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:
Sep. 29, 1992
Filed:
Dec. 21, 1990
Jiri Marek, Reutlingen, DE;
Frank Bantien, Ditzingen, DE;
Dietmar Haack, Reutlingen, DE;
Martin Warth, Schwaikhein, DE;
Robert Bosch GmbH, Stuttgart, DE;
Abstract
A semiconductor plate having an epitaxial layer of a conductivity type opposite to that of the substrate on which it is formed has a depression, including one or more elongate channels. The depression is etched into a depth passing entirely through the epitaxial layer to isolate at least one tongue extending from a tongue pedestal into the etched depression and having parallel major sides which are perpendicular to the principal planes of the semiconductor plate. The tongue is under-etched so that it will be free to vibrate by motion in directions parallel to the principal planes of the plate. One of the major sides of the tongue faces a stationary electrode across a gap and the electrode and the tongue are insulated from each other, at least in one embodiment, by the fact that the etched depression extends all the way through the epitaxial layer in its depth. Deflection or vibration of the tongue changes the capacitance between the electrode and the tongue and contacts are provided for measuring the capacitance. Various embodiments utilizing multiple tongues and one or more electrodes are shown.