ApplicationNo. 06/059552 filed on 07/23/1979
US Classes:73/718, Capacitive361/283.4By diaphragm
ExaminersPrimary: Woodiel, Donald O.
Attorney, Agent or Firm
International ClassesG01L 13/02 (20060101)
G01L 9/00 (20060101)
G01L 13/00 (20060101)
Foreign Application Priority Data1978-07-21 JP
AbstractA 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.