Patents by Inventor Hirohisa Oyama

Hirohisa Oyama 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: 20230387062
    Abstract: A semiconductor device encompasses a mounting member having a copper-based wiring layer; first covering layer which contains nickel, covering the wiring layer so that a part of upper surface of the wiring layer is exposed in opening; joint layer metallurgically joined to the wiring layer in the opening; second covering layer which contains nickel, metallurgically joined to the joint layer on upper surface of the joint layer; semiconductor chip having bottom surface covered with the second covering layer. The joint layer has lower layer in contact with the wiring layer, upper layer in contact with the second covering layer, and intermediate layer between the lower layer and the upper layer, the lower layer and the upper layer have intermetallic compounds as main components which contain tin, copper and nickel, and the intermediate layer is alloy containing tin as the main component and no lead.
    Type: Application
    Filed: April 24, 2023
    Publication date: November 30, 2023
    Applicant: FUJI ELECTRIC CO., LTD.
    Inventors: Fumihiko MOMOSE, Hirohisa OYAMA, Yasuaki HOZUMI
  • Publication number: 20230014848
    Abstract: A semiconductor device includes first semiconductor chips that each include a first control electrode and a first output electrode, second semiconductor chips each include a second control electrode and a second output electrode, first and second input circuit patterns on which the first and second input electrodes are disposed, respectively, first and second control circuit patterns electrically connected to the first and second control electrodes, respectively, first and second resistive elements, and a first inter-board wiring member. The first control electrodes and first resistive element are electrically connected via the first control circuit pattern, the second control electrodes and second resistive element are electrically connected via the second control circuit pattern, and at least one of the first output electrodes and at least one of the second output electrodes are electrically connected to each other via the first inter-board wiring member.
    Type: Application
    Filed: May 31, 2022
    Publication date: January 19, 2023
    Applicant: FUJI ELECTRIC CO., LTD.
    Inventors: Rikihiro MARUYAMA, Norihiro KOMIYAMA, Kunio KOBAYASHI, Yuto KOBAYASHI, Takahito HARADA, Hirohisa OYAMA, Masahiro SASAKI, Ryousuke USUI
  • Patent number: 11120829
    Abstract: A magnetic recording medium with a reduced average grain diameter and reduced grain diameter dispersion is provided. A magnetic recording medium having a magnetic property (magnetic anisotropy energy) applicable as a magnetic recording medium is provided. It is a magnetic recording medium containing a substrate, a grain diameter control layer, a first seed layer, a second seed layer, and a magnetic recording layer containing an ordered alloy in this order, in which the second seed layer is composed of crystal grains having TiN as a main component, and a grain boundary material having at least one or more selected from the group consisting of metal oxides and carbon as a main component.
    Type: Grant
    Filed: February 27, 2019
    Date of Patent: September 14, 2021
    Assignee: FUJI ELECTRIC CO., LTD.
    Inventors: Hiroyasu Kataoka, Tsuyoshi Yoshizawa, Tomohiro Moriya, Shinji Uchida, Hirohisa Oyama, Takehito Shimatsu
  • Publication number: 20190198051
    Abstract: A magnetic recording medium with a reduced average grain diameter and reduced grain diameter dispersion is provided. A magnetic recording medium having a magnetic property (magnetic anisotropy energy) applicable as a magnetic recording medium is provided. It is a magnetic recording medium containing a substrate, a grain diameter control layer, a first seed layer, a second seed layer, and a magnetic recording layer containing an ordered alloy in this order, in which the second seed layer is composed of crystal grains having TiN as a main component, and a grain boundary material having at least one or more selected from the group consisting of metal oxides and carbon as a main component.
    Type: Application
    Filed: February 27, 2019
    Publication date: June 27, 2019
    Applicant: FUJI ELECTRIC CO., LTD.
    Inventors: Hiroyasu KATAOKA, Tsuyoshi YOSHIZAWA, Tomohiro MORIYA, Shinji UCHIDA, Hirohisa OYAMA, Takehito SHIMATSU
  • Patent number: 10170145
    Abstract: A magnetic recording medium is provided that includes, in the order recited, a substrate; a first seed layer; a second seed layer containing ZnO; a third seed layer containing MgO; and a magnetic recording layer containing an ordered alloy. The first seed layer contains Ru and at least one material selected from the group consisting of oxides, carbides, and nitrides. Employing seed layers enables the magnetic recording medium to be a perpendicular magnetic recording medium by having the magnetic recording layer contain an ordered alloy suitable for perpendicular magnetic recording. Recording density is improved thereby while ensuring required thermal stability. Further, the invention achieves an increased thickness of the magnetic layer and a reduced grain size.
    Type: Grant
    Filed: December 28, 2017
    Date of Patent: January 1, 2019
    Assignee: FUJI ELECTRIC CO., LTD.
    Inventors: Shinji Uchida, Hitoshi Nakata, Tomohiro Moriya, Akira Furuta, Hirohisa Oyama, Takehito Shimatsu
  • Publication number: 20180122416
    Abstract: A magnetic recording medium is provided that includes, in the order recited, a substrate; a first seed layer; a second seed layer containing ZnO; a third seed layer containing MgO; and a magnetic recording layer containing an ordered alloy. The first seed layer contains Ru and at least one material selected from the group consisting of oxides, carbides, and nitrides. Employing seed layers enables the magnetic recording medium to be a perpendicular magnetic recording medium by having the magnetic recording layer contain an ordered alloy suitable for perpendicular magnetic recording. Recording density is improved thereby while ensuring required thermal stability. Further, the invention achieves an increased thickness of the magnetic layer and a reduced grain size.
    Type: Application
    Filed: December 28, 2017
    Publication date: May 3, 2018
    Applicant: FUJI ELECTRIC CO., LTD.
    Inventors: Shinji UCHIDA, Hitoshi NAKATA, Tomohiro MORIYA, Akira FURUTA, Hirohisa OYAMA, Takehito SHIMATSU
  • Patent number: 9697858
    Abstract: A perpendicular magnetic recording medium is disclosed in which crystal axis orientation dispersion, crystal grain diameter, and crystal grain diameter dispersion in a magnetic recording layer are reduced. The perpendicular magnetic recording medium has a structure having, stacked sequentially on a non-magnetic substrate, at least an amorphous underlayer, a lower orientation control layer made of Ru or Ru alloy of an hcp structure, an upper orientation control layer that is made of alloy containing an element selected from the group consisting of Co and Ni and an element selected from the group consisting of Cr, W, and Mo and that has an fcc or hcp structure, an intermediate layer, and a magnetic recording layer.
    Type: Grant
    Filed: February 20, 2015
    Date of Patent: July 4, 2017
    Assignee: FUJI ELECTRIC (MALAYSIA) SDN, BHD.
    Inventors: Hirohisa Oyama, Kenichiro Soma, Isamu Sugai
  • Patent number: 9659592
    Abstract: A perpendicular magnetic recording medium exhibits reduced noise and improved performance in such measures as SN ratio, and can realize high magnetic recording densities. In the perpendicular magnetic recording medium, at least a first nonmagnetic intermediate layer, second nonmagnetic intermediate layer, and magnetic recording layer are stacked in order on a nonmagnetic substrate. The first nonmagnetic intermediate layer is formed from a CoCrRuW alloy, and the second nonmagnetic intermediate layer is formed from an Ru-base alloy.
    Type: Grant
    Filed: May 1, 2012
    Date of Patent: May 23, 2017
    Assignee: FUJI ELECTRIC CO., LTD.
    Inventors: Toyoji Ataka, Shunji Takenoiri, Sadayuki Watanabe, Hirohisa Oyama, Yasuaki Hozumi, Satoshi Takahashi
  • Publication number: 20150162043
    Abstract: A perpendicular magnetic recording medium is disclosed in which crystal axis orientation dispersion, crystal grain diameter, and crystal grain diameter dispersion in a magnetic recording layer are reduced. The perpendicular magnetic recording medium has a structure having, stacked sequentially on a non-magnetic substrate, at least an amorphous underlayer, a lower orientation control layer made of Ru or Ru alloy of an hcp structure, an upper orientation control layer that is made of alloy containing an element selected from the group consisting of Co and Ni and an element selected from the group consisting of Cr, W, and Mo and that has an fcc or hcp structure, an intermediate layer, and a magnetic recording layer.
    Type: Application
    Filed: February 20, 2015
    Publication date: June 11, 2015
    Inventors: Hirohisa OYAMA, Kenichiro SOMA, Isamu SUGAI
  • Publication number: 20130209836
    Abstract: A perpendicular magnetic recording medium exhibits reduced noise and improved performance in such measures as SN ratio, and can realize high magnetic recording densities. In the perpendicular magnetic recording medium, at least a first nonmagnetic intermediate layer, second nonmagnetic intermediate layer, and magnetic recording layer are stacked in order on a nonmagnetic substrate. The first nonmagnetic intermediate layer is formed from a CoCrRuW alloy, and the second nonmagnetic intermediate layer is formed from an Ru-base alloy.
    Type: Application
    Filed: May 1, 2012
    Publication date: August 15, 2013
    Applicant: FUJI ELECTRIC CO., LTD.
    Inventors: Toyoji Ataka, Shunji Takenoiri, Sadayuki Watanabe, Hirohisa Oyama, Yasuaki Hozumi, Satoshi Takahashi