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:
Oct. 23, 1990
Filed:
Mar. 16, 1989
Donald C Young, Pangbourne, GB;
Philim B Daniels, Hounslow, GB;
Thorn Emi plc, London, GB;
Abstract
A microengineered pressure actuated switch includes a domed diaphragm having a snap-action response between defined states (d.sub.1, d.sub.5) of the diaphragm. This response is to an applied pressure differential across the diaphragm. The diaphragm is supported on a substrate of semiconductor material. In a method of making such a switch, a layer of inorganic material is provided on one side of a substrate of semiconductor material. Semiconductor material is removed from the substrate such that a defined region of the layer is not in contact with the semiconductor material, this defined region forming the diaphragm. The layer of inorganic material is so stressed that after semiconductor material is removed, the layer assumes a domed configuration and incorporates a pre-bias in the direction of doming.