Patents by Inventor Katsuhiro Imai

Katsuhiro Imai 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: 20200130014
    Abstract: An ultrasonic element includes an element substrate including a first surface, a second surface having a front-back relation with the first surface, an opening section piercing through the element substrate from the first surface to the second surface, and a partition wall section surrounding the opening section, a supporting film provided on the first surface of the element substrate to cover the opening section and including a third surface facing the opening section and a fourth surface having a front-back relation with the third surface, a piezoelectric element provided on the fourth surface of the supporting film and disposed in a region overlapping the opening section of the supporting film in a plan view from a film thickness direction extending from the third surface to the fourth surface, a sealing plate provided to be opposed to the fourth surface of the supporting film and joined to the supporting film by an adhesive member via a beam section projecting toward the supporting film, and a wall sectio
    Type: Application
    Filed: October 23, 2019
    Publication date: April 30, 2020
    Inventors: Hironori SUZUKI, Chikara KOJIMA, Koji OHASHI, Yasuyuki MATSUMOTO, Katsuhiro IMAI
  • Patent number: 10598369
    Abstract: A heat discharge structure that includes a film of a nitride of a group 13 element having a first main face, a second main face and an outer side end face. The structure further includes a portion for containing the light source device. The portion has a through hole opening at the first main face and the second main face, and a fixing face for fixing the light source device. The fixing face faces the through hole and contacts the light source device.
    Type: Grant
    Filed: June 18, 2018
    Date of Patent: March 24, 2020
    Assignee: NGK INSULATORS, LTD.
    Inventors: Masahiko Namerikawa, Takashi Yoshino, Katsuhiro Imai, Yoshitaka Kuraoka
  • Publication number: 20190242029
    Abstract: It is provided a layer of a nitride of a group 13 element having a first main face and second main face. The layer of the nitride of the group 13 element includes a first void-depleted layer provided on the side of the first main face, a second void-depleted layer provided on the side of the second main face, and the void-distributed layer provided between the first void-depleted layer and second void-depleted layer.
    Type: Application
    Filed: April 16, 2019
    Publication date: August 8, 2019
    Applicant: NGK INSULATORS, LTD.
    Inventors: Yoshinori ISODA, Suguru NOGUCHI, Tetsuya UCHIKAWA, Takayuki HIRAO, Takanao SHIMODAIRA, Katsuhiro IMAI
  • Patent number: 10332958
    Abstract: A supporting substrate for a composite substrate comprises a ceramic and has a polished surface for use in bonding. An orientation degree of the ceramic forming the supporting substrate at the polished surface is 50% or higher, and an aspect ratio of each crystal grain included in the supporting substrate is 5.0 or less.
    Type: Grant
    Filed: October 28, 2015
    Date of Patent: June 25, 2019
    Assignee: NGK Insulators, Ltd.
    Inventors: Jun Yoshikawa, Mikiya Ichimura, Katsuhiro Imai
  • Patent number: 10249494
    Abstract: A self-supporting substrate includes a first nitride layer grown by a hydride vapor deposition method or ammonothermal method and comprising a nitride of one or more elements selected from the group consisting of gallium, aluminum and indium; and a second nitride layer grown by a sodium flux method on the first nitride layer and comprising a nitride of one or more elements selected from the group consisting of gallium, aluminum and indium. The first nitride layer includes a plurality of single crystal grains arranged therein and extending between a pair of main faces of the first nitride layer. The second nitride layer includes a plurality of single crystal grains arranged therein and extending between a pair of main faces of the second nitride layer. The first nitride layer has a thickness larger than a thickness of the second nitride layer.
    Type: Grant
    Filed: July 27, 2017
    Date of Patent: April 2, 2019
    Assignee: NGK INSULATORS, LTD.
    Inventors: Takashi Yoshino, Katsuhiro Imai, Masahiro Sakai
  • Patent number: 10156022
    Abstract: It is produced a crystal of a nitride of a group 13 element in a melt including the group 13 element and a flux including at least an alkali metal under atmosphere comprising a nitrogen-containing gas. An amount of carbon is made 0.005 to 0.018 atomic percent, provided that 100 atomic percent is assigned to a total amount of said flux, said group 13 element and carbon in said melt.
    Type: Grant
    Filed: February 18, 2016
    Date of Patent: December 18, 2018
    Assignee: NGK INSULATORS, LTD.
    Inventors: Takayuki Hirao, Shuhei Higashihara, Katsuhiro Imai
  • Publication number: 20180351038
    Abstract: There is provided a self-supporting polycrystalline gallium nitride substrate having excellent characteristics such as high luminous efficiency and high conversion efficiency when used for devices, such as light emitting devices and solar cells. The self-supporting polycrystalline gallium nitride substrate is composed of gallium nitride-based single crystal grains having a specific crystal orientation in a direction approximately normal to the substrate, and has a top surface and a bottom surface. The crystal orientations of individual gallium nitride-based single crystal grains as determined from inverse pole figure mapping by electron backscatter diffraction (EBSD) analysis on the top surface are distributed at various tilt angles from the specific crystal orientation, in which the average tilt angle thereof is 0.1° or more and less than 1° and the cross-sectional average diameter DT of the gallium nitride-based single crystal grains at the outermost surface exposed on the top surface is 10 ?m or more.
    Type: Application
    Filed: August 9, 2018
    Publication date: December 6, 2018
    Applicant: NGK INSULATORS, LTD.
    Inventors: Morimichi WATANABE, Kei Sato, Yoshitaka Kuraoka, Katsuhiro Imai, Tsutomu Nanataki
  • Publication number: 20180350918
    Abstract: A free-standing substrate of a polycrystalline nitride of a group 13 element contains a plurality of monocrystalline particles having a particular crystal orientation in approximately a normal direction. The polycrystalline nitride of the group 13 element is composed of gallium nitride, aluminum nitride, indium nitride or a mixed crystal thereof. The free-standing substrate has a top surface and bottom surface. The free-standing substrate contains at least one of zinc and calcium. A root mean square roughness Rms at the top surface is 3.0 nm or less.
    Type: Application
    Filed: August 9, 2018
    Publication date: December 6, 2018
    Inventors: Katsuhiro IMAI, Yoshitaka KURAOKA, Mikiya ICHIMURA, Takayuki HIRAO
  • Publication number: 20180351041
    Abstract: A free-standing substrate of a polycrystalline nitride of a group 13 element is composed of a plurality of monocrystalline particles having a particular crystal orientations in approximately a normal direction. The free-standing substrate has a top surface and a bottom surface. The polycrystalline nitride of the group 13 element is gallium nitride, aluminum nitride, indium nitride or a mixed crystal thereof and contains zinc at a concentration of 1×1017 atoms/cm3 or more and 1×1020 atoms/cm3 or less.
    Type: Application
    Filed: August 9, 2018
    Publication date: December 6, 2018
    Inventors: Katsuhiro IMAI, Yoshitaka KURAOKA, Mikiya ICHIMURA, Takayuki HIRAO
  • Patent number: 10138570
    Abstract: A crystal growth apparatus includes a pressure-resistant vessel; a plurality of support tables arranged inside the pressure-resistant vessel; inner vessels each placed over the support tables, respectively; growth vessels contained the inner vessels, respectively; a heating means for heating the growth vessels; and a central rotating shaft connected to the support tables. The central rotating shaft is distant from central axes of the inner vessels, respectively. A seed crystal, a raw material of the Group 13 element and a flux are charged in each of the growth vessels, and the growth vessels are heated to form a melt and a nitrogen-containing gas is supplied to the melt to grow a crystal of a nitride of said Group 13 element while the central rotating shaft is rotated.
    Type: Grant
    Filed: May 25, 2017
    Date of Patent: November 27, 2018
    Assignee: NGK INSULATORS, LTD.
    Inventors: Takashi Yoshino, Katsuhiro Imai, Takanao Shimodaira, Takashi Wada
  • Publication number: 20180306428
    Abstract: A heat discharge structure that includes a film of a nitride of a group 13 element having a first main face, a second main face and an outer side end face. The structure further includes a portion for containing the light source device. The portion has a through hole opening at the first main face and the second main face, and a fixing face for fixing the light source device. The fixing face faces the through hole and contacts the light source device.
    Type: Application
    Filed: June 18, 2018
    Publication date: October 25, 2018
    Applicant: NGK INSULATORS, LTD.
    Inventors: Masahiko Namerikawa, Takashi Yoshino, Katsuhiro Imai, Yoshitaka Kuraoka
  • Publication number: 20180277738
    Abstract: A piezoelectric element has a first electrode layer, a piezoelectric layer on the first electrode layer, a second electrode layer on the piezoelectric layer, a third electrode layer on part of the second electrode layer and including third metal, and an insulating layer covering at least a part of the piezoelectric layer not provided with the second electrode layer and having an aperture exposing a part of the second electrode layer. The second electrode layer has a first layer including first metal and a second layer including second metal on the first layer. The second layer is exposed in the aperture. A difference in standard redox potential between the second metal and the third metal is smaller than a difference in standard redox potential between the first metal and the third metal.
    Type: Application
    Filed: March 26, 2018
    Publication date: September 27, 2018
    Inventors: Koji OHASHI, Takahiro KAMIJO, Katsuhiro IMAI, Takumi YAMAOKA, Chikara KOJIMA
  • Patent number: 10041186
    Abstract: It is used a crucible containing a flux and a source material, a reaction vessel containing the crucible, an intermediate vessel containing the reaction vessel, and a pressure vessel containing the intermediate vessel and used to fill a gas comprising at least a nitrogen atom. When the flux and the source material are melted by heating to grow the nitride crystal, a vapor of an organic compound is provided in a space outside of the reaction vessel and inside of the intermediate vessel.
    Type: Grant
    Filed: August 17, 2016
    Date of Patent: August 7, 2018
    Assignee: NGK INSULATORS, LTD.
    Inventors: Katsuhiro Imai, Makoto Iwai, Masahiro Sakai, Takanao Shimodaira, Shuhei Higashihara, Takayuki Hirao
  • Publication number: 20180202067
    Abstract: An underlying substrate including a seed crystal layer of a group 13 nitride, wherein projections and recesses repeatedly appear in stripe shapes at a principal surface of the seed crystal layer, and the projections have a level difference of 0.3 to 40 ?m and a width of 5 to 100 ?m, and the recesses have a bottom thickness of 2 ?m or more and a width of 50 to 500 ?m.
    Type: Application
    Filed: March 14, 2018
    Publication date: July 19, 2018
    Inventors: Takayuki HIRAO, Makoto IWAI, Katsuhiro IMAI, Takashi YOSHINO
  • Patent number: 9960316
    Abstract: A composite substrate includes a sapphire substrate and a layer of a nitride of a group 13 element provided on the sapphire substrate. The layer of the nitride of the group 13 element is composed of gallium nitride, aluminum nitride or gallium aluminum nitride. The composite substrate satisfies the following formulas (1), (2) and (3). A laser light is irradiated to the composite substrate from the side of the sapphire substrate to decompose crystal lattice structure at an interface between the sapphire substrate and the layer of the nitride of the group 13 element. 5.0?(an average thickness (?m) of the layer of the nitride of the group 13 element/a diameter (mm) of the sapphire substrate)?10.0 . . . (1); 0.1? a warpage (mm) of said composite substrate×(50/a diameter (mm) of said composite substrate)2?0.6 . . . (2); 1.10?a maximum value (?m) of a thickness of said layer of said nitride of said group 13 element/a minimum value (?m) of said thickness of said layer of said nitride of said group 13 element . . .
    Type: Grant
    Filed: May 31, 2017
    Date of Patent: May 1, 2018
    Assignee: NGK INSULATORS, LTD.
    Inventors: Katsuhiro Imai, Makoto Iwai, Takanao Shimodaira
  • Patent number: 9919931
    Abstract: Provided is a zinc oxide-based sputtering target capable of improving the film formation rate while suppressing arcing in the formation of a zinc oxide-based transparent conductive film by sputtering. This zinc oxide-based sputtering target includes a zinc oxide-based sintered body mainly including zinc oxide crystal grains, and has a degree of (002) orientation of 50% or greater at a sputtering surface and a density of 5.30 g/cm3 or greater.
    Type: Grant
    Filed: September 9, 2015
    Date of Patent: March 20, 2018
    Assignee: NGK Insulators, Ltd.
    Inventors: Jun Yoshikawa, Katsuhiro Imai, Koichi Kondo, Koki Kanno
  • Patent number: 9893234
    Abstract: Provided is a light emitting device composite substrate suitable for manufacturing large-area light emitting devices at low cost. The light emitting device composite substrate comprises a substrate composed of an oriented polycrystalline alumina sintered body, and a light emitting functional layer formed on the substrate and having two or more layers composed of semiconductor single crystal grains, wherein each of the two or more layers has a single crystal structure in a direction approximately normal to the substrate.
    Type: Grant
    Filed: June 15, 2016
    Date of Patent: February 13, 2018
    Assignee: NGK Insulators, Ltd.
    Inventors: Morimichi Watanabe, Jun Yoshikawa, Tsutomu Nanataki, Katsuhiro Imai, Tomohiko Sugiyama, Takashi Yoshino, Yukihisa Takeuchi, Kei Sato
  • Publication number: 20170330749
    Abstract: A self-supporting substrate includes a first nitride layer grown by hydride vapor deposition method or ammonothermal method and comprising a nitride of one or more element selected from the group consisting of gallium, aluminum and indium; and a second nitride layer grown by a sodium flux method on the first nitride layer and comprising a nitride of one or more element selected from the group consisting of gallium, aluminum and indium. The first nitride layer includes a plurality of single crystal grains arranged therein and being extended between a pair of main faces of the first nitride layer. The second nitride layer includes a plurality of single crystal grains arranged therein and being extended between a pair of main faces of the second nitride layer. The first nitride layer has a thickness larger than a thickness of the second nitride layer.
    Type: Application
    Filed: July 27, 2017
    Publication date: November 16, 2017
    Applicant: NGK INSULATORS, LTD.
    Inventors: Takashi YOSHINO, Katsuhiro IMAI, Masahiro SAKAI
  • Patent number: 9816198
    Abstract: The present invention provides a method capable of stably producing a zinc oxide single crystal in which a large amount of dopant forms a solid solution at a high level of productivity and reproducibility without using a harmful substance. The method of the present invention comprises providing a raw material powder that is mainly composed of zinc oxide, comprises at least one dopant element selected from B, Al, Ga, In, C, F, Cl, Br, I, H, Li, Na, K, N, P, As, Cu, and Ag in a total amount of 0.01 to 1 at %, and is substantially free of a crystal phase other than zinc oxide, and injecting the raw material powder to form a film mainly composed of zinc oxide on a seed substrate comprising a zinc oxide single crystal and also to crystallize the formed film in a solid phase state.
    Type: Grant
    Filed: August 7, 2014
    Date of Patent: November 14, 2017
    Assignee: NGK Insulators, Ltd.
    Inventors: Jun Yoshikawa, Katsuhiro Imai
  • Publication number: 20170263810
    Abstract: A composite substrate includes a sapphire substrate and a layer of a nitride of a group 13 element provided on the sapphire substrate. The layer of the nitride of the group 13 element is composed of gallium nitride, aluminum nitride or gallium aluminum nitride. The composite substrate satisfies the following formulas (1), (2) and (3). A laser light is irradiated to the composite substrate from the side of the sapphire substrate to decompose crystal lattice structure at an interface between the sapphire substrate and the layer of the nitride of the group 13 element. 5.0?(an average thickness (?m) of the layer of the nitride of the group 13 element/a diameter (mm) of the sapphire substrate)?10.0 . . . (1); 0.1? a warpage (mm) of said composite substrate×(50/a diameter (mm) of said composite substrate)20.6 . . . (2); 1.10?a maximum value (?m) of a thickness of said layer of said nitride of said group 13 element/a minimum value (?m) of said thickness of said layer of said nitride of said group 13 element . . .
    Type: Application
    Filed: May 31, 2017
    Publication date: September 14, 2017
    Applicant: NGK INSULATORS, LTD.
    Inventors: Katsuhiro Imai, Makoto Iwai, Takanao Shimodaira