Patents by Inventor Yoshitsugu Sakamoto
Yoshitsugu Sakamoto 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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Publication number: 20240071861Abstract: A semiconductor device includes a semiconductor element, a wiring member, a sintered member between a first main electrode of the semiconductor element and the wiring member, and a sealing body. The wiring member includes a base material, a metal film on a face of the base material, and an uneven oxide film. The uneven oxide film includes a thick film portion and a thin film portion. An opposing face of the wiring member opposing the semiconductor element includes a mounting portion to which the first main electrode is bonded, an outer peripheral portion formed with the thick film portion and surrounding the semiconductor element, and an intermediate portion formed with the thin film portion between the mounting portion and the outer peripheral portion. The sintered member overlaps with the mounting portion and the intermediate portion in the plan view, and is in contact with the thin film portion.Type: ApplicationFiled: November 8, 2023Publication date: February 29, 2024Inventors: Ryo KIMURA, Yuji KOJIMA, Takashi SATO, Yoshitsugu SAKAMOTO, Tomomi OKUMURA
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Patent number: 11710709Abstract: A semiconductor device includes a semiconductor chip made of a SiC substrate and having main electrodes on one surface and a rear surface, first and second heat sinks, respectively, disposed adjacent to the one surface and the rear surface, a terminal member interposed between the second heat sink and the semiconductor chip, and a plurality of bonding members disposed between the main electrodes, the first and second heat sinks, and the terminal member. The terminal member includes plural types of metal layers symmetrically layered in the plate thickness direction. The terminal member as a whole has a coefficient of linear expansion at least in a direction orthogonal to the plate thickness direction in a range larger than that of the semiconductor chip and smaller than that of the second heat sink.Type: GrantFiled: April 12, 2021Date of Patent: July 25, 2023Assignee: DENSO CORPORATIONInventors: Ryoichi Kaizu, Takumi Nomura, Tetsuto Yamagishi, Yuki Inaba, Yoshitsugu Sakamoto
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Publication number: 20230130647Abstract: A semiconductor device includes a semiconductor chip having first and second main electrodes disposed on opposite surfaces of a silicon carbide substrate, first and second heat dissipation members disposed so as to sandwich the semiconductor chip, and joining members disposed between the first main electrode and the first heat dissipation member and between the second main electrode and the second heat dissipation member. At least one of the joining members is made of a lead-free solder having an alloy composition that contains 3.2 to 3.8 mass % Ag, 0.6 to 0.8 mass % Cu, 0.01 to 0.2 mass % Ni, x mass % Sb, y mass % Bi, 0.001 to 0.3 mass % Co, 0.001 to 0.2 mass % P, and a balance of Sn, where x and y satisfy relational expressions of x+2y?11 mass %, x+14y?42 mass %, and x?5.1 mass %.Type: ApplicationFiled: December 27, 2022Publication date: April 27, 2023Inventors: Tetsuto YAMAGISHI, Yoshitsugu SAKAMOTO, Ryoichi KAIZU, Yuki INABA, Hiroki YOSHIKAWA
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Publication number: 20210233871Abstract: A semiconductor device includes a semiconductor chip made of a SiC substrate and having main electrodes on one surface and a rear surface, first and second heat sinks, respectively, disposed adjacent to the one surface and the rear surface, a terminal member interposed between the second heat sink and the semiconductor chip, and a plurality of bonding members disposed between the main electrodes, the first and second heat sinks, and the terminal member. The terminal member includes plural types of metal layers symmetrically layered in the plate thickness direction. The terminal member as a whole has a coefficient of linear expansion at least in a direction orthogonal to the plate thickness direction in a range larger than that of the semiconductor chip and smaller than that of the second heat sink.Type: ApplicationFiled: April 12, 2021Publication date: July 29, 2021Inventors: RYOICHI KAIZU, TAKUMI NOMURA, TETSUTO YAMAGISHI, YUKI INABA, YOSHITSUGU SAKAMOTO
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Patent number: 10081852Abstract: A mixed mother alloy is prepared from a solder mixture comprising a pyrolyzable flux and high melting point metal particles, the mixed mother alloy is charged into a large amount of molten solder and stirred, and a billet is prepared. The billet can then be extruded, rolled, and punched to form a pellet or a washer, for example.Type: GrantFiled: September 14, 2010Date of Patent: September 25, 2018Assignees: Senju Metal Industry Co., Ltd., Denso CorporationInventors: Naohiko Hirano, Akira Tanahashi, Yoshitsugu Sakamoto, Kaichi Tsuruta, Takashi Ishii, Satoshi Soga
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Publication number: 20150027589Abstract: A solder paste which solves any nozzle clogging that suddenly occurs in a case of being used in a discharging method and which also realizes residue-free because flux is decomposed by heating during soldering. In the solder paste produced by mixing solder powders with the flux, the flux is flux containing polyalkyl-methacrylate of not less than 1.0 mass % and less than 2.0 mass % as methacrylate polymer of an amount such that it prevents the solder powders from being sedimented at ordinary temperature and it is decomposed or evaporated in the process of heating during the soldering, and containing stearic acid amide of not less than 5.0 mass % and less than 15.0 mass %, as viscosity modifier, wherein viscosity is 50 through 150 Pa·s. It is preferable that the content of flux in the solder paste is not less than 11 mass % and less than 13 mass %.Type: ApplicationFiled: December 25, 2012Publication date: January 29, 2015Applicants: Senju Metal Industry Co., Ltd., Denso CorporationInventors: Sakie Okada, Motoki Koroki, Hiroaki Iseki, Taro Itoyama, Yoshitsugu Sakamoto, Hiromasa Hayashi
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Patent number: 8896119Abstract: A semiconductor device is provided which has internal bonds which do not melt at the time of mounting on a substrate. A bonding material is used for internal bonding of the semiconductor device. The bonding material is obtained by filling the pores of a porous metal body having a mesh-like structure and covering the surface thereof with Sn or an Sn-based solder alloy.Type: GrantFiled: August 3, 2011Date of Patent: November 25, 2014Assignee: Senju Metal Industry Co., Ltd.Inventors: Yoshitsugu Sakamoto, Hiroyuki Yamada, Yoshie Yamanaka, Tsukasa Ohnishi, Shunsaku Yoshikawa, Kenzo Tadokoro
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Publication number: 20130134591Abstract: A semiconductor device is provided which has internal bonds which do not melt at the time of mounting on a substrate. A bonding material is used for internal bonding of the semiconductor device. The bonding material is obtained by filling the pores of a porous metal body having a mesh-like structure and covering the surface thereof with Sn or an Sn-based solder alloy.Type: ApplicationFiled: August 3, 2011Publication date: May 30, 2013Inventors: Yoshitsugu Sakamoto, Hiroyuki Yamada, Yoshie Yamanaka, Tsukasa Ohnishi, Shunsaku Yoshikawa, Kenzo Tadokoro
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Patent number: 8029918Abstract: A brazing method includes assembling a first member and a second member, the first member including a base plate made of a ferrous material and a diffusion suppressing layer laminated on the base plate and made of a Ni—Cr alloy including more than about 15% and less than about 40% of Cr, the second member being disposed on the first member with a brazing material of a Cu—Ni alloy including more than about 10% and less than about 20% of Ni therebetween, and maintaining the temporary assembly at a temperature of more than about 1,200° C. to fuse the brazing material and diffuse Ni atoms and Cr atoms into the fused brazing material to form the braze joint, causing the resulting brazing material to have an increased melting point due to the Ni and Cr contents of the braze joint to self-solidify the braze joint, and then cooling the resulting assembly.Type: GrantFiled: July 2, 2010Date of Patent: October 4, 2011Assignee: Neomax Materials Co., Ltd.Inventors: Tsuyoshi Hasegawa, Masaaki Ishio, Shunji Kajikawa, Yoshitsugu Sakamoto, Takayuki Hayashi
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Publication number: 20110068149Abstract: A mixed mother alloy is prepared from a solder mixture comprising a pyrolyzable flux and high melting point metal particles, the mixed mother alloy is charged into a large amount of molten solder and stirred, and a billet is prepared. The billet can then be extruded, rolled, and punched to form a pellet or a washer, for example.Type: ApplicationFiled: September 14, 2010Publication date: March 24, 2011Inventors: Naohiko Hirano, Akira Tanahashi, Yoshitsugu Sakamoto, Kaichi Tsuruta, Takashi Ishii, Satoshi Soga
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Publication number: 20100273025Abstract: A brazing method which provides a braze joint having excellent corrosion resistance and a brazed structure including such a braze joint includes assembling a first member and a second member to be joined into a temporary assembly, the first member including a base plate made of a ferrous material and a diffusion suppressing layer laminated on the base plate and composed of a N—Cr alloy essentially including not less than about 15% and not greater than about 40% of Cr, the second member being disposed on the diffusion suppressing layer of the first member with intervention of a brazing material of a Cu—Ni alloy essentially including not less than about 10% and not greater than about 20% of Ni, and maintaining the temporary assembly at a temperature of not less than about 1,200° C.Type: ApplicationFiled: July 2, 2010Publication date: October 28, 2010Applicant: NEOMAX MATERIALS CO., LTD.Inventors: Tsuyoshi Hasegawa, Masaaki Ishio, Shunji Kajikawa, Yoshitsugu Sakamoto, Takayuki Hayashi
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Patent number: 7800230Abstract: A solder preform according to the present invention has a variation in the size of high melting point metal particles which is at most 20 micrometers when the metal particle diameter is 50 micrometers, and an alloy layer of the high melting point metal particles and the main component of solder is formed around the high melting point metal particles. In addition, no voids at all are present in the solder. An electronic component according to the present invention has a semiconductor element bonded to a substrate with the above-described solder preform and has excellent resistance to heat cycles.Type: GrantFiled: April 26, 2007Date of Patent: September 21, 2010Assignees: DENSO CORPORATION, Senju Metal Industry Co., Ltd.Inventors: Naohiko Hirano, Yoshitsugu Sakamoto, Tomomi Okumura, Kaichi Tsuruta, Minoru Ueshima, Takashi Ishii
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Patent number: 7793820Abstract: A mixed mother alloy is prepared from a solder mixture comprising a pyrolyzable flux and high melting point metal particles, the mixed mother alloy is charged into a large amount of molten solder and stirred, and a billet is prepared. The billet can then be extruded, rolled, and punched to form a pellet or a washer, for example.Type: GrantFiled: March 7, 2008Date of Patent: September 14, 2010Assignees: Senju Metal Industry Co., Ltd., Denso CorporationInventors: Naohiko Hirano, Akira Tanahashi, Yoshitsugu Sakamoto, Kaichi Tsuruta, Takashi Ishii, Satoshi Soga
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Patent number: 7601625Abstract: A method for manufacturing a semiconductor device having a solder layer includes the steps of: grinding a mounting surface of a semiconductor chip; etching the mounting surface of the chip; forming an electrode on the mounting surface of the chip; assembling the chip, the solder layer and a base in this order; and heating the chip, the solder layer and the base to be equal to or higher than a solidus temperature of the solder layer so that the solder layer is reflowed for soldering the chip on the base.Type: GrantFiled: April 19, 2005Date of Patent: October 13, 2009Assignees: DENSO CORPORATION, Toyota Jidosha Kabushiki KaishaInventors: Chikage Noritake, Yoshitsugu Sakamoto, Akira Tanahashi, Hideki Okada, Tomomasa Yoshida
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Publication number: 20090236725Abstract: An electronic component having a semiconductor element bonded to a substrate with solder has a decreased bonding strength if there is not a suitable clearance between the semiconductor element and the substrate. Therefore, a solder preform having high melting point metal particles dispersed in solder has been used in the manufacture of electronic components. However, when an electronic component was manufactured using a conventional solder preform, there were cases in which the semiconductor element leaned or the bonding strength was not adequate. A solder preform according to the present invention has a variation in the size of high melting point metal particles which is at most 20 micrometers when the metal particle diameter is 50 micrometers, and an alloy layer of the high melting point metal particles and the main component of solder is formed around the high melting point metal particles. In addition, no voids at all are present in the solder.Type: ApplicationFiled: April 26, 2007Publication date: September 24, 2009Inventors: Naohiko Hirano, Yoshitsugu Sakamoto, Tomomi Okumura, Kaichi Tsuruta, Minoru Ueshima, Takashi Ishii
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Patent number: 7468318Abstract: A method for manufacturing a mold type semiconductor device is provided. The device includes a semiconductor chip having a semiconductor part and a metallic member connecting to the chip via a conductive layer and a connecting member. The method includes: forming the semiconductor part on a semiconductor substrate so that a cell portion is provided; forming the conductive layer on the substrate; forming a first resist layer to cover a part of the conductive layer corresponding to the cell portion; etching the conductive layer with the first resist layer as a mask so that a first conductive layer is provided; removing the first resist layer and forming a second conductive layer to cover a surface and an edge of the first conductive layer. The second conductive layer has a Young's modulus equal to or larger than the semiconductor substrate.Type: GrantFiled: February 6, 2007Date of Patent: December 23, 2008Assignee: DENSO CORPORATIONInventors: Naohiko Hirano, Nobuyuki Kato, Takanori Teshima, Yoshitsugu Sakamoto, Shoji Miura, Akihiro Niimi
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Publication number: 20080237301Abstract: A mixed mother alloy is prepared from a solder mixture comprising a pyrolyzable flux and high melting point metal particles, the mixed mother alloy is charged into a large amount of molten solder and stirred, and a billet is prepared. The billet can then be extruded, rolled, and punched to form a pellet or a washer, for example.Type: ApplicationFiled: March 7, 2008Publication date: October 2, 2008Inventors: Naohiko Hirano, Akira Tanahashi, Yoshitsugu Sakamoto, Kaichi Tsuruta, Takashi Ishii, Satoshi Soga
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Publication number: 20070158850Abstract: A mold type semiconductor device includes a semiconductor chip including a semiconductor part; a metallic layer; a solder layer; and a metallic member connecting to the semiconductor chip through the metallic layer and the solder layer. The solder layer is made of solder having yield stress smaller than that of the metallic layer. Even when the semiconductor chip is sealed with a resin mold, the metallic layer is prevented from cracking.Type: ApplicationFiled: February 6, 2007Publication date: July 12, 2007Applicant: DENSO CORPORATIONInventors: Naohiko Hirano, Nobuyuki Kato, Takanori Teshima, Yoshitsugu Sakamoto, Shoji Miura, Akihiro Niimi
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Publication number: 20070148490Abstract: A brazing method which provides a braze joint having excellent corrosion resistance and a brazed structure including such a braze joint includes assembling a first member and a second member to be joined into a temporary assembly, the first member including a base plate made of a ferrous material and a diffusion suppressing layer laminated on the base plate and composed of a Ni—Cr alloy essentially including not less than about 15% and not greater than about 40% of Cr, the second member being disposed on the diffusion suppressing layer of the first member with intervention of a brazing material of a Cu—Ni alloy essentially including not less than about 10% and not greater than about 20% of Ni, and maintaining the temporary assembly at a temperature of not less than about 1,200° C.Type: ApplicationFiled: December 22, 2004Publication date: June 28, 2007Applicant: NEOMAX MATERIALS CO., LTD.Inventors: Tsuyoshi Hasegawa, Masaaki Ishio, Shunji Kajikawa, Yoshitsugu Sakamoto, Takayuki Hayashi
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Patent number: 7235876Abstract: A semiconductor device includes: first and second metallic plates, each of which includes a heat radiation surface and an inner surface; a semiconductor element between the metallic plates; a block between the second metallic plate and the semiconductor element; a solder member between the second metallic plate and the block; and a resin mold. The heat radiation surface is exposed from the resin mold. The second metallic plate includes a groove for preventing the solder member from expanding outside of the block. The groove is disposed on the inner surface and disposed on an outer periphery of the block. The second metallic plate further includes an inner surface member on an inner surface of the groove. The inner surface member has a solder wettability, which is larger than a solder wettability of the block.Type: GrantFiled: September 7, 2006Date of Patent: June 26, 2007Assignee: Denso CorporationInventors: Tomomi Okumura, Yoshitsugu Sakamoto, Naohiko Hirano, Kuniaki Mamitsu