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:
Feb. 29, 2000
Filed:
Jun. 04, 1997
Paul E Grandmont, Whitman, MA (US);
Clifford D Fung, Mansfield, MA (US);
Other;
Abstract
A structure and method of fabrication is provided for a micromechanical overrange protected pressure sensor. A pressure sensor having a silicon substrate is provided with a cavity and a deformable diaphragm wherein deflection of the diaphragm in response to pressure is limited by a forward pressure stop. A method is provided for electrodepositing a metal layer which is attached to the substrate adjacent to the diaphragm to provide a reverse pressure stop in response to pressure supplied to the underside of a diaphragm. The metal layer has a relatively low thermal coefficient of expansion and is patterned through use of a photo-resist layer. A previously deposited precision spacer between the diaphragm and reverse pressure stop is removed to provide a precision gap between the reverse pressure stop and the diaphragm. Micromechanical elements of relatively great size, yet having precision dimensions or positioning are herein fabricated by lithography of patterned resist films up to several hundred microns thick, exposed and developed to great depth with faithful pattern delineation. The patterns formed by development of the exposed resist are then metallized, preferably by pulse electroplating, to form structural or mechanical elements. Deep film patterning may be achieved by laying down successive layers of a dry film resist and exposing each layer after it is deposited.