Pressure transducer apparatus with monolithic body of ceramic material
US5499158A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 14, 1994 |
| Grant date | Mar 12, 1996 |
| Priority date | — |
| Expiry date | Nov 14, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L9/0075
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A monolithic capacitive pressure transducer (12) is shown composed of ceramic material having a first closed cavity (12) separated from a surface thereof by a flexible wall member and a second closed cavity (16) defined by rigid wall members. Capacitor plates (32, 36; 40, 44) are formed on two opposed surfaces defining each cavity. Vias (33, 37; 41, 45) are formed extending from the capacitor plates to permit electrical connection therewith. The transducer is made by separately forming under pressure a diaphragm (20) and first and second base portions (22, 30) having recesses (24) in the top and bottom surfaces using ceramic powder coated with an organic binder. A metal layer is deposited on the pieces which are then joined together to form a single unit. A spacer (26) may be inserted in the recesses to ensure that a predetermined gap is maintained in each cavity during the joining operation. The parts are then debinderized by heating to a first temperature level to allow the binder organics, as well as the spacer organics if a spacer is employed, to be vaporized and/or decomposed and removed through the open pores of the diaphragm and base. The unit is then brought up to a sinteri…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.