Patents by Inventor Peter D. Andrews

Peter D. Andrews 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).

  • Wafer probe station having integrated guarding, Kelvin connection and shielding systems
    Patent number: 5434512
    Abstract: A probe station is equipped with an integrated guarding system which facilitates the use of the station for low-current measurements, as well as integrated Kelvin connections to eliminate voltage losses caused by line resistances. The station has a chuck assembly which consists of at least three chuck assembly elements. A first element supports the test device, while an underlying second element acts as a guard to reduce leakage currents. These elements are electrically insulated from each other and from their underlying supporting structure, which is the third element. Ready-to-use, selectively detachable electrical connector assemblies provide for signal and guard connections to the first and second chuck assembly elements, respectively, as well as providing Kelvin connections thereto. The capacitance between the respective chuck assembly elements is extremely low due to the provision of air space as the primary electrical insulator.
    Type: Grant
    Filed: May 18, 1994
    Date of Patent: July 18, 1995
    Assignee: Cascade Microtech, Inc.
    Inventors: Randy J. Schwindt, Warren K. Harwood, Paul A. Tervo, Kenneth R. Smith, Richard H. Warner, Peter D. Andrews
  • Wafer probe station having integrated guarding, Kelvin connection and shielding systems
    Patent number: 5345170
    Abstract: A probe station is equipped with an integrated guarding system which facilitates the use of the station for low-current measurements, as well as integrated Kelvin connections to eliminate voltage losses caused by line resistances. The station has a chuck assembly which consists of at least three chuck assembly elements. A first element supports the test device, while an underlying second element acts as a guard to reduce leakage currents. These elements are electrically insulated from each other and from their underlying supporting structure, which is the third element. Ready-to-use, selectively detachable electrical connector assemblies provide for signal and guard connections to the first and second chuck assembly elements, respectively, as well as providing Kelvin connections thereto. The capacitance between the respective chuck assembly elements is extremely low due to the provision of air space as the primary electrical insulator.
    Type: Grant
    Filed: June 11, 1992
    Date of Patent: September 6, 1994
    Assignee: Cascade Microtech, Inc.
    Inventors: Randy J. Schwindt, Warren K. Harwood, Paul A. Tervo, Kenneth R. Smith, Richard H. Warner, Peter D. Andrews