Claims
- 1. A capacitive ceramic relative-pressure sensor comprising:a diaphragm having a surface on which a first electrode is deposited; and a substrate having a bore for guiding reference air from a first surface to an opposite, second surface, the first surface of the substrate being polished and provided with at least a second electrode, which substrate and which diaphragm are soldered or brazed together along the periphery by means of a spacer to form a chamber, which chamber is covered from inside with a thin layer of hydrophobic material that is introduced through the bore after the soldering or brazing.
- 2. The pressure sensor as claimed in claim 1 wherein the hydrophobic material is a silicone oil, a paraffin oil, or a silicone resin based on fluorinated siloxanes or on methyl-polysiloxanes.
- 3. The pressure sensor as claim in claim 1 wherein the substrate and the diaphragm are made of alumina ceramic.
- 4. The pressure sensor as claim in claim 2 wherein the substrate and the diaphragm are made of alumina ceramic.
Priority Claims (1)
Number |
Date |
Country |
Kind |
99111580 |
Jun 1999 |
EP |
|
Parent Case Info
This application claims the benefit of provisional application No. 60/165,835, filed Nov. 16, 1999.
US Referenced Citations (12)
Foreign Referenced Citations (1)
Number |
Date |
Country |
08189870 |
Jul 1996 |
EP |
Provisional Applications (1)
|
Number |
Date |
Country |
|
60/165835 |
Nov 1999 |
US |