Patents by Inventor Sho KUMADA

Sho KUMADA 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: 11094664
    Abstract: A semiconductor device includes an electrode having a flat part and a non-flat part made up of a concave part, a joint layer being made of a sintered body of metal crystal grains provided on the flat part and the non-flat part of the electrode, and a semiconductor element being joined to the electrode with the joint layer therebetween, wherein the joint layer has a first region sandwiched between the non-flat part and the semiconductor element and a second region sandwiched between the flat part and the semiconductor element, and either one of the first region and the second region having a larger film thickness has a filling rate of the metal crystal grains smaller than the other one of the first region and the second region having a smaller film thickness. The present invention enhances reliability of a joint layer made of a sintered body of metal crystal grains.
    Type: Grant
    Filed: January 17, 2020
    Date of Patent: August 17, 2021
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Hiroaki Tatsumi, Sho Kumada, Osamu Suzuki, Daisuke Kawabata
  • Publication number: 20200194399
    Abstract: A semiconductor device includes an electrode having a flat part and a non-flat part made up of a concave part, a joint layer being made of a sintered body of metal crystal grains provided on the flat part and the non-flat part of the electrode, and a semiconductor element being joined to the electrode with the joint layer therebetween, wherein the joint layer has a first region sandwiched between the non-flat part and the semiconductor element and a second region sandwiched between the flat part and the semiconductor element, and either one of the first region and the second region having a larger film thickness has a filling rate of the metal crystal grains smaller than the other one of the first region and the second region having a smaller film thickness. The present invention enhances reliability of a joint layer made of a sintered body of metal crystal grains.
    Type: Application
    Filed: January 17, 2020
    Publication date: June 18, 2020
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Hiroaki TATSUMI, Sho KUMADA, Osamu SUZUKI, Daisuke KAWABATA
  • Patent number: 10573617
    Abstract: A semiconductor device includes an electrode having a flat part and a non-flat part made up of a concave part, a joint layer being made of a sintered body of metal crystal grains provided on the flat part and the non-flat part of the electrode, and a semiconductor element being joined to the electrode with the joint layer therebetween, wherein the joint layer has a first region sandwiched between the non-flat part and the semiconductor element and a second region sandwiched between the flat part and the semiconductor element, and either one of the first region and the second region having a larger film thickness has a filling rate of the metal crystal grains smaller than the other one of the first region and the second region having a smaller film thickness. The present invention enhances reliability of a joint layer made of a sintered body of metal crystal grains.
    Type: Grant
    Filed: June 28, 2016
    Date of Patent: February 25, 2020
    Assignee: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Hiroaki Tatsumi, Sho Kumada, Osamu Suzuki, Daisuke Kawabata
  • Patent number: 10468368
    Abstract: Provided is a technique of improving joint strength between a joining layer and a resin. A power semiconductor device includes a wiring member, a semiconductor element, a joining layer joining the wiring member and the semiconductor element to each other, and a resin covering the wiring member, the semiconductor element, and the joining layer. The joining layer includes a first joining layer provided to be adjacent to the resin and having a void filled with the resin. A filler contained in the resin has a maximum width greater than a minimum diameter of the void in the first joining layer.
    Type: Grant
    Filed: July 9, 2018
    Date of Patent: November 5, 2019
    Assignee: Mitsubishi Electric Corporation
    Inventor: Sho Kumada
  • Publication number: 20190103374
    Abstract: Provided is a technique of improving joint strength between a joining layer and a resin. A power semiconductor device includes a wiring member, a semiconductor element, a joining layer joining the wiring member and the semiconductor element to each other, and a resin covering the wiring member, the semiconductor element, and the joining layer. The joining layer includes a first joining layer provided to be adjacent to the resin and having a void filled with the resin. A filler contained in the resin has a maximum width greater than a minimum diameter of the void in the first joining layer.
    Type: Application
    Filed: July 9, 2018
    Publication date: April 4, 2019
    Applicant: Mitsubishi Electric Corporation
    Inventor: Sho KUMADA
  • Publication number: 20180190611
    Abstract: A semiconductor device includes an electrode having a flat part and a non-flat part made up of a concave part, a joint layer being made of a sintered body of metal crystal grains provided on the flat part and the non-flat part of the electrode, and a semiconductor element being joined to the electrode with the joint layer therebetween, wherein the joint layer has a first region sandwiched between the non-flat part and the semiconductor element and a second region sandwiched between the flat part and the semiconductor element, and either one of the first region and the second region having a larger film thickness has a filling rate of the metal crystal grains smaller than the other one of the first region and the second region having a smaller film thickness. The present invention enhances reliability of a joint layer made of a sintered body of metal crystal grains.
    Type: Application
    Filed: June 28, 2016
    Publication date: July 5, 2018
    Applicant: MITSUBISHI ELECTRIC CORPORATION
    Inventors: Hiroaki TATSUMI, Sho KUMADA, Osamu SUZUKI, Daisuke KAWABATA