Patents by Inventor Toshitaka Yamagata
Toshitaka Yamagata 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).
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Patent number: 11492299Abstract: A nitride-based ceramics resin composite body having thermal conductivity, electrical insulation, and adhesion to adherends equal to conventional products, and having improved heat resistance reliability during the reflow process, and a thermal conductive insulating adhesive sheet using the same are provided. A nitride-based ceramics resin composite body in which a thermosetting resin composition is impregnated in a porous nitride-based ceramics sintered body is provided. The thermosetting resin composition includes a specific epoxy resin and a bismaleimide triazine resin, and a water absorption of the thermosetting resin composition in a completely cured state measured in accordance with method A in JIS K7209 (2000) is 1% by mass or less.Type: GrantFiled: December 5, 2018Date of Patent: November 8, 2022Assignee: DENKA COMPANY LIMITEDInventors: Yoshitaka Minakata, Eri Sasaki, Toshitaka Yamagata, Saori Inoue, Ryo Yoshimatu, Ryuji Koga
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Patent number: 11034623Abstract: A thermal conductive member includes: first and second surface layers including an insulating material A, and an intermediate layer including an insulating material B. The insulating material A includes a first boron nitride sintered body having an orientation degree of hexagonal boron nitride primary particles of 0.6 to 1.4, and a first heat curable resin composition impregnating in the first boron nitride sintered body. The insulating material B includes a second boron nitride sintered body having an orientation degree of hexagonal boron nitride primary particles of 0.01 to 0.05, and a second heat curable resin composition impregnating in the second boron nitride sintered body.Type: GrantFiled: March 28, 2018Date of Patent: June 15, 2021Assignee: DENKA COMPANY LIMITEDInventors: Saori Inoue, Toshitaka Yamagata, Yoshitaka Minakata, Ryo Yoshimatsu, Ryuji Koga
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Publication number: 20210032171Abstract: A nitride-based ceramics resin composite body having thermal conductivity, electrical insulation, and adhesion to adherends equal to conventional products, and having improved heat resistance reliability during the reflow process, and a thermal conductive insulating adhesive sheet using the same are provided. A nitride-based ceramics resin composite body in which a thermosetting resin composition is impregnated in a porous nitride-based ceramics sintered body is provided. The thermosetting resin composition includes a specific epoxy resin and a bismaleimide triazine resin, and a water absorption of the thermosetting resin composition in a completely cured state measured in accordance with method A in JIS K7209 (2000) is 1% by mass or less.Type: ApplicationFiled: December 5, 2018Publication date: February 4, 2021Applicant: DENKA COMPANY LIMITEDInventors: Yoshitaka MINAKATA, Eri SASAKI, Toshitaka YAMAGATA, Saori INOUE, Ryo YOSHIMATU, Ryuji KOGA
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Publication number: 20200406586Abstract: A ceramic-metal temporary bonding body to inhibit breakage and degradation of a ceramic resin composite having low strength includes: a ceramic resin composite in which a non-oxide ceramic sintered body is impregnated with a thermosetting resin composition having cyanate groups in such a manner that a degree of cure calculated by differential scanning calorimetry is 5.0% or more and 70% or less; and a metal plate temporarily bonded to at least one surface of the ceramic resin composite. A shear bond strength between the ceramic resin composite and the metal plate is 0.1 MPa or more and 1.0 MPa or less.Type: ApplicationFiled: March 6, 2019Publication date: December 31, 2020Applicant: DENKA COMPANY LIMITEDInventors: Yoshitaka MINAKATA, Toshitaka YAMAGATA, Saori INOUE, Ryo YOSHIMATU, Ryuji KOGA
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Patent number: 10615096Abstract: Provided is a heat dissipation structure for an electric circuit device excellent in mass-productivity and heat radiation performance. A heat dissipation structure for an electric circuit device, the structure including a layered structure comprising: a heatsink exposed on the electric circuit device; a thermal conductive member; and a cooler, wherein the thermal conductive member is a ceramic-resin composite in which a resin composition is impregnated in a ceramic sintered body, the ceramic sintered body comprising ceramic primary particles integrated into a three-dimensional structure, and wherein the thermal conductive member is arranged such that the thermal conductive member directly contacts with at least one of the heatsink and the cooler.Type: GrantFiled: August 2, 2017Date of Patent: April 7, 2020Assignee: DENKA COMPANY LIMITEDInventors: Toshitaka Yamagata, Saori Inoue, Hideki Hirotsuru, Ryoh Yoshimatu, Ryuji Koga
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Publication number: 20200031723Abstract: A thermal conductive member includes: first and second surface layers including an insulating material A, and an intermediate layer including an insulating material B. The insulating material A includes a first boron nitride sintered body having an orientation degree of hexagonal boron nitride primary particles of 0.6 to 1.4, and a first heat curable resin composition impregnating in the first boron nitride sintered body. The insulating material B includes a second boron nitride sintered body having an orientation degree of hexagonal boron nitride primary particles of 0.01 to 0.05, and a second heat curable resin composition impregnating in the second boron nitride sintered body.Type: ApplicationFiled: March 28, 2018Publication date: January 30, 2020Applicant: DENKA COMPANY LIMITEDInventors: Saori INOUE, Toshitaka YAMAGATA, Yoshitaka MINAKATA, Ryo YOSHIMATSU, Ryuji KOGA
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Publication number: 20190189534Abstract: Provided is a heat dissipation structure for an electric circuit device excellent in mass-productivity and heat radiation performance. A heat dissipation structure for an electric circuit device, the structure including a layered structure comprising: a heatsink exposed on the electric circuit device; a thermal conductive member; and a cooler, wherein the thermal conductive member is a ceramic-resin composite in which a resin composition is impregnated in a ceramic sintered body, the ceramic sintered body comprising ceramic primary particles integrated into a three-dimensional structure, and wherein the thermal conductive member is arranged such that the thermal conductive member directly contacts with at least one of the heatsink and the cooler.Type: ApplicationFiled: August 2, 2017Publication date: June 20, 2019Applicant: Denka Company LimitedInventors: Toshitaka YAMAGATA, Saori INOUE, Hideki HIROTSURU, Ryoh YOSHIMATU, Ryuji KOGA
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Patent number: 9497857Abstract: An object of the present invention is to provide an insulating sheet superior in heat dissipation efficiency, heat resistance, insulation efficiency and moldability. Provided is a sheet-shaped insulating sheet of a resin composition containing an epoxy resin, a curing agent and an inorganic filler, wherein one or both of the epoxy resin and the curing agent have a naphthalene structure, the inorganic filler contains hexagonal boron nitride, and the inorganic filler is contained in an amount of 70 to 85 vol % in the entire resin composition. It is possible to increase the filling efficiency of an inorganic filler in the insulating sheet by using an epoxy resin and/or a curing agent having a naphthalene structure, which are favorably compatible with the hexagonal boron nitride contained in the inorganic filler.Type: GrantFiled: September 13, 2010Date of Patent: November 15, 2016Assignee: Denka Company LimitedInventors: Kenji Miyata, Toshitaka Yamagata
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Patent number: 8921458Abstract: To provide a resin composition having excellent thermal conductivity and excellent insulation reliability, a molded object, a substrate material, and a circuit board. [Solution] Provided is a resin composition which comprises an epoxy resin, a hardener, and an inorganic filler, wherein the epoxy resin and/or the hardener has a naphthalene structure, the inorganic filler comprises hexagonal boron nitride, and the inorganic filler accounts for 50-85 vol. % of the whole resin composition. Since a naphthalene structure, which imparts the satisfactory ability to wet the hexagonal boron nitride included in the inorganic filler, has been introduced into the epoxy resin and/or the hardener to heighten the inorganic-filler loading characteristics, this resin composition attains excellent heat dissipation properties, heat resistance, insulating properties, etc.Type: GrantFiled: August 26, 2010Date of Patent: December 30, 2014Assignee: Denki Kagaku Kogyo Kabushiki KaishaInventors: Kenji Miyata, Toshitaka Yamagata
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Publication number: 20130248755Abstract: Provided is a high durability thermally conductive composite containing 0.5-10 volume % of a high molecular weight silicone with vinyl groups on both ends with viscosity at 25 DEG C. of 10000-15000 Pa·s, 1-10 volume % of an alkylalkoxysilane, and 40-65 volume % of an inorganic filler with the remainder being an addition-reacting low molecular weight silicone with viscosity at 25 DEG C. of 0.2-0.5 Pa·s. Also provided is a grease characterized in containing 38-48 volume % of an addition-reacting low molecular weight silicone with viscosity at 25 DEG C. of 0.2-0.5 Pa·s, 2-8 volume % of a high molecular weight silicone with vinyl groups on both ends with viscosity at 25 DEG C. of 10000-15000 Pa·s, and 50-60 volume % of an inorganic filler. It is preferable that the alkylalkoxysilane is a triethoxysilane or trimethoxysilane wherein the number of carbons in the alkyl groups is six to ten.Type: ApplicationFiled: May 13, 2013Publication date: September 26, 2013Applicant: DENKI KAGAKU KOGYO KABUSHIKI KAISHAInventors: Takashi DOHMOTO, Kazuhiro OSHIMA, Toshitaka YAMAGATA
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Publication number: 20130143981Abstract: To provide a resin composition having excellent thermal conductivity and excellent insulation reliability, a molded object, a substrate material, and a circuit board. [Solution] Provided is a resin composition which comprises an epoxy resin, a hardener, and an inorganic filler, wherein the epoxy resin and/or the hardener has a naphthalene structure, the inorganic filler comprises hexagonal boron nitride, and the inorganic filler accounts for 50-85 vol. % of the whole resin composition. Since a naphthalene structure, which imparts the satisfactory ability to wet the hexagonal boron nitride included in the inorganic filler, has been introduced into the epoxy resin and/or the hardener to heighten the inorganic-filler loading characteristics, this resin composition attains excellent heat dissipation properties, heat resistance, insulating properties, etc.Type: ApplicationFiled: August 26, 2010Publication date: June 6, 2013Applicant: DENKI KAGAKU KOGYO KABUSHIKI KAISHAInventors: Kenji Miyata, Toshitaka Yamagata
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Publication number: 20120188730Abstract: An object of the present invention is to provide an insulating sheet superior in heat dissipation efficiency, heat resistance, insulation efficiency and moldability. Provided is a sheet-shaped insulating sheet of a resin composition containing an epoxy resin, a curing agent and an inorganic filler, wherein one or both of the epoxy resin and the curing agent have a naphthalene structure, the inorganic filler contains hexagonal boron nitride, and the inorganic filler is contained in an amount of 70 to 85 vol % in the entire resin composition. It is possible to increase the filling efficiency of an inorganic filler in the insulating sheet by using an epoxy resin and/or a curing agent having a naphthalene structure, which are favorably compatible with the hexagonal boron nitride contained in the inorganic filler.Type: ApplicationFiled: September 13, 2010Publication date: July 26, 2012Applicant: DENKI KAGAKU KOGYO KABUSHIKI KAISHAInventors: Kenji Miyata, Toshitaka Yamagata
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Publication number: 20100048435Abstract: The present invention provides a grease showing low thermal resistance, which is not significantly deteriorated by a heat cycle, particularly, a grease suitable as a thermally conductive material for heat-generating electronic components. A grease containing one type or at least two types of thermally conductive material powder selected from the group consisting of a thermally conductive material (A), a thermally conductive material (B) and a thermally conductive material (C), wherein the particle size distribution of the thermally conductive material powder measured by a laser diffraction type particle size distribution method, has population peaks in the ranges of from 2.0 to 10 ?m, from 1.0 to 1.9 ?m and from 0.1 to 0.9 ?m, respectively, and the grease contains a base oil having a surface tension of from 25 to 40 dyn/cm at 25° C.Type: ApplicationFiled: October 16, 2007Publication date: February 25, 2010Applicant: Denki Kagaku Kogyo Kabushiki KaishaInventors: Toshitaka Yamagata, Takuya Okada, Akira Ubukata
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Patent number: 4539459Abstract: A wire-cut electrical discharge machine which effects an electrical discharges between a wire electrode and the workpiece. The wire-cut machine has a supply nozzle for supplying a machining fluid to an electrical discharge machining zone and a power-feed element for supplying pulse power to the wire electrode. The power-feed element contacting the wire electrode is provided inside the supply nozzle.Type: GrantFiled: May 18, 1983Date of Patent: September 3, 1985Assignee: Amada Company, LimitedInventor: Toshitaka Yamagata