Capacitive pressure sensor and method therefor
US7448277B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 31, 2007 |
| Grant date | Nov 11, 2008 |
| Priority date | — |
| Expiry date | Aug 31, 2027 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB81B2201/0264
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A capacitive pressure sensor and method for its fabrication. The sensor is fabricated from first and second wafers to have a mechanical capacitor comprising a fixed electrode and a moving electrode defined by a conductive plate. The sensor further has a diaphragm on a surface of the first wafer that is mechanically coupled but electrically insulated from the conductive plate. A conductive layer on the surface of the first wafer is spaced apart from the conductive plate to define the fixed electrode. The second wafer is bonded to the first wafer and carries interface circuitry for the sensor, including the conductive plate and the fixed electrode which are between the first and second wafers and electrically connected to the interface circuitry. At least an opening is present in the first wafer and its first conductive layer by which the diaphragm is released and exposed to an environment surrounding the sensor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.