Patents by Inventor Takuya Nakajo

Takuya Nakajo 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: 9177833
    Abstract: Conventional surface roughening plating technology cannot always improve the adhesion between a leadframe and a plating film and it depends on the material used for surface roughening plating. Conventional surface roughening technology by etching can only be used for leadframes made of limited materials. Improved adhesion cannot therefore be achieved between a metal member such as leadframe and a sealing resin. A manufacturing method of a semiconductor device according to one embodiment is to carry out resin sealing using a metal member such as leadframe which has been subjected to alloying treatment of a base material and Zn plated on the surface thereof.
    Type: Grant
    Filed: February 15, 2013
    Date of Patent: November 3, 2015
    Assignee: Renesas Electronics Corporation
    Inventors: Takuya Nakajo, Masaki Tamura, Yasushi Takahashi, Keiichi Okawa, Ryoichi Kajiwara, Sigehisa Motowaki, Hiroshi Hozouji
  • Publication number: 20140264383
    Abstract: A semiconductor device includes a die pad, an SiC chip mounted on the die pad, a porous first sintered Ag layer bonding the die pad and the SiC chip, and a reinforcing resin portion covering a surface of the first sintered Ag layer and formed in a fillet shape. The semiconductor device further includes a source lead electrically connected to a source electrode of the SiC chip, a gate lead electrically connected to a gate electrode, a drain lead electrically connected to a drain electrode, and a sealing body which covers the SiC chip, the first sintered Ag layer, and a part of the die pad, and the reinforcing resin portion covers a part of a side surface of the SiC chip.
    Type: Application
    Filed: March 14, 2014
    Publication date: September 18, 2014
    Applicant: RENESAS ELECTRONICS CORPORATION
    Inventors: Ryoichi KAJIWARA, Takuya NAKAJO, Katsuo ARAI, Yuichi YATO, Hiroi OKA, Hiroshi HOZOJI
  • Patent number: 8643185
    Abstract: A die bonding portion is metallically bonded by well-conductive Cu metal powders with a maximum particle diameter of about 15 ?m to 200 ?m and adhesive layers of Ag, and minute holes are evenly dispersed in a joint layer. With this structure, the reflow resistance of about 260° C. and reliability under thermal cycle test can be ensured without using lead.
    Type: Grant
    Filed: October 7, 2008
    Date of Patent: February 4, 2014
    Assignee: Renesas Electronics Corporation
    Inventors: Ryoichi Kajiwara, Kazutoshi Itou, Hiroi Oka, Takuya Nakajo, Yuichi Yato
  • Publication number: 20130228907
    Abstract: Conventional surface roughening plating technology cannot always improve the adhesion between a leadframe and a plating film and it depends on the material used for surface roughening plating. Conventional surface roughening technology by etching can only be used for leadframes made of limited materials. Improved adhesion cannot therefore be achieved between a metal member such as leadframe and a sealing resin. A manufacturing method of a semiconductor device according to one embodiment is to carry out resin sealing using a metal member such as leadframe which has been subjected to alloying treatment of a base material and Zn plated on the surface thereof.
    Type: Application
    Filed: February 15, 2013
    Publication date: September 5, 2013
    Applicant: RENESAS ELECTRONICS CORPORATION
    Inventors: Takuya NAKAJO, Masaki TAMURA, Yasushi TAKAHASHI, Keiichi OKAWA, Ryoichi KAJIWARA, Sigehisa MOTOWAKI, Hiroshi HOZOUJI
  • Patent number: 8492202
    Abstract: In a structure of a semiconductor device, a Si chip and a metal leadframe are jointed by metallic bond via a porous joint layer made of high conductive metal, having a three-dimensional network structure and using Ag as a bonding material, and a film containing Zn oxide or Al oxide is formed on a surface of a semiconductor assembly contacting to a polymer resin. In this manner, by the joint with the joint layer having the porous structure mainly made of Ag, thermal stress load of the Si chip can be reduced, and fatigue life of the joint layer itself can be improved. Besides, since adhesion of the polymer resin to the film can be enhanced by the anchor effect, occurrence of cracks in a bonding portion can be prevented, so that a highly-reliable Pb-free semiconductor device can be provided.
    Type: Grant
    Filed: November 15, 2012
    Date of Patent: July 23, 2013
    Assignee: Renesas Electronics Corporation
    Inventors: Ryoichi Kajiwara, Shigehisa Motowaki, Kazutoshi Ito, Toshiaki Ishii, Katsuo Arai, Takuya Nakajo, Hidemasa Kagii
  • Patent number: 8314484
    Abstract: In a structure of a semiconductor device, a Si chip and a metal leadframe are jointed by metallic bond via a porous joint layer made of high conductive metal, having a three-dimensional network structure and using Ag as a bonding material, and a film containing Zn oxide or Al oxide is formed on a surface of a semiconductor assembly contacting to a polymer resin. In this manner, by the joint with the joint layer having the porous structure mainly made of Ag, thermal stress load of the Si chip can be reduced, and fatigue life of the joint layer itself can be improved. Besides, since adhesion of the polymer resin to the film can be enhanced by the anchor effect, occurrence of cracks in a bonding portion can be prevented, so that a highly-reliable Pb-free semiconductor device can be provided.
    Type: Grant
    Filed: January 21, 2010
    Date of Patent: November 20, 2012
    Assignee: Renesas Electronics Corporation
    Inventors: Ryoichi Kajiwara, Shigehisa Motowaki, Kazutoshi Ito, Toshiaki Ishii, Katsuo Arai, Takuya Nakajo, Hidemasa Kagii
  • Patent number: 8252632
    Abstract: The present invention enables improvement of bonding reliability of the conductive adhesive interposed between a semiconductor chip and a die pad portion. Provided is a semiconductor device, in which a silicon chip is mounted over the die pad portion integrally formed with a drain lead, has a source pad over the main surface and a drain electrode of a power MOSFET over the back side, and is bonded onto the die pad portion via an Ag paste. In the device, a source lead and the source pad are electrically coupled via an Al ribbon. Over the back surface of the silicon chip, an Ag nanoparticle coated film is formed, while another Ag nanoparticle coated film is formed over the die pad portion and lead (drain lead and source lead).
    Type: Grant
    Filed: June 8, 2011
    Date of Patent: August 28, 2012
    Assignee: Renesas Electronics Corporation
    Inventors: Yuichi Yato, Takuya Nakajo, Hiroi Oka
  • Publication number: 20110237031
    Abstract: The present invention enables improvement of bonding reliability of the conductive adhesive interposed between a semiconductor chip and a die pad portion. Provided is a semiconductor device, in which a silicon chip is mounted over the die pad portion integrally formed with a drain lead, has a source pad over the main surface and a drain electrode of a power MOSFET over the back side, and is bonded onto the die pad portion via an Ag paste. In the device, a source lead and the source pad are electrically coupled via an Al ribbon. Over the back surface of the silicon chip, an Ag nanoparticle coated film is formed, while another Ag nanoparticle coated film is formed over the die pad portion and lead (drain lead and source lead).
    Type: Application
    Filed: June 8, 2011
    Publication date: September 29, 2011
    Inventors: Yuichi YATO, Takuya NAKAJO, Hiroi OKA
  • Patent number: 7977775
    Abstract: The present invention enables improvement of bonding reliability of the conductive adhesive interposed between a semiconductor chip and a die pad portion. Provided is a semiconductor device, in which a silicon chip is mounted over the die pad portion integrally formed with a drain lead, has a source pad over the main surface and a drain electrode of a power MOSFET over the back side, and is bonded onto the die pad portion via an Ag paste. In the device, a source lead and the source pad are electrically coupled via an Al ribbon. Over the back surface of the silicon chip, an Ag nanoparticle coated film is formed, while another Ag nanoparticle coated film is formed over the die pad portion and lead (drain lead and source lead).
    Type: Grant
    Filed: January 27, 2009
    Date of Patent: July 12, 2011
    Assignee: Renesas Electronics Corporation
    Inventors: Yuichi Yato, Takuya Nakajo, Hiroi Oka
  • Publication number: 20100187678
    Abstract: In a structure of a semiconductor device, a Si chip and a metal leadframe are jointed by metallic bond via a porous joint layer made of high conductive metal, having a three-dimensional network structure and using Ag as a bonding material, and a film containing Zn oxide or Al oxide is formed on a surface of a semiconductor assembly contacting to a polymer resin. In this manner, by the joint with the joint layer having the porous structure mainly made of Ag, thermal stress load of the Si chip can be reduced, and fatigue life of the joint layer itself can be improved. Besides, since adhesion of the polymer resin to the film can be enhanced by the anchor effect, occurrence of cracks in a bonding portion can be prevented, so that a highly-reliable Pb-free semiconductor device can be provided.
    Type: Application
    Filed: January 21, 2010
    Publication date: July 29, 2010
    Applicant: Renesas Technology Corp.
    Inventors: Ryoichi KAJIWARA, Shigehisa MOTOWAKI, Kazutoshi ITO, Toshiaki ISHII, Katsuo ARAI, Takuya NAKAJO, Hidemasa KAGII
  • Publication number: 20090189264
    Abstract: The present invention enables improvement of bonding reliability of the conductive adhesive interposed between a semiconductor chip and a die pad portion. Provided is a semiconductor device, in which a silicon chip is mounted over the die pad portion integrally formed with a drain lead, has a source pad over the main surface and a drain electrode of a power MOSFET over the back side, and is bonded onto the die pad portion via an Ag paste. In the device, a source lead and the source pad are electrically coupled via an Al ribbon. Over the back surface of the silicon chip, an Ag nanoparticle coated film is formed, while another Ag nanoparticle coated film is formed over the die pad portion and lead (drain lead and source lead).
    Type: Application
    Filed: January 27, 2009
    Publication date: July 30, 2009
    Inventors: Yuichi Yato, Takuya Nakajo, Hiroi Oka
  • Publication number: 20090096100
    Abstract: A die bonding portion is metallically bonded by well-conductive Cu metal powders with a maximum particle diameter of about 15 ?m to 200 ?m and adhesive layers of Ag, and minute holes are evenly dispersed in a joint layer. With this structure, the reflow resistance of about 260° C. and reliability under thermal cycle test can be ensured without using lead.
    Type: Application
    Filed: October 7, 2008
    Publication date: April 16, 2009
    Inventors: Ryoichi KAJIWARA, Kazutoshi Itou, Hiroi Oka, Takuya Nakajo, Yuichi Yato
  • Publication number: 20080268577
    Abstract: A semiconductor chip is sealed by resin without covering an outer terminal of a semiconductor device having a power transistor. A semiconductor chip having a power transistor is housed within a recess of a metal cap while a drain electrode on a first surface of the semiconductor chip is bonded to a bottom of the recess via a connection material. A gate electrode and a source electrode are formed on a second surface opposite to the first surface of the semiconductor chip, and the gate electrode and the source electrode are bonded with metal plate terminals 6G, 6S via connection materials 5b, 5c. In addition, the semiconductor chip is sealed by a resin sealing body with mounting-surfaces of the metal plate terminals 6G, 6S being exposed. Mounting surfaces of the metal plate terminals 6G, 6S and a third part of the metal cap are bonded to electrodes on a mounting board 10 via connection materials 5e, 5f and 5g.
    Type: Application
    Filed: June 30, 2008
    Publication date: October 30, 2008
    Inventors: Hidemasa KAGII, Akira Muto, Ichio Shimizu, Katsuo Arai, Hiroshi Sato, Hiroyuki Nakamura, Masahiko Osaka, Takuya Nakajo, Keiichi Okawa, Hiroi Oka
  • Publication number: 20080220568
    Abstract: A semiconductor device in the form of a resin sealed semiconductor package is disclosed, wherein a gate terminal connected to a gate pad electrode formed on a surface of a semiconductor chip and a source terminal connected to a source pad electrode formed on the chip surface exposed to a back surface of a sealing resin portion, a first portion of a drain terminal connected to a back-surface drain electrode of the semiconductor chip is exposed to an upper surface of the sealing resin portion, and a second portion of the drain terminal formed integrally with the first portion of the drain terminal is exposed to the back surface of the sealing resin portion.
    Type: Application
    Filed: May 8, 2008
    Publication date: September 11, 2008
    Inventors: Akira MUTO, Ichio Shimizu, Katsuo Arai, Hidemasa Kagii, Hiroshi Sato, Hiroyuki Nakamura, Takuya Nakajo, Keiichi Okawa, Masahiko Osaka
  • Patent number: 7405469
    Abstract: A semiconductor chip is sealed by resin without covering an outer terminal of a semiconductor device having a power transistor. A semiconductor chip having a power transistor is housed within a recess of a metal cap while a drain electrode on a first surface of the semiconductor chip is bonded to a bottom of the recess via a connection material. A gate electrode and a source electrode are formed on a second surface opposite to the first surface of the semiconductor chip, and the gate electrode and the source electrode are bonded with metal plate terminals 6G, 6S via connection materials 5b, 5c. In addition, the semiconductor chip is sealed by a resin sealing body with mounting-surfaces of the metal plate terminals 6G, 6S being exposed. Mounting surfaces of the metal plate terminals 6G, 6S and a third part of the metal cap are bonded to electrodes on a mounting board 10 via connection materials 5e, 5f and 5g.
    Type: Grant
    Filed: April 13, 2007
    Date of Patent: July 29, 2008
    Assignee: Renesas Technology Corp.
    Inventors: Hidemasa Kagii, Akira Muto, Ichio Shimizu, Katsuo Arai, Hiroshi Sato, Hiroyuki Nakamura, Masahiko Osaka, Takuya Nakajo, Keiichi Okawa, Hiroi Oka
  • Patent number: 7374965
    Abstract: A semiconductor device in the form of a resin sealed semiconductor package is disclosed, wherein a gate terminal connected to a gate pad electrode formed on a surface of a semiconductor chip and a source terminal connected to a source pad electrode formed on the chip surface exposed to a back surface of a sealing resin portion, a first portion of a drain terminal connected to a back-surface drain electrode of the semiconductor chip is exposed to an upper surface of the sealing resin portion, and a second portion of the drain terminal formed integrally with the first portion of the drain terminal is exposed to the back surface of the sealing resin portion.
    Type: Grant
    Filed: February 7, 2006
    Date of Patent: May 20, 2008
    Assignee: Renesas Technology Corp.
    Inventors: Akira Muto, Ichio Shimizu, Katsuo Arai, Hidemasa Kagii, Hiroshi Sato, Hiroyuki Nakamura, Takuya Nakajo, Keiichi Okawa, Masahiko Osaka
  • Publication number: 20070210430
    Abstract: A semiconductor chip is sealed by resin without covering an outer terminal of a semiconductor device having a power transistor. A semiconductor chip having a power transistor is housed within a recess of a metal cap while a drain electrode on a first surface of the semiconductor chip is bonded to a bottom of the recess via a connection material. A gate electrode and a source electrode are formed on a second surface opposite to the first surface of the semiconductor chip, and the gate electrode and the source electrode are bonded with metal plate terminals 6G, 6S via connection materials 5b, 5c. In addition, the semiconductor chip is sealed by a resin sealing body with mounting-surfaces of the metal plate terminals 6G, 6S being exposed. Mounting surfaces of the metal plate terminals 6G, 6S and a third part of the metal cap are bonded to electrodes on a mounting board 10 via connection materials 5e, 5f and 5g.
    Type: Application
    Filed: April 13, 2007
    Publication date: September 13, 2007
    Inventors: Hidemasa Kagii, Akira Muto, Ichio Shimizu, Katsuo Arai, Hiroshi Sato, Hiroyuki Nakamura, Masahiko Osaka, Takuya Nakajo, Keiichi Okawa, Hiroi Oka
  • Patent number: 7220617
    Abstract: A semiconductor chip is sealed by resin without covering an outer terminal of a semiconductor device having a power transistor. A semiconductor chip having a power transistor is housed within a recess of a metal cap while a drain electrode on a first surface of the semiconductor chip is bonded to a bottom of the recess via a connection material. A gate electrode and a source electrode are formed on a second surface opposite to the first surface of the semiconductor chip, and the gate electrode and the source electrode are bonded with metal plate terminals. In addition, the semiconductor chip is sealed by a resin sealing body with mounting-surfaces of the metal plate terminals being exposed. Mounting surfaces of the metal plate terminals and a third part of the metal cap are bonded to electrodes on a mounting board.
    Type: Grant
    Filed: February 8, 2006
    Date of Patent: May 22, 2007
    Assignee: Renesas Technology, Corp.
    Inventors: Hidemasa Kagii, Akira Muto, Ichio Shimizu, Katsuo Arai, Hiroshi Sato, Hiroyuki Nakamura, Masahiko Osaka, Takuya Nakajo, Keiichi Okawa, Hiroi Oka
  • Publication number: 20060177967
    Abstract: A semiconductor device in the form of a resin sealed semiconductor package is disclosed, wherein a gate terminal connected to a gate pad electrode formed on a surface of a semiconductor chip and a source terminal connected to a source pad electrode formed on the chip surface exposed to a back surface of a sealing resin portion, a first portion of a drain terminal connected to a back-surface drain electrode of the semiconductor chip is exposed to an upper surface of the sealing resin portion, and a second portion of the drain terminal formed integrally with the first portion of the drain terminal is exposed to the back surface of the sealing resin portion.
    Type: Application
    Filed: February 7, 2006
    Publication date: August 10, 2006
    Inventors: Akira Muto, Ichio Shimizu, Katsuo Arai, Hidemasa Kagii, Hiroshi Sato, Hiroyuki Nakamura, Takuya Nakajo, Keiichi Okawa, Masahiko Osaka
  • Publication number: 20060175700
    Abstract: A semiconductor chip is sealed by resin without covering an outer terminal of a semiconductor device having a power transistor. A semiconductor chip having a power transistor is housed within a recess of a metal cap while a drain electrode on a first surface of the semiconductor chip is bonded to a bottom of the recess via a connection material. A gate electrode and a source electrode are formed on a second surface opposite to the first surface of the semiconductor chip, and the gate electrode and the source electrode are bonded with metal plate terminals In addition, the semiconductor chip is sealed by a resin sealing body with mounting-surfaces of the metal plate terminals being exposed. Mounting surfaces of the metal plate terminals and a third part of the metal cap are bonded to electrodes on a mounting board.
    Type: Application
    Filed: February 8, 2006
    Publication date: August 10, 2006
    Inventors: Hidemasa Kagii, Akira Muto, Ichio Shimizu, Katsuo Arai, Hiroshi Sato, Hiroyuki Nakamura, Masahiko Osaka, Takuya Nakajo, Keiichi Okawa, Hiroi Oka