Patents by Inventor Hiromasa Kato
Hiromasa Kato 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: 11277911Abstract: A ceramic copper circuit board according to an embodiment includes a ceramic substrate and a first copper part. The first copper part is bonded at a first surface of the ceramic substrate via a first brazing material part. The thickness of the first copper part is 0.6 mm or more. The side surface of the first copper part includes a first sloped portion. The width of the first sloped portion is not more than 0.5 times the thickness of the first copper part. The first brazing material part includes a first jutting portion jutting from the end portion of the first sloped portion. The length of the first jutting portion is not less than 0 ?m and not more than 200 ?m. The contact angle between the first jutting portion and the first sloped portion is 65° or less.Type: GrantFiled: November 11, 2020Date of Patent: March 15, 2022Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA MATERIALS CO., LTD.Inventors: Hiromasa Kato, Takashi Sano
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Publication number: 20220037225Abstract: A ceramic copper circuit board including a ceramic substrate, and a copper circuit part located on the ceramic substrate, wherein an arbitrary line parallel to a first direction at a cross section of the copper circuit part parallel to the first direction crosses multiple copper crystal grains, the first direction is from the ceramic substrate toward the copper circuit part, an average of multiple distances in a second direction between the line and edges of the copper crystal grains is not more than 300 ?m, and the second direction is perpendicular to the first direction.Type: ApplicationFiled: September 7, 2021Publication date: February 3, 2022Applicants: KABUSHIKI KAISHA TOSHIBA, TOSHIBA MATERIALS CO., LTD.Inventors: Takayuki NABA, Hiromasa KATO, Keiichi YANO
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Patent number: 11129282Abstract: According to one embodiment, a method for manufacturing a ceramic circuit board is disclosed. The ceramic circuit board includes a copper plate bonded to at least one surface of a ceramic substrate via a brazing material layer including Ag, Cu, and a reactive metal. The method includes: preparing a ceramic circuit board in which a copper plate is bonded on a ceramic substrate via a brazing material layer, and a portion of the brazing material layer is exposed between a pattern shape of the copper plate; a first chemical polishing process of chemically polishing the portion of the brazing material layer; and a first brazing material etching process of etching the chemically polished portion of the brazing material layer by using an etchant having a pH of 6 or less and including one type or two types selected from hydrogen peroxide and ammonium peroxodisulfate.Type: GrantFiled: January 28, 2020Date of Patent: September 21, 2021Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA MATERIALS CO., LTD.Inventors: Hiromasa Kato, Hideaki Hirabayashi, Fumiyuki Kawashima, Akito Sasaki
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Patent number: 11013112Abstract: According to one embodiment, a ceramic copper circuit board a ceramic substrate, a copper circuit board provided at one surface of the ceramic substrate. A ratio of a thickness of the copper circuit board to a thickness of the ceramic substrate is 1.25 or more. A number of grain boundaries is not less than 5 and not more than 250 along every 10-mm straight line drawn in a front surface of the copper circuit board.Type: GrantFiled: June 28, 2019Date of Patent: May 18, 2021Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA MATERIALS CO., LTD.Inventors: Hiromasa Kato, Takashi Sano
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Patent number: 10952317Abstract: A ceramic circuit board comprises: a ceramic substrate with a 1.0 mm thickness or less including a first surface and a second surface, the first surface including a first area and a second area; a first metal plate joined to the first area; and a second metal plate joined to the second surface. The second area has a first waviness profile along a first side of the first surface, the first waviness profile having one extreme value or less. The second area has a second waviness profile along a second side of the first surface, the second waviness profile has not less than two nor more than three extreme values.Type: GrantFiled: February 4, 2020Date of Patent: March 16, 2021Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA MATERIALS CO., LTD.Inventors: Takayuki Naba, Hiromasa Kato, Keiichi Yano
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Publication number: 20210068253Abstract: A ceramic copper circuit board according to an embodiment includes a ceramic substrate and a first copper part. The first copper part is bonded at a first surface of the ceramic substrate via a first brazing material part. The thickness of the first copper part is 0.6 mm or more. The side surface of the first copper part includes a first sloped portion. The width of the first sloped portion is not more than 0.5 times the thickness of the first copper part. The first brazing material part includes a first jutting portion jutting from the end portion of the first sloped portion. The length of the first jutting portion is not less than 0 ?m and not more than 200 ?m. The contact angle between the first jutting portion and the first sloped portion is 65° or less.Type: ApplicationFiled: November 11, 2020Publication date: March 4, 2021Applicants: KABUSHIKI KAISHA TOSHIBA, TOSHIBA MATERIALS CO., LTD.Inventors: Hiromasa KATO, Takashi SANO
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Patent number: 10872841Abstract: The present invention provides a ceramic metal circuit board including a ceramic substrate and metal plates bonded to both surfaces of the ceramic substrate through respective bonding layers, wherein a metal film is provided on a surface of one metal plate bonded to one surface of the ceramic substrate; and at least a part of another metal plate bonded to another surface of the ceramic substrate is not provided with the metal film. Preferably, a protruding portion is formed as a portion of the bonding layer so as to protrude from a side surface of each of the metal plates. According to the above-described configuration, it is possible to provide a ceramic circuit board which is easy to use according to the parts to be bonded and is excellent in heat-cycle resistance characteristics.Type: GrantFiled: June 1, 2016Date of Patent: December 22, 2020Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA MATERIALS CO., LTD.Inventors: Takayuki Naba, Hiromasa Kato, Noboru Kitamori
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Patent number: 10818565Abstract: A circuit board includes: a ceramic substrate that has a first surface and a second surface; a first metal part that has a first metal plate joined to the first surface and a protrusion projecting from a front surface of the first metal plate; and a second metal part that has a second metal plate joined to the second surface. When the ceramic substrate is equally divided into first to third sections along a longer side direction, V1, V2, V3, V4, V5, and V6 are numbers satisfying formula V4/V1+V6/V3?2(V5/V2), 0.5?V4/V1?2, 0.5?V5/V2?2, and 0.5?V6/V3?2.Type: GrantFiled: January 25, 2019Date of Patent: October 27, 2020Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA MATERIALS CO., LTD.Inventors: Hiromasa Kato, Takashi Sano
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Patent number: 10790214Abstract: To improve a TCT characteristic of a circuit substrate. The circuit substrate comprises a ceramic substrate including a first and second surfaces, and first and second metal plates respectively bonded to the first and second surfaces via first and second bonding layers. A three-point bending strength of the ceramic substrate is 500 MPa or more. At least one of L1/H1 of a first protruding portion of the first bonding layer and L2/H2 of a second protruding portion of the second bonding layer is 0.5 or more and 3.0 or less. At least one of an average value of first Vickers hardnesses of 10 places of the first protruding portion and an average value of second Vickers hardnesses of 10 places of the second protruding portion is 250 or less.Type: GrantFiled: September 18, 2019Date of Patent: September 29, 2020Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA MATERIALS CO., LTD.Inventors: Takayuki Naba, Hiromasa Kato, Masashi Umehara
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Publication number: 20200178387Abstract: A ceramic circuit board comprises: a ceramic substrate with a 1.0 mm thickness or less including a first surface and a second surface, the first surface including a first area and a second area; a first metal plate joined to the first area; and a second metal plate joined to the second surface. The second area has a first waviness profile along a first side of the first surface, the first waviness profile having one extreme value or less. The second area has a second waviness profile along a second side of the first surface, the second waviness profile has not less than two nor more than three extreme values.Type: ApplicationFiled: February 4, 2020Publication date: June 4, 2020Applicants: KABUSHIKI KAISHA TOSHIBA, TOSHIBA MATERIALS CO., LTD.Inventors: Takayuki NABA, Hiromasa KATO, Keiichi YANO
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Publication number: 20200170118Abstract: According to one embodiment, a method for manufacturing a ceramic circuit board is disclosed. The ceramic circuit board includes a copper plate bonded to at least one surface of a ceramic substrate via a brazing material layer including Ag, Cu, and a reactive metal. The method includes: preparing a ceramic circuit board in which a copper plate is bonded on a ceramic substrate via a brazing material layer, and a portion of the brazing material layer is exposed between a pattern shape of the copper plate; a first chemical polishing process of chemically polishing the portion of the brazing material layer; and a first brazing material etching process of etching the chemically polished portion of the brazing material layer by using an etchant having a pH of 6 or less and including one type or two types selected from hydrogen peroxide and ammonium peroxodisulfate.Type: ApplicationFiled: January 28, 2020Publication date: May 28, 2020Applicants: KABUSHIKI KAISHA TOSHIBA, TOSHIBA MATERIALS CO., LTD.Inventors: Hiromasa KATO, Hideaki HIRABAYASHI, Fumiyuki KAWASHIMA, Akito SASAKI
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Patent number: 10595403Abstract: A ceramic circuit board comprises: a ceramic substrate with a 1.0 mm thickness or less including a first surface and a second surface, the first surface including a first area and a second area; a first metal plate joined to the first area; and a second metal plate joined to the second surface. The second area has a first waviness profile along a first side of the first surface, the first waviness profile having one extreme value or less. The second area has a second waviness profile along a second side of the first surface, the second waviness profile has not less than two nor more than three extreme values.Type: GrantFiled: January 11, 2019Date of Patent: March 17, 2020Assignees: KABUSHIKI KAISHA TOSHIBA, TOSHIBA MATERIALS CO., LTD.Inventors: Takayuki Naba, Hiromasa Kato, Keiichi Yano
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Publication number: 20200013696Abstract: To improve a TCT characteristic of a circuit substrate. The circuit substrate comprises a ceramic substrate including a first and second surfaces, and first and second metal plates respectively bonded to the first and second surfaces via first and second bonding layers. A three-point bending strength of the ceramic substrate is 500 MPa or more. At least one of L1/H1 of a first protruding portion of the first bonding layer and L2/H2 of a second protruding portion of the second bonding layer is 0.5 or more and 3.0 or less. At least one of an average value of first Vickers hardnesses of 10 places of the first protruding portion and an average value of second Vickers hardnesses of 10 places of the second protruding portion is 250 or less.Type: ApplicationFiled: September 18, 2019Publication date: January 9, 2020Applicants: Kabushiki Kaisha Toshiba, Toshiba Materials Co., Ltd.Inventors: Takayuki NABA, Hiromasa KATO, Masashi UMEHARA
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Patent number: 10515868Abstract: To improve a TCT characteristic of a circuit substrate. The circuit substrate comprises a ceramic substrate including a first and second surfaces, and first and second metal plates respectively bonded to the first and second surfaces via first and second bonding layers. A three-point bending strength of the ceramic substrate is 500 MPa or more. At least one of L1/H1 of a first protruding portion of the first bonding layer and L2/H2 of a second protruding portion of the second bonding layer is 0.5 or more and 3.0 or less. At least one of an average value of first Vickers hardnesses of 10 places of the first protruding portion and an average value of second Vickers hardnesses of 10 places of the second protruding portion is 250 or less.Type: GrantFiled: August 29, 2017Date of Patent: December 24, 2019Assignees: Kabushiki Kaisha Toshiba, Toshiba Materials Co., Ltd.Inventors: Takayuki Naba, Hiromasa Kato, Masashi Umehara
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Publication number: 20190385926Abstract: According to one embodiment, a ceramic metal circuit board is a ceramic metal circuit board formed by bonding metal circuit plates to at least one surface of a ceramic substrate. At least one of the metal circuit plates has an area of not less than 100 mm2 and includes a concave portion having a depth of not less than 0.02 mm within a range of 1% to 70% of a surface of the at least one of the metal circuit plates. The concave portion is provided not less than 3 mm inside from an end of the metal circuit plate.Type: ApplicationFiled: August 21, 2019Publication date: December 19, 2019Inventors: Takayuki NABA, Keiichi YANO, Hiromasa KATO
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Publication number: 20190327831Abstract: According to one embodiment, a ceramic copper circuit board a ceramic substrate, a copper circuit board provided at one surface of the ceramic substrate. A ratio of a thickness of the copper circuit board to a thickness of the ceramic substrate is 1.25 or more. A number of grain boundaries is not less than 5 and not more than 250 along every 10-mm straight line drawn in a front surface of the copper circuit board.Type: ApplicationFiled: June 28, 2019Publication date: October 24, 2019Applicants: Kabushiki Kaisha Toshiba, Toshiba Materials Co., Ltd.Inventors: Hiromasa KATO, Takashi SANO
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Patent number: 10366938Abstract: The present invention provides a silicon nitride circuit board in which metal plates are attached on front and rear sides of a silicon nitride substrate having a three-point flexural strength of 500 MPa or higher, wherein assuming that a thickness of the metal plate on the front side is denoted by t1, and a thickness of the metal plate on the rear side is denoted by t2, a numerical relation: |t1?t2|?0.30 mm is satisfied, and a warp is formed in the silicon nitride substrate so that the silicon nitride substrate is convex toward the metal plate on one of the front side or the rear side; and warp amounts of the silicon nitride substrate in a long-side direction and a short-side direction both fall within a range from 0.01 to 1.0 mm. It is preferable that a longitudinal width (L1) of the silicon nitride substrate falls within a range from 10 to 200 mm, and a transverse width (L2) of the silicon nitride substrate falls within a range from 10 to 200 mm.Type: GrantFiled: September 6, 2018Date of Patent: July 30, 2019Assignees: Kabushiki Kaisha Toshiba, Toshiba Materials Co., Ltd.Inventors: Hiromasa Kato, Noboru Kitamori, Takayuki Naba, Masashi Umehara
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Publication number: 20190172765Abstract: A circuit board includes: a ceramic substrate that has a first surface and a second surface; a first metal part that has a first metal plate joined to the first surface and a protrusion projecting from a front surface of the first metal plate; and a second metal part that has a second metal plate joined to the second surface. When the ceramic substrate is equally divided into first to third sections along a longer side direction, V1, V2, V3, V4, V5, and V6 are numbers satisfying formula V4/V1+V6/V3?2(V5/V2), 0.5?V4/V1?2, 0.5?V5/V2?2, and 0.5?V6/V3?2.Type: ApplicationFiled: January 25, 2019Publication date: June 6, 2019Applicants: Kabushiki Kaisha Toshiba, Toshiba Materials Co., Ltd.Inventors: Hiromasa KATO, Takashi SANO
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Publication number: 20190150278Abstract: A ceramic circuit board comprises: a ceramic substrate with a 1.0 mm thickness or less including a first surface and a second surface, the first surface including a first area and a second area; a first metal plate joined to the first area; and a second metal plate joined to the second surface. The second area has a first waviness profile along a first side of the first surface, the first waviness profile having one extreme value or less. The second area has a second waviness profile along a second side of the first surface, the second waviness profile has not less than two nor more than three extreme values.Type: ApplicationFiled: January 11, 2019Publication date: May 16, 2019Applicants: Kabushiki Kaisha Toshiba, Toshiba Materials Co., Ltd.Inventors: Takayuki NABA, Hiromasa KATO, Keiichi YANO
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Publication number: 20190006261Abstract: The present invention provides a silicon nitride circuit board in which metal plates are attached on front and rear sides of a silicon nitride substrate having a three-point flexural strength of 500 MPa or higher, wherein assuming that a thickness of the metal plate on the front side is denoted by t1, and a thickness of the metal plate on the rear side is denoted by t2, a numerical relation: |t1?t2|?0.30 mm is satisfied, and a warp is formed in the silicon nitride substrate so that the silicon nitride substrate is convex toward the metal plate on one of the front side or the rear side; and warp amounts of the silicon nitride substrate in a long-side direction and a short-side direction both fall within a range from 0.01 to 1.0 mm. It is preferable that a longitudinal width (L1) of the silicon nitride substrate falls within a range from 10 to 200 mm, and a transverse width (L2) of the silicon nitride substrate falls within a range from 10 to 200 mm.Type: ApplicationFiled: September 6, 2018Publication date: January 3, 2019Applicants: KABUSHIKI KAISHA TOSHIBA, TOSHIBA MATERIALS CO., LTD.Inventors: Hiromasa KATO, Noboru KITAMORI, Takayuki NABA, Masashi UMEHARA