Patents by Inventor Asumi NAGAI

Asumi NAGAI 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: 11926570
    Abstract: A composite sintered body includes a base material that includes ceramic as a main component, and an electrode arranged inside the base material or on a surface of the base material. The electrode contains W and ZrO2.
    Type: Grant
    Filed: August 20, 2021
    Date of Patent: March 12, 2024
    Assignee: NGK INSULATORS, LTD.
    Inventors: Kyohei Atsuji, Keita Miyanishi, Asumi Nagai, Hirofumi Yamaguchi
  • Patent number: 11845697
    Abstract: The composite sintered body includes Al2O3, and MgAl2O4. The content of Al2O3 in the composite sintered body is not less than 95.5% by weight. The average sintered grain size of Al2O3 in the composite sintered body is not less than 2 ?m and not greater than 4 ?m. The standard deviation of sintered grain size distribution of Al2O3 in the composite sintered body is not greater than 0.35. The bulk density of the composite sintered body is not less than 3.94 g/cm3 and not greater than 3.98 g/cm3. In the composite sintered body, the ratio of amount of crystal phase of MgAl2O4 to that of Al2O3 is not less than 0.003 and not greater than 0.01.
    Type: Grant
    Filed: September 16, 2020
    Date of Patent: December 19, 2023
    Assignee: NGK INSULATORS, LTD.
    Inventors: Kyohei Atsuji, Noboru Nishimura, Asumi Nagai, Yuji Katsuda
  • Patent number: 11837488
    Abstract: A method of manufacturing a composite sintered body includes a step (Step S11) of molding mixed powder in which Al2O3, SiC, and MgO are mixed, into a green body having a predetermined shape and a step (Step S12) of generating a composite sintered body by sintering the green body. Then, in Step S11, the ratio of SiC to the mixed powder is not lower than 4.0 weight percentage and not higher than 13.0 weight percentage. Further, the purity of Al2O3 in Step S11 is not lower than 99.9%. It is thereby possible to suppress the abnormal grain growth of Al2O3 and suitably manufacture a composite sintered body having high relative dielectric constant and withstand voltage, and low tan ?.
    Type: Grant
    Filed: July 21, 2020
    Date of Patent: December 5, 2023
    Assignee: NGK INSULATORS, LTD.
    Inventors: Asumi Nagai, Katsuhiro Inoue, Yuji Katsuda
  • Patent number: 11830753
    Abstract: A composite sintered body includes a base material that contains Al2O3 as a main component, and an electrode arranged inside or on a surface of the base material. The electrode contains Ru, ZrO2, and Al2O3.
    Type: Grant
    Filed: September 8, 2021
    Date of Patent: November 28, 2023
    Assignee: NGK INSULATORS, LTD.
    Inventors: Keita Miyanishi, Kyohei Atsuji, Asumi Nagai, Hirofumi Yamaguchi, Soichiro Aoyagi
  • Patent number: 11548829
    Abstract: According to the present invention, a dense composite material includes titanium silicide in an amount of 43 to 63 mass %; silicon carbide in an amount less than the mass percentage of the titanium silicide; and titanium carbide in an amount less than the mass percentage of the titanium silicide. In the dense composite material, a maximum value of interparticle distances of the silicon carbide is 40 ?m or less, a standard deviation of the interparticle distances is 10 or less, and an open porosity of the dense composite material is 1% or less.
    Type: Grant
    Filed: January 20, 2021
    Date of Patent: January 10, 2023
    Assignee: NGK Insulators, Ltd.
    Inventors: Asumi Nagai, Noboru Nishimura, Hirofumi Yamaguchi
  • Publication number: 20220081365
    Abstract: A composite sintered body includes a base material that includes ceramic as a main component, and an electrode arranged inside the base material or on a surface of the base material. The electrode contains W and ZrO2.
    Type: Application
    Filed: August 20, 2021
    Publication date: March 17, 2022
    Applicant: NGK INSULATORS, LTD.
    Inventors: Kyohei ATSUJI, Keita MIYANISHI, Asumi NAGAI, Hirofumi YAMAGUCHI
  • Publication number: 20220084865
    Abstract: A composite sintered body includes a base material that contains Al2O3 as a main component, and an electrode arranged inside or on a surface of the base material. The electrode contains Ru, ZrO2, and Al2O3.
    Type: Application
    Filed: September 8, 2021
    Publication date: March 17, 2022
    Applicant: NGK INSULATORS, LTD.
    Inventors: Keita MIYANISHI, Kyohei ATSUJI, Asumi NAGAI, Hirofumi YAMAGUCHI, Soichiro AOYAGI
  • Publication number: 20210305083
    Abstract: A stacked structure includes a first structure formed of a composite sintered body that contains AlN and MgAl2O4 as main phases, and a second structure formed of a ceramic sintered body and stacked on and bonded to the first structure. A difference in linear thermal expansion coefficient between the first structure and the second structure is less than or equal to 0.3 ppm/K.
    Type: Application
    Filed: March 15, 2021
    Publication date: September 30, 2021
    Applicant: NGK INSULATORS, LTD.
    Inventors: Asumi NAGAI, Noboru NISHIMURA, Hirofumi YAMAGUCHI
  • Publication number: 20210230074
    Abstract: According to the present invention, a dense composite material includes titanium silicide in an amount of 43 to 63 mass %; silicon carbide in an amount less than the mass percentage of the titanium silicide; and titanium carbide in an amount less than the mass percentage of the titanium silicide. In the dense composite material, a maximum value of interparticle distances of the silicon carbide is 40 ?m or less, a standard deviation of the interparticle distances is 10 or less, and an open porosity of the dense composite material is 1% or less.
    Type: Application
    Filed: January 20, 2021
    Publication date: July 29, 2021
    Applicant: NGK INSULATORS, LTD.
    Inventors: Asumi NAGAI, Noboru NISHIMURA, Hirofumi YAMAGUCHI
  • Publication number: 20200407279
    Abstract: The composite sintered body includes Al2O3, and MgAl2O4. The content of Al2O3 in the composite sintered body is not less than 95.5% by weight. The average sintered grain size of Al2O3 in the composite sintered body is not less than 2 ?m and not greater than 4 ?m. The standard deviation of sintered grain size distribution of Al2O3 in the composite sintered body is not greater than 0.35. The bulk density of the composite sintered body is not less than 3.94 g/cm3 and not greater than 3.98 g/cm3. In the composite sintered body, the ratio of amount of crystal phase of MgAl2O4 to that of Al2O3 is not less than 0.003 and not greater than 0.01.
    Type: Application
    Filed: September 16, 2020
    Publication date: December 31, 2020
    Applicant: NGK INSULATORS, LTD.
    Inventors: Kyohei ATSUJI, Noboru NISHIMURA, Asumi NAGAI, Yuji KATSUDA
  • Publication number: 20200350196
    Abstract: A method of manufacturing a composite sintered body includes a step (Step S11) of molding mixed powder in which Al2O3, SiC, and MgO are mixed, into a green body having a predetermined shape and a step (Step S12) of generating a composite sintered body by sintering the green body. Then, in Step S11, the ratio of SiC to the mixed powder is not lower than 4.0 weight percentage and not higher than 13.0 weight percentage. Further, the purity of Al2O3 in Step S11 is not lower than 99.9%. It is thereby possible to suppress the abnormal grain growth of Al2O3 and suitably manufacture a composite sintered body having high relative dielectric constant and withstand voltage, and low tan ?.
    Type: Application
    Filed: July 21, 2020
    Publication date: November 5, 2020
    Applicant: NGK INSULATORS, LTD.
    Inventors: Asumi NAGAI, Katsuhiro INOUE, Yuji KATSUDA
  • Patent number: 10631370
    Abstract: A member for a semiconductor manufacturing apparatus according to the present invention is a member that is to be joined to an aluminum nitride base member. The member is composed of a composite material including principal constituent phases that are aluminum nitride and a pseudopolymorph of aluminum nitride which includes silicon, aluminum, oxygen, and nitrogen. The pseudopolymorph of aluminum nitride has at least one periodic structure selected from a 27R phase and a 21R phase or an X-ray diffraction peak at least at 2?=59.8° to 60.8°. The composite material has a thermal conductivity of 50 W/mK or less at room temperature.
    Type: Grant
    Filed: October 20, 2016
    Date of Patent: April 21, 2020
    Assignee: NGK Insulators, Ltd.
    Inventors: Asumi Nagai, Noboru Nishimura, Yuji Katsuda
  • Publication number: 20170127475
    Abstract: A member for a semiconductor manufacturing apparatus according to the present invention is a member that is to be joined to an aluminum nitride base member. The member is composed of a composite material including principal constituent phases that are aluminum nitride and a pseudopolymorph of aluminum nitride which includes silicon, aluminum, oxygen, and nitrogen. The pseudopolymorph of aluminum nitride has at least one periodic structure selected from a 27R phase and a 21R phase or an X-ray diffraction peak at least at 2?=59.8° to 60.8°. The composite material has a thermal conductivity of 50 W/mK or less at room temperature.
    Type: Application
    Filed: October 20, 2016
    Publication date: May 4, 2017
    Applicant: NGK INSULATORS, LTD.
    Inventors: Asumi NAGAI, Noboru NISHIMURA, Yuji KATSUDA