Patents by Inventor Kozo Sakamoto

Kozo Sakamoto 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: 11931290
    Abstract: An object of the present invention is to provide a water absorbent resin powder for a heat-generating element composition, which suppresses the generation of the aggregates derived from the water absorbent resin and the adhesion of the water absorbent resin in the production of a heat-generating element composition. A present inventive water absorbent resin powder for a heat-generating element composition includes polyacrylic acid (salt)-based water absorbent resin powder which have a bulk specific gravity (specified by JIS K3362) of 0.630 g/cm3 or less, fluid retention capacity without load (CRC) for a 0.9% by weight aqueous solution of sodium chloride (specified by ERT441.01-2) of 32.0 g/g or less, a weight-average particle diameter (specified by sieve classification) of 250 ?m or more, and an amount of a residual glycidyl-based crosslinking agent of 10 ppm or less.
    Type: Grant
    Filed: December 21, 2018
    Date of Patent: March 19, 2024
    Assignee: NIPPON SHOKUBAI CO., LTD.
    Inventors: Sachie Kitabata, Shigeru Sakamoto, Sumito Kumagai, Kozo Nogi, Kunihiko Ishizaki
  • Patent number: 8508258
    Abstract: A driver circuit that lowers the dependence of the loss in the wide gap semiconductor device upon the temperature is provided. A gate driver circuit for voltage driven power semiconductor switching device includes a power semiconductor switching device, a driver circuit for supplying a drive signal to a gate terminal of the switching device with reference to an emitter control terminal or a source control terminal of the switching device, and a unit for detecting a temperature of the switching device. The temperature of the power semiconductor switching device is detected, and a gate drive voltage or a gate drive resistance value is changed based on the detected temperature.
    Type: Grant
    Filed: January 25, 2007
    Date of Patent: August 13, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Katsumi Ishikawa, Sunao Funakoshi, Kozo Sakamoto, Hidekatsu Onose
  • Patent number: 7952339
    Abstract: A synchronous rectifying drive type semiconductor circuit wherein voltages between drains and sources of power switching elements are detected, temporarily held and compared with a reference voltage. First control signals are generated for turning on the power switching elements depending on comparison result and dead times for the power switching elements are minimized by ORing first control signals and second control signals inputted at input terminals. The first control signals cause the power switching elements to be in “on” state for a constant time until the second control signals as “on” control signals arrive at the input terminals, and then the first control signals as “on” control signals are terminated before the second control signals as “off” signals arrive at the input terminals, thereby swiftly turning off the power switching elements by the second control signals arriving at the input terminals.
    Type: Grant
    Filed: February 8, 2008
    Date of Patent: May 31, 2011
    Assignee: Hitachi, Ltd.
    Inventor: Kozo Sakamoto
  • Patent number: 7671462
    Abstract: A power semiconductor device, having a first semiconductor region, and a second semiconductor region; mounted with a first electrode pad on a semiconductor substrate main surface at the inside surrounded by the third semiconductor region, mounted in the second semiconductor region, and a multilayer substrate having first and second wiring layers, to take out an electrode of the semiconductor chip; joining the first wiring layer part for the first electrode, mounted on the multilayer substrate, in a region opposing to the semiconductor substrate main surface at the inside surrounded by the third semiconductor region, and the first electrode pad, by a conductive material; joining the first wiring layer part for the first electrode, and the second wiring layer at a conductive part; and extending the second wiring layer to the outside of a region opposing the semiconductor substrate main surface at the inside surrounded by the third semiconductor region.
    Type: Grant
    Filed: March 19, 2009
    Date of Patent: March 2, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Kozo Sakamoto, Toshiaki Ishii
  • Publication number: 20090179321
    Abstract: A power semiconductor device, having a first semiconductor region, and a second semiconductor region; mounted with a first electrode pad on a semiconductor substrate main surface at the inside surrounded by the third semiconductor region, mounted in the second semiconductor region, and a multilayer substrate having first and second wiring layers, to take out an electrode of the semiconductor chip; joining the first wiring layer part for the first electrode, mounted on the multilayer substrate, in a region opposing to the semiconductor substrate main surface at the inside surrounded by the third semiconductor region, and the first electrode pad, by a conductive material; joining the first wiring layer part for the first electrode, and the second wiring layer at a conductive part; and extending the second wiring layer to the outside of a region opposing the semiconductor substrate main surface at the inside surrounded by the third semiconductor region.
    Type: Application
    Filed: March 19, 2009
    Publication date: July 16, 2009
    Inventors: Kozo Sakamoto, Toshiaki Ishii
  • Patent number: 7557637
    Abstract: A semiconductor circuit suitable for normally-on switching elements or switching elements low in threshold voltage. A negative power supply is charged by a high-voltage power supply. A high-voltage switch controls the advisability of applying a voltage to a high-voltage terminal. With deducing the power supply to power switching elements, the high-voltage switch is turned off, and even in the case where the voltage of the controlling circuits of the power switching elements is reduced, the power supply capacitors for the controlling circuits are charged by the high-voltage terminal thereby to operate the controlling circuits. Further, a negative power source voltage generating circuit utilizes the energy charged to the capacitors from output terminals. A voltage terminal is inserted between the high-voltage terminal and a reference voltage terminal. The negative power source voltage generating circuit is interposed between the voltage terminal and a plurality of the output terminals.
    Type: Grant
    Filed: February 27, 2007
    Date of Patent: July 7, 2009
    Assignee: Hitachi, Ltd.
    Inventor: Kozo Sakamoto
  • Patent number: 7514780
    Abstract: A power semiconductor device, having a first semiconductor region, and a second semiconductor region; mounted with a first electrode pad on a semiconductor substrate main surface at the inside surrounded by the third semiconductor region, mounted in the second semiconductor region, and a multilayer substrate having first and second wiring layers, to take out an electrode of the semiconductor chip; joining the first wiring layer part for the first electrode, mounted on the multilayer substrate, in a region opposing to the semiconductor substrate main surface at the inside surrounded by the third semiconductor region, and the first electrode pad, by a conductive material; joining the first wiring layer part for the first electrode, and the second wiring layer at a conductive part; and extending the second wiring layer to the outside of a region opposing the semiconductor substrate main surface at the inside surrounded by the third semiconductor region.
    Type: Grant
    Filed: March 14, 2007
    Date of Patent: April 7, 2009
    Assignee: Hitachi, Ltd.
    Inventors: Kozo Sakamoto, Toshiaki Ishii
  • Publication number: 20080205100
    Abstract: A synchronous rectifying drive type semiconductor circuit wherein voltages between drains and sources of power switching elements are detected, temporarily held and compared with a reference voltage. First control signals are generated for turning on the power switching elements depending on comparison result and dead times for the power switching elements are minimized by ORing first control signals and second control signals inputted at input terminals. The first control signals cause the power switching elements to be in “on” state for a constant time until the second control signals as “on” control signals arrive at the input terminals, and then the first control signals as “on” control signals are terminated before the second control signals as “off” signals arrive at the input terminals, thereby swiftly turning off the power switching elements by the second control signals arriving at the input terminals.
    Type: Application
    Filed: February 8, 2008
    Publication date: August 28, 2008
    Inventor: Kozo Sakamoto
  • Publication number: 20070221953
    Abstract: A semiconductor device such as a reverse blocking type switching element is provided with a switching element made of a wide band gap semiconductor on the side of a first major plane where a first terminal is formed, while the wide band gap semiconductor is operable at a high voltage and in low loss. In a reverse blocking type switching element having a hetero junction diode for blocking a reverse direction current on the side of a second major plane where a second terminal is formed, a silicon semiconductor region is provided in a side surface of the semiconductor so as to prevent a deterioration of a withstanding voltage of the hetero junction diode.
    Type: Application
    Filed: March 22, 2007
    Publication date: September 27, 2007
    Inventor: Kozo Sakamoto
  • Publication number: 20070221994
    Abstract: A driver circuit that lowers the dependence of the loss in the wide gap semiconductor device upon the temperature is provided. A gate driver circuit for voltage driven power semiconductor switching device includes a power semiconductor switching device, a driver circuit for supplying a drive signal to a gate terminal of the switching device with reference to an emitter control terminal or a source control terminal of the switching device, and a unit for detecting a temperature of the switching device. The temperature of the power semiconductor switching device is detected, and a gate drive voltage or a gate drive resistance value is changed based on the detected temperature.
    Type: Application
    Filed: January 25, 2007
    Publication date: September 27, 2007
    Inventors: Katsumi Ishikawa, Sunao Funakoshi, Kozo Sakamoto, Hidekatsu Onose
  • Publication number: 20070215903
    Abstract: A power semiconductor device, having a first semiconductor region, and a second semiconductor region; mounted with a first electrode pad on a semiconductor substrate main surface at the inside surrounded by the third semiconductor region, mounted in the second semiconductor region, and a multilayer substrate having first and second wiring layers, to take out an electrode of the semiconductor chip; joining the first wiring layer part for the first electrode, mounted on the multilayer substrate, in a region opposing to the semiconductor substrate main surface at the inside surrounded by the third semiconductor region, and the first electrode pad, by a conductive material; joining the first wiring layer part for the first electrode, and the second wiring layer at a conductive part; and extending the second wiring layer to the outside of a region opposing the semiconductor substrate main surface at the inside surrounded by the third semiconductor region.
    Type: Application
    Filed: March 14, 2007
    Publication date: September 20, 2007
    Inventors: Kozo Sakamoto, Toshiaki Ishii
  • Publication number: 20070216469
    Abstract: A semiconductor circuit suitable for normally-on switching elements or switching elements low in threshold voltage. A negative power supply is charged by a high-voltage power supply. A high-voltage switch controls the advisability of applying a voltage to a high-voltage terminal. With deducing the power supply to power switching elements, the high-voltage switch is turned off, and even in the case where the voltage of the controlling circuits of the power switching elements is reduced, the power supply capacitors for the controlling circuits are charged by the high-voltage terminal thereby to operate the controlling circuits. Further, a negative power source voltage generating circuit utilizes the energy charged to the capacitors from output terminals. A voltage terminal is inserted between the high-voltage terminal and a reference voltage terminal. The negative power source voltage generating circuit is interposed between the voltage terminal and a plurality of the output terminals.
    Type: Application
    Filed: February 27, 2007
    Publication date: September 20, 2007
    Inventor: Kozo SAKAMOTO
  • Patent number: 7019362
    Abstract: The gate resistance of a power MOSFET in a semiconductor chip is reduced and the reliability and yield of the gate of the power MOSFET are improved The semiconductor chip includes two or more control electrode pads functioning as control electrodes for a power semiconductor device formed within a semiconductor chip. The two or more control electrode pads are distributed within the periphery of the gate area of the power semiconductor device such that the gate resistance of the power semiconductor device can be reduced. The two or more control electrode pads are connected via bumps or a conductive bonding material to an electrode layer of a multilayer circuit board disposed outside the semiconductor chip.
    Type: Grant
    Filed: February 20, 2004
    Date of Patent: March 28, 2006
    Assignee: Renesas Technology, Corp.
    Inventors: Kozo Sakamoto, Takayuki Iwasaki, Masaki Shiraishi
  • Patent number: 7005834
    Abstract: In a power supply of a synchronous rectification type, the self-turn on phenomenon of MOSFET is suppressed without increase of the drive loss to thereby improve the power efficiency. In a synchronous rectifier circuit, a threshold value of a commutation MOSFET is made higher than that of a rectification MOSFET and particularly a threshold value of a commutation MOSFET 3 is made 0.5V or more higher than that of a rectification MOSFET 2. The threshold value of the rectification MOSFET 2 is lower than 1.5V and the threshold of the commutation MOSFET 3 is higher than 2.0V.
    Type: Grant
    Filed: July 2, 2004
    Date of Patent: February 28, 2006
    Assignee: Renesas Technology Corp.
    Inventors: Takayuki Iwasaki, Kozo Sakamoto, Masaki Shiraishi, Nobuyoshi Matsuura, Tomoaki Uno
  • Publication number: 20050007078
    Abstract: In a power supply of a synchronous rectification type, the self-turn on phenomenon of MOSFET is suppressed without increase of the drive loss to thereby improve the power efficiency. In a synchronous rectifier circuit, a threshold value of a commutation MOSFET is made higher than that of a rectification MOSFET and particularly a threshold value of a commutation MOSFET 3 is made 0.5V or more higher than that of a rectification MOSFET 2. The threshold value of the rectification MOSFET 2 is lower than 1.5V and the threshold of the commutation MOSFET 3 is higher than 2.0V.
    Type: Application
    Filed: July 2, 2004
    Publication date: January 13, 2005
    Inventors: Takayuki Iwasaki, Kozo Sakamoto, Masaki Shiraishi, Nobuyoshi Matsuura, Tomoaki Uno
  • Patent number: 6842346
    Abstract: Disclosed is a technique capable of improving a power supply efficiency in a power supply circuit. A power MOSFET in a high side of a combined power MOSFET constituting a DC-DC converter is constituted of a horizontal MOSFET, and a power MOSFET in a low side thereof is constituted of a vertical MOSFET.
    Type: Grant
    Filed: December 23, 2003
    Date of Patent: January 11, 2005
    Assignee: Renesas Technology Corp.
    Inventors: Kyouichi Takagawa, Kozo Sakamoto, Nobuyoshi Matsuura, Masashi Koyano
  • Publication number: 20040227163
    Abstract: The gate resistance of a power MOSFET in a semiconductor chip is reduced and the reliability and yield of the gate of the power MOSFET are improved The semiconductor chip includes two or more control electrode pads functioning as control electrodes for a power semiconductor device formed within a semiconductor chip. The two or more control electrode pads are distributed within the periphery of the gate area of the power semiconductor device such that the gate resistance of the power semiconductor device can be reduced. The two or more control electrode pads are connected via bumps or a conductive bonding material to an electrode layer of a multilayer circuit board disposed outside the semiconductor chip.
    Type: Application
    Filed: February 20, 2004
    Publication date: November 18, 2004
    Inventors: Kozo Sakamoto, Takayuki Iwasaki, Masaki Shiraishi
  • Publication number: 20040135248
    Abstract: Disclosed is a technique capable of improving a power supply efficiency in a power supply circuit. A power MOSFET in a high side of a combined power MOSFET constituting a DC-DC converter is constituted of a horizontal MOSFET, and a power MOSFET in a low side thereof is constituted of a vertical MOSFET.
    Type: Application
    Filed: December 23, 2003
    Publication date: July 15, 2004
    Applicant: Renesas Technology Corporation
    Inventors: Kyouichi Takagawa, Kozo Sakamoto, Nobuyoshi Matsuura, Masashi Koyano
  • Patent number: 6700793
    Abstract: Disclosed is a technique capable of improving a power supply efficiency in a power supply circuit. A power MOSFET in a high side of a combined power MOSFET constituting a DC-DC converter is constituted of a horizontal MOSFET, and a power MOSFET in a low side thereof is constituted of a vertical MOSFET.
    Type: Grant
    Filed: January 16, 2002
    Date of Patent: March 2, 2004
    Assignee: Renesas Technology Corporation
    Inventors: Kyouichi Takagawa, Kozo Sakamoto, Nobuyoshi Matsuura, Masashi Koyano
  • Patent number: 6498368
    Abstract: In a semiconductor device having a first terminal 101 (source terminal) and a second terminal 102 (drain terminal), the substrate main surface of a semiconductor chip is on the (110) face, the main contact face of an n-type region 2 and a p-type region 4 is the {111} face perpendicular to the (110) face, elongated n-type regions 2 and elongated p-type regions 4, which are arranged alternately, form a voltage holding area. The first terminal 101 is connected to the p-type regions through wiring, and the second terminal 102 is connected to the n-type regions 2. Also, the p-type region is formed to cover the bottom comers of a gate polycrystalline silicon layer 8.
    Type: Grant
    Filed: December 11, 2000
    Date of Patent: December 24, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Kozo Sakamoto, Yosuke Inoue, Akihiro Miyauchi, Masaki Shiraishi, Mutsuhiro Mori, Atsuo Watanabe, Takasumi Ohyanagi