Patents by Inventor Leif R. Bergstedt

Leif R. Bergstedt 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: 6108205
    Abstract: The present invention relates to a method and device for making a temperature-compensated bedding for chips on printed boards, at which a temperature-compensated device is totally or partly recessed in a carrier in the printed board. The chips is placed over the temperature-compensated device.The temperature-compensated device includes a piece of metal recessed in the carrier under the chip. A layer of copper is fixed against the upper side of the carrier and the upper side of the metal piece. The thickness of the copper layer and the thickness of the metal piece are dimensioned so that the resulting coefficient of linear expansion at the upper side of the copper layer is equally big as or a bit bigger than the coefficient of linear expansion of the chip.The temperature-compensated device can as an alternative to the above include a module recessed in the carrier under the chip.
    Type: Grant
    Filed: October 20, 1997
    Date of Patent: August 22, 2000
    Assignee: Telefonaktiebolaget LM Ericsson
    Inventor: Leif R. Bergstedt