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:
Mar. 06, 1989
Filed:
Nov. 26, 1987
Youngkee Ahn, Buffalo Grove, IL (US);
Donald O Myers, Elgin, IL (US);
Motorola, Inc., , US;
Abstract
A pressure sensor assembly (10, 10') is disclosed in which a pressure sensing element (11, 11', 11') is protected from external contaminants in an externally-applied pressure (P) to be sensed. This is accomplished by filling an external cavity (36) of a tubular portion (32) of a cover member (30) which fits over the pressure sensing element that has previously been mounted on a metallized substrate (14). The external cavity (36) is totally filled with an incompressibel liquid (35), such as silicon oil, and a thin diaphragm (40), preferably comprising a polyimide film, seals this external cavity and provides a compliant barrier between the externally-applied pressure (P) and the imcompressible fluid (35) and pressure sensing element (11). Chemical inertness of the diaphragm (40) and incompressible fluid (35) prevents contaminants in the sensed pressure (P) from attacking the pressure sensing element (11, 11', 11'), while transmitting changes in the sensed pressure (P) substantially directly to the pressure sensing element.