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:
Jun. 07, 2005
Filed:
Mar. 20, 2001
Altti Torkkeli, Espoo, FI;
Altti Torkkeli, Espoo, FI;
Nokia Corporation, Espoo, FI;
VTI Hamlin Oy, Vantaa, FI;
Abstract
This invention relates to a differential pressure sensor, one embodiment of which is a microphone. The differential pressure sensor comprises: a flexible membrane () made of conductive material, which membrane forms a first electrode of the differential pressure sensor, and a perforated plate () made of conductive material, which plate is essentially more rigid than said membrane (), which plate is arranged at a distance from the membrane, and which plate forms a second electrode of the differential pressure sensor. In order to provide a differential pressure sensor with as good properties as possible, the differential pressure sensor comprises a substrate (), a cavity () extending through the substrate, the walls of which cavity are formed of said substrate (). The membrane () is closely connected to the walls of the cavity (), whereby the membrane forms a dense wall in said cavity, and said perforated plate () has been attached to the substrate with an insulating layer ().