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:
Jun. 18, 1991
Filed:
Sep. 20, 1989
Volker Graeger, Buchholz, DE;
Rolf U Kobs, Tornesch, DE;
U.S. Philips Corporation, New York, NY (US);
Abstract
A pressure sensor comprising a silicon body (1) which is arranged on a substrate (2). The silicon body (1) comprises a cavity (4) in the form of a blind hole, or enclosed chamber which thus forms a diaphragm (5). On the outer surface thereof there is arranged a Wheatstone bridge consisting of piezoresistive resistance elements (6, 7, 8, 9). The voltage/pressure characteristic of this pressure sensor exhibits a non-linearity of more than 1% in the case of pressure loads in excess of 250 bar. This non-linearity must be reduced. Therefore, a further cavity (10) is provided in the silicon body (1) on both sides of the resistance elements (8, 9) arranged at the edge of the diaphragm (5).