Patents by Inventor Sayuki Hieda

Sayuki Hieda 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).

  • Method of laser-marking semiconductor devices
    Patent number: 4945204
    Abstract: The surface of the resin on a semiconductor device is subjected to a marking by a pulsed laser having an energy density of 3 to 60 J/cm.sup.2 and a pulse width of 0.1 ms or less. By applying the laser beam to the surface a resin encapsulation, the resin can be instantaneously burnt and vaporized, as a result of which, the quantity of the cinders from burning of the resin at the time of the laser-marking is reduced.
    Type: Grant
    Filed: October 19, 1989
    Date of Patent: July 31, 1990
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Masakatsu Nakamura, Sayuki Hieda