Patents by Inventor Masaki Shiraishi

Masaki Shiraishi 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: 9412701
    Abstract: The present invention provides a non-insulated type DC-DC converter having a circuit in which a power MOS•FET for a high side switch and a power MOS•FET for a low side switch are connected in series. In the non-insulated type DC-DC converter, the power transistor for the high side switch, the power transistor for the low side switch, and driver circuits that drive these are respectively constituted by different semiconductor chips. The three semiconductor chips are accommodated in one package, and the semiconductor chip including the power transistor for the high side switch, and the semiconductor chip including the driver circuits are disposed so as to approach each other.
    Type: Grant
    Filed: July 2, 2014
    Date of Patent: August 9, 2016
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventors: Yukihiro Satou, Tomoaki Uno, Nobuyoshi Matsuura, Masaki Shiraishi
  • Publication number: 20160109896
    Abstract: In order to reduce parasitic inductance of a main circuit in a power supply circuit, a non-insulated DC-DC converter is provided having a circuit in which a power MOS·FET for a high-side switch and a power MOS·FET for a low-side switch are connected in series. In the non-insulated DC-DC converter, the power MOS·FET for the high-side switch is formed by a p channel vertical MOS·FET, and the power MOS·FET for the low-side switch is formed by an n channel vertical MOS·FET. Thus, a semiconductor chip formed with the power MOS·FET for the high-side switch and a semiconductor chip formed with the power MOS·FET for the low-side switch are mounted over the same die pad and electrically connected to each other through the die pad.
    Type: Application
    Filed: December 27, 2012
    Publication date: April 21, 2016
    Inventors: Masaki SHIRAISHI, Noboru AKIYAMA, Tomoaki UNO, Nobuyoshi MATSUURA
  • Publication number: 20160020309
    Abstract: The problem addressed by the present invention is to provide a semiconductor device capable of improving dv/dt controllability via a gate drive circuit during turn-on switching. The semiconductor device comprises a plurality of trench gate groups, each trench gate group including mutually adjoining three or more trench gates, and the distance between adjoining two trench gate groups is larger than the distance between adjoining two trench gates in one trench gate group. Thereby, gate-emitter capacity increases, and therefore the semiconductor device may improve dv/dt controllability via a gate drive circuit during turn-on switching.
    Type: Application
    Filed: December 3, 2013
    Publication date: January 21, 2016
    Inventors: Hiroshi Suzuki, Masaki Shiraishi, So Watanabe, Tetsuya Ishimaru
  • Publication number: 20160005854
    Abstract: In a non-insulated DC-DC converter having a circuit in which a power MOS•FET high-side switch and a power MOS•FET low-side switch are connected in series, the power MOS•FET low-side switch and a Schottky barrier diode to be connected in parallel with the power MOS•FET low-side switch are formed within one semiconductor chip. The formation region SDR of the Schottky barrier diode is disposed in the center in the shorter direction of the semiconductor chip, and on both sides thereof, the formation regions of the power MOS•FET low-side switch are disposed. From the gate finger in the vicinity of both long sides on the main surface of the semiconductor chip toward the formation region SDR of the Schottky barrier diode, a plurality of gate fingers are disposed so as to interpose the formation region SDR between them.
    Type: Application
    Filed: September 17, 2015
    Publication date: January 7, 2016
    Inventors: Masaki SHIRAISHI, Tomoaki UNO, Nobuyoshi MATSUURA
  • Patent number: 9153686
    Abstract: In a non-insulated DC-DC converter having a circuit in which a power MOS•FET high-side switch and a power MOS•FET low-side switch are connected in series, the power MOS•FET low-side switch and a Schottky barrier diode to be connected in parallel with the power MOS•FET low-side switch are formed within one semiconductor chip. The formation region SDR of the Schottky barrier diode is disposed in the center in the shorter direction of the semiconductor chip, and on both sides thereof, the formation regions of the power MOS•FET low-side switch are disposed. From the gate finger in the vicinity of both long sides on the main surface of the semiconductor chip toward the formation region SDR of the Schottky barrier diode, a plurality of gate fingers are disposed so as to interpose the formation region SDR between them.
    Type: Grant
    Filed: July 24, 2014
    Date of Patent: October 6, 2015
    Assignee: RENESAS ELECTRONICS CORPORATION
    Inventors: Masaki Shiraishi, Tomoaki Uno, Nobuyoshi Matsuura
  • Patent number: 9082814
    Abstract: A semiconductor device includes first semiconductor layer of a first conductivity type; a second semiconductor layer of a second conductivity type that is formed near a surface of the first semiconductor layer; a first main electrode that is electrically connected to the second semiconductor layer; a third semiconductor layer of the second conductivity type that neighbors the first semiconductor layer; a fourth semiconductor layer of the first conductivity type that is selectively disposed in an upper portion of the third semiconductor layer; a second main electrode that is electrically connected to the third semiconductor layer and the fourth semiconductor layer; a trench whose side face is in contact with the third semiconductor layer and the fourth semiconductor layer; a gate electrode that is formed along the side face of the trench by a sidewall of polysilicon; and a polysilicon electrode.
    Type: Grant
    Filed: January 11, 2012
    Date of Patent: July 14, 2015
    Assignee: Hitachi Power Semiconductor Device, Ltd.
    Inventors: Masaki Shiraishi, Mutsuhiro Mori, Hiroshi Suzuki, So Watanabe
  • Publication number: 20140332878
    Abstract: In a non-insulated DC-DC converter having a circuit in which a power MOS•FET high-side switch and a power MOS•FET low-side switch are connected in series, the power MOS•FET low-side switch and a Schottky barrier diode to be connected in parallel with the power MOS•FET low-side switch are formed within one semiconductor chip. The formation region SDR of the Schottky barrier diode is disposed in the center in the shorter direction of the semiconductor chip, and on both sides thereof, the formation regions of the power MOS•FET low-side switch are disposed. From the gate finger in the vicinity of both long sides on the main surface of the semiconductor chip toward the formation region SDR of the Schottky barrier diode, a plurality of gate fingers are disposed so as to interpose the formation region SDR between them.
    Type: Application
    Filed: July 24, 2014
    Publication date: November 13, 2014
    Inventors: Masaki SHIRAISHI, Tomoaki UNO, Nobuyoshi MATSUURA
  • Publication number: 20140312510
    Abstract: The present invention provides a non-insulated type DC-DC converter having a circuit in which a power MOS•FET for a high side switch and a power MOS•FET for a low side switch are connected in series. In the non-insulated type DC-DC converter, the power transistor for the high side switch, the power transistor for the low side switch, and driver circuits that drive these are respectively constituted by different semiconductor chips. The three semiconductor chips are accommodated in one package, and the semiconductor chip including the power transistor for the high side switch, and the semiconductor chip including the driver circuits are disposed so as to approach each other.
    Type: Application
    Filed: July 2, 2014
    Publication date: October 23, 2014
    Inventors: Yukihiro SATOU, Tomoaki UNO, Nobuyoshi MATSUURA, Masaki SHIRAISHI
  • Patent number: 8853846
    Abstract: In a non-insulated DC-DC converter having a circuit in which a power MOS•FET high-side switch and a power MOS•FET low-side switch are connected in series, the power MOS•FET low-side switch and a Schottky barrier diode to be connected in parallel with the power MOS•FET low-side switch are formed within one semiconductor chip. The formation region SDR of the Schottky barrier diode is disposed in the center in the shorter direction of the semiconductor chip, and on both sides thereof, the formation regions of the power MOS•FET low-side switch are disposed. From the gate finger in the vicinity of both long sides on the main surface of the semiconductor chip toward the formation region SDR of the Schottky barrier diode, a plurality of gate fingers are disposed so as to interpose the formation region SDR between them.
    Type: Grant
    Filed: November 5, 2013
    Date of Patent: October 7, 2014
    Assignee: Renesas Electronics Corporation
    Inventors: Masaki Shiraishi, Tomoaki Uno, Nobuyoshi Matsuura
  • Patent number: 8796827
    Abstract: The present invention provides a non-insulated type DC-DC converter having a circuit in which a power MOS•FET for a high side switch and a power MOS•FET for a low side switch are connected in series. In the non-insulated type DC-DC converter, the power transistor for the high side switch, the power transistor for the low side switch, and driver circuits that drive these are respectively constituted by different semiconductor chips. The three semiconductor chips are accommodated in one package, and the semiconductor chip including the power transistor for the high side switch, and the semiconductor chip including the driver circuits are disposed so as to approach each other.
    Type: Grant
    Filed: August 29, 2013
    Date of Patent: August 5, 2014
    Assignee: Renesas Electronics Corporation
    Inventors: Yukihiro Satou, Tomoaki Uno, Nobuyoshi Matsuura, Masaki Shiraishi
  • Publication number: 20140054692
    Abstract: In a non-insulated DC-DC converter having a circuit in which a power MOS•FET high-side switch and a power MOS•FET low-side switch are connected in series, the power MOS•FET low-side switch and a Schottky barrier diode to be connected in parallel with the power MOS•FET low-side switch are formed within one semiconductor chip. The formation region SDR of the Schottky barrier diode is disposed in the center in the shorter direction of the semiconductor chip, and on both sides thereof, the formation regions of the power MOS•FET low-side switch are disposed. From the gate finger in the vicinity of both long sides on the main surface of the semiconductor chip toward the formation region SDR of the Schottky barrier diode, a plurality of gate fingers are disposed so as to interpose the formation region SDR between them.
    Type: Application
    Filed: November 5, 2013
    Publication date: February 27, 2014
    Applicant: RENESAS ELECTRONICS CORPORATION
    Inventors: Masaki SHIRAISHI, Tomoaki UNO, Nobuyoshi MATSUURA
  • Patent number: 8653588
    Abstract: A semiconductor device includes: a first semiconductor layer of a first conductivity type; a second semiconductor layer of a second conductivity type on the first semiconductor layer; trenches in the first semiconductor layer; a semiconductor protruding part on the first semiconductor layer; a third semiconductor layer on the semiconductor protruding part; a fourth semiconductor layer on the third semiconductor layer; a gate insulating layer disposed along the trench; a first interlayer insulating layer disposed along the trench; a first conductive layer facing to the fourth semiconductor layer; a second conductive layer on the first interlayer insulating layer; a second interlayer insulating layer covering the second conductive layer; a third conductive layer on the third semiconductor layer and fourth semiconductor layer; a contacting part connecting the third conductive layer and third semiconductor layer; and a fourth conductive layer formed on the second semiconductor layer.
    Type: Grant
    Filed: July 19, 2012
    Date of Patent: February 18, 2014
    Assignee: Hitachi, Ltd.
    Inventors: So Watanabe, Masaki Shiraishi, Hiroshi Suzuki, Mutsuhiro Mori
  • Patent number: 8653606
    Abstract: It is intended to provide a semiconductor device capable to improve a controllability of dv/dt by a gate drive circuit during a turn-on switching period, while maintaining a low loss and a high breakdown voltage. Trench gates are disposed so as to have narrow distance regions and wide distance regions, wherein each of the narrow distance regions is provided with a channel region, and each of the wide distance regions is provided with trenches, each trench having an electrode electrically connected to the emitter electrode. In this manner, even if a floating-p layer is removed, it is possible to reduce a feedback capacity and maintain a breakdown voltage.
    Type: Grant
    Filed: June 27, 2013
    Date of Patent: February 18, 2014
    Assignee: Hitachi, Ltd.
    Inventor: Masaki Shiraishi
  • Patent number: 8638577
    Abstract: In a non-isolated DC/DC converter, a reference potential for a low-side pre-driver which drives a gate of a low-side MOSFET is applied from a portion except for a main circuit passing through a high-side MOSFET and the low-side MOSFET so that a parasitic inductance between a source of the low-side MOSFET and the pre-driver is increased without increasing the sum of parasitic inductances in the main circuit and negative potential driving of the gate of the low-side MOSFET can be performed and a self turn-on phenomenon can be prevented without adding any member and changing drive system.
    Type: Grant
    Filed: September 13, 2011
    Date of Patent: January 28, 2014
    Assignee: Renesas Electronics Corporation
    Inventors: Masaki Shiraishi, Takayuki Hashimoto, Noboru Akiyama
  • Publication number: 20140003002
    Abstract: The present invention provides a non-insulated type DC-DC converter having a circuit in which a power MOS•FET for a high side switch and a power MOS•FET for a low side switch are connected in series. In the non-insulated type DC-DC converter, the power transistor for the high side switch, the power transistor for the low side switch, and driver circuits that drive these are respectively constituted by different semiconductor chips. The three semiconductor chips are accommodated in one package, and the semiconductor chip including the power transistor for the high side switch, and the semiconductor chip including the driver circuits are disposed so as to approach each other.
    Type: Application
    Filed: August 29, 2013
    Publication date: January 2, 2014
    Applicant: Renesas Electronics Corporation
    Inventors: Yukihiro SATOU, Tomoaki UNO, Nobuyoshi MATSUURA, Masaki SHIRAISHI
  • Publication number: 20140003109
    Abstract: It is intended to provide a semiconductor device capable to improve a controllability of dv/dt by a gate drive circuit during a turn-on switching period, while maintaining a low loss and a high breakdown voltage. Trench gates are disposed so as to have narrow distance regions and wide distance regions, wherein each of the narrow distance regions is provided with a channel region, and each of the wide distance regions is provided with trenches, each trench having an electrode electrically connected to the emitter electrode. In this manner, even if a floating-p layer is removed, it is possible to reduce a feedback capacity and maintain a breakdown voltage.
    Type: Application
    Filed: June 27, 2013
    Publication date: January 2, 2014
    Inventor: Masaki SHIRAISHI
  • Patent number: 8592904
    Abstract: In a non-insulated DC-DC converter having a circuit in which a power MOS•FET high-side switch and a power MOS•FET low-side switch are connected in series, the power MOS•FET low-side switch and a Schottky barrier diode to be connected in parallel with the power MOS•FET low-side switch are formed within one semiconductor chip. The formation region SDR of the Schottky barrier diode is disposed in the center in the shorter direction of the semiconductor chip, and on both sides thereof, the formation regions of the power MOS•FET low-side switch are disposed. From the gate finger in the vicinity of both long sides on the main surface of the semiconductor chip toward the formation region SDR of the Schottky barrier diode, a plurality of gate fingers are disposed so as to interpose the formation region SDR between them.
    Type: Grant
    Filed: August 17, 2012
    Date of Patent: November 26, 2013
    Assignee: Renesas Electronics Corporation
    Inventors: Masaki Shiraishi, Tomoaki Uno, Nobuyoshi Matsuura
  • Patent number: 8575733
    Abstract: The present invention provides a non-insulated type DC-DC converter having a circuit in which a power MOS•FET for a high side switch and a power MOS•FET for a low side switch are connected in series. In the non-insulated type DC-DC converter, the power transistor for the high side switch, the power transistor for the low side switch, and driver circuits that drive these are respectively constituted by different semiconductor chips. The three semiconductor chips are accommodated in one package, and the semiconductor chip including the power transistor for the high side switch, and the semiconductor chip including the driver circuits are disposed so as to approach each other.
    Type: Grant
    Filed: December 17, 2012
    Date of Patent: November 5, 2013
    Assignee: Renesas Electronics Corporation
    Inventors: Yohihiro Satou, Tomoaki Uno, Nobuyoshi Matsuura, Masaki Shiraishi
  • Patent number: 8519533
    Abstract: In a non-insulated DC-DC converter having a circuit in which a power MOS•FET high-side switch and a power MOS•FET low-side switch are connected in series, the power MOS•FET low-side switch and a Schottky barrier diode to be connected in parallel with the power MOS•FET low-side switch are formed within one semiconductor chip. The formation region SDR of the Schottky barrier diode is disposed in the center in the shorter direction of the semiconductor chip, and on both sides thereof, the formation regions of the power MOS•FET low-side switch are disposed. From the gate finger in the vicinity of both long sides on the main surface of the semiconductor chip toward the formation region SDR of the Schottky barrier diode, a plurality of gate fingers are disposed so as to interpose the formation region SDR between them.
    Type: Grant
    Filed: February 14, 2012
    Date of Patent: August 27, 2013
    Assignee: Renesas Electronics Corporation
    Inventors: Masaki Shiraishi, Tomoaki Uno, Nobuyoshi Matsuura
  • Patent number: 8482345
    Abstract: A non-insulated DC-DC converter has a power MOS•FET for a highside switch and a power MOS•FET for a lowside switch. In the non-insulated DC-DC converter, the power MOS•FET for the highside switch and the power MOS•FET for the lowside switch, driver circuits that control operations of these elements, respectively, and a Schottky barrier diode connected in parallel with the power MOS•FET for the lowside switch are respectively formed in four different semiconductor chips. These four semiconductor chips are housed in one package. The semiconductor chips are mounted over the same die pad. The semiconductor chips are disposed so as to approach each other.
    Type: Grant
    Filed: November 10, 2011
    Date of Patent: July 9, 2013
    Assignee: Renesas Electronics Corporation
    Inventors: Tomoaki Uno, Masaki Shiraishi, Nobuyoshi Matsuura, Toshio Nagasawa