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Miniature silicon based thermal vacuum sensor and method of measuring vacuum pressures

  • US 5,557,972 A
  • Filed: 09/13/1994
  • Issued: 09/24/1996
  • Est. Priority Date: 09/13/1994
  • Status: Expired due to Term
First Claim
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1. A gas pressure sensor for sensing gas pressures in the approximate range of 760 Torr to 1×

  • 10 Torr, the pressure sensor comprising;

    a single piece base having a thickness dimension of at least 100 microns and having a cavity which extends from a bottom surface of the base to a top surface of the base,an opening in a side wall of the base to the cavity,a membrane on the top surface of the base dimensioned to cover the cavity,a first resistive element on the membrane,a second resistive element on the base,a cover over the membrane, the cover having a top surface and a bottom surface, the bottom surface of the cap attached to the top surface of the base and spaced from the membrane a distance less than 10 microns,a controlled voltage source for applying voltages to the first and second resistive elements, anda measuring circuit for measuring voltage applied to the first and second resistive elements, the voltage measurements being indicative of pressure about the sensor.

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