Patents Examined by Brian L. Dutton
  • Patent number: 5656530
    Abstract: An electrostatic discharge device having a small separation between two traces wherein a voltage above a desired threshold will discharge across the separation through the mechanism of cold cathode electric field emission. Conditions which permit quantum mechanical tunneling of electrons across the emitting cathode/vacuum potential barrier, such as low emitter work function, electric field enhancing geometry, and cathode/anode separation size, determine the voltage necessary for discharge by this mechanism. One device has a first conductive trace formed on an insulating layer and then masked and etched to leave an undercut with a sharp point. A second conductive trace is formed in the undercut opposite the point, resulting in a three-dimensional cross section having a very small separation. A second device has the point formed by depositing a metal layer over a spacing in a dielectric layer, and then etching out the dielectric layer.
    Type: Grant
    Filed: June 26, 1995
    Date of Patent: August 12, 1997
    Assignee: Hewlett-Packard Co.
    Inventor: David J. Leary