. The distribution of exciting current density vectors in the electric conductor is obtained form the initial condition so as to meet the condition of continuity of electric current. The electromagnetic field of the region is analyzed by using the obtained distribution of exciting current density vectors.
    Type: Grant
    Filed: July 19, 1993
    Date of Patent: April 15, 1997
    Assignee: Nippon Steel Corporation
    Inventors: Keiji Iwata, Hosei Hirano, Takatsugu Ueyama, Kenji Umetsu
  • Patent number: 5621636
    Abstract: A thin DC-DC converter arrangement which includes an inductor including a thin ring-shaped coil having a hole in its center and a thin ferrite core for providing a closed magnetic path passing through the central hole of the coil and interlinking the ring-shaped coil, a thin circuit board formed on its one surface with an electric circuit of the DC-DC converter, and a radiator having at least one flat part, wherein the inductor, the circuit board and the radiator are integrally assembled.
    Type: Grant
    Filed: November 16, 1994
    Date of Patent: April 15, 1997
    Assignee: Nippon Steel Corporation
    Inventors: Kenichi Tanigawa, Hosei Hirano, Shingo Katayama, Nobuyoshi Tanaka, Sueyuki Yahagi