Patents by Inventor Takaaki Shirasawa

Takaaki Shirasawa 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: 20230187225
    Abstract: A method for manufacturing a semiconductor device includes steps (a) to (e). In the step (a), a lead frame including a plurality of lead portions, tie bars, a frame body, and ring portions is prepared. In the step (b), an assembled body is formed. In the step (c), the assembled body is placed in a cavity. In the step (d), a molding resin in a liquid form is injected into the cavity and cured in a state in which a pin is inserted through a hole of the ring portion and an upper surface of the ring portion is in contact with an inner surface of the upper die, and a resin-molded body is formed. In the step (e), the frame body, the tie bars, and connecting portions are cut after the resin-molded body is taken out from the molding die.
    Type: Application
    Filed: July 14, 2020
    Publication date: June 15, 2023
    Applicant: Mitsubishi Electric Corporation
    Inventors: Naoki YOSHIMATSU, Takaaki SHIRASAWA
  • Patent number: 11621213
    Abstract: An object of the present invention is to provide a semiconductor device in which the effect of dimensional tolerance can be reduced, and a method for manufacturing the same. The semiconductor device according to the present invention includes: a plurality of cooling plates each having a coolant passage inside; spacers disposed to stack the cooling plates with spaces; at least one semiconductor package disposed on at least one principal surface of at least one of the cooling plates; and a spring plate disposed between adjacent ones of the cooling plates, the spring plate biasing the at least one semiconductor package toward the cooling plates.
    Type: Grant
    Filed: December 1, 2017
    Date of Patent: April 4, 2023
    Assignee: Mitsubishi Electric Corporation
    Inventors: Hideo Komo, Takaaki Shirasawa, Shintaro Araki, Nobuyoshi Kimoto, Takeshi Omaru
  • Publication number: 20220189851
    Abstract: It is an object to provide a technique allowing for suppression of the height of a protrusion from the surface of a semiconductor module. A semiconductor device includes: a semiconductor module having a first groove; a Belleville washer having a recess in an outer surface and a protrusion on an inner surface; and a screw passing through the hole of the Belleville washer and the first groove of the semiconductor module to fasten the semiconductor module and an attached body. A head of the screw is accommodated in the recess of the Belleville washer, and at least portion of the protrusion of the Belleville washer is accommodated in the first groove of the semiconductor module.
    Type: Application
    Filed: June 25, 2019
    Publication date: June 16, 2022
    Applicant: Mitsubishi Electric Corporation
    Inventors: Tsuyoshi TAKAYAMA, Takaaki SHIRASAWA, Mitsunori AIKO
  • Patent number: 11302655
    Abstract: A semiconductor device includes a semiconductor element having an electrode, material of which is first metal, a lead frame through which a plurality of holes extend with an outer contour of the electrode being avoided in a first portion, and having the first portion, material of which is second metal, a bonding layer interposed between the first portion and the electrode, and solder being inside the plurality of holes and adjoining the bonding layer, the solder being thicker than the bonding layer. The plurality of holes have a plurality of first holes extending through the first portion in a thickness direction of the first portion. The bonding layer has a first bonding layer located on the electrode side and being an alloy of the first metal and tin, and a second bonding layer located on the first portion side and being an alloy of the second metal and tin. The plurality of first holes are located in an annular region inside the outer contour of the electrode.
    Type: Grant
    Filed: June 29, 2018
    Date of Patent: April 12, 2022
    Assignee: Mitsubishi Electric Corporation
    Inventors: Nobuyoshi Kimoto, Mitsunori Aiko, Takaaki Shirasawa
  • Publication number: 20210233869
    Abstract: A semiconductor device includes a semiconductor element having an electrode, material of which is first metal, a lead frame through which a plurality of holes extend with an outer contour of the electrode being avoided in a first portion, and having the first portion, material of which is second metal, a bonding layer interposed between the first portion and the electrode, and solder being inside the plurality of holes and adjoining the bonding layer, the solder being thicker than the bonding layer. The plurality of holes have a plurality of first holes extending through the first portion in a thickness direction of the first portion. The bonding layer has a first bonding layer located on the electrode side and being an alloy of the first metal and tin, and a second bonding layer located on the first portion side and being an alloy of the second metal and tin. The plurality of first holes are located in an annular region inside the outer contour of the electrode.
    Type: Application
    Filed: June 29, 2018
    Publication date: July 29, 2021
    Applicant: Mitsubishi Electric Corporation
    Inventors: Nobuyoshi KIMOTO, Mitsunori AIKO, Takaaki SHIRASAWA
  • Patent number: 10950558
    Abstract: An object is to provide a technique for reducing process steps, and a stress generated at the peripheral portion of the joint portion between an electrode of a semiconductor element and a lead frame. A semiconductor device includes the following: a semiconductor element disposed on a heat spreader; a lead frame joined to an emitter electrode of the semiconductor element via solder, which is a joining material; a metal film disposed on a surface of the emitter electrode; and an anti-oxidation film disposed on a surface of the metal film. The metal film has a peripheral portion that is entirely exposed from the anti-oxidation film.
    Type: Grant
    Filed: March 27, 2017
    Date of Patent: March 16, 2021
    Assignee: Mitsubishi Electric Corporation
    Inventors: Nobuyoshi Kimoto, Mitsunori Aiko, Takaaki Shirasawa
  • Patent number: 10916483
    Abstract: An object of the present invention is to provide a semiconductor device having a structure in which a resin hardly enters between an insert electrode and a nut at a time of resin sealing. The semiconductor device according to the present invention includes an insert electrode having an insert hole into which a bolt is inserted from outside, a nut which has a screw hole to be screwed with the bolt and is disposed on an inside of the insert electrode so that the screw hole is communicated with the insert hole, at least one semiconductor element being electrically connected to the insert electrode, and a resin sealing the inside of the insert electrode, the nut, and the at least one semiconductor element, wherein a burr is provided on an outer periphery of a direct contact surface of the nut being in direct contact with the insert electrode.
    Type: Grant
    Filed: April 23, 2019
    Date of Patent: February 9, 2021
    Assignee: Mitsubishi Electric Corporation
    Inventors: Takahiko Murakami, Mitsunori Aiko, Takaaki Shirasawa, Natsuki Tsuji
  • Publication number: 20200286811
    Abstract: An object of the present invention is to provide a semiconductor device in which the effect of dimensional tolerance can be reduced, and a method for manufacturing the same. The semiconductor device according to the present invention includes: a plurality of cooling plates each having a coolant passage inside; spacers disposed to stack the cooling plates with spaces; at least one semiconductor package disposed on at least one principal surface of at least one of the cooling plates; and a spring plate disposed between adjacent ones of the cooling plates, the spring plate biasing the at least one semiconductor package toward the cooling plates.
    Type: Application
    Filed: December 1, 2017
    Publication date: September 10, 2020
    Applicant: Mitsubishi Electric Corporation
    Inventors: Hideo KOMO, Takaaki SHIRASAWA, Shintaro ARAKI, Nobuyoshi KIMOTO, Takeshi OMARU
  • Patent number: 10714404
    Abstract: A technique disclosed in the Description relates to a technique for improving the heat dissipation capability of a semiconductor element and the heat dissipation capability of a lead electrode without increasing the size of a product. A semiconductor device of the technique includes the following: a semiconductor element; a lead electrode having a lower surface connected to an upper surface of the semiconductor element at one end of the lead electrode, the lead electrode being an external terminal; a cooling mechanism disposed on a lower surface side of the semiconductor element; and a heat dissipation mechanism provided to be thermally joined between the lower surface of the lead electrode and the cooling mechanism, the lower surface being more adjacent to an other-end side of the lead electrode than the one end, the heat dissipation mechanism including at least one insulating layer.
    Type: Grant
    Filed: January 29, 2016
    Date of Patent: July 14, 2020
    Assignee: Mitsubishi Electric Corporation
    Inventors: Ryoji Murai, Mitsunori Aiko, Takaaki Shirasawa
  • Publication number: 20200013730
    Abstract: An object is to provide a technique for reducing process steps, and a stress generated at the peripheral portion of the joint portion between an electrode of a semiconductor element and a lead frame. A semiconductor device includes the following: a semiconductor element disposed on a heat spreader; a lead frame joined to an emitter electrode of the semiconductor element via solder, which is a joining material; a metal film disposed on a surface of the emitter electrode; and an anti-oxidation film disposed on a surface of the metal film. The metal film has a peripheral portion that is entirely exposed from the anti-oxidation film.
    Type: Application
    Filed: March 27, 2017
    Publication date: January 9, 2020
    Applicant: Mitsubishi Electric Corporation
    Inventors: Nobuyoshi KIMOTO, Mitsunori AIKO, Takaaki SHIRASAWA
  • Patent number: 10529682
    Abstract: A semiconductor device includes a semiconductor module having a semiconductor element, a radiator plate which is connected to the semiconductor element and which has at least one radiator plate through hole formed therein, and resin covering the semiconductor element and the radiator plate with a lower surface of the radiator plate exposed, a cooler, first insulating grease provided between the lower surface of the radiator plate and the cooler to thermally connect the radiator plate and the cooler, and second insulating grease provided in the at least one radiator plate through hole to be connected to the first insulating grease.
    Type: Grant
    Filed: August 30, 2018
    Date of Patent: January 7, 2020
    Assignee: Mitsubishi Electric Corporation
    Inventors: Yuki Hata, Shintaro Araki, Takaaki Shirasawa
  • Publication number: 20190252276
    Abstract: An object of the present invention is to provide a semiconductor device having a structure in which a resin hardly enters between an insert electrode and a nut at a time of resin sealing. The semiconductor device according to the present invention includes an insert electrode having an insert hole into which a bolt is inserted from outside, a nut which has a screw hole to be screwed with the bolt and is disposed on an inside of the insert electrode so that the screw hole is communicated with the insert hole, at least one semiconductor element being electrically connected to the insert electrode, and a resin sealing the inside of the insert electrode, the nut, and the at least one semiconductor element, wherein a burr is provided on an outer periphery of a direct contact surface of the nut being in direct contact with the insert electrode.
    Type: Application
    Filed: April 23, 2019
    Publication date: August 15, 2019
    Applicant: Mitsubishi Electric Corporation
    Inventors: Takahiko MURAKAMI, Mitsunori AIKO, Takaaki SHIRASAWA, Natsuki TSUJI
  • Patent number: 10304748
    Abstract: An object of the present invention is to provide a semiconductor device having a structure in which a resin hardly enters between an insert electrode and a nut at a time of resin sealing. The semiconductor device according to the present invention includes an insert electrode having an insert hole into which a bolt is inserted from outside, a nut which has a screw hole to be screwed with the bolt and is disposed on an inside of the insert electrode so that the screw hole is communicated with the insert hole, at least one semiconductor element being electrically connected to the insert electrode, and a resin sealing the inside of the insert electrode, the nut, and the at least one semiconductor element, wherein a burr is provided on an outer periphery of a direct contact surface of the nut being in direct contact with the insert electrode.
    Type: Grant
    Filed: July 27, 2015
    Date of Patent: May 28, 2019
    Assignee: Mitsubishi Electric Corporation
    Inventors: Takahiko Murakami, Mitsunori Aiko, Takaaki Shirasawa, Natsuki Tsuji
  • Patent number: 10224267
    Abstract: A first switching element and a second switching element are thermally connected to each other since the first switching element and the second switching element are fixed on a second substrate. An upper arm is capable of increasing the current capacity of the semiconductor device because of the parallel connection of the first switching element and the second switching element. The lower arm is capable of increasing the current capacity of the semiconductor device because of the parallel connection of the first switching element and the second switching element.
    Type: Grant
    Filed: July 16, 2013
    Date of Patent: March 5, 2019
    Assignee: Mitsubishi Electric Corporation
    Inventors: Shintaro Araki, Mitsunori Aiko, Takaaki Shirasawa, Khalid Hassan Hussein
  • Publication number: 20180374814
    Abstract: A semiconductor device includes a semiconductor module having a semiconductor element, a radiator plate which is connected to the semiconductor element and which has at least one radiator plate through hole formed therein, and resin covering the semiconductor element and the radiator plate with a lower surface of the radiator plate exposed, a cooler, first insulating grease provided between the lower surface of the radiator plate and the cooler to thermally connect the radiator plate and the cooler, and second insulating grease provided in the at least one radiator plate through hole to be connected to the first insulating grease.
    Type: Application
    Filed: August 30, 2018
    Publication date: December 27, 2018
    Applicant: Mitsubishi Electric Corporation
    Inventors: Yuki HATA, Shintaro ARAKI, Takaaki SHIRASAWA
  • Publication number: 20180350713
    Abstract: A technique disclosed in the Description relates to a technique for improving the heat dissipation capability of a semiconductor element and the heat dissipation capability of a lead electrode without increasing the size of a product. A semiconductor device of the technique includes the following: a semiconductor element; a lead electrode having a lower surface connected to an upper surface of the semiconductor element at one end of the lead electrode, the lead electrode being an external terminal; a cooling mechanism disposed on a lower surface side of the semiconductor element; and a heat dissipation mechanism provided to be thermally joined between the lower surface of the lead electrode and the cooling mechanism, the lower surface being more adjacent to an other-end side of the lead electrode than the one end, the heat dissipation mechanism including at least one insulating layer.
    Type: Application
    Filed: January 29, 2016
    Publication date: December 6, 2018
    Applicant: Mitsubishi Electric Corporation
    Inventors: Ryoji MURAI, Mitsunori AIKO, Takaaki SHIRASAWA
  • Patent number: 10096566
    Abstract: A semiconductor device includes a semiconductor module having a semiconductor element, a radiator plate which is connected to the semiconductor element and which has at least one radiator plate through hole formed therein, and resin covering the semiconductor element and the radiator plate with a lower surface of the radiator plate exposed, a cooler, first insulating grease provided between the lower surface of the radiator plate and the cooler to thermally connect the radiator plate and the cooler, and second insulating grease provided in the at least one radiator plate through hole to be connected to the first insulating grease.
    Type: Grant
    Filed: July 9, 2014
    Date of Patent: October 9, 2018
    Assignee: Mitsubishi Electric Corporation
    Inventors: Yuki Hata, Shintaro Araki, Takaaki Shirasawa
  • Patent number: 10049960
    Abstract: According to the present invention, a grease layer having a grease as a constituent material is provided in a filling region lying between a heat dissipation surface that is a bottom surface of a heat dissipation material of a semiconductor module and a surface of a cooler. Further, a seal material is formed on the surface of the cooler and covers the entire side surface region of the grease layer without any gap. The seal material has a liquid curable sealing agent as a constituent material.
    Type: Grant
    Filed: January 6, 2014
    Date of Patent: August 14, 2018
    Assignee: Mitsubishi Electric Corporation
    Inventors: Ryoji Murai, Shintaro Araki, Takaaki Shirasawa, Korehide Okamoto
  • Publication number: 20180068913
    Abstract: An object of the present invention is to provide a semiconductor device having a structure in which a resin hardly enters between an insert electrode and a nut at a time of resin sealing. The semiconductor device according to the present invention includes an insert electrode having an insert hole into which a bolt is inserted from outside, a nut which has a screw hole to be screwed with the bolt and is disposed on an inside of the insert electrode so that the screw hole is communicated with the insert hole, at least one semiconductor element being electrically connected to the insert electrode, and a resin sealing the inside of the insert electrode, the nut, and the at least one semiconductor element, wherein a burr is provided on an outer periphery of a direct contact surface of the nut being in direct contact with the insert electrode.
    Type: Application
    Filed: July 27, 2015
    Publication date: March 8, 2018
    Applicant: Mitsubishi Electric Corporation
    Inventors: Takahiko MURAKAMI, Mitsunori AIKO, Takaaki SHIRASAWA, Natsuki TSUJI
  • Publication number: 20170047265
    Abstract: A semiconductor device includes a semiconductor module having a semiconductor element, a radiator plate which is connected to the semiconductor element and which has at least one radiator plate through hole formed therein, and resin covering the semiconductor element and the radiator plate with a lower surface of the radiator plate exposed, a cooler, first insulating grease provided between the lower surface of the radiator plate and the cooler to thermally connect the radiator plate and the cooler, and second insulating grease provided in the at least one radiator plate through hole to be connected to the first insulating grease.
    Type: Application
    Filed: July 9, 2014
    Publication date: February 16, 2017
    Applicant: Mitsubishi Electric Corporation
    Inventors: Yuki HATA, Shintaro ARAKI, Takaaki SHIRASAWA