Patents by Inventor Vincent D. Gravdahl

Vincent D. Gravdahl 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).

  • Thin film techniques for fabricating narrow track ferrite heads
    Patent number: 4375390
    Abstract: A process for producing a reactive ion-etched structure with height and width dimensions of the order of 25 microns or less on a ferrite substrate surface is disclosed. A mask of positive water saturated photoresist is formed on the substrate. A metal taken from the group consisting of nickel and a nickel-iron alloy is plated through the mask. The photoresist mask is removed to leave a pattern in the plated metal. The ferrite substrate surface that is exposed by the pattern is reactive ion etched with a power density of >1w/cm.sup.2 and a bias voltage <-100 volts.
    Type: Grant
    Filed: March 15, 1982
    Date of Patent: March 1, 1983
    Inventors: Nathaniel C. Anderson, Larry E. Daby, Vincent D. Gravdahl, Patrick M. McCaffrey, Bruce A. Murray, Bruce W. Wright