Patents by Inventor Howard M. Maassen

Howard M. Maassen 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: 6794861
    Abstract: Method and apparatus for calibrating timing accuracy during testing of integrated circuits. An ATE type (automatic test equipment) integrated circuit tester calibrates itself to reference blocks (dummy ICs) that have the same relevant dimensions as the integrated circuits to be tested and have fit into the test fixture. The number of reference blocks required is equal to the number of signal terminals on the integrated circuit to be tested subject to timing calibration where typically the number of signal terminals is less than the total number of signal terminals on the IC being tested and is typically a relatively small number, e.g., 9. This is useful in the case of high pin count integrated circuits where the pins are grouped into relatively small numbers of pins which are source synchronous. A signal trace electrically connects a different signal terminal to a common reference terminal on each reference block in the set.
    Type: Grant
    Filed: March 25, 2002
    Date of Patent: September 21, 2004
    Assignee: NPTest, LLC
    Inventors: Howard M. Maassen, William A. Fritzsche
  • Patent number: 6492797
    Abstract: A method and apparatus for calibrating tester timing accuracy during testing of integrated circuits. An ATE tester measures itself through reference blocks that have the same relevant dimensions as the integrated circuits to be tested. The number of reference blocks required is equal to the number of signal terminals on an integrated circuit to be tested being subject to timing calibration. A signal trace electrically connects a different signal terminal to a common reference terminal on each reference block. Each signal trace used should be closely matched both physically and electrically to the other signal traces used in the set of reference blocks, so that the electrical path length associated with each trace is nearly identical. To perform the timing calibration, the reference blocks may be mounted on a single fixture one at a time, or using multi-site fixtures, multiple reference blocks may be used in parallel.
    Type: Grant
    Filed: February 28, 2000
    Date of Patent: December 10, 2002
    Assignee: Schlumberger Technologies, Inc.
    Inventors: Howard M. Maassen, William A. Fritzsche, Thomas P. Ho, Joseph C. Helland
  • Publication number: 20020135357
    Abstract: Method and apparatus for calibrating timing accuracy during testing of integrated circuits. An ATE type (automatic test equipment) integrated circuit tester calibrates itself to reference blocks (dummy ICs) that have the same relevant dimensions as the integrated circuits to be tested and have fit into the test fixture. The number of reference blocks required is equal to the number of signal terminals on the integrated circuit to be tested subject to timing calibration where typically the number of signal terminals is less than the total number of signal terminals on the IC being tested and is typically a relatively small number, e.g., 9. This is useful in the case of high pin count integrated circuits where the pins are grouped into relatively small numbers of pins which are source synchronous. A signal trace electrically connects a different signal terminal to a common reference terminal on each reference block in the set.
    Type: Application
    Filed: March 25, 2002
    Publication date: September 26, 2002
    Inventors: Howard M. Maassen, William A. Fritzsche