Capacitive pressure sensor
US4257274A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 23, 1979 |
| Grant date | Mar 24, 1981 |
| Priority date | — |
| Expiry date | Jul 23, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L9/0073
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A 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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.