Hermatic Chamber With Electrical Feedthroughs

• US 20070261497A1
• Filed: 05/15/2007
• Published: 11/15/2007
• Est. Priority Date: 02/10/2005
• Status: Active Grant

• Current Assignee: St. Jude Medical Luxembourg Holdings Ii S.A.R.L.
• Original Assignee: CardioMEMS Incorporated
• Inventors: O'Brien, David, You, Liang, Courcimault, Christophe
• Granted Patent: US 7,647,836 B2
• Time in Patent Office: Days
• US Class Current: 73/724
• CPC Class Codes: G01L 9/0042 Constructional details associated with semiconductive diaphragm sensors, e.g. etching, or constructional details of non-semiconductive diaphragms details about the integration or bonding of piezoresistor in or on the diaphragm G01L9/0052 and G01L9/0057 respectively
• CPC Class Codes: G01L 9/0055 bonded on a diaphragm
• CPC Class Codes: G01L 9/0075 using a ceramic diaphragm, e.g. alumina, fused quartz, glass
• CPC Class Codes: Y10T 29/49002 Electrical device making

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. Mi cromachined, 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) a housing having walls defining a chamber, a first one of said walls defining said chamber comprising an exterior wall of said housing; and

(b) a chip bearing electronics located within said housing and comprising at least one wire bond, for enabling electrical communication to said electronics;

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

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

(e) means for establishing electrical connection between said wire bond and said electrode;

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, further comprising a second electrode deposited on said first one of said walls within said chamber;

and

said chip further comprising a second wire bond for enabling electrical communication to said electronics; and

means for establishing electrical connection between said second wire bond and said second electrode.

10. The device of claim 9, further comprising:

(a) a second one of said walls defining said chamber located opposite said first wall, said second one of said walls comprising

(i) an exterior wall of said housing, and

(ii) a deflectable region;

(b) a third electrode deposited on said second one of said walls within said chamber in said deflectable region;

(c) a fourth electrode deposited on said first one of said walls and a third wire bond operatively associated with said chip,

(d) means for establishing electrical connection between said third wire bond and said fourth electrode;

(e) a fifth electrode deposited on said first one of said walls and a fourth wire bond operatively associated with said chip; and

(f) means for establishing electrical connection between said fourth wire bond and said fifth electrode;

wherein said third, fourth and fifth electrodes comprise a capacitor.

11. 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.

12. The device of claim 11, wherein the remainder of said passage is filled with a different material.

13. The device of claim 12, wherein said different material comprises a ceramic.

14. The device of claim 11, wherein said electrically conductive material is hermetic and is hermetically disposed in said passage.

15. The device of claim 11, wherein said electrically conductive material comprises a non-refractory metal.

16. The device of claim 15, wherein said non-refractory metal is selected from the group consisting of gold, platinum, nickel, and silver and alloys thereof.

17. The device of claim 11, wherein said electrically conductive material comprises a refractory metal.

18. The device of claim 17, wherein said refractory metal is selected from the group consisting of niobium, titanium, tungsten, tantalum, molybdenum, chromium, and platinum/iridium alloy and alloys thereof.

19. 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.

20. The device of claim 19, wherein said electrically conductive material is hermetic and is hermetically disposed in said passage.

21. The device of claim 19, wherein said electrically conductive material comprises a non-refractory metal.

22. The device of claim 21, wherein said non-refractory metal is selected from the group consisting of gold, platinum, nickel, and silver and alloys thereof.

23. The device of claim 19, wherein said electrically conductive material comprises a refractory metal.

24. The device of claim 23, wherein said refractory metal is selected from the group consisting of niobium, titanium, tungsten, tantalum, molybdenum, chromium, and platinum/iridium alloy and alloys thereof.

25. A method of manufacturing a device for securing micro-devices, comprising:

selecting a first substrate having a height less than the height of the microdevice;

cutting holes through the first substrate shaped to conform to the configuration of a micro-device intended to be held there within;

placing a second substrate in contact with the first substrate and bonding the first and second substrates; and

placing at least one micro-device into a corresponding recess.

26. The method of claim 25, further comprising capping the first substrate on the side opposite the second substrate so as to retain said at least one micro-device within said corresponding recess.

27. The method of claim 25, wherein each of the first and second substrates are fused silica.

28. The method of claim 25, wherein cutting holes through the first substrate comprises cutting holes using a CO₂ laser operating at a peak wavelength of 10 microns.

29. The method of claim 25, wherein said bonding of the first and second substrates further comprises direct bonding.

30. The method of claim 25, wherein said bonding of the first and second substrates further comprises using adhesives.

31. The method of claim 25, wherein said bonding of the first and second substrates further comprises heat bonding using highly localized heat.

32. The method of claim 25, wherein said bonding of the first and second substrates further comprises using a mechanical clamp.

33. The method of claim 25, further comprising overlaying a shadow mask having openings therethrough on the surface of the device, comprising:

placing the device on a first platform;

connecting a shadow mask to a base wafer and aligning the mask;

securing the mask and the device; and

applying metal to the device through said openings in said shadow mask.

34. A method of manufacturing a device for securing micro-devices, comprising:

(a) providing a silicon substrate;

(b) cutting holes through the substrate shaped to conform to the configuration of a micro-device intended to be held there within;

(c) placing at least one micro-device into a corresponding recess; and

(d) capping the substrate with a cover layer of substrate so as to retain said at least one micro-device within said corresponding recess.

35. The method of claim 34, wherein cutting holes through the substrate further comprises cutting holes using inductively-coupled plasma.

36. A system for securing micro-devices, comprising:

(a) a device comprising a plurality of recesses, each recess shaped to house a micro-device;

(b) at least one micro-device housed in one of said recesses; and

(c) a mask;

wherein said device protects said at least one micro-device during processing or shipping.