Patents by Inventor Bradley D. Bunn

Bradley D. Bunn 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: 6192969
    Abstract: A method and apparatus are provided for making high purity and preferably oxygen free substantially void free and inclusion free copper castings such as billets from high purity copper. The castings are particularly useful to make sputtering targets used in sputtering deposition processes in the fabrication of electronic components. The method comprises melting high purity copper in a covered crucible using a non-contaminating heating source such as a coil induction furnace. The melted copper in the crucible is solidified using a specially controlled cooling procedure wherein the bottom of the crucible is cooled so that molten copper is maintained on top of solidified and solidifying copper until the copper is solidified.
    Type: Grant
    Filed: March 22, 1999
    Date of Patent: February 27, 2001
    Assignee: ASARCO Incorporated
    Inventors: Bradley D. Bunn, Jeffrey Burton, Margaret W. Staub