Patents by Inventor Takekazu Sakai

Takekazu Sakai 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).

  • Publication number: 20010020744
    Abstract: A method of forming a solder film on a metallic surface such as a pad of a metallic circuit of a printed circuit board and a lead frame of electronic parts, which is capable of forming a precise and fine pattern and which comprises selectively imparting tackiness to only a predetermined part of the metallic surface by means of a tacky layer-forming solution containing at least one compound selected from benzotriazole derivatives, naphthotriazole derivatives, imidazole derivatives, benzoimidazole derivatives, mercaptobenzothiazole derivatives, benzothiazole thiofatty acid derivatives, and triazine derivatives, adhering a powdered solder to the resulting tacky part, and then melting the solder by heating to thereby form a solder film.
    Type: Application
    Filed: January 8, 2001
    Publication date: September 13, 2001
    Inventors: Takeo Kuramoto, Masataka Watabe, Satoshi Noda, Takashi Shoji, Takekazu Sakai
  • Patent number: 6221692
    Abstract: A circuit board mounted with a semiconductor device is fabricated by forming on a silicon substrate at least one first metal layer, overlaying a second metal layer to completely cover the first metal layer, covering the whole surface of the second metal layer with an insulating material, etching the insulating material to open a window at a prescribed region of the surface of the second metal layer, selectively imparting adhesiveness to the portion at the window, adhering solder powder to the adhesive portion, melting the solder powder by heating to form a solder bump, selectively imparting adhesiveness to at least one electrode portion of a wiring board, adhering solder powder to the adhesive portion, melting the adhered solder powder by heating to form a solder bump on the electrode portion, and contacting and fusing the solder bump of the silicon substrate and the solder bump of the wiring board so as to form and maintain a prescribed gap between the silicon substrate and the wiring board.
    Type: Grant
    Filed: August 25, 1999
    Date of Patent: April 24, 2001
    Assignee: Showa Denko, K.K.
    Inventors: Takashi Shoji, Takekazu Sakai
  • Patent number: 5982629
    Abstract: A circuit board mounted with a semiconductor device is fabricated by forming on a silicon substrate at least one first metal layer, overlaying a second metal layer to completely cover the first metal layer, covering the whole surface of the second metal layer with an insulating material, etching the insulating material to open a window at a prescribed region of the surface of the second metal layer, selectively imparting adhesiveness to the portion at the window, adhering solder powder to the adhesive portion, melting the solder powder by heating to form a solder bump, selectively imparting adhesiveness to at least one electrode portion of a wiring board, adhering solder powder to the adhesive portion, melting the adhered solder powder by heating to form a solder bump on the electrode portion, and contacting and fusing the solder bump of the silicon substrate and the solder bump of the wiring board so as to form and maintain a prescribed gap between the silicon substrate and the wiring board.
    Type: Grant
    Filed: August 25, 1998
    Date of Patent: November 9, 1999
    Assignee: Showa Denko K.K.
    Inventors: Takashi Shoji, Takekazu Sakai
  • Patent number: 5928440
    Abstract: A method of forming a solder film on a metallic surface such as a pad of a metallic circuit of a printed circuit board and a lead frame of electronic parts, which is capable of forming a precise and fine pattern and which comprises selectively imparting tackiness to only a predetermined part of the metallic surface by means of a tacky layer-forming solution, adhering a powdered solder to the resulting tacky part, and then melting the solder by heating to thereby form a solder film.
    Type: Grant
    Filed: August 10, 1995
    Date of Patent: July 27, 1999
    Assignee: Showa Denko K.K.
    Inventors: Takeo Kuramoto, Masataka Watabe, Satoshi Noda, Takashi Shoji, Takekazu Sakai
  • Patent number: 5750271
    Abstract: A method of forming a solder film on a metallic surface such as a pad of a metallic circuit of a printed circuit board and a lead frame of electronic parts, which is capable of forming a precise and fine pattern and which comprises selectively imparting tackiness to only a predetermined part of the metallic surface by means of a tacky layer-forming solution, adhering a powdered solder to the resulting tacky part, and then melting the solder by heating to thereby form a solder film.
    Type: Grant
    Filed: August 10, 1995
    Date of Patent: May 12, 1998
    Assignee: Showa Denko K.K.
    Inventors: Takeo Kuramoto, Masataka Watabe, Satoshi Noda, Takashi Shoji, Takekazu Sakai
  • Patent number: 5713997
    Abstract: A method of forming a solder film on a metallic surface such as a pad of a metallic circuit of a printed circuit board and a lead frame of electronic parts, which is capable of forming a precise and fine pattern and which comprises selectively imparting tackiness to only a predetermined part of the metallic surface by means of a tacky layer-forming solution, adhering a powdered solder to the resulting tacky part, and then melting the solder by heating to thereby form a solder film.
    Type: Grant
    Filed: August 10, 1995
    Date of Patent: February 3, 1998
    Assignee: Showa Denko K.K.
    Inventors: Takeo Kuramoto, Masataka Watabe, Satoshi Noda, Takashi Shoji, Takekazu Sakai
  • Patent number: 5556023
    Abstract: A method is available for forming a solder film on a metallic surface such as a pad of a metallic circuit of a printed circuit board and a lead frame of electronic parts which is capable of forming a precise and fine pattern. The method comprises selectively imparting tackiness to only a predetermined part of the metallic surface by use of a tacky layer-forming solution, adhering a powdered solder to the resulting tacky part, and then melting the solder by heating to thereby form a solder film.
    Type: Grant
    Filed: October 31, 1994
    Date of Patent: September 17, 1996
    Assignee: Showa Denko K.K.
    Inventors: Takeo Kuramoto, Masataka Watabe, Satoshi Noda, Takashi Shoji, Takekazu Sakai