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:
Apr. 25, 1989
Filed:
Mar. 14, 1988
Leslie B Wilner, Palo Alto, CA (US);
Endevco Corporation, San Juan Capistrano, CA (US);
Abstract
A differential variable capacitance acceleration sensor includes a sandwich structure having three stacked plates of silicon with the center plate mounted such that its center portion is enabled to move in a sealed cavity with each side thereof moving toward and away from a fixed cooperating plate forming the opposite side of a capacitive circuit. The center portion or mass of the center plate is suspended from its rim by means of a large number of integral fingers extending from the rim to the top and bottom surfaces of the center portion. This center mass includes a number of through holes to permit the passage of air from one side to the other and may also include grooves to aid in the flow of air. The fixed top plate or lid and the base also have, or may have, grooves to assist in the passage of air. An alternative embodiment includes a smaller number of more compliant fingers to provide a more compliant structure. A number of spaced stops are provided in the lid and base to overcome electrostatic and pneumatic latch up. The method of forming the individual parts is also taught.