High pressure piezoresistive transducer
US5614678A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 5, 1996 |
| Grant date | Mar 25, 1997 |
| Priority date | — |
| Expiry date | Feb 5, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L9/0055
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method of fabricating a high pressure piezoresistive pressure transducer having a substantially linear pressure versus stress output over its full range of operation. The method involves bonding a carrier wafer having a dielectric isolating layer on one surface and a supporting member on the opposite surface, to a pattern wafer containing at least two single crystalline longitudinal piezoresistive sensing elements of a second conductivity. Both the pattern wafer and sections of the carrier wafer are etched leaving the piezoresistive sensing elements bonded directly to the dielectric isolating layer, and a diaphragm member having a deflecting portion and a non-deflecting portion. The diaphragm member is constructed to have an aspect ratio which is of the order of magnitude of one. The piezoresistive sensing elements have a large transverse piezoresistive coefficient normal to the plane of the diaphragm and both a large longitudinal piezoresistive coefficient and a small transverse piezoresistive coefficient in the plane of the diaphragm. One of the at least two piezoresistive sensing elements is positioned above the non-deflection portion of the diaphragm in an area of minimal lon…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.