FEEDTHROUGH ASSEMBLY INCLUDING UNDERFILL ACCESS CHANNEL AND ELECTRICALLY INSULATING MATERIAL

• US 20130058004A1
• Filed: 11/30/2011
• Published: 03/07/2013
• Est. Priority Date: 09/01/2011
• Status: Abandoned Application

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Iyer, Rajesh V., Goldman, Simon E., Miltich, Thomas P.
• Application Number:
  US13/308,222
• Publication Number:
  US 20130058004A1
• Time in Patent Office: Days
• US Class Current: 361/302
• CPC Class Codes: A61N 1/3754 Feedthroughs
• CPC Class Codes: A61N 1/3968 Constructional arrangements, e.g. casings A61N1/375 takes precedence
• CPC Class Codes: H03H 2001/0042 Wound, ring or feed-through type capacitor
• CPC Class Codes: H03H 7/0138 Electrical filters or coupling circuits
• CPC Class Codes: H05K 13/00 Apparatus or processes specially adapted for manufacturing or adjusting assemblages of electric components
• CPC Class Codes: Y10T 29/43 Electric condenser making
• CPC Class Codes: Y10T 29/435 Solid dielectric type
• CPC Class Codes: Y10T 29/49002 Electrical device making
• CPC Class Codes: Y10T 29/49165 by forming conductive walled aperture in base
• CPC Class Codes: Y10T 29/49171 with encapsulating
• CPC Class Codes: Y10T 29/49208 by assembling plural parts

Abstract

A feedthrough assembly may include a ferrule defining a ferrule opening, a feedthrough at least partially disposed within the ferrule opening, a capacitive filter array at least partially disposed within the ferrule opening, and an electrically insulating material disposed between an externally-facing filter array side and an internally-facing feedthrough side. In some examples, the feedthrough includes at least one feedthrough conductive pathway extending between an internally-facing feedthrough side and an externally-facing feedthrough side. In some examples, the capacitive filter array includes at least one filter array conductive pathway extending between an internally-facing filter array side and an externally-facing filter array side. In some examples, at least one of the ferrule, the feedthrough, or the capacitive filter array defines an underfill access channel through which the electrically insulating material is introduced.

Claims

1. A feedthrough assembly comprising:

a ferrule defining a ferrule opening;

a feedthrough at least partially disposed within the ferrule opening, wherein the feedthrough defines an internally-facing feedthrough side and an externally-facing feedthrough side, and wherein the feedthrough includes at least one feedthrough conductive pathway extending between the internally-facing feedthrough side and the externally-facing feedthrough side;

a capacitive filter array at least partially disposed within the ferrule opening, wherein the capacitive filter array defines an internally-facing filter array side and an externally-facing filter array side, and wherein the capacitive filter array includes at least one filter array conductive pathway extending between the internally-facing filter array side and the externally-facing filter array side; and

an electrically insulating material disposed between the externally-facing filter array side and the internally-facing feedthrough side, wherein at least one of the ferrule, the feedthrough, or the capacitive filter array defines an underfill access channel through which the electrically insulating material is introduced.

2. The feedthrough assembly of claim 1, wherein the ferrule defines the underfill access channel, and wherein the underfill access channel extends between an exterior wall of the ferrule and an interior wall of the ferrule.

3. The feedthrough assembly of claim 1, wherein the feedthrough defines the underfill access channel, and wherein the underfill access channel extends between the internally-facing feedthrough side and the externally-facing feedthrough side.

4. The feedthrough assembly of claim 3, wherein the electrically insulating material forms a hermetic seal with the feedthrough.

5. The feedthrough assembly of claim 3, further comprising a material disposed within the underfill access channel that forms a hermetic seal with the feedthrough.

6. The feedthrough assembly of claim 5, wherein the material comprises gold, a nickel-gold alloy, platinum, or platinum-iridium.

7. The feedthrough assembly of claim 1, wherein the capacitive filter array defines the underfill access channel, and wherein the underfill access channel extends between the internally-facing filter array side and the externally-facing filter array side.

8. The feedthrough assembly of claim 1, wherein the electrically insulating material comprises at least one of a non-conductive polyimide, an epoxy, or a glass.

9. The feedthrough assembly of claim 1, wherein the electrically insulating material extends substantially continuously from the externally-facing filter array side and the internally-facing feedthrough side.

10. The feedthrough assembly of claim 1, wherein the electrical insulating material is disposed between an exterior wall of the feedthrough and an interior wall of the ferrule.

11. The feedthrough assembly of claim 1, wherein the electrical insulating material is disposed between an exterior wall of the capacitive filter array and an interior wall of the ferrule.

12. The feedthrough assembly of claim 1, further comprising a thick film conductive paste that electrically and mechanically connects the at least one filter array conductive pathway and the at least one feedthrough conductive pathway, and wherein the electrically insulating materially substantially fully surrounds the thick film conductive paste between the externally-facing filter array side and the internally-facing feedthrough side.

13. The feedthrough assembly of claim 1, wherein the capacitive filter array comprises a capacitive filter electrically connected to the at least one filter array conductive pathway and a perimeter conductive contact electrically connected to the capacitive filter, wherein the feedthrough assembly further comprises a thick film conductive past that electrically connects the perimeter conductive contact and the ferrule.

14. The feedthrough assembly of claim 13, wherein the electrical insulating material is disposed between the perimeter conductive contact and an interior wall of the ferrule.

15. The feedthrough assembly of claim 1, further comprising lead frame assembly that electrically and mechanically connects the at least one filter array conductive pathway and the at least one feedthrough conductive pathway, and wherein the electrically insulating materially substantially fully surrounds the lead frame assembly between the externally-facing filter array side and the internally-facing feedthrough side.

16. The feedthrough assembly of claim 15, wherein the capacitive filter array comprises a plurality of filter array conductive pathways, wherein the feedthrough comprises a plurality of feedthrough conductive pathways, wherein the lead frame assembly comprises a plurality of electrically conductive leads, and wherein respective ones of the plurality of electrically conductive leads electrically connect respective ones of filter array conductive pathways with respective ones of feedthrough conductive pathways, and wherein the electrically insulating materially substantially fully surrounds the plurality of electrically conductive leads between the externally-facing filter array side and the internally-facing feedthrough side.

17. An implantable medical device comprising:

a housing defining an opening; and

a feedthrough assembly disposed in the opening and attached to the housing, wherein the feedthrough assembly comprises;

a ferrule defining a ferrule opening;

a feedthrough at least partially disposed within the ferrule opening, wherein the feedthrough defines an internally-facing feedthrough side and an externally-facing feedthrough side, and wherein the feedthrough includes at least one feedthrough conductive pathway extending between the internally-facing feedthrough side and the externally-facing feedthrough side;

a capacitive filter array at least partially disposed within the ferrule opening, wherein the capacitive filter array defines an internally-facing filter array side and an externally-facing filter array side, and wherein the capacitive filter array includes at least one filter array conductive pathway extending between the internally-facing filter array side and the externally-facing filter array side; and

an electrically insulating material disposed between the externally-facing filter array side and the internally-facing feedthrough side, wherein at least one of the ferrule, the feedthrough, or the capacitive filter array defines an underfill access channel through which the electrically insulating material is introduced.

18. The implantable medical device of claim 17, wherein the ferrule defines the underfill access channel, wherein the underfill access channel extends between an exterior wall of the ferrule and an interior wall of the ferrule, and wherein the underfill access channel is disposed within the housing when the feedthrough assembly is attached to the housing.

19. The implantable medical device of claim 17, wherein the feedthrough defines the underfill access channel, and wherein the underfill access channel extends between the internally-facing feedthrough side and the externally-facing feedthrough side.

20. The implantable medical device of claim 19, wherein the electrically insulating material forms a hermetic seal with the feedthrough.

21. The implantable medical device of claim 19, further comprising a material disposed within the underfill access channel that forms a hermetic seal with the feedthrough, and wherein the material comprises gold, a nickel-gold alloy, platinum, or platinum-iridium.

22. The implantable medical device of claim 17, wherein the capacitive filter array defines the underfill access channel, and wherein the underfill access channel extends between the internally-facing filter array side and the externally-facing filter array side.

23. The implantable medical device of claim 17, wherein the electrically insulating material extends substantially continuously from the externally-facing filter array side and the internally-facing feedthrough side.

24. The implantable medical device of claim 17, wherein the electrically insulating material comprises at least one of a non-conductive polyimide, an epoxy, or a glass.

25. The implantable medical device of claim 17, further comprising a thick film conductive paste that electrically and mechanically connects the at least one filter array conductive pathway and the at least one feedthrough conductive pathway, and wherein the electrically insulating materially substantially fully surrounds the thick film conductive paste between the externally-facing filter array side and the internally-facing feedthrough side.

26. The implantable medical device of claim 17, wherein the capacitive filter array comprises a capacitive filter electrically connected to the at least one filter array conductive pathway and a perimeter conductive contact electrically connected to the capacitive filter, wherein the feedthrough assembly further comprises a thick film conductive past that electrically connects the perimeter conductive contact and the ferrule.

27. The implantable medical device of claim 26, wherein the electrical insulating material is disposed between the perimeter conductive contact and an interior wall of the ferrule.

28. The implantable medical device of claim 17, further comprising lead frame assembly that electrically and mechanically connects the at least one filter array conductive pathway and the at least one feedthrough conductive pathway, and wherein the electrically insulating materially substantially fully surrounds the lead frame assembly between the externally-facing filter array side and the internally-facing feedthrough side.

29. The implantable medical device of claim 28, wherein the capacitive filter array comprises a plurality of filter array conductive pathways, wherein the feedthrough comprises a plurality of feedthrough conductive pathways, wherein the lead frame assembly comprises a plurality of electrically conductive leads, and wherein respective ones of the plurality of electrically conductive leads electrically connect respective ones of filter array conductive pathways with respective ones of feedthrough conductive pathways, and wherein the electrically insulating materially substantially fully surrounds the plurality of electrically conductive leads between the externally-facing filter array side and the internally-facing feedthrough side.

30. A method comprising:

attaching a perimeter wall of a feedthrough to an interior wall of a ferrule to form a hermetic seal between the feedthrough and the ferrule, wherein the feedthrough defines and externally-facing feedthrough side and an internally-facing feedthrough side;

attaching a capacitive filter array to the feedthrough, wherein the capacitive filter array comprises an externally-facing filter array side and an internally-facing filter array side;

attaching a perimeter wall of the capacitive filter array to the interior wall of the ferrule; and

introducing an electrically insulating material into a gap between the externally-facing filter array side and the internally-facing feedthrough side through an underfill access port, wherein at least one of the ferrule, the feedthrough, or the capacitive filter array defines the underfill access port.

31. The method of claim 30, wherein attaching the capacitive filter array to the feedthrough comprises electrically connecting a filter array conductive pathway to a feedthrough conductive pathway using a thick film conductive paste.

32. The method of claim 30, wherein attaching the capacitive filter array to the feedthrough comprises electrically connecting a filter array conductive pathway to a feedthrough conductive pathway using a lead frame assembly.

33. The method of claim 30, wherein attaching the perimeter wall of the capacitive filter array to the interior wall of the ferrule comprises electrically connecting a perimeter conductive contact on the perimeter wall to the ferrule using a thick film conductive paste.

34. The method of claim 30, wherein attaching the perimeter wall of the capacitive filter array to the interior wall of the ferrule comprises electrically connecting a perimeter conductive contact on the perimeter wall to the ferrule using a lead frame assembly.

35. The method of claim 30, wherein the electrically insulating material comprises at least one of a non-conductive polyimide, an epoxy, or a glass, and wherein introducing the electrically insulating material into the gap between the externally-facing filter array side and the internally-facing feedthrough through an underfill access port comprises introducing the electrically insulating material in a flowable state into the gap between the externally-facing filter array side and the internally-facing feedthrough through an underfill access port and converting the electrically insulating material from the flowable state to a relatively solid state once the electrically insulating material is disposed in the gap between the externally-facing filter array side and the internally-facing feedthrough side.