Pressure transducer and method for fabricating same
US4838088A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 16, 1987 |
| Grant date | Jun 13, 1989 |
| Priority date | — |
| Expiry date | Jul 16, 2007 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB81C2201/0136
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A pressure transducer is composed of a substrate, a pressure sensing diaphragm layer and a support layer interposed between the substrate and the diaphragm layer, and a transduction element for coverting a displacement of the diaphragm layer into an electric signal. The support layer has an opening which is hermetically sandwiched between the substrate and the diaphragm layer so that there is formed sealed internal cavity used as a built-in reference pressure chamber. Preferably, the diaphragm layer includes a perforated inner layer extending over the cavity and a cover layer formed on the inner layer so as to seal the cavity. This transducer is fabricated by a process including a first step of forming the support layer on the substrate, a second step of forming the inner layer of the diaphragm layer on the support layer and forming perforations in the inner layer by etching, a third step of forming the opening in the support layer by etching through the perforations and a fourth step of forming the cover layer on the perforated inner layer to seal the internal cavity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.