Patents by Inventor Yasufumi Nakasu

Yasufumi Nakasu 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: 6854671
    Abstract: A nozzle ejects molten metal in an ejecting direction. The nozzle has a solder-philic surface in a first region and a solder-repellent surface in a second region. The second region is located forward of the first region in the ejecting direction. Before molten metal is ejected, the peripheral edge of the liquid surface of the molten metal is held at a position located further forward in the ejecting direction than the boundary between the solder-philic surface and the solder-repellent surface. The peripheral edge of the liquid surface is thus held before being ejected so that solder drops can be ejected steadily with a uniform diameter, constant direction, and constant speed.
    Type: Grant
    Filed: October 22, 2002
    Date of Patent: February 15, 2005
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Jyunichi Aizawa, Hiroshi Fukumoto, Yasufumi Nakasu
  • Publication number: 20030205628
    Abstract: A nozzle (2) ejects molten metal (20) in an ejecting direction Z. The nozzle (2) has a solder-philic surface in a region P1 and a solder-repellent surface in a region P2. The region P2 is located forward of the region P1 in the ejecting direction Z. Before ejected, the peripheral edge of the liquid surface of the molten metal is held at a position A located further forward by a distance &dgr; (>0) in the ejecting direction Z than the boundary between the solder-philic surface and the solder-repellent surface. The peripheral edge of the liquid surface is thus held before ejected so that the solder drops can be ejected steadily with a steady diameter, steady direction, and steady speed.
    Type: Application
    Filed: October 22, 2002
    Publication date: November 6, 2003
    Applicant: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Jyunichi Aizawa, Hiroshi Fukumoto, Yasufumi Nakasu
  • Patent number: 6213356
    Abstract: A bump forming apparatus includes a first tank storing fused solder, a cavity having an inlet for the fused solder, a nozzle arranged on a lower portion of the cavity, a pressure element formed by a diaphragm and a piezoelectric element, and a first heater heating the first tank, a pipe and the cavity. The bump forming apparatus further comprises a static pressure control part having a second tank storing solid solder, a second heater provided around a second opening, a level detector detecting the surface level of the fused solder in the first tank and a level control part controlling driving of the second heater on the basis of a detection signal from the level detector. Thus obtained are a bump forming apparatus and a bump forming method capable of properly avoiding defective discharge, increasing the speed of discharge, avoiding dispersion of an amount of discharge and stabilizing discharge.
    Type: Grant
    Filed: September 14, 1999
    Date of Patent: April 10, 2001
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Yasufumi Nakasu, Masaharu Yoshida, Makoto Kanda, Hiroshi Fukumoto
  • Patent number: 5305944
    Abstract: A bonding apparatus according to the present invention bonds a semiconductor chip to a conductive member in the face-down style without heating the semiconductor chip. The semiconductor chip which consists essentially of silicon is placed on leads which are put on a TAB tape. A glass plate member is mounted on the semiconductor chip. An infrared light beam is irradiated onto the semiconductor chip from above the semiconductor chip. Transmitted by the semiconductor chip, the infrared light beam illuminates bumps. As a result, the bumps heat up and melt. Since the semiconductor chip does not absorb the infrared light beam, bonding of the semiconductor chip to the leads does not cause a rise in temperature of the semiconductor chip. The bonding apparatus according to the present invention makes the face-down style bonding possible.
    Type: Grant
    Filed: March 30, 1993
    Date of Patent: April 26, 1994
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Masaharu Yoshida, Yasufumi Nakasu, Masataka Takehara