Methods for fabricating apparatus having a hermetic seal
Apparatus and Methods for fabricating apparatus having a hermetic seal to seal a portion of an apparatus, for example and without limitation, a portion having a MEMS sensor. One such method uses crimping devices to compress a seal in a cavity formed in a housing that includes a MEMS sensor attached to a stress isolator. Under such compression, the seal deforms to hermetically seal surfaces around the inside, outside and bottom of the stress isolator.
1. An apparatus having a hermetic seal comprising:
a housing with a top and bottom and a first hole that passes through the housing from the top to the bottom wherein the housing further comprises a first cavity with an inner wall, outer wall and first cavity bottom and the first cavity extends down into the housing from the top and surrounds the first hole and wherein the housing further comprises a second cavity that extends down into the housing from the top and surrounds, and is coaxial with, the first cavity;
a disk shaped metal seal with a second hole through a center of the disk wherein the disk shaped metal seal is located on the first cavity bottom wherein the disk shaped metal seal surrounds and is coaxial with the inner wall;
an isolation member coupled to a sensor and extending down into the first cavity on top of the disk shaped metal seal between the inner wall and outer wall of the first cavity; and
a collar pressed down into the housing and into the second cavity wherein the collar has a third hole that passes through the collar and the sensor extends up into the third hole and wherein the collar crimps the outer wall against the isolation member.
2. The apparatus of claim 1 , wherein the disk shaped metal seal covers the bottom of the first cavity.
3. The apparatus of claim 1 , wherein the housing is cylinder shaped.
4. The apparatus of claim 1 , wherein the disk shaped metal seal is made from copper.
5. The apparatus of claim 1 , wherein the disk shaped metal seal is a copper alloy.
6. The apparatus of claim 1 , wherein the sensor is a MEMS sensor.
7. The apparatus of claim 1 , wherein the collar is made from steel.
8. The apparatus of claim 1 , wherein the housing comprises of one or more of stainless steel, brass and aluminum.
9. The apparatus of claim 1 wherein the third hole is coaxial with the first hole, first cavity and second cavity.
10. The apparatus of claim 1 wherein the sensor is a pressure sensor.
11. An apparatus having a hermetic seal comprising:
a housing with a top and bottom and a first hole that passes through the housing from the top to the bottom wherein the housing further comprises a first cavity that extends down into the housing from the top and surrounds the first hole and has a first cavity bottom and wherein the housing further comprises a protrusion that surrounds the first hole and extends up from the first cavity bottom into the first cavity and wherein the housing further comprises a second cavity that extends down into the housing from the top and surrounds, and is coaxial with, the first cavity;
a disk shaped metal seal with a second hole through a center of the disk wherein the disk shaped metal seal is located on the first cavity bottom wherein the disk shaped metal seal surrounds and is coaxial with the protrusion;
an isolation member coupled to a sensor and extending down into the first cavity on top of the disk shaped metal seal between the protrusion and an outer wall of the first cavity; and
a collar pressed down into the housing and into the second cavity wherein the collar has a third hole that passes through the collar and the sensor extends up into the third hole and wherein the collar crimps the outer wall against the isolation member.
12. The apparatus of claim 11 , wherein the disk shaped metal seal covers the bottom of the first cavity.
13. The apparatus of claim 11 , wherein the housing is cylinder shaped.
14. The apparatus of claim 11 , wherein the disk shape metal seal is a copper alloy.
15. The apparatus of claim 11 , wherein the sensor is a MEMS sensor.
16. The apparatus of claim 11 , wherein the collar is made from steel.
17. The apparatus of claim 11 , wherein the housing comprises of one or more of stainless steel, brass and aluminum.
18. The apparatus of claim 11 , wherein the third hole is coaxial with the first hole, first cavity and second cavity.
19. The apparatus of claim 11 , wherein the sensor is a pressure sensor.
20. The apparatus of claim 11 , wherein the disk shaped metal seal is made from copper.
21. An apparatus having a hermetic seal comprising:
a housing with a top and bottom and a first hole that passes through the housing from the top to the bottom wherein the housing further comprises a first cavity that extends down into the housing from the top and surrounds the first hole and has a first cavity bottom and wherein the housing further comprises a pipe that surrounds the first hole and extends up from the first cavity bottom into the first cavity and wherein the housing further comprises a second cavity that extends down into the housing from the top and surrounds, and is coaxial with, the first cavity;
a disk shaped metal seal with a second hole through a center of the disk wherein the disk shaped metal seal is located on the first cavity bottom wherein the disk shaped metal seal surrounds and is coaxial with the pipe;
an isolation member coupled to a sensor and extending down into the first cavity on top of the disk shaped metal seal between the pipe and an outer wall of the first cavity; and
a collar pressed down into the housing and into the second cavity wherein the collar has a third hole that passes through the collar and the sensor extends up into the third hole and the collar crimps the outer wall against the isolation member.