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:
Aug. 23, 1983
Filed:
Feb. 23, 1981
Ronald E Brown, Kokomo, IN (US);
Lamonte R Edison, Kokomo, IN (US);
William D Higdon, Greentown, IN (US);
General Motors Corporation, Detroit, MI (US);
Abstract
A diaphragm is formed in a silicon chip by etching a rectangular cavity in one side thereof and piezoresistive resistors are formed in the other surface of the chip to sense stress changes on the diaphragm due to pressure changes. At least one resistor is placed along the edge of the diaphragm where a sharp stress peak occurs. To avoid the problem of inaccurate placement of the resistor relative to the peak, the resistor is slanted with respect to the stress ridge at a small angle of 10.degree. to 20.degree.. This makes the resistor placement and cavity alignment much less critical thereby assuring greater uniformity of response from one sensor to another at the expense of signal size for a given pressure change on the device.