Capacitive pressure sensor
Patent 4257274 Issued on March 24, 1981. Estimated Expiration Date: 
July 23, 1999. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
July 23, 1999. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3232114 3397278 3405559 3697918 3748571 3793885 3800264 InventorsAssigneeApplicationNo. 06/059552 filed on 07/23/1979US Classes:73/718, Capacitive361/283.4By diaphragmExaminersPrimary: Woodiel, Donald O.Attorney, Agent or FirmInternational ClassesG01L 13/02 (20060101)G01L 9/00 (20060101) G01L 13/00 (20060101) Foreign Application Priority Data1978-07-21 JPAbstractA capacitive pressure sensor is provided which has a conductive silicon diaphragm having a thick supporting portion at the periphery thereof and a thin inner deflecting portion which is reduced in thickness from the supporting portion by means of an etching process which makes possible a very accurate dimensioning of the hollow formed by the deflecting portion of the diaphragm. A substrate of borosilicate glass has a flat surface which is placed against the side of the diaphragm in contact with the supporting portion and the two elements are joined by a process of anodic bonding so that a pressure chamber is formed between the substrate and the thin deflecting portion of the diaphragm. Within the pressure chamber, a thin electrode is provided on the surface of the substrate thereby forming electrostatic capacity between the substrate and the diaphragm and a hole is provided through the substrate for supplying of fluid into the pressure chamber. | |
