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:
Nov. 28, 1978
Filed:
Feb. 22, 1977
J Hardy House, Yorba Linda, CA (US);
Conrac Corporation, Stamford, CT (US);
Abstract
The limited temperature range for operation of conventional semiconductive force transducers is greatly extended in both directions, typically attaining a range from about 4.degree. Kelvin to at least about 400.degree. C. A piezoresistive strain gage is typically formed in a monocrystalline layer of semiconductive material grown epitaxially to a thickness of only a few microns on a monocrystalline support member which has high inherent resistivity and serves directly as force responsive member. For example, silicon is grown epitaxially on one face of a sapphire pressure responsive diaphragm with suitably oriented crystal axes. The diaphragm is typically mounted in hermetically sealed relation on an alumina support with an interlayer of fused glass having selected properties. Transition from the alumina support to a conventional housing is preferably made via a metal such as Kovar in described configuration. Electrical connections to the silicon capable of withstanding high temperatures are preferably made via platinum with a shield of silicon/platinum alloy.