Patents by Inventor Gerald N. Wallmark

Gerald N. Wallmark 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).

  • System for contactless testing of printed circuit boards
    Patent number: 6621274
    Abstract: A system for testing for opens in and shorts between conductor traces on a printed circuit board includes an electron gun assembly for generating an electron beam and an electron optics assembly for directing the beam to the traces which have a reference potential. A grid located proximate to and substantially parallel with the surface of the board is placed at a first potential before the beam is directed to a first point on a trace to charge the trace to a first potential. The grid is then placed at a second potential, the second potential being between the reference potential and the first potential, before the beam is directed to a second point on the trace to cause emission of secondary electrons. The secondary electrons that reach the grid are collected thereby, and signal processing electronics are used to determine whether or not an open or short exists.
    Type: Grant
    Filed: November 8, 2001
    Date of Patent: September 16, 2003
    Assignee: Image Graphics Incorporated
    Inventor: Gerald N. Wallmark
  • System for contactless testing of printed circuit boards
    Publication number: 20020089333
    Abstract: A system for testing for opens in and shorts between conductor traces on a printed circuit board is provided. The system includes an electron gun assembly for generating an electron beam and an electron optics assembly for directing the electron beam to the traces on the surface of the board, the traces having a reference potential. A grid located proximate to and substantially parallel with the surface of the board is placed at a first potential before the electron beam is directed to a first point on a trace to charge the trace to a first potential.
    Type: Application
    Filed: November 8, 2001
    Publication date: July 11, 2002
    Inventor: Gerald N. Wallmark
  • System for contactless testing of printed circuit boards
    Patent number: 6359451
    Abstract: A system for testing for opens in and shorts between conductor traces on a printed circuit board is provided. The system includes an electron gun assembly for generating an electron beam and an electron optics assembly for directing the electron beam to the traces on the surface of the board, the traces having a reference potential. A grid located proximate to and substantially parallel with the surface of the board is placed at a first potential before the electron beam is directed to a first point on a trace to charge the trace to a first potential. The grid is then placed at a second potential, the second potential being between the reference potential and the first potential, before the electron beam is directed to a second point on the trace to cause emission of secondary electrons.
    Type: Grant
    Filed: February 11, 2000
    Date of Patent: March 19, 2002
    Assignee: Image Graphics Incorporated
    Inventor: Gerald N. Wallmark