HERMETIC CONDUCTIVE FEEDTHROUGHS FOR A SEMICONDUCTOR WAFER

• US 20150101841A1
• Filed: 10/10/2013
• Published: 04/16/2015
• Est. Priority Date: 10/10/2013
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Ruben, David A., Sandlin, Michael S.
• Granted Patent: US 10,464,836 B2
• Time in Patent Office: Days
• US Class Current: 174/50.52
• CPC Class Codes: A61N 1/3754 Feedthroughs
• CPC Class Codes: A61N 1/3756 Casings with electrodes thereon, e.g. leadless stimulators
• CPC Class Codes: B81B 2207/095 through the lid
• 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: C03B 23/20 Uniting glass pieces by fusing without substantial reshaping
• CPC Class Codes: H01L 23/057 the leads being parallel to the base
• CPC Class Codes: H01L 23/10 characterised by the material or arrangement of seals between parts, e.g. between cap and base of the container or between leads and walls of the container
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H05K 5/0095 hermetically-sealed

Abstract

A glass wafer has an internal surface and an opposing external surface separated by a wafer thickness. A hermetic, electrically conductive feedthrough extends through the wafer from the internal surface to the opposing external surface. The feedthrough includes a feedthrough member having an inner face exposed along the internal surface for electrically coupling to an electrical circuit. The feedthrough member extends from the inner face partially through the wafer thickness to an exteriorly-facing outer face hermetically embedded within the wafer.

Claims

1. An enclosure, comprising:

a glass lid having an internal surface facing an internal cavity of the enclosure and an opposing external surface facing away from the cavity and separated from the internal surface by a lid thickness; and

an electrically conductive feedthrough extending through the glass lid, the feedthrough comprising;

a first feedthrough member having an inner face electrically coupled to an electrical circuit, the first feedthrough member extending from the inner face partially through the lid thickness to an exteriorly-facing outer face embedded within the lid, and

an electrically conductive trace at least partially embedded in the lid, extending away from the exteriorly-facing outer face and electrically coupling the exteriorly-facing outer face to an electrical connection point located along the lid external surface.

2. The enclosure of claim 1, wherein the connection point is spaced apart laterally from the embedded exteriorly-facing outer face.

3. The enclosure of claim 1, wherein the glass lid comprises:

a base layer defining the internal surface;

a top layer defining the external surface; and

a hermetically sealed interface between the base layer and the top layer.

4. The enclosure of claim 3, wherein the feedthrough member extends from the internal surface to the interface.

5. The enclosure of claim 4, wherein the trace extends laterally along the interface.

6. The enclosure of claim 3, wherein the top layer comprises an interior sidewall extending from the lid external surface to a top surface of the base layer, the connection point being along a portion of the trace exposed within the cavity.

7. The enclosure of claim 6, further comprising a sensor positioned in the cavity and electrically coupled to the trace.

8. The enclosure of claim 4, wherein the top layer comprises a second feedthrough member extending from the interface to the lid external surface, the second feedthrough member spaced apart laterally from the first feedthrough member,

the trace embedded in the lid and extending from the exteriorly-facing outer face of the first feedthrough member to the second feedthrough member.

9. The enclosure of claim 8, wherein the second feedthrough member comprises an interiorly-facing inner face embedded within the lid.

10. The enclosure of claim 3, wherein the top layer has a first thickness and the base layer has a second thickness greater than the first thickness.

11. An implantable medical device, comprising:

an electrical circuit; and

a hermetic enclosure defining a cavity for retaining the electrical circuit and comprising;

a glass lid having an internal surface facing the cavity and an opposing external surface facing away from the cavity and separated from the internal surface by a lid thickness; and

an electrically conductive feedthrough extending through the glass lid, the feedthrough comprising;

a first feedthrough member having an inner face electrically coupled to the electrical circuit, the first feedthrough member extending from the inner face partially through the lid thickness and to an exteriorly-facing outer face embedded within the lid, and

an electrically conductive trace at least partially embedded in the lid, extending away from the exteriorly-facing outer face and electrically coupling the exteriorly-facing outer face to an electrical connection point located along the lid external surface.

12. The device of claim 11, wherein the connection point is spaced apart laterally from the embedded exteriorly-facing outer face.

13. The device of claim 11, wherein the glass lid comprises:

a base layer defining the internal surface;

a top layer defining the external surface; and

a hermetically sealed interface between the base layer and the top layer.

14. The device of claim 13, wherein the feedthrough member extends from the internal surface to the interface.

15. The device of claim 14, wherein the trace extends laterally along the interface.

16. The device of claim 13, wherein the top layer comprises an interior sidewall defining a cavity extending from the lid external surface to a top surface of the base layer,

the connection point being along a portion of the trace exposed within the cavity.

17. The device of claim 16, further comprising a sensor positioned in the cavity and electrically coupled to the trace.

18. The device of claim 14, wherein the top layer comprises a second feedthrough member extending from the interface to the lid external surface, the second feedthrough member spaced apart laterally from the first feedthrough member,

the trace embedded in the lid and extending from the exteriorly-facing outer face of the first feedthrough member to the second feedthrough member.

19. The device of claim 18, wherein the second feedthrough member comprises an interiorly-facing inner face embedded within the lid.

20. The device of claim 13, wherein the top layer has a first thickness and the base layer has a second thickness greater than the first thickness.

21. A method for manufacturing a hermetic feedthrough in a glass wafer, the method comprising:

depositing a first feedthrough member in a via in the glass wafer;

depositing an electrically conductive trace along the glass wafer so that the trace and an exteriorly-facing outer face of the first feedthrough member are in direct electrical connection;

embedding the exteriorly-facing outer face of the first feedthrough member and at least a portion of the electrically conductive trace in the glass wafer;

electrically coupling the exteriorly-facing outer face to an electrical connection point located along an external surface of the glass wafer by the electrically conductive trace extending away from the embedded exteriorly-facing outer face.

22. The method of claim 21, further comprising positioning the connection point spaced apart laterally from the embedded exteriorly-facing face.

23. The method of claim 21, further comprising hermetically sealing a base layer to a top layer along an interface, the base layer defining an internal surface of the glass wafer and the top layer defining the external surface.

24. The method of claim 23, further comprising depositing the first feedthrough member in the base layer to extend from the internal surface to a top surface of the base layer.

25. The method of claim 24, further comprising depositing the trace along a surface of one of the top layer and the base layer so that the trace is embedded along the interface.

26. The method of claim 23, further comprising:

forming an interior sidewall in the top layer that defines a cavity that extends from the wafer external surface to a bottom surface of the top layer; and

exposing an end of the trace within the cavity.

27. The method of claim 26, further comprising positioning a sensor in the cavity and electrically coupling the sensor to the trace.

28. The method of claim 24, further comprising depositing a second feedthrough member in the top layer extending from a bottom surface of the top layer to the wafer external surface, the second feedthrough spaced apart laterally from the first feedthrough member,

embedding the trace in the lid from the exteriorly-facing outer face of the first feedthrough member to the second feedthrough member.

29. The method of claim 28, further comprising embedding an interiorly-facing inner face of the second feedthrough member within the lid.

30. The method of claim 23, further comprising grinding the top layer to a first thickness, wherein the base layer has a second thickness greater than the first thickness.

31. A glass wafer having a first surface and an opposing second surface separated from the first surface by a wafer thickness, the wafer comprising:

a first feedthrough member having a first face and a second face, the first face exposed along the first surface and extending partially through the wafer thickness the second face embedded within the glass wafer, and

an electrically conductive trace at least partially embedded in the wafer extending away from the second face and electrically coupling the second face to an electrical connection point located along the second opposing surface.

32. The glass wafer of claim 31, wherein the connection point is spaced apart laterally from the embedded first face.

33. The glass wafer of claim 31, further comprising:

a base layer defining the first surface;

a top layer defining the second surface; and

a hermetically sealed interface between the base layer and the top layer.

34. The glass wafer of claim 33, wherein the trace extends laterally along the interface.

35. The glass wafer of claim 33, wherein the top layer comprises an interior sidewall defining a cavity extending from the second surface to a top surface of the base layer,

the connection point being along a portion of the trace exposed within the cavity.

36. The glass wafer of claim 35, further comprising a sensor positioned in the cavity and electrically coupled to the trace.

37. The glass wafer of claim 33, wherein the top layer comprises a second feedthrough member extending from the interface to the second surface, the second feedthrough member spaced apart laterally from the first feedthrough member,

the trace embedded in the glass wafer and extending from the first face of the first feedthrough member to the second feedthrough member.

38. The glass wafer of claim 37, wherein the second feedthrough member comprises a face embedded within the glass wafer.

39. The device of claim 33, wherein the top layer has a first thickness and the base layer has a second thickness greater than the first thickness.