Patents by Inventor Donald Harlem Apgar

Donald Harlem Apgar 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: 4029351
    Abstract: A pickup head, which is of the type referred to in the art as a Bernoulli pickup head, is used to lift and/or transport a semiconductor wafer. The head is provided with a central positive pressure gas coupled orifice or port and at least three auxiliary positive pressure gas coupled orifices disposed symmetrically about the central orifice. The gas flow from the central orifice effects the main lifting force and the gas flow from the auxiliary orifices effects additional restoring torque to correct for any wafer tilt, if present. Thus, the integrity of the non-contacting relationship between the head and wafer surface is enhanced and/or preserved and this is particularly advantageous on lift-off.
    Type: Grant
    Filed: June 2, 1976
    Date of Patent: June 14, 1977
    Assignee: International Business Machines Corporation
    Inventors: Donald Harlem Apgar, Richard Fleming Kilburn