Electromechanical pressure transducer
US4178621A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 23, 1978 |
| Grant date | Dec 11, 1979 |
| Priority date | — |
| Expiry date | Jan 23, 1998 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L9/0075
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An improved ceramic capacitive pressure sensor adaptable for use in automobiles is disclosed. The pressure sensor comprises a thin flexible diaphragm disc having a capacitor electrode deposited on it. A thick cylindrical base substrate has a top surface with a second capacitor electrode deposited thereon and the diaphragm is bonded to the top surface of the base substrate by an annular glass ring such that the first and second electrodes are separated from each other and face each other directly across an air gap. The diaphragm, the top surface of the base substrate and the annular glass ring form an internal cavity in which a reference vacuum is stored. In response to pressure changes outside of this cavity, the diaphragm will flex and thereby change the capacitance created by the first and second electrodes. At least one channel portion is provided in the base substrate top surface which opens into the cavity storing the reference vacuum. This improves the electrical and mechanical characteristics of the pressure sensor. The diaphragm electrode is substantially larger than the base electrode and extends substantially over all of the central portion of the diaphragm within the gla…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.