Pressure transducer for gaseous hydrogen environment
View Patent ↗A silicon-based hydrogen pressure sensor module incorporates a low temperature cofired ceramic (LTCC) substrate that shields the cavity formed by the silicon membrane and cell body from hydrogen permeation. A bossed container filled with an oil material is mounted on the substrate and houses a sensor cell. The oil material may be impregnated with a hydrogen getter material.
1. A sensor assembly comprising:
a ceramic substrate;
a container located on the ceramic substrate, the container and the ceramic substrate defining a container volume;
a sensor cell located within the container volume, the sensor cell comprising a sensor handle wafer and a diaphragm located proximate the sensor handle wafer, the sensor cell defining a reference cavity; and
a substantially incompressible liquid disposed within the container volume, the substantially incompressible liquid comprising a hydrogen getter material.
2. The sensor assembly of claim 1 , wherein the substantially incompressible liquid comprises an oil material selected from the group consisting of silicone, fluorinated oil, low-temperature oil, and a biocompatible oil, and wherein the oil material is impregnated with the hydrogen getter material.
3. The sensor assembly of claim 1 , wherein the substantially incompressible liquid has high intrinsic hydrogen gettering properties.
4. The sensor assembly of claim 1 , wherein the container comprises a can formed from a metal selected from the group consisting of stainless steel, aluminum, and alloy 42 .
5. The sensor assembly of claim 1 , wherein the ceramic substrate is formed from a low temperature cofired ceramic (LTCC) material.
6. The sensor assembly of claim 1 , wherein the ceramic substrate defines a port for introducing the oil material into the container volume.
7. The sensor assembly of claim 1 , wherein the container defines a port for introducing the oil material into the container volume.
8. The sensor assembly of claim 1 , wherein the sensor cell comprises a hydrogen-hardened silicon pressure cell.
9. The sensor assembly of claim 1 , wherein the container has a boss formed on a surface of the container.
10. The sensor assembly of claim 1 , wherein the sensor assembly comprises a differential pressure sensor.
11. A pressure sensor arrangement comprising:
a ceramic substrate;
a container located on the ceramic substrate and having a boss formed on a surface of the container, the container and the ceramic substrate defining a container volume;
a silicon pressure sensor handle wafer located within the container volume;
a silicon diaphragm located within the container volume and attached to the silicon pressure sensor handle wafer so as to define a reference cavity located between the silicon diaphragm and the silicon pressure sensor handle wafer; and
an oil material disposed within the container volume, the oil material comprising a hydrogen getter material.
12. The pressure sensor arrangement of claim 11 , wherein the oil material is selected from the group consisting of silicone, fluorinated oil, low-temperature oil, and a biocompatible oil, and wherein the oil material is impregnated with the hydrogen getter material.
13. The pressure sensor arrangement of claim 11 , wherein the oil material has high intrinsic hydrogen gettering properties.
14. The pressure sensor arrangement of claim 11 , wherein the container comprises a can formed from a metal selected from the group consisting of stainless steel, aluminum, and alloy 42 .
15. The pressure sensor arrangement of claim 11 , wherein the ceramic substrate is formed from a low temperature cofired ceramic (LTCC) material.
16. The pressure sensor arrangement of claim 11 , wherein the ceramic substrate defines a port for introducing the oil material into the container volume.
17. The pressure sensor arrangement of claim 11 , wherein the container defines a port for introducing the oil material into the container volume.
18. The pressure sensor arrangement of claim 11 , wherein the silicon pressure sensor handle wafer comprises a hydrogen-hardened silicon pressure cell.
19. The pressure sensor arrangement of claim 11 , wherein the container has a boss formed on a surface of the container.
20. The pressure sensor arrangement of claim 11 , wherein the sensor assembly comprises a differential pressure sensor.