Patents by Inventor Michiyasu Komatsu

Michiyasu Komatsu 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: 9440887
    Abstract: The present invention provides a silicon nitride sintered body comprising a silicon nitride crystalline particle and a grain boundary phase, the silicon nitride sintered body having an area ratio of the grain boundary phase per 100 ?m×100 ?m unit area of 15 to 35% when an arbitrary cross section thereof is photographed. Further, it is preferable that the area ratio of the grain boundary phase per 100 ?m×100 ?m unit area is 15 to 25%. Furthermore, the silicon nitride sintered body is suitable for a wear resistant member. Due to above structure, there can be provided a silicon nitride sintered body and a wear resistant member having a high processability (workability) and an excellent sliding property.
    Type: Grant
    Filed: October 21, 2013
    Date of Patent: September 13, 2016
    Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA MATERIALS CO., LTD.
    Inventors: Kai Funaki, Michiyasu Komatsu, Haruhiko Yamaguti, Katsuyuki Aoki
  • Publication number: 20150251957
    Abstract: The present invention provides a silicon nitride sintered body comprising a silicon nitride crystalline particle and a grain boundary phase, the silicon nitride sintered body having an area ratio of the grain boundary phase per 100 ?m×100 ?m unit area of 15 to 35% when an arbitrary cross section thereof is photographed. Further, it is preferable that the area ratio of the grain boundary phase per 100 ?m×100 ?m unit area is 15 to 25%. Furthermore, the silicon nitride sintered body is suitable for a wear resistant member. Due to above structure, there can be provided a silicon nitride sintered body and a wear resistant member having a high processability (workability) and an excellent sliding property.
    Type: Application
    Filed: October 21, 2013
    Publication date: September 10, 2015
    Applicants: KABUSHIKI KAISHA TOSHIBA, TOSHIBA MATERIALS CO., LTD.
    Inventors: Kai Funaki, Michiyasu Komatsu, Haruhiko Yamaguti, Katsuyuki Aoki
  • Patent number: 8518554
    Abstract: A ceramic-metal composite includes a ceramic substrate, an active metal brazing alloy layer, and a metal plate bonded to the ceramic substrate through the active metal brazing alloy layer disposed therebetween. The active metal brazing alloy layer contains a transition metal that is at least one element selected from Group-8 elements specified in the periodic table. According to the above configuration, the following composite and device can be provided: the ceramic-metal composite that exhibits high bonding strength, heat cycle resistance, durability, and reliability even if the ceramic-metal composite is used in a power module and a semiconductor device including the ceramic-metal composite.
    Type: Grant
    Filed: July 3, 2007
    Date of Patent: August 27, 2013
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Materials Co., Ltd.
    Inventors: Takayuki Naba, Michiyasu Komatsu, Noritaka Nakayama, Hiromasa Kato
  • Publication number: 20130157445
    Abstract: There is provided a polycrystalline aluminum nitride base material having a linear expansion coefficient similar to GaN. The polycrystalline aluminum nitride base material as a substrate material for crystal growth of GaN-base semiconductors has a mean linear expansion coefficient of 4.9×10?6/K to 6.1×10?6/K between 20° C. and 600° C. and 5.5×10?6/K to 6.6×10?6/K between 20° C. and 1100° C.
    Type: Application
    Filed: August 3, 2011
    Publication date: June 20, 2013
    Inventors: Kimiya Miyashita, Michiyasu Komatsu, Katsuyuki Aoki, Kai Funaki
  • Patent number: 8133830
    Abstract: A silicon nitride sintered compact contains silicon nitride grains, and a sintering aid component in a range of 2 to 15 mass %. The silicon nitride grains include needle crystal grains each having a long diameter L of 10 ?m or less and a ratio (L/S) of the long diameter L to a short diameter S of 5 or more, by 50% or more in area ratio in a crystalline structure of the silicon nitride sintered compact. The silicon nitride sintered compact is used as a sliding member like a bearing ball (2).
    Type: Grant
    Filed: March 11, 2008
    Date of Patent: March 13, 2012
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Materials Co., Ltd.
    Inventors: Minoru Takao, Michiyasu Komatsu
  • Publication number: 20100054652
    Abstract: A silicon nitride sintered compact contains silicon nitride grains, and a sintering aid component in a range of 2 to 15 mass %. The silicon nitride grains include needle crystal grains each having a long diameter L of 10 ?m or less and a ratio (L/S) of the long diameter L to a short diameter S of 5 or more, by 50% or more in area ratio in a crystalline structure of the silicon nitride sintered compact. The silicon nitride sintered compact is used as a sliding member like a bearing ball (2).
    Type: Application
    Filed: March 11, 2008
    Publication date: March 4, 2010
    Inventors: Minoru Takao, Michiyasu Komatsu
  • Patent number: 7662736
    Abstract: The high thermal conductive aluminum nitride sintered body according to the present invention has: a thermal conductivity of 220 W/m·K or more; and a three point bending strength of 250 MPa or more; wherein a ratio (IAl2Y4O9/IAlN) of X-ray diffraction intensity (IAl2Y4O9) of Al2Y4O9 (201 plane) with respect to X-ray diffraction intensity (IAlN) of aluminum nitride (101 plane) is 0.002 to 0.03. According to the foregoing structure, there can be provided an aluminum nitride sintered body having a high thermal conductivity and excellent heat radiating property.
    Type: Grant
    Filed: November 17, 2008
    Date of Patent: February 16, 2010
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Materials Co., Ltd.
    Inventors: Michiyasu Komatsu, Kimiya Miyashita
  • Publication number: 20090283309
    Abstract: Problem is to provide a ceramic-metal composite and a semiconductor device that exhibits high bonding strength, heat cycle resistance, durability, and reliability even if the ceramic-metal composite is used in a power module. A ceramic-metal composite includes a ceramic substrate, an active metal brazing alloy layer, and a metal plate bonded to the ceramic substrate through the active metal brazing alloy layer disposed therebetween. The active metal brazing alloy layer contains a transition metal.
    Type: Application
    Filed: July 3, 2007
    Publication date: November 19, 2009
    Applicants: Kabushiki Kaisha Toshiba, Toshiba Materials Co., LTD
    Inventors: Takayuki Naba, Michiyasu Komatsu, Noritaka Nakayama, Hiromasa Kato
  • Patent number: 7521388
    Abstract: A silicon nitride abrasion resistant member is formed of silicon nitride sintered body containing 2% to 4% by mass of a rare earth element in terms of oxide thereof as a sintering aid, 2% to 6% by mass of an Al component in terms of oxide thereof, and 2% to 7% by mass of silicon carbide. The silicon nitride sintered body has a porosity of 1% or less, a three-point bending strength of 800 to 1000 MPa, and a fracture toughness of 5.7 to 6.5 MPa·m1/2. According to this structure, even when an inexpensive silicon nitride powder manufactured by metal nitriding method is used, there can be provided a silicon nitride abrasion resistant member having a mechanical strength, high abrasion resistance, and a rolling life, equal to or higher than those of conventional silicon nitride sintered bodies, and excellent workability, and a method for manufacturing the member can be provided.
    Type: Grant
    Filed: September 27, 2004
    Date of Patent: April 21, 2009
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Materials Co., Ltd.
    Inventors: Michiyasu Komatsu, Minoru Takao
  • Publication number: 20090090452
    Abstract: In the production of a ceramic substrate (1) with a level difference (3), a surface of a fired substrate obtained by firing of a ceramic green sheet is honed to form the level difference (3). Alternatively, a level difference is first formed through processing of a ceramic green sheet, laminating of a ceramic green sheet, or the like, and thereafter the ceramic green sheet is fired to obtain a fired substrate (ceramic substrate) (1) with a level difference (3).
    Type: Application
    Filed: June 26, 2006
    Publication date: April 9, 2009
    Inventors: Takayuki Naba, Michiyasu Komatsu, Takao Shirai, Noritaka Nakayama, Mitsuhiro Okamoto
  • Publication number: 20090075071
    Abstract: The high thermal conductive aluminum nitride sintered body according to the present invention has: a thermal conductivity of 220 W/m·K or more; and a three point bending strength of 250 MPa or more; wherein a ratio (IAl2Y4O9/IAlN) of X-ray diffraction intensity (IAl2Y4O9) of Al2Y4O9 (201 plane) with respect to X-ray diffraction intensity (IAlN) of aluminum nitride (101 plane) is 0.002 to 0.03. According to the foregoing structure, there can be provided an aluminum nitride sintered body having a high thermal conductivity and excellent heat radiating property.
    Type: Application
    Filed: November 17, 2008
    Publication date: March 19, 2009
    Applicants: KABUSHIKI KAISHA TOSHIBA, TOSHIBA MATERIALS CO., LTD.
    Inventors: Michiyasu Komatsu, Kimiya Miyashita
  • Patent number: 7479467
    Abstract: The high thermal conductive aluminum nitride sintered body according to the present invention has: a thermal conductivity of 220 W/m·K or more; and a three point bending strength of 250 MPa or more; wherein a ratio (IAl2Y4O9/IAlN) of X-ray diffraction intensity (IAl2Y4O9) of Al2Y4O9 (201 plane) with respect to X-ray diffraction intensity (IAlN) of aluminum nitride (101 plane) is 0.002 to 0.03. According to the foregoing structure, there can be provided an aluminum nitride sintered body having a high thermal conductivity and excellent heat radiating property.
    Type: Grant
    Filed: November 18, 2004
    Date of Patent: January 20, 2009
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Materials Co., Ltd.
    Inventors: Michiyasu Komatsu, Kimiya Miyashita
  • Publication number: 20070161493
    Abstract: A silicon nitride abrasion resistant member is formed of silicon nitride sintered body containing 2% to 4% by mass of a rare earth element in terms of oxide thereof as a sintering aid, 2% to 6% by mass of an Al component in terms of oxide thereof, and 2% to 7% by mass of silicon carbide. The silicon nitride sintered body has a porosity of 1% or less, a three-point bending strength of 800 to 1000 MPa, and a fracture toughness of 5.7 to 6.5 MPa·m1/2. According to this structure, even when an inexpensive silicon nitride powder manufactured by metal nitriding method is used, there can be provided a silicon nitride abrasion resistant member having a mechanical strength, high abrasion resistance, and a rolling life, equal to or higher than those of conventional silicon nitride sintered bodies, and excellent workability, and a method for manufacturing the member can be provided.
    Type: Application
    Filed: September 27, 2004
    Publication date: July 12, 2007
    Applicants: Kabushiki Kaisha Toshiba, Toshiba Materials Co., Ltd.
    Inventors: Michiyasu Komatsu, Minoru Takao
  • Publication number: 20070161495
    Abstract: The high thermal conductive aluminum nitride sintered body according to the present invention has: a thermal conductivity of 220 W/m·K or more; and a three point bending strength of 250 MPa or more; wherein a ratio (IAl2Y4O9/IAlN) of X-ray diffraction intensity (IAl2Y4O9) of Al2Y4O9 (201 plane) with respect to X-ray diffraction intensity (IAlN) of aluminum nitride (101 plane) is 0.002 to 0.03. According to the foregoing structure, there can be provided an aluminum nitride sintered body having a high thermal conductivity and excellent heat radiating property.
    Type: Application
    Filed: November 18, 2004
    Publication date: July 12, 2007
    Applicants: Kabushikikasha Toshiba, Toshiba Materials Co., LTD.
    Inventors: Michiyasu Komatsu, Kimiya Miyashita
  • Patent number: 7192899
    Abstract: A silicon nitride sintered body exhibiting a high heat conductivity, the silicon nitride sintered body includes a rare earth element in an amount of 2 to 17.5 mass % in terms of the oxide thereof, Fe in an amount of 0.07 to 0.5 mass % in terms of the oxide thereof, Ca in an amount of 0.07 to 0.5 mass % in terms of the oxide thereof, Al in an amount of 0.1 to 0.6 mass % in terms of the oxide thereof, Mg in an amount of 0.3 to 4 mass % in terms of the oxide thereof, and Hf in an amount not larger than 5 mass % (including 0 mass %) in terms of the oxide thereof.
    Type: Grant
    Filed: February 9, 2006
    Date of Patent: March 20, 2007
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Materials Co., Ltd.
    Inventor: Michiyasu Komatsu
  • Patent number: 7151066
    Abstract: A silicon nitride wear resistant member is composed of a ceramic sintered body containing 55 to 75 mass % of silicon nitride, 12 to 28 mass % of silicon carbide, 3 to 15 mass % of at least one element selected from the group consisting of Mo, W, Ta, and Nb in terms of silicide thereof, and 5 to 15 mass % of grain boundary phase composed of a rare earth element-Si—Al—O—N, the wear resistant member having an electrical resistance of 107 to 104 ?·cm, a porosity of 1% or less, and a three point bending strength of 900 MPa or more. The wear resistant member has a predetermined electric resistance (electro-conductivity) in addition to the high strength and toughness inherent in silicon nitride per se, especially has a high sliding characteristic. Also, a method of manufacturing the wear resistant member is provided.
    Type: Grant
    Filed: April 2, 2003
    Date of Patent: December 19, 2006
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Michiyasu Komatsu, Kimiya Miyashita
  • Publication number: 20060128552
    Abstract: A silicon nitride sintered body exhibiting a high heat conductivity, the silicon nitride sintered body includes a rare earth element in an amount of 2 to 17.5 mass % in terms of the oxide thereof, Fe in an amount of 0.07 to 0.5 mass % in terms of the oxide thereof, Ca in an amount of 0.07 to 0.5 mass % in terms of the oxide thereof, Al in an amount of 0.1 to 0.6 mass % in terms of the oxide thereof, Mg in an amount of 0.3 to 4 mass % in terms of the oxide thereof, and Hf in an amount not larger than 5 mass % (including 0 mass %) in terms of the oxide thereof.
    Type: Application
    Filed: February 9, 2006
    Publication date: June 15, 2006
    Applicants: KABUSHIKI KAISHA TOSHIBA, TOSHIBA MATERIALS CO., LTD
    Inventor: Michiyasu Komatsu
  • Patent number: 7056850
    Abstract: The present invention provides a wear resistant member composed of silicon nitride sintered body containing 2–10 mass % of rare earth element in terms of oxide thereof as sintering agent, 2–7 mass % of MgAl2O4 spinel, 1–10 mass % of silicon carbide, and 5 mass % or less of at least one element selected from the group consisting of Ti, Zr, Hf, W, Mo, Ta, Nb and Cr in terms of oxide thereof, wherein a porosity of said silicon nitride sintered body is 1 vol. % or less, a three-point bending strength is 900 MPa or more, and a fracture toughness is 6.3 MPa·m1/2 or more. According to the above structure of the present invention, there can be provided a silicon nitride wear resistant member and a method of manufacturing the member having a high strength and a toughness property, and particularly excellent in rolling and sliding characteristics.
    Type: Grant
    Filed: July 23, 2002
    Date of Patent: June 6, 2006
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Michiyasu Komatsu
  • Publication number: 20050224763
    Abstract: A silicon nitride wear resistant member is composed of a ceramic sintered body containing 55 to 75 mass % of silicon nitride, 12 to 28 mass % of silicon carbide, 3 to 15 mass % of at least one element selected from the group consisting of Mo, W, Ta, and Nb in terms of silicide thereof, and 5 to 15 mass % of grain boundary phase composed of a rare earth element-Si—Al—O—N, the wear resistant member having an electrical resistance of 107 to 104 ?·cm, a porosity of 1% or less, and a three point bending strength of 900 MPa or more. The wear resistant member has a predetermined electric resistance (electro-conductivity) in addition to the high strength and toughness inherent in silicon nitride per se, especially has a high sliding characteristic. Also, a method of manufacturing the wear resistant member is provided.
    Type: Application
    Filed: April 2, 2003
    Publication date: October 13, 2005
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Michiyasu Komatsu, Kimiya Miyashita
  • Publication number: 20040191535
    Abstract: The present invention provides a wear resistant member composed of silicon nitride sintered body containing 2-10 mass % of rare earth element in terms of oxide thereof as sintering agent, 2-7 mass % of MgAl2O4 spinel, 1-10 mass % of silicon carbide, and 5 mass % or less of at least one element selected from the group consisting of Ti, Zr, Hf, W, Mo, Ta, Nb and Cr in terms of oxide thereof, wherein a porosity of said silicon nitride sintered body is 1 vol. % or less, a three-point bending strength is 900 MPa or more, and a fracture toughness is 6.3 MPa·m1/2 or more. According to the above structure of the present invention, there can be provided a silicon nitride wear resistant member and a method of manufacturing the member having a high strength and a toughness property, and particularly excellent in rolling and sliding characteristics.
    Type: Application
    Filed: January 26, 2004
    Publication date: September 30, 2004
    Inventor: Michiyasu Komatsu