Patents by Inventor Yasuhiro Kagawa

Yasuhiro Kagawa 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).

  • Publication number: 20130285140
    Abstract: A trench-gate type semiconductor device that can prevent breakdown of a gate insulating film caused by a displacement current flowing into a protective diffusion layer at a portion of a trench underlying a gate electrode at a turn-off time and simultaneously improves a current density by narrowing a cell pitch. The semiconductor device includes a gate electrode embedded into a trench penetrating a base region. The gate electrode is disposed into a lattice shape in a planar view, and a protective diffusion layer is formed in a drift layer at the portion underlying thereof. At least one of blocks divided by the gate electrode is a protective contact region on which the trench is entirely formed. A protective contact for connecting the protective diffusion layer at a bottom portion of the trench and a source electrode is disposed on the protective contact region.
    Type: Application
    Filed: December 5, 2011
    Publication date: October 31, 2013
    Applicant: Mitsubishi Electric Corporation
    Inventors: Yasuhiro Kagawa, Akihiko Furukawa, Shiro Hino, Hiroshi Watanabe, Masayuki Imaizumi
  • Publication number: 20130168700
    Abstract: In a high speed switching power semiconductor device having a sense pad, a high voltage is generated during switching operations in well regions under the sense pad due to a displacement current flowing through its flow path with a resistance, whereby the power semiconductor device sometimes breaks down by dielectric breakdown of a thin insulating film such as a gate insulating film. In a power semiconductor device according to the invention, sense-pad well contact holes are provided on well regions positioned under the sense pad and penetrate a field insulating film thicker than the gate insulating film to connect to the source pad, thereby improving reliability.
    Type: Application
    Filed: June 24, 2010
    Publication date: July 4, 2013
    Applicant: Mitsubishi Electric Corporation
    Inventors: Akihiko Furukawa, Yasuhiro Kagawa, Naruhisa Miura, Shiro Hino, Shuhei Nakata, Kenichi Ohtsuka, Shoyu Watanabe, Masayuki Imaizumi
  • Publication number: 20130140582
    Abstract: The present invention relates to a semiconductor device and a method for manufacturing the same. A RESURF layer (101) including a plurality of P-type implantation layers having a relatively low concentration of P-type impurity is formed adjacent to an active region (2). The RESURF layer (101) includes a first RESURF layer (11), a second RESURF layer (12), a third RESURF layer (13), a fourth RESURF layer (14), and a fifth RESURF layer (15) that are arranged sequentially from the P-type base (2) side so as to surround the P-type base (2). The second RESURF layer (12) is configured with small regions (11?) having an implantation amount equal to that of the first RESURF layer (11) and small regions (13?) having an implantation amount equal to that of the third RESURF layer (13) being alternately arranged in multiple.
    Type: Application
    Filed: April 15, 2011
    Publication date: June 6, 2013
    Applicant: Mitsubishi Electric Corporation
    Inventors: Tsuyoshi Kawakami, Akihiko Furukawa, Naruhisa Miura, Yasuhiro Kagawa, Kenji Hamada, Yoshiyuki Nakaki
  • Patent number: 8093950
    Abstract: A power amplifier amplifying and compositing differential signals and capable of suppressing harmonics is provided. The power amplifier includes first amplifiers amplifying a first input signal and a second input signal, which are differential signals, a first coil receiving the first input signal and the second input signal amplified by the first amplifiers, a second coil magnetically coupled with the first coil and outputting a composite signal of the amplified first input signal and second input signal, a third coil magnetically coupled with the second coil, and a first capacitor coupled between both ends of the third coil, wherein one end of the first capacitor is coupled to a ground node.
    Type: Grant
    Filed: November 19, 2009
    Date of Patent: January 10, 2012
    Assignee: Renesas Electronics Corporation
    Inventors: Akihiko Furukawa, Tsuyoshi Kawakami, Yasuhiro Kagawa, Satoshi Yamakawa
  • Publication number: 20100148872
    Abstract: A power amplifier amplifying and compositing differential signals and capable of suppressing harmonics is provided. The power amplifier includes first amplifiers amplifying a first input signal and a second input signal, which are differential signals, a first coil receiving the first input signal and the second input signal amplified by the first amplifiers, a second coil magnetically coupled with the first coil and outputting a composite signal of the amplified first input signal and second input signal, a third coil magnetically coupled with the second coil, and a first capacitor coupled between both ends of the third coil, wherein one end of the first capacitor is coupled to a ground node.
    Type: Application
    Filed: November 19, 2009
    Publication date: June 17, 2010
    Inventors: Akihiko FURUKAWA, Tsuyoshi Kawakami, Yasuhiro Kagawa, Satoshi Yamakawa
  • Patent number: 5337113
    Abstract: A photosensitive material processing apparatus which processes a photosensitive material by a processing solution stored in a processing tank, while the photosensitive material is being conveyed. The photosensitive material processing apparatus is equipped with an integration device which integrates processed amounts of the photosensitive material. By detecting a discharging of the processing solution or detecting a changing of a filter, a processed amount integrated value of the integration device is reset automatically. The processing solution and the filter can be changed at appropriate times, and the performance of the photosensitive material processing apparatus can be maintained at optimal conditions.
    Type: Grant
    Filed: August 28, 1992
    Date of Patent: August 9, 1994
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Yasuhiro Kagawa, Yohko Takegawa