Hermetic Chamber with Electrical Feedthroughs

• US 20090145623A1
• Filed: 02/17/2009
• Published: 06/11/2009
• Est. Priority Date: 02/10/2005
• Status: Active Grant

• Current Assignee: St. Jude Medical Luxembourg Holdings Ii S.A.R.L.
• Original Assignee: David O'Brien, Florent Cros, Jin Woo Park, Liang You, Mark Allen, Michael Fonseca
• Inventors: Park, Jin Woo, O'Brien, David, Allen, Mark, You, Liang, Cros, Florent, Fonseca, Michael
• Granted Patent: US 7,854,172 B2
• Time in Patent Office: Days
• US Class Current: 174/50.520
• CPC Class Codes: A61B 2562/0247 Pressure sensors
• CPC Class Codes: A61B 5/03 Detecting, measuring or recording fluid pressure within the body other than blood pressure, e.g. cerebral pressure; Measuring pressure in body tissues or organs A61B5/205 takes precedence
• CPC Class Codes: B81B 2201/0264 Pressure sensors
• CPC Class Codes: B81B 2201/06 Bio-MEMS
• CPC Class Codes: B81B 2207/096 through the substrate
• CPC Class Codes: B81B 7/007 Interconnections between the MEMS and external electrical signals
• CPC Class Codes: B81C 1/00301 Connecting electric signal lines from the MEMS device with external electrical signal lines, e.g. through vias
• CPC Class Codes: G01L 9/0073 using a semiconductive diaphragm
• CPC Class Codes: G01L 9/0075 using a ceramic diaphragm, e.g. alumina, fused quartz, glass

Abstract

A pressure cavity is durable, stable, and biocompatible and configured in such a way that it constitutes pico to nanoliter-scale volume. The pressure cavity is hermetically sealed from the exterior environment while maintaining the ability to communicate with other devices. Micromachined, hermetically-sealed sensors are configured to receive power and return information through direct electrical contact with external electronics. The pressure cavity and sensor components disposed therein are hermetically sealed from the ambient in order to reduce drift and instability within the sensor. The sensor is designed for harsh and biological environments, e.g. intracorporeal implantation and in vivo use. Additionally, novel manufacturing methods are employed to construct the sensors.

Claims

1. A device comprising:

a housing having walls defining a chamber, a first one of said walls defining said chamber comprising an exterior wall of said housing;

a passage through said first one of said walls placing the chamber of said housing in communication with the ambient; and

an electrode hermetically imposed over said passage within said chamber of said housing, whereby said passage is hermetically sealed;

whereby said chamber is hermetically sealed; and

whereby an external electrical device can be placed in electrical communication with said electrode through said passage.

2. The device of claim 1, wherein said housing further comprises a unitary housing.

3. The device of claim 1, wherein said housing is comprised of a ceramic material.

4. The device of claim 3, wherein said housing is comprised of glass, fused silica, sapphire, quartz or silicon.

5. The device of claim 4, wherein the housing is comprised of fused silica.

6. The device of claim 1, wherein said passage has a surface area of from 10⁻

6 to 10<sup>−

12</sup> meters².

7. The device of claim 6, wherein said passage has a surface area of from 10⁻

6 to 10<sup>−

9</sup> meters².

8. The device of claim 1, wherein said housing has a volume of from 10⁻

8 to 10<sup>−

15</sup> meters³.

9. The device of claim 1, wherein said passage comprises a first passage, and wherein said device further comprises:

a second passage through said first one of said walls defining said chamber placing said chamber of said housing in communication with the ambient; and

a second electrode hermetically imposed over said second passage within said chamber, whereby said second passage is hermetically sealed;

whereby said chamber is hermetically sealed; and

whereby a second electrical feedthrough can be placed in electrical communication with said second electrode through said second passage.

10. The device of claim 9, wherein a second one of said walls defining said chamber and opposite said first wall comprises an exterior wall of said housing;

wherein said second one of said walls defining said chamber comprises a deflectable region;

wherein a third electrode is deposited on said second one of said walls within said chamber in said deflectable region; and

wherein said third electrode is placed in electrical communication with one of said first electrode or said second electrode.

11. The device of claim 9, wherein one of said first or second electrodes and said third electrode comprise a capacitor.

12. The device of claim 9, wherein a third electrode is deposited on an interior wall of said chamber opposite to said first wall;

wherein said first, second, and third electrodes are electrically isolated from one another; and

wherein said interior wall of said chamber opposite to said first wall further comprises a deflectable region.

13. The device of claim 12, wherein said first, second, and third electrodes comprise a capacitor.

14. The device of claim 9, wherein a second one of said walls defining said chamber and opposite said first wall comprises an exterior wall of said housing;

wherein said second one of said walls defining said chamber comprises a deflectable region;

wherein at least one piezoresistor is deposited on said second one of said walls defining said chamber in said deflectable region thereof,

wherein said first electrode is in electrical contact with a first side of said piezoresistor; and

wherein said second electrode is in electrical contact with a second side of said piezoresistor.

15. The device of claim 1, wherein said passage is partially filled with an electrically conductive material such that said electrically conductive material is in electrical contact with said electrode.

16. The device of claim 15, wherein the remainder of said passage is filled with a different material.

17. The device of claim 16, wherein said different material comprises a ceramic.

18. The device of claim 15, wherein said electrically conductive material is hermetic and is hermetically disposed in said passage.

19. The device of claim 15, wherein said electrically conductive material is selected from the group consisting of gold, platinum, nickel, and silver and alloys thereof.

20. The device of claim 1, wherein said passage is completely filled with an electrically conductive material, whereby an external electrical device can be placed in electrical communication with said electrode by electrically connecting said electrical device to said electrically conductive material.

21. The device of claim 20, wherein said electrically conductive material is hermetic and is hermetically disposed in said passage.

22. The device of claim 20, wherein said electrically conductive material is selected from the group consisting of gold, platinum, nickel, and silver and alloys thereof.

23. A device comprising:

a unitary housing having walls defining first and second internal chambers, said first and second chambers having a common wall;

a passage through said common wall; and

an electrode within said first chamber hermetically imposed over said passage, whereby said passage is hermetically sealed;

whereby said first chamber is hermetically sealed from said second chamber; and

whereby said second chamber can be placed in electrical communication with said electrode through said passage.

24. The device of claim 23, wherein said passage comprises a first passage, wherein said electrode comprises a first electrode, and wherein said device further comprises:

a second passage through said common wall; and

a second electrode within said first chamber hermetically imposed over said second passage.

25. The device of claim 24, wherein said second chamber is at least partially defined by an exterior wall of said unitary housing, and wherein said device further comprises:

a third passage through said exterior wall; and

a third electrode within said second chamber imposed across said third passage;

whereby an external electrical device can be placed in electrical communication with said third electrode through said third passage.

26. The device of claim 25, further comprising:

a fourth passage through said exterior wall;

a fourth electrode within said second chamber imposed across said fourth passage,

whereby an external electrical device can be placed in electrical communication with said fourth electrode through said fourth passage.

27. The device of claim 26, wherein said third and fourth electrodes comprise hermetic material which is hermetically imposed over said third and fourth passages.

28. The device of claim 25, further comprising an electrical circuit disposed within said second chamber and in electrical communication with said first and second electrodes, said electrical circuit being operable to manipulate an electrical signal input through said first and second electrodes.

29. The device of claim 28, wherein said electrical circuit being operable to manipulate an electrical signal input through said first and second electrodes comprises an integrated circuit.

30. The device of claim 29, wherein said integrated circuit is operable to condition an electrical signal passing between said first and second electrodes.

31. The device of claim 29, wherein said integrated circuit is operable to condition an electrical signal passing between said first and second electrodes and external electronics.

32. A device comprising:

a substrate having first and second sides;

a passage through said substrate from said first side to said second side; and

an electrode hermetically imposed against said first side of said substrate over said passage;

whereby an electrical device on the second side of said substrate can be placed in electrical communication with said electrode on said first side of said substrate through said passage.

33. The device of claim 32, further comprising a conductive material located within said passage and in electrical contact with said electrode, whereby an electrical device on the second side of said substrate can be placed in electrical communication with said electrode on said first side of said substrate through said conductive material.