Elevated hermetic feedthrough insulator adapted for side attachment of electrical conductors on the body fluid side of an active implantable medical device

• US 8,938,309 B2
• Filed: 01/16/2013
• Issued: 01/20/2015
• Est. Priority Date: 01/16/2012
• Status: Active Grant

• Current Assignee: Greatbatch Limited (Greatbatch Incorporated)
• Original Assignee: Greatbatch Limited (Greatbatch Incorporated)
• Inventors: Marzano, Thomas, Seitz, Keith W., Stevenson, Robert A., Tang, Xiaohong, Thiebolt, William C., Frysz, Christine A., Brendel, Richard L., Woods, Jason, Winn, Steven W., Frustaci, Dominick J., Truex, Buehl E., Hickel, Donald Jr.
• Primary Examiner(s): Koharski, Christopher D
• Assistant Examiner(s): So, Elizabeth K
• Application Number:
  US13/742,781
• Publication Number:
  US 20130184796A1
• Time in Patent Office: 734 Days
• US Class Current: 607/116
• CPC Class Codes: A61N 1/05 for implantation or insertion into the body, e.g. heart electrode A61N1/06 takes precedence
• CPC Class Codes: A61N 1/08 Arrangements or circuits for monitoring, protecting, controlling or indicating for external stimulators A61N1/3603; for implantable neurostimulators A61N1/36128; for heart stimulators A61N1/37; for defibrillators A61N1/3925
• CPC Class Codes: A61N 1/372 Arrangements in connection with the implantation of stimulators
• CPC Class Codes: A61N 1/375 Constructional arrangements, e.g. casings
• CPC Class Codes: A61N 1/37512 Pacemakers
• CPC Class Codes: A61N 1/3754 Feedthroughs
• CPC Class Codes: B23K 35/3013 Au as the principal constituent
• CPC Class Codes: C22C 29/12 based on oxides
• CPC Class Codes: H01G 2/103 Sealings, e.g. for lead-in wires; Covers
• CPC Class Codes: H01G 4/005 Electrodes
• CPC Class Codes: H01G 4/12 Ceramic dielectrics H01G4/085 takes precedence
• CPC Class Codes: H01G 4/30 Stacked capacitors H01G4/33 takes precedence
• CPC Class Codes: H01G 4/35 Feed-through capacitors or anti-noise capacitors
• CPC Class Codes: H01G 4/40 Structural combinations of fixed capacitors with other electric elements, the structure mainly consisting of a capacitor, e.g. RC combinations
• CPC Class Codes: H01R 43/00 Apparatus or processes specially adapted for manufacturing, assembling, maintaining, or repairing of line connectors or current collectors or for joining electric conductors of trolley lines B60M1/28
• CPC Class Codes: H02G 3/22 Installations of cables or lines through walls, floors or ceilings, e.g. into buildings
• CPC Class Codes: Y10T 156/1052 with cutting, punching, tearing or severing

Abstract

An elevated feedthrough is attachable to a top or a side of an active implantable medical device. The feedthrough includes a conductive ferrule and a dielectric substrate. The dielectric substrate is defined as comprising a body fluid side and a device side disposed within the conductive ferrule. The dielectric substrate includes a body fluid side elevated portion generally raised above the conductive ferrule. At least one via hole is disposed through the dielectric substrate from the body fluid side to the device side. A conductive fill is disposed within the at least one via hole forming a hermetic seal and electrically conductive between the body fluid side and the device side. A leadwire connection feature is on the body fluid side electrically coupled to the conductive fill and disposed adjacent to the elevated portion of the dielectric substrate.

Claims

1. A feedthrough for an active implantable medical device, the feedthrough comprising:

a) a conductive ferrule comprising a ferrule sidewall having an inner ferrule surface defining a ferrule opening, wherein the ferrule sidewall extends from a first ferrule end surface spaced from a second ferrule end surface;

b) a dielectric substrate disposed partially within and hermetically sealed to the inner ferrule surface, wherein the dielectric substrate comprises an elevated portion extending outwardly from the first ferrule end surface to an opposed dielectric end surface adjacent to the second ferrule end surface;

c) at least one via hole extending through the dielectric substrate from an outer surface of the elevated portion to the opposed dielectric end surface;

d) a conductive fill comprising platinum, wherein the conductive fill is disposed within the at least one via hole in a hermetically sealed relationship therewith to thereby provide an electrically conductive path extending from a first fill end adjacent to an outer surface of the elevated portion of the dielectric substrate to a second fill end adjacent to the second dielectric end surface; and

e) a leadwire connection feature comprising gold and having a proximal connection portion extending to a distal connection portion, wherein the proximal connection portion is physically and electrically coupled to the first fill end with the distal connection portion contacting the elevated dielectric portion, but spaced from the ferrule,

f) wherein the distal connection portion is configured for direct electrical connection to a leadwire.

2. The feedthrough of claim 1, wherein the leadwire connection feature comprises a wire bond pad.

3. The feedthrough of claim 2, wherein the wire bond pad is substantially L-shaped.

4. The feedthrough of claim 3, wherein the L-shape comprises a curve.

5. The feedthrough of claim 2, wherein the wire bond pad is characterized as being a stamped and bent wire bond pad.

6. The feedthrough of claim 1, wherein the proximal connection portion of the leadwire connection feature is characterized as having been co-fired within the conductive fill.

7. The feedthrough of claim 1, including a braze preform physically and electrically coupling the leadwire connection feature to the conductive fill.

8. The feedthrough of claim 1, including a laser weld physically and electrically coupling the leadwire connection feature to the conductive fill.

9. The feedthrough of claim 1, wherein the distal connection portion of the leadwire connection feature comprises a leadwire insertion hole and the proximal connection portion comprises a laser weld access hole and wherein the laser weld access hole is physically and electrically connected to the conductive fill.

10. The feedthrough of claim 1, wherein the distal connection portion of the leadwire connection feature comprises a leadwire insertion hole and a threaded set screw hole in open communication with the leadwire insertion hole.

11. The feedthrough of claim 1, wherein the first fill end of the conductive fill is located inside the dielectric substrate, spaced along the at least one via hole from the outer surface of the elevated portion of the dielectric substrate and wherein the proximal connection portion of the leadwire connection feature comprises a contact spring located within an unfilled portion of the at least one via hole extending along the via hole from the outer surface of the elevated portion and wherein the contact spring is electrically coupled to the conductive fill in the via hole.

12. The feedthrough of claim 1, wherein the dielectric substrate comprises at least 96% alumina.

13. The feedthrough of claim 1, wherein the dielectric substrate comprises at least 99% alumina.

14. The feedthrough of claim 1, wherein the conductive fill comprises a substantially closed pore and fritless platinum fill.

15. The feedthrough of claim 14, wherein a hermetic seal comprising a tortuous and mutually conformal knitline is provided between the dielectric substrate at the at least one via hole and the platinum fill.

16. The feedthrough of claim 15, wherein the knitline comprises a glass that is at least about 60% silica.

17. The feedthrough of claim 1 wherein the elevated portion of the dielectric substrate comprises a dielectric radius and wherein the leadwire connection feature is radiused to match the dielectric radius.

18. The feedthrough of claim 1 wherein the leadwire connection feature is a gold braze.

19. A feedthrough for an active implantable medical device, the feedthrough comprising:

a) a conductive ferrule comprising a ferrule sidewall having an inner ferrule surface defining a ferrule opening, wherein the ferrule sidewall extends from a first ferrule end surface spaced from a second ferrule end surface;

b) a dielectric substrate disposed partially within and hermetically sealed to the inner ferrule surface, wherein the dielectric substrate comprises an elevated portion extending outwardly from the first ferrule end surface to an opposed dielectric end surface adjacent to the second ferrule end surface;

c) at least one via hole extending through the dielectric substrate from an outer surface of the elevated portion to the opposed dielectric end surface;

d) a conductive fill comprising platinum, wherein the conductive fill is disposed within the at least one via hole in a hermetically sealed relationship therewith to thereby provide an electrically conductive path extending from a first fill end adjacent to an outer surface of the elevated portion of the dielectric substrate to a second fill end adjacent to the second dielectric end surface; and

e) a leadwire connection feature comprising gold and having a proximal connection portion extending to a distal connection portion, wherein the proximal connection portion is physically and electrically coupled to the first fill end and the distal connection portion provides an exposed surface adjacent to the elevated dielectric portion, but spaced from the ferrule,

f) wherein the distal connection portion is configured for direct electrical connection to a leadwire.

20. The feedthrough of claim 19 wherein the leadwire connection feature is a gold braze.

21. The feedthrough of claim 19 wherein the leadwire connection feature comprises a wire bond pad.

22. The feedthrough of claim 19 wherein the proximal connection portion of the leadwire connection feature is characterized as having been co-fired within the conductive fill.

23. The feedthrough of claim 19 wherein the distal connection portion of the leadwire connection feature comprises a leadwire insertion hole and the proximal connection portion comprises a laser weld access hole and wherein the laser weld access hole is physically and electrically connected to the conductive fill.

24. The feedthrough of claim 19 wherein the dielectric substrate comprises at least 96% alumina.

25. The feedthrough of claim 19 wherein the conductive fill comprises a substantially closed pore and fritless platinum fill.

26. The feedthrough of claim 19 wherein a hermetic seal comprising a tortuous and mutually conformal knitline is provided between the dielectric substrate at the at least one via hole and the platinum fill.

27. The feedthrough of claim 19 wherein the elevated portion of the dielectric substrate comprises a dielectric radius and wherein the leadwire connection feature is radiused to match the dielectric radius.

28. A feedthrough for an active implantable medical device, the feedthrough comprising:

a) a conductive ferrule comprising a ferrule sidewall having an inner ferrule surface defining a ferrule opening, wherein the ferrule sidewall extends from a first ferrule end surface spaced from a second ferrule end surface;

b) a dielectric substrate disposed partially within and hermetically sealed to the inner ferrule surface, wherein the dielectric substrate comprises an elevated portion extending outwardly from the first ferrule end surface to a second dielectric end surface adjacent to the second ferrule end surface, wherein the elevated dielectric portion has an elevated dielectric height, and wherein diametrically opposed points on the elevated dielectric portion provide a dielectric thickness;

c) at least one castellation recess extending part-way along the height of the elevated dielectric portion and into the thickness thereof, wherein the castellation recess has a castellation floor recessed into the elevated portion;

d) at least one via hole extending through the dielectric substrate from the castellation floor to the second dielectric end surface;

e) a conductive fill comprising platinum, wherein the conductive fill is disposed within the at least one via hole in a hermetically sealed relationship therewith to thereby provide an electrically conductive path extending from a first fill end adjacent to the castellation floor to a second fill end adjacent to the second dielectric end surface; and

f) a leadwire connection feature received in the castellation, wherein the leadwire connection feature comprises gold and has a first connection surface contacting the conductive fill adjacent to the castellation floor and a spaced apart second connection surface adjacent to the elevated dielectric portion, but spaced from the ferrule,

g) wherein the distal connection portion is configured for direct electrical connection to a leadwire.

29. The feedthrough of claim 28 wherein the first connection surface of the leadwire connection feature comprises a post received in the at least one via hole.

30. The feedthrough of claim 29 wherein the knitline comprises a glass that is at least about 60% silica.

31. The feedthrough of claim 28 wherein the second connection surface of the leadwire connection feature comprises a wire bond pad.

32. The feedthrough of claim 28 wherein the first connection surface of the leadwire connection feature is characterized as having been co-fired within the conductive fill.

33. The feedthrough of claim 28 wherein the dielectric substrate comprises at least 96% alumina.

34. The feedthrough of claim 28 wherein the conductive fill comprises a substantially closed pore and fritless platinum fill.

35. The feedthrough of claim 28 wherein a hermetic seal comprising a tortuous and mutually conformal knitline is provided between the dielectric substrate at the at least one via hole and the platinum fill.

36. The feedthrough of claim 35 wherein the knitline comprises a glass that is at least about 60% silica.

37. The feedthrough of claim 28 wherein the leadwire connection feature is a gold braze.

38. A feedthrough for an active implantable medical device, the feedthrough comprising:

a) a conductive ferrule comprising a ferrule sidewall having an inner ferrule surface defining a ferrule opening, wherein the ferrule sidewall extends from a first ferrule end surface spaced from a second ferrule end surface;

b) a dielectric substrate disposed partially within and hermetically sealed to the inner ferrule surface, wherein the dielectric substrate comprises an elevated portion extending outwardly from the first ferrule end surface to an opposed dielectric end surface adjacent to the second ferrule end surface;

c) at least one ground via hole extending through the dielectric substrate from an outer surface of the elevated portion to the opposed dielectric end surface;

d) at least one active via hole extending through the dielectric substrate from the outer surface of the elevated portion to the opposed dielectric end surface;

e) at least one ground electrode plate supported by the dielectric substrate, wherein an end of the ground electrode plate extends to the at least one ground via hole;

g) a conductive fill comprising platinum, wherein the conductive fill is disposed within the at least one ground via hole and within the at least one active via hole in respective hermetically sealed relationships therewith to thereby provide electrically conductive paths extending from a first ground fill end to a second ground fill end and from a first active fill end to a second active fill end, the respective first ground and active fill ends being adjacent to an outer surface of the elevated portion of the dielectric substrate and the respective second ground and active fill ends being adjacent to the second dielectric end surface, and wherein the conductive fill in the ground via hole is electrically connected to the at least one ground plate; and

h) a leadwire connection feature comprising gold and having a proximal connection portion extending to a distal connection portion, wherein the proximal connection portion is physically and electrically coupled to the first fill end of the conductive fill in the at least one active via hole and the distal connection portion is exposed adjacent to the elevated dielectric portion, but spaced from the ferrule,

i) wherein the distal connection portion is configured for direct electrical connection to a leadwire.

39. The feedthrough of claim 38 wherein the dielectric substrate supports at least one second ground electrode plate extending to a metallization at the elevated dielectric portion and wherein the metallization is electrically connected to the ferrule, but spaced from the leadwire connection feature.

40. The feedthrough of claim 38 wherein the leadwire connection feature comprises a wire bond pad.

41. The feedthrough of claim 38 wherein the proximal connection, portion of the leadwire connection feature is characterized as having been co-fired within the conductive fill in the at least one active via hole.

42. The feedthrough of claim 38 wherein the distal connection portion of the leadwire connection feature comprises a leadwire insertion hole and the proximal connection portion comprises a laser weld access hole and wherein the laser weld access hole is physically and electrically connected to the conductive fill.

43. The feedthrough of claim 38 wherein the dielectric substrate comprises at least 96% alumina.

44. The feedthrough of claim 38 wherein the conductive fill comprises a substantially closed pore and fritless platinum fill.

45. The feedthrough of claim 38 wherein a hermetic seal comprising a tortuous and mutually conformal knitline is provided between the dielectric substrate at the at least one via hole and the platinum fill.

46. The feedthrough of claim 45 wherein the knitline comprises a glass that is at least about 60% silica.

47. The feedthrough of claim 38 wherein the leadwire connection feature is a gold braze.

48. A feedthrough for an active implantable medical device, the feedthrough comprising:

a) a conductive ferrule comprising a ferrule sidewall having an inner ferrule surface defining a ferrule opening, wherein the ferrule sidewall extends from a first ferrule end surface spaced from a second ferrule end surface;

b) a dielectric substrate disposed partially within and hermetically sealed to the inner ferrule surface, wherein the dielectric substrate comprises an elevated portion extending outwardly from the first ferrule end surface to an opposed dielectric end surface adjacent to the second ferrule end surface;

c) at least one via hole extending through the dielectric substrate from an outer surface of the elevated portion to the opposed dielectric end surface;

d) a conductive fill comprising platinum, wherein the conductive fill is disposed within the at least one via hole in a hermetically sealed relationship therewith to thereby provide an electrically conductive path extending from a first fill end adjacent to an outer surface of the elevated portion of the dielectric substrate to a second fill end adjacent to the second dielectric end surface; and

e) a leadwire connection feature comprising gold and having a proximal connection portion extending to a distal connection portion;

f) an electrically conductive pin comprising a proximal pin end spaced from a distal pin end, wherein the proximal pin end is characterized as having been co-fired within the conductive fill adjacent to the elevated dielectric portion and the distal pin end is physically and electrically contacted to the proximal connection portion of the leadwire connection feature with the distal connection portion exposed adjacent to the elevated dielectric portion, but spaced from the ferrule, g) wherein the distal connection portion is configured for direct electrical connection to a leadwire.

49. A feedthrough for an active implantable medical device, the feedthrough comprising:

a) a conductive ferrule comprising a ferrule sidewall having an inner ferrule surface defining a ferrule opening, wherein the ferrule sidewall, extends from a first ferrule end surface spaced from a second ferrule end surface;

b) a dielectric substrate disposed partially within and hermetically sealed to the inner ferrule surface, wherein the dielectric substrate comprises an elevated portion extending outwardly from the first ferrule end surface to an opposed dielectric end surface adjacent to the second ferrule end surface;

c) at least one via hole extending through the dielectric substrate from an outer surface of the elevated portion to the opposed dielectric end surface;

d) a conductive fill comprising platinum, wherein the conductive fill is disposed within the at least one via hole in a hermetically sealed relationship therewith to thereby provide an electrically conductive path extending from a first fill end adjacent to an outer surface of the elevated portion of the dielectric substrate to a second fill end adjacent to the second dielectric end surface; and

e) a leadwire connection feature comprising gold and having a proximal connection portion extending to a distal connection portion, wherein the proximal connection portion is physically and electrically connected to the conductive fill adjacent to the elevated dielectric portion with the distal connection portion spaced from the ferrule; and

g) a connection post connected to the distal connection portion, wherein the connection post is configured for direct electrical connection to a leadwire.