Patents by Inventor Yoshimichi Ohki

Yoshimichi Ohki 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: 10681808
    Abstract: A highly thermally conductive printed circuit board prevents electrochemical migration by inhibiting elution of copper ions. The printed circuit board is a metal-base printed circuit board including a metal base plate having an insulating resin layer and a copper foil layer stacked thereon in this order. In the printed circuit board, the insulating resin layer contains a first inorganic filler made of inorganic particles having particle diameters of 0.1 nm to 600 nm with an average particle diameter (D50) of 1 nm to 300 nm, and a second inorganic filler made of inorganic particles having particle diameters of 100 nm to 100 ?m with an average particle diameter (D50) of 500 nm to 20 ?m, and the first inorganic filler and the second inorganic filler are uniformly dispersed in the insulating resin layer.
    Type: Grant
    Filed: November 17, 2016
    Date of Patent: June 9, 2020
    Assignees: Waseda University, Fuji Electric Co., Ltd.
    Inventors: Yoshimichi Ohki, Yuichi Hirose, Genta Wada, Toshikatsu Tanaka, Kenji Okamoto
  • Publication number: 20170127514
    Abstract: A highly thermally conductive printed circuit board prevents electrochemical migration by inhibiting elution of copper ions. The printed circuit board is a metal-base printed circuit board including a metal base plate having an insulating resin layer and a copper foil layer stacked thereon in this order. In the printed circuit board, the insulating resin layer contains a first inorganic filler made of inorganic particles having particle diameters of 0.1 nm to 600 nm with an average particle diameter (D50) of 1 nm to 300 nm, and a second inorganic filler made of inorganic particles having particle diameters of 100 nm to 100 ?m with an average particle diameter (D50) of 500 nm to 20 ?m, and the first inorganic filler and the second inorganic filler are uniformly dispersed in the insulating resin layer.
    Type: Application
    Filed: November 17, 2016
    Publication date: May 4, 2017
    Inventors: Yoshimichi Ohki, Yuichi Hirose, Genta Wada, Toshikatsu Tanaka, Kenji Okamoto
  • Patent number: 9554464
    Abstract: A highly thermally conductive printed circuit board prevents electrochemical migration by inhibiting elution of copper ions. The printed circuit board is a metal-base printed circuit board including a metal base plate having an insulating resin layer and a copper foil layer stacked thereon in this order. In the printed circuit board, the insulating resin layer contains a first inorganic filler made of inorganic particles having particle diameters of 0.1 nm to 600 nm with an average particle diameter (D50) of 1 nm to 300 nm, and a second inorganic filler made of inorganic particles having particle diameters of 100 nm to 100 ?m with an average particle diameter (D50) of 500 nm to 20 ?m, and the first inorganic filler and the second inorganic filler are uniformly dispersed in the insulating resin layer.
    Type: Grant
    Filed: August 1, 2013
    Date of Patent: January 24, 2017
    Assignees: Waseda University, Fuji Electric Co., Ltd.
    Inventors: Yoshimichi Ohki, Yuichi Hirose, Genta Wada, Toshikatsu Tanaka, Kenji Okamoto
  • Publication number: 20150140293
    Abstract: A highly thermally conductive printed circuit board prevents electrochemical migration by inhibiting elution of copper ions. The printed circuit board is a metal-base printed circuit board including a metal base plate having an insulating resin layer and a copper foil layer stacked thereon in this order. In the printed circuit board, the insulating resin layer contains a first inorganic filler made of inorganic particles having particle diameters of 0.1 nm to 600 nm with an average particle diameter (D50) of 1 nm to 300 nm, and a second inorganic filler made of inorganic particles having particle diameters of 100 nm to 100 ?m with an average particle diameter (D50) of 500 nm to 20 ?m, and the first inorganic filler and the second inorganic filler are uniformly dispersed in the insulating resin layer.
    Type: Application
    Filed: August 1, 2013
    Publication date: May 21, 2015
    Applicants: WASEDA UNIVERSITY, Fuji Electric Co., Ltd.
    Inventors: Yoshimichi Ohki, Yuichi Hirose, Genta Wada, Toshikatsu Tanaka, Kenji Okamoto
  • Patent number: 7105145
    Abstract: Ferroelectric metal oxide crystalline particles are produced by first producing nanoparticles of a ferroelectric metal oxide and dispersing the nanoparticles in a gas phase. Then, the nanoparticles are processed by heat treatment with the nanoparticles being maintained in the gas phase in a dispersed state. The nanoparticles may be produced by using a laser ablation method. The ferroelectric metal oxide may have a perovskite crystal structure.
    Type: Grant
    Filed: October 30, 2002
    Date of Patent: September 12, 2006
    Assignee: RIKEN
    Inventors: Kwang-Soo Seol, Kazuo Takeuchi, Takeshi Miyagawa, Yoshimichi Ohki
  • Publication number: 20040086452
    Abstract: In a method of producing ferroelectric metal oxide crystalline particles, used is an apparatus including a particle producing device, a heat treatment device and a particle collecting device. The particle producing device produces nanoparticles of a ferroelectric metal oxide from a particle source placed in a vessel by a laser ablation method, in which the particle source is irradiated with a laser beam emitted by a laser device, and the nanoparticles are dispersed in an oxygen atmosphere (gas phase). The nanoparticles produced in the vessel and dispersed in a carrier gas is supplied through a connecting pipe into a vessel included in the heat treatment device. The heat treatment device processes the nanoparticles by a heat treatment that heats the nanoparticles dispersed in the oxygen gas atmosphere at a predetermined temperature for a predetermined time while the nanoparticles flow together with the carrier gas through the vessel.
    Type: Application
    Filed: October 30, 2002
    Publication date: May 6, 2004
    Inventors: Kwang-Soo Seol, Kazuo Takeuchi, Takeshi Miyagawa, Yoshimichi Ohki
  • Patent number: 6516117
    Abstract: A grating formation method comprises the steps of accelerating ions; causing the accelerated ions to pass through a mask having a shape corresponding to the grating; and implanting the ions, which have passed through the mask, into the core, to form refractive index-variation portions for the grating in the core. The other formation method comprises the steps of accelerating ions, converging an ion beam formed of the accelerated ions, to make a beam diameter identical with or smaller than a width of refractive index-variation portions in a direction of the central axis of the optical waveguide so as to provide a converged ion beam; and intermittently irradiating the converged ion beam to the core, while moving an irradiation position in the direction of the central axis, to implant the ions into the core so as to form the refractive index-variation portions in the core.
    Type: Grant
    Filed: August 3, 2000
    Date of Patent: February 4, 2003
    Assignees: Waseda University, Universite de Montreal
    Inventors: Makoto Fujimaki, Yoshimichi Ohki, John L. Brebner, Sjoerd Roorda