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. 08, 1995
Filed:
Apr. 21, 1994
Clifford D Fung, Mansfield, MA (US);
Kevin H-L. Chau, Franklin, MA (US);
P Rowe Harris, East Wareham, MA (US);
John G Panagou, South Attleboro, MA (US);
Gary A Dahrooge, Worcester, MA (US);
The Foxboro Company, Foxboro, MA (US);
Abstract
An overpressure-protected, differential pressure sensor 37 is formed by depositing diaphragm material 24 over a cavity 23 formed and filled with sacrificial material 22 into a front surface of a substrate. The sacrificial material 22 is then removed to create a free diaphragm. The floor of the cavity 23 defines a first pressure stop to limit the deflection of the diaphragm in response to pressure applied to the top of the diaphragm. A port 33 is created to allow pressure to be applied to the bottom side of the diaphragm 24. An optional second pressure stop, which limits the deflection of the diaphragm in response to pressure applied to the bottom side of the diaphragm, is formed by bonding a cap 35 to standoffs 34 placed around the top of the diaphragm. The standoffs are spaced to allow pressure to be applied to the top of the diaphragm.