Overpressure-protected, differential pressure sensor and method of making the same
US5220838A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 28, 1991 |
| Grant date | Jun 22, 1993 |
| Priority date | — |
| Expiry date | Mar 28, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49996
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An overpressure-protected, differential pressure sensor (37) is formed by depositing diaphragm material (24) over a cavity (23) formed and filled with sacrificial material (22) into a front surface of a substrate. The sacrificial material (22) is then removed to create a free diaphragm. The floor of the cavity (23) defines a first pressure stop to limit the deflection of the diaphragm in response to pressure applied to the top of the diaphragm. A port (33) is created to allow pressure to be applied to the bottom side of the diaphragm (24). An optional second pressure stop, which limits the deflection of the diaphragm in response to pressure applied to the bottom side of the diaphragm, is formed by bonding a cap (35) to standoffs (34) placed around the top of the diaphragm. The standoffs are spaced to allow pressure to be applied to the top of the diaphragm.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.