The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 13, 1983
Filed:
Apr. 02, 1982
Keith W Golke, Hennepin County, MN (US);
Thomas E Hendrickson, Hennepin County, MN (US);
Charles C Huang, Hennepin County, MN (US);
Honeywell Inc., Minneapolis, MN (US);
Abstract
A semiconductor capacitance transducer includes adjoining integrated sensor and reference capacitance transducers formed from silicon wafers. The transducers are parallel plate transducers which are structurally the same except that one plate of the sensor transducer is a thin force sensing diaphragm which deflects in response to selected environmental phenomena while the corresponding plate of the reference transducer is adapted to deform in response to some, but not all, of the selected environmental phenomena. By comparing the capacitance of the transducers, the effects of the phenomena which deform the reference transducer can be distinguished from the effects of the phenomena which do not deform the reference transducer. A particular application of the present invention allows thermal effects on the sensor transducer to be distinguished from the effects of pressure. Also, the sensor and reference transducers are rendered substantially free from thermal stress by constructing their plates of the same semiconductor material and electrically isolating the plates with surface passivation layers.