Patents by Inventor Robert B. Chesnut

Robert B. Chesnut 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: 4481071
    Abstract: Process for lift-off fabrication of sputtered dielectric or nonmagnetic gap materials and thin-film heads for either a single-element thin-film head or side-by-side elements on a thin-film head. The lift-off process utilizes a copper coating that is removed by a twenty percent solution of ammonium persulfate with a pH in the range of seven to nine to assure complete removal of gap material from the back closure of the thin-film head without damage to the underlying permalloy. The process can also be utilized to obtain a multiple layer deposits on a single thin-film had by repeating the steps of the process. The process provides for a clean hole, no dielectric on the surface nor any attacking on the magnetic material.
    Type: Grant
    Filed: December 29, 1983
    Date of Patent: November 6, 1984
    Assignee: International Business Machines Corporation
    Inventors: Nathaniel C. Anderson, Robert B. Chesnut, Larry E. Daby