Patents by Inventor Akira Fukuizumi
Akira Fukuizumi 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: 6849930Abstract: The present invention provides a semiconductor device whose reliability is improved by improving the adhesion strength of a metal plate or connecting chip, said plurality of electrodes and a lead frame with a molding resin. Further, the semiconductor device of the present invention prevents flow out of a conductive joining material to be employed for joining a lead terminal and the metal plate other than the joining range of the metal plate and the lead terminal, and mounts the metal plate at high precision. In a semiconductor device (a plastic package) in which a source electrode of a semiconductor chip and source terminal of a lead frame are electrically connected by a copper plate and sealed by a resin, the surface of the copper plate is roughened to improve the adhesion strength to a molding resin. Further, a stepped part is formed in the source terminal to prevent a conductive paste from flowing out. The structure is so formed as to fit claw parts in the lead frame.Type: GrantFiled: August 30, 2001Date of Patent: February 1, 2005Assignee: NEC CorporationInventors: Yoshihiro Nakajima, Akira Fukuizumi
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Patent number: 6747360Abstract: Conductive hardening resin for a semiconductor device of the present invention contains metal powder for providing electric conduction between electrodes positioned on the front of a semiconductor chip and a wiring material including lead terminals via a conductive plate. The resin has a modulus of elasticity of 2.0×109 Pa or below when hardened. The resin prevents the contact resistance of the metal plate, lead terminals and semiconductor chip from increasing in the event of temperature cycling tests and a pressure cooker tests. Further, the resin frees the metal plate and chip from peel-off and corrosion, respectively.Type: GrantFiled: June 10, 2003Date of Patent: June 8, 2004Assignees: NEC Electronics Corporation, Sumitomo Bakelite Co., Ltd.Inventors: Akira Fukuizumi, Kazuto Oonami
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Patent number: 6733695Abstract: An electrically conductive paste comprises 80% by weight or more of silver powder and 20% by weight or less of a thermosetting resin. The silver powder has a particle size distribution having two peaks at specific positions. Viscosities of the paste measured under a low shearing stress and under a high shearing stress are in respective specific ranges and the ratio of these viscosities is in a specific range. A cured product obtained by heating the paste has a tensile modulus in a specific range. The paste has thermal and electric conductivities approximately the same as those of solder, shows little change in properties under a high temperature and a high humidity or under cyclic cooling and heating, exhibits excellent workability in coating and can be applied to coating by using nozzles having a wide range of diameters. A reliable semiconductor device is prepared by using the paste.Type: GrantFiled: June 21, 2002Date of Patent: May 11, 2004Assignee: Sumitomo Bakelite Company Ltd.Inventors: Kazuto Onami, Toshiro Takeda, Akira Fukuizumi, Yoshihiro Nakajima
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Patent number: 6720647Abstract: In a semiconductor device, an insulating substrate has a plurality of through holes. A plurality of conductive posts are buried in the through-holes. The conductive posts are classified to at least one first conductive post and a pair of second conductive posts. A semiconductor element has at least one surface electrode at a surface side. The surface electrode is connected to the first conductive post by a face-down method. A metal block is formed to a square-arch shape in a cross sectional view and has a ceiling portion and both end portions. A back surface of the semiconductor element is secured to the ceiling portion while the both end portions are secured to the second conductive posts. A sealing-resin seals the semiconductor element.Type: GrantFiled: June 4, 2001Date of Patent: April 13, 2004Assignee: NEC Electronics CorporationInventor: Akira Fukuizumi
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Publication number: 20030214032Abstract: Conductive hardening resin for a semiconductor device of the present invention contains metal powder for providing electric conduction between electrodes positioned on the front of a semiconductor chip and a wiring material including lead terminals via a conductive plate. The resin has a modulus of elasticity of 2.0×109 Pa or below when hardened. The resin prevents the contact resistance of the metal plate, lead terminals and semiconductor chip from increasing in the event of temperature cycling tests and a pressure cooker tests. Further, the resin frees the metal plate and chip from peel-off and corrosion, respectively.Type: ApplicationFiled: June 10, 2003Publication date: November 20, 2003Applicants: NEC ELECTRONICS CORPORATION, SUMITOMO BAKELITE CO., LTD.Inventors: Akira Fukuizumi, Kazuto Oonami
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Patent number: 6613829Abstract: Conductive hardening resin for a semiconductor device of the present invention contains metal powder for providing electric conduction between electrodes positioned on the front of a semiconductor chip and a wiring material including lead terminals via a conductive plate. The resin has a modulus of elasticity of 2.0×109 Pa or below when hardened. The resin prevents the contact resistance of the metal plate, lead terminals and semiconductor chip from increasing in the event of temperature cycling tests and a pressure cooker tests. Further, the resin frees the metal plate and chip from peel-off and corrosion, respectively.Type: GrantFiled: January 23, 2002Date of Patent: September 2, 2003Assignees: NEC Electronics Corporation, Sumitomo Bakelite Co., Ltd.Inventors: Akira Fukuizumi, Kazuto Oonami
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Publication number: 20030122257Abstract: An electrically conductive paste comprises 80% by weight or more of silver powder and 20% by weight or less of a thermosetting resin. The silver powder has a particle size distribution having two peaks at specific positions. Viscosities of the paste measured under a low shearing stress and under a high shearing stress are in respective specific ranges and the ratio of these viscosities is in a specific range. A cured product obtained by heating the paste has a tensile modulus in a specific range. The paste has thermal and electric conductivities approximately the same as those of solder, shows little change in properties under a high temperature and a high humidity or under cyclic cooling and heating, exhibits excellent workability in coating and can be applied to coating by using nozzles having a wide range of diameters. A reliable semiconductor device is prepared by using the paste.Type: ApplicationFiled: June 21, 2002Publication date: July 3, 2003Inventors: Kazuto Onami, Toshiro Takeda, Akira Fukuizumi, Yoshihiro Nakajima
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Publication number: 20020098625Abstract: Conductive hardening resin for a semiconductor device of the present invention contains metal powder for providing electric conduction between electrodes positioned on the front of a semiconductor chip and a wiring material including lead terminals via a conductive plate. The resin has a modulus of elasticity of 2.0×109 Pa or below when hardened. The resin prevents the contact resistance of the metal plate, lead terminals and semiconductor chip from increasing in the event of temperature cycling tests and a pressure cooker tests. Further, the resin frees the metal plate and chip from peel-off and corrosion, respectively.Type: ApplicationFiled: January 23, 2002Publication date: July 25, 2002Applicant: NEC CORPORATIONInventors: Akira Fukuizumi, Kazuto Oonami
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Publication number: 20020047187Abstract: The present invention provides a semiconductor device whose reliability is improved by improving the adhesion strength of a metal plate or connecting chip, said plurality of electrodes and a lead frame with a molding resin. Further, the semiconductor device of the present invention prevents flow out of a conductive joining material to be employed for joining a lead terminal and the metal plate other than the joining range of the metal plate and the lead terminal, and mounts the metal plate at high precision. In a semiconductor device (a plastic package) in which a source electrode of a semiconductor chip and source terminal of a lead frame are electrically connected by a copper plate and sealed by a resin, the surface of the copper plate is roughened to improve the adhesion strength to a molding resin. Further, a stepped part is formed in the source terminal to prevent a conductive paste from flowing out. The structure is so formed as to fit claw parts in the lead frame.Type: ApplicationFiled: August 30, 2001Publication date: April 25, 2002Applicant: NEC CORPORATIONInventors: Yoshihiro Nakajima, Akira Fukuizumi
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Publication number: 20010048156Abstract: In a semiconductor device, an insulating substrate has a plurality of through holes. A plurality of conductive posts are buried in the through-holes. The conductive posts are classified to at least one first conductive post and a pair of second conductive posts. A semiconductor element has at least one surface electrode at a surface side. The surface electrode is connected to the first conductive post by a face-down method. A metal block is formed to a square-arch shape in a cross sectional view and has a ceiling portion and both end portions. A back surface of the semiconductor element is secured to the ceiling portion while the both end portions are secured to the second conductive posts. A sealing-resin seals the semiconductor element.Type: ApplicationFiled: June 4, 2001Publication date: December 6, 2001Applicant: NEC CORPORATION.Inventor: Akira Fukuizumi