Patents by Inventor Takeshi Asada

Takeshi Asada 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: 10475917
    Abstract: A MOSFET includes a semiconductor base substrate where a super junction structure is formed of an n-type column region and a p-type column region. A total amount of a dopant in the n-type column region is set to a value greater than a total amount of a dopant in the p-type column region. The MOSFET is configured to be operated during a period from a point of time when a drain current starts to decrease to a point of time when the drain current becomes 0 for the first time in response to turning off of the MOSFET such that a first period during which the drain current is decreased, a second period during which the drain current is increased or the drain current becomes constant, and a third period during which the drain current is decreased again occur in this order.
    Type: Grant
    Filed: May 21, 2018
    Date of Patent: November 12, 2019
    Assignee: SHINDENGEN ELECTRIC MANUFACTURING CO., LTD.
    Inventors: Daisuke Arai, Shigeru Hisada, Mizue Kitada, Takeshi Asada
  • Patent number: 10468518
    Abstract: A power semiconductor device of the present invention includes: a semiconductor base body which has a super junction structure formed of a plurality of first conductive-type columnar regions and a plurality of second conductive-type columnar regions; a plurality of trenches; gate insulation films; gate electrodes; an interlayer insulation film; contact holes formed such that two or more contact holes are formed between two trenches disposed adjacently to each other; metal plugs formed by filling the inside of the contact holes with metal; and an electrode, wherein a first conductive-type high concentration diffusion region is formed only between the trench and the metal plug disposed closest to the trench between each two trenches disposed adjacently to each other. According to the power semiconductor device of the present invention, it is possible to provide a power semiconductor device which satisfies a demand for reduction in cost and downsizing of electronic equipment, and has a large breakdown strength.
    Type: Grant
    Filed: January 16, 2017
    Date of Patent: November 5, 2019
    Assignee: SHINDENGEN ELECTRIC MANUFACTURING CO., LTD.
    Inventors: Mizue Kitada, Takeshi Asada, Takeshi Yamaguchi, Noriaki Suzuki, Daisuke Arai
  • Patent number: 10439056
    Abstract: A power semiconductor device according to the present invention has a super junction structure, and includes a low-resistance semiconductor layer, an n?-type column region, p?-type column regions, a base region, trenches, gate insulation films, gate electrodes, source regions, interlayer insulation films, contact holes, metal plugs, p+-type diffusion regions, a source electrode and a gate pad electrode. An active element part includes an n?-type column region between a predetermined p?-type column region disposed closest to a gate pad part and a predetermined n?-type column region disposed closest to the gate pad part among the n?-type column regions which are in contact with the trenches. The present invention provides a power semiconductor device which can satisfy a demand for reduction in cost and downsizing of electronic equipment, can lower ON resistance while maintaining a high withstand voltage, and can possess a large breakdown resistance.
    Type: Grant
    Filed: March 31, 2016
    Date of Patent: October 8, 2019
    Assignee: SHINDENGEN ELECTRIC MANUFACTURING CO., LTD.
    Inventors: Daisuke Arai, Mizue Kitada, Takeshi Asada, Takeshi Yamaguchi, Noriaki Suzuki
  • Patent number: 10411141
    Abstract: A semiconductor device includes: a semiconductor base body where a second semiconductor layer is stacked on a first semiconductor layer, a trench is formed on a surface of the second semiconductor layer, and a third semiconductor layer which is formed of an epitaxial layer is formed in the inside of the trench; a first electrode; an interlayer insulation film which has a predetermined opening; and a second electrode, wherein metal is filled in the opening, the opening is disposed at a position avoiding a center portion of the third semiconductor layer, the second electrode is connected to the third semiconductor layer through the metal, and a surface of the center portion of the third semiconductor layer is covered by the interlayer insulation film.
    Type: Grant
    Filed: February 27, 2017
    Date of Patent: September 10, 2019
    Assignee: SHINDENGEN ELECTRIC MANUFACTURING CO., LTD.
    Inventors: Mizue Kitada, Takeshi Asada, Takeshi Yamaguchi, Noriaki Suzuki, Daisuke Arai
  • Publication number: 20190221664
    Abstract: A MOSFET used in a power conversion circuit having a reactor, a power source, the MOSFET, and a rectifier element, includes a semiconductor base substrate with a super junction structure formed of an n-type column region and a p-type column region. A total amount of a dopant in the n-type column region is higher than a total amount of a dopant in the p-type column region. The MOSFET is configured to be operated during a period from a point of time when a drain current starts to decrease to a point of time when the drain current becomes 0 for the first time in response to turning off of the MOSFET such that a first period during which the drain current decreases, a second period during which the drain current increases, and a third period during which the drain current decreases again appear in this order.
    Type: Application
    Filed: September 2, 2016
    Publication date: July 18, 2019
    Inventors: Daisuke ARAI, Shigeru HISADA, Mizue KITADA, Takeshi ASADA
  • Publication number: 20190214496
    Abstract: A MOSFET used in a power conversion circuit including a reactor, a power source, the MOSFET, and a rectifier element, includes a semiconductor base substrate having an n-type column region and a p-type column region, the n-type column region and the p-type column region forming a super junction structure, the n-type column region and the p-type column region are formed such that a total amount of a dopant in the p-type column region is set higher than a total amount of a dopant in the n-type column region, and the MOSFET is configured to be operated in response to turning on of the MOSFET such that at a center of the n-type column region as viewed in a plan view, a low electric field region having lower field intensity than areas of the n-type column region other than the center of the n-type column region appears.
    Type: Application
    Filed: September 16, 2016
    Publication date: July 11, 2019
    Inventors: Daisuke ARAI, Shigeru HISADA, Mizue KITADA, Takeshi ASADA
  • Publication number: 20190165161
    Abstract: A MOSFET includes a semiconductor base substrate where a super junction structure is formed of an n-type column region and a p-type column region. A total amount of a dopant in the n-type column region is set to a value greater than a total amount of a dopant in the p-type column region. The MOSFET is configured to be operated during a period from a point of time when a drain current starts to decrease to a point of time when the drain current becomes 0 for the first time in response to turning off of the MOSFET such that a first period during which the drain current is decreased, a second period during which the drain current is increased or the drain current becomes constant, and a third period during which the drain current is decreased again occur in this order.
    Type: Application
    Filed: May 21, 2018
    Publication date: May 30, 2019
    Inventors: Daisuke ARAI, Shigeru HISADA, Mizue KITADA, Takeshi ASADA
  • Publication number: 20190152131
    Abstract: A method for producing a stretched film including the steps of: stretching a long-length multilayer film (D) including a pre-stretch film (A) formed of a thermoplastic resin, a shrinkable film (B) having a shrinkage ratio in a lengthwise direction of the film under conditions of 140° C. and 60 seconds in the air of 10% or more and 40% or less, a shrinkage ratio in the widthwise direction thereof of 5% or less, and an adhesion layer (C) bonding the pre-stretch film (A) to the shrinkable film (B), at a stretching ratio of less than 1.5 times in a direction of 45°±15° with respect to the widthwise direction of the multilayer film (D), and peeling the shrinkable film (B) and the adhesion layer (C).
    Type: Application
    Filed: February 28, 2017
    Publication date: May 23, 2019
    Applicant: ZEON CORPORATION
    Inventor: Takeshi ASADA
  • Publication number: 20190006526
    Abstract: A semiconductor device includes: a semiconductor base body where a second semiconductor layer is stacked on a first semiconductor layer, a trench is formed on a surface of the second semiconductor layer, and a third semiconductor layer which is formed of an epitaxial layer is formed in the inside of the trench; a first electrode; an interlayer insulation film which has a predetermined opening; and a second electrode, wherein metal is filled in the opening, the opening is disposed at a position avoiding a center portion of the third semiconductor layer, the second electrode is connected to the third semiconductor layer through the metal, and a surface of the center portion of the third semiconductor layer is covered by the interlayer insulation film.
    Type: Application
    Filed: February 27, 2017
    Publication date: January 3, 2019
    Inventors: Mizue KITADA, Takeshi ASADA, Takeshi YAMAGUCHI, Noriaki SUZUKI, Daisuke ARAI
  • Publication number: 20180374939
    Abstract: A power semiconductor device according to the present invention has a super junction structure, and includes a low-resistance semiconductor layer, an n?-type column region, p?-type column regions, a base region, trenches, gate insulation films, gate electrodes, source regions, interlayer insulation films, contact holes, metal plugs, p+-type diffusion regions, a source electrode and a gate pad electrode. An active element part includes an n?-type column region between a predetermined p?-type column region disposed closest to a gate pad part and a predetermined n?-type column region disposed closest to the gate pad part among the n?-type column regions which are in contact with the trenches. The present invention provides a power semiconductor device which can satisfy a demand for reduction in cost and downsizing of electronic equipment, can lower ON resistance while maintaining a high withstand voltage, and can possess a large breakdown resistance.
    Type: Application
    Filed: March 31, 2016
    Publication date: December 27, 2018
    Inventors: Daisuke ARAI, Mizue KITADA, Takeshi ASADA, Takeshi YAMAGUCHI, Noriaki SUZUKI
  • Publication number: 20180269318
    Abstract: A power semiconductor device of the present invention includes: a semiconductor base body which has a super junction structure formed of a plurality of first conductive-type columnar regions and a plurality of second conductive-type columnar regions; a plurality of trenches; gate insulation films; gate electrodes; an interlayer insulation film; contact holes formed such that two or more contact holes are formed between two trenches disposed adjacently to each other; metal plugs formed by filling the inside of the contact holes with metal; and an electrode, wherein a first conductive-type high concentration diffusion region is formed only between the trench and the metal plug disposed closest to the trench between each two trenches disposed adjacently to each other. According to the power semiconductor device of the present invention, it is possible to provide a power semiconductor device which satisfies a demand for reduction in cost and downsizing of electronic equipment, and has a large breakdown strength.
    Type: Application
    Filed: January 16, 2017
    Publication date: September 20, 2018
    Inventors: Mizue KITADA, Takeshi ASADA, Takeshi YAMAGUCHI, Noriaki SUZUKI, Daisuke ARAI
  • Patent number: 10036841
    Abstract: A lengthy stretched film made of a thermoplastic resin, having, over the width direction of at least 1300 mm, a value of an orientation angle ? to a take-up direction in a range of 40° to 50° and fluctuation thereof of 1.0° or less, and a value of an average Nz coefficient in a range of 1.3 to 2.0 and fluctuation thereof of 0.10 or less. A lengthy circularly polarizing plate constituted by laminating the lengthy stretched film with a lengthy polarizer. A reflective display type liquid crystal display device provided with the circularly polarizing plate constituted by trimming the lengthy circularly polarizing plate to a desired size.
    Type: Grant
    Filed: March 19, 2015
    Date of Patent: July 31, 2018
    Assignee: ZEON CORPORATION
    Inventor: Takeshi Asada
  • Patent number: 9859414
    Abstract: A semiconductor device includes a drift layer 20 of a first conductivity type, a base layer 30 of a second conductivity type that is disposed on the drift layer 20 and is connected to a source electrode 90, and a column layer 50 of a second conductivity type that is connected to the source electrode 90 and penetrates the base layer 30 to extend into the drift layer 20.
    Type: Grant
    Filed: March 31, 2014
    Date of Patent: January 2, 2018
    Assignee: Shindengen Electric Manufacturing Co., Ltd.
    Inventors: Takeshi Asada, Mizue Kitada, Takeshi Yamaguchi, Noriaki Suzuki
  • Patent number: 9689440
    Abstract: A power transfer device includes a hydraulic clutch capable of coupling and decoupling a secondary shaft of a CVT and axles to and from each other. A secondary pulley of the CVT includes a movable sheave movably supported by the secondary shaft, and a secondary piston that rotates together with the secondary shaft and that constitutes a second hydraulic actuator together with the movable sheave. The secondary piston of the second hydraulic actuator is used to define an engagement oil chamber of the hydraulic clutch.
    Type: Grant
    Filed: February 14, 2014
    Date of Patent: June 27, 2017
    Assignee: AISIN AW CO., LTD.
    Inventors: Kazumichi Tsukuda, Takeshi Asada
  • Publication number: 20160118492
    Abstract: A semiconductor device includes a drift layer 20 of a first conductivity type, a base layer 30 of a second conductivity type that is disposed on the drift layer 20 and is connected to a source electrode 90, and a column layer 50 of a second conductivity type that is connected to the source electrode 90 and penetrates the base layer 30 to extend into the drift layer 20.
    Type: Application
    Filed: March 31, 2014
    Publication date: April 28, 2016
    Applicant: Shindengen Electric Manufacturing Co., Ltd.
    Inventors: Takeshi ASADA, Mizue KITADA, Takeshi YAMAGUCHI, Noriaki SUZUKI
  • Publication number: 20150345570
    Abstract: A power transfer device includes a hydraulic clutch capable of coupling and decoupling a secondary shaft of a CVT and axles to and from each other. A secondary pulley of the CVT includes a movable sheave movably supported by the secondary shaft, and a secondary piston that rotates together with the secondary shaft and that constitutes a second hydraulic actuator together with the movable sheave. The secondary piston of the second hydraulic actuator is used to define an engagement oil chamber of the hydraulic clutch.
    Type: Application
    Filed: February 14, 2014
    Publication date: December 3, 2015
    Applicant: AISIN AW CO., LTD.
    Inventors: Kazumichi TSUKUDA, Takeshi ASADA
  • Publication number: 20150192722
    Abstract: A lengthy stretched film made of a thermoplastic resin, having, over the width direction of at least 1300 mm, a value of an orientation angle ? to a take-up direction in a range of 40° to 50° and fluctuation thereof of 1.0° or less, and a value of an average Nz coefficient in a range of 1.3 to 2.0 and fluctuation thereof of 0.10 or less. A lengthy circularly polarizing plate constituted by laminating the lengthy stretched film with a lengthy polarizer. A reflective display type liquid crystal display device provided with the circularly polarizing plate constituted by trimming the lengthy circularly polarizing plate to a desired size.
    Type: Application
    Filed: March 19, 2015
    Publication date: July 9, 2015
    Applicant: ZEON CORPORATION
    Inventor: Takeshi ASADA
  • Patent number: 9011991
    Abstract: A lengthy stretched film made of a thermoplastic resin, having, over the width direction of at least 1300 mm, a value of an orientation angle ? to a take-up direction in a range of 40° to 50° and fluctuation thereof of 1.0° or less, and a value of an average Nz coefficient in a range of 1.3 to 2.0 and fluctuation thereof of 0.10 or less. A lengthy circularly polarizing plate constituted by laminating the lengthy stretched film with a lengthy polarizer. A reflective display type liquid crystal display device provided with the circularly polarizing plate constituted by trimming the lengthy circularly polarizing plate to a desired size.
    Type: Grant
    Filed: March 26, 2007
    Date of Patent: April 21, 2015
    Assignee: Zeon Corporation
    Inventor: Takeshi Asada
  • Patent number: 8139501
    Abstract: A relay device for multicast communications. The relay device transmitting a user data packet, containing a content, in which to set a multicast address associated with the content, to a plurality of base stations belonging to a same zone in order to wirelessly transmit the content substantially simultaneously from the plurality of base stations, comprises a storing unit storing information indicative of a multicast group in which the mobile terminal participates together with information about the zone to which the base station performing wireless communications with the mobile terminal belongs, and generates a query packet for checking if the mobile terminal continues to participate in the multicast group stored therein, and transmits the user data packet containing the query packet to each of the base stations belonging to the same zone.
    Type: Grant
    Filed: October 5, 2007
    Date of Patent: March 20, 2012
    Assignee: Fujitsu Limited
    Inventors: Tadanao Andou, Takeshi Asada
  • Patent number: 8097200
    Abstract: A method for producing a stretched film comprising supplying a film composed of a thermoplastic resin along a direction D1 that is different from a taking-up direction D2 of a post-stretch film, and obliquely stretching the film while transferring the film with the edges thereof being gripped by gripping devices, to produce the stretched film having an orientation angle ? being within 45±5° with respect to the taking-up direction.
    Type: Grant
    Filed: September 11, 2008
    Date of Patent: January 17, 2012
    Assignee: Zeon Corporation
    Inventor: Takeshi Asada