Hermetically sealed feedthrough with co-fired filled via and conductive insert for an active implantable medical device

1. A hermetically sealed feedthrough for attachment to an active implantable medical device (AIMD), the feedthrough comprising:

a) a dielectric substrate hermetically sealed to a ferrule by a gold braze;

b) a via hole disposed through the dielectric substrate from a first side to a second side;

c) a conductive sintered paste fill disposed within the via hole forming a filled via electrically conductive between the first side and the second side; and

d) a conductive solid metallic insert at least partially disposed within the conductive fill;

e) wherein the conductive sintered paste fill and the conductive solid metallic insert are co-fired with the dielectric substrate forming a hermetically sealed and electrically conductive pathway through the dielectric substrate between the first side and the second side.

2. The feedthrough of claim 1 , wherein the conductive fill comprises a metallic fill.

3. The feedthrough of claim 1 , wherein an inherent shrink rate during a co-firing treatment of the insulator in a green state is greater than that of an inherent shrink rate during the co-firing treatment of the metallic fill in a green state.

4. The feedthrough of claim 1 , wherein the first and second insert ends are substantially flush with the respective first and second insulator end surfaces.

5. The feedthrough of claim 1 , wherein at least one of the first and second insert ends extends outwardly beyond a respective one of the first and second insulator end surfaces.

6. The feedthrough of claim 5 , wherein the insert comprises an enlarged end cap at least one of its first and second insert ends.

7. A hermetically sealed feedthrough for attachment to an active implantable medical device (AIMD), 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 to a second ferrule end surface, and wherein the ferrule is configured to be attachable to an opening in a housing of an active implantable medical device;

b) an insulator residing at least partially within the inner ferrule surface, wherein the insulator comprises an outer insulator surface extending from a first insulator end surface disposed adjacent to the first ferrule end surface to an opposed second insulator end surface disposed adjacent to the second ferrule end surface;

c) a first metallization contacting at least a portion of the outer surface of the insulator;

d) an electrically conductive material hermetically sealing the ferrule sidewall to the first metallization contacting the outer surface of the insulator;

e) at least one via hole extending through the insulator from the first insulator end surface to the second insulator end surface;

f) an electrically conductive insert residing in the via hole and comprising an insert sidewall extending from a first insert end to a second insert end, wherein the first insert end is disposed at or adjacent to the first insulator end surface and the second insert end is disposed at or adjacent to the second insulator end surface; and

g) a conductive fill residing in the at least one via hole in contact with the insert sidewall, the conductive fill extending from a first fill end disposed at or adjacent to the first insulator end surface to a second fill end disposed at or adjacent to the second insulator end surface,

h) wherein the conductive fill is in a hermetically sealed relationship with both the insulator at the at least one via hole and the insert sidewall so that the conductive insert provides an electrically conductive pathway extending through the insulator to or adjacent to the first insulator end surface and to or adjacent to the second insulator end surface.

8. The feedthrough of claim 7 , wherein the conductive fill comprises a metallic fill.

9. The feedthrough of claim 8 , wherein the conductive insert comprises a metallic insert, and where the metallic insert and the metallic fill are of the same metallic material.

10. The feedthrough of claim 8 , wherein an inherent shrink rate during a co-firing treatment of the insulator in a green state is greater than that of an inherent shrink rate during the co-firing treatment of the metallic fill in a green state.

11. The feedthrough of claim 7 , wherein the conductive fill comprises a platinum fill.

12. The feedthrough of claim 11 , wherein the conductive insert comprises a platinum insert.

13. The feedthrough of claim 12 , wherein the insulator comprises an alumina ceramic substrate comprised of at least 96 percent alumina.

14. The feedthrough of claim 7 , wherein the conductive fill is a platinum fill that forms a first tortuous and mutually conformal knitline with the insulator at the at least one via hole.

15. The feedthrough of claim 7 , wherein the conductive fill is a platinum fill that forms a second tortuous and mutually conformal knitline with the insert sidewall, the insert being a platinum insert.

16. The feedthrough of claim 7 , wherein the conductive fill does not contact:

i) the first insert end disposed adjacent to the first insulator end surface, and

ii) the second insert end disposed adjacent to the second insulator end surface.

17. The feedthrough of claim 7 , wherein the first and second insert ends are substantially flush with the respective first and second insulator end surfaces.

18. The feedthrough of claim 7 , wherein at least one of the first and second insert ends extends outwardly beyond a respective one of the first and second insulator end surfaces.

19. The feedthrough of claim 18 , wherein the insert comprises an enlarged end cap at at least one of its first and second insert ends.

20. The feedthrough of claim 7 , wherein the conductive insert comprises a first insert portion separate and distinct from a second insert portion, and wherein the first and second insert portions are adjacent to or abut one another at an intermediate location along a length of the at least one via hole in which the insert resides.

21. The feedthrough of claim 7 , wherein the conductive insert comprises a crimp post portion extending outwardly beyond at least one of the first and second insulator end surfaces.

22. The feedthrough of claim 21 , wherein the crimp post portion comprises a receptacle configured to receive a conductive wire, and wherein the crimp post portion comprises a cross-sectional shape selected from the group consisting of a circle, an oval, a rectangle, and a square.

23. The feedthrough of claim 22 , wherein the receptacle of the crimp post portion of the conductive insert is disposed perpendicular to a longitudinal length of the crimp post portion.

24. The feedthrough of claim 22 , wherein the receptacle of the crimp post portion of the conductive insert is aligned along a longitudinal length of the crimp post portion.

25. The feedthrough of claim 22 , wherein the crimp post portion of the conductive insert comprises at least one slot that is at least partially disposed along a longitudinal length of the crimp post portion.

26. The feedthrough of claim 7 , wherein the conductive insert has a length extending from the first insert end to the second insert end and wherein at least one slot extends along the length of the conductive insert from the first insert end to the second insert end.

27. The feedthrough of claim 7 , wherein the conductive insert is selected from the group consisting of titanium, platinum, platinum-iridium alloys, tantalum, niobium, zirconium, hafnium, nitinol, Co—Cr—Ni alloys, stainless steel, gold, gold alloys, ZrC, ZrN, TiN, NbO, TiC, TaC, and combinations thereof.

28. The feedthrough of claim 7 , wherein the at least one via hole has a via hole length extending from the first insulator end surface to the second insulator end surface, and wherein the conductive insert has a larger cross-sectional area at or adjacent to at least one of the first and second insulator end surfaces than at an intermediate location along the via hole length between the first and second insulator end surfaces.

29. The feedthrough of claim 7 , wherein the first insulator end surface is one of a body fluid side and a device side, and the second insulator end surface is the other of the body fluid side and the device side.

30. The feedthrough of claim 7 , wherein the conductive insert is a drawn filled tube comprising a silver core provided with an MP35N cladding.

31. The feedthrough of claim 7 , wherein the conductive fill and the conductive insert are characterized as having been co-fired with the insulator to thereby form a hermetically sealed and electrically conductive pathway from the first insulator end surface to the second insulator end surface.

32. The feedthrough of claim 7 , wherein both of the first and second insert ends extends axially outwardly beyond the respective first and second conductive fill ends.

33. A hermetically sealed feedthrough assembly for attachment to an active implantable medical device (AIMD), the feedthrough comprising:

a) a feedthrough, comprising:

i) 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 to a second ferrule end surface, and wherein the ferrule is configured to be attachable to an opening in a housing of an active implantable medical device;

ii) an alumina insulator residing at least partially within the inner ferrule surface, wherein the insulator comprises an outer insulator surface extending from a first insulator end surface disposed adjacent to the first ferrule end surface to an opposed second insulator end surface disposed adjacent to the second ferrule end surface;

iii) a first metallization contacting at least a portion of the outer surface of the insulator;

iv) a first electrically conductive material hermetically sealing the ferrule sidewall to the first metallization contacting the outer surface of the insulator;

v) at least one via hole extending through the alumina insulator from the first insulator end surface to the second end surface;

vi) a platinum insert residing in the via hole and comprising an insert sidewall extending from a first insert end to a second insert end, wherein at least the first insert end extends outwardly beyond the first insulator end surface and the second insert end is disposed at or adjacent to the second insulator end surface; and

vii) a platinum fill residing in the at least one via hole in contact with the platinum insert sidewall, the platinum fill extending from a first fill end disposed at or adjacent to the first insulator end surface to a second fill end disposed at or adjacent to the second insulator end surface,

viii) wherein the platinum fill is in a hermetically sealed relationship with both the insulator at the at least one via hole and the platinum insert sidewall so that the platinum insert provides as electrically conductive pathway extending through the alumina insulator to or adjacent to the first insulator end surface and to or adjacent to the second insulator end surface;

b) a feedthrough capacitor, comprising:

i) a capacitor dielectric body;

ii) at least one active electrode plate and at least one ground electrode plate supported in the capacitor dielectric body in spaced relation with each other;

iii) at least one open bore formed axially through the capacitor dielectric body;

iv) a second metallization contacting the bore in conductive relation with the active electrode plate; and

v) a third metallization contacting an outer surface of the capacitor dielectric body in conductive relation with the ground electrode plate;

c) a second electrically conductive material physically contacting and electrically coupling the second metallization in the open bore of the capacitor dielectric body to the second insert end at or adjacent to the second insulator end surface to thereby electrically connect the at least one active electrode plate to the conductive insert, wherein the opposed first insert end extends outwardly beyond the first insulator end surface; and

d) a third electrically conductive material physically contacting and electrically coupling the third metallization to the conductive ferrule.

34. The feedthrough assembly of claim 33 , wherein the second insert end extends outwardly beyond the second insert end surface.

35. A hermetically sealed feedthrough assembly for attachment to an active implantable medical device (AIMD), the feedthrough comprising:

a) a feedthrough, comprising:

i) 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 to a second ferrule end surface, and wherein the ferrule is configured to be attachable to an opening in a housing of an active implantable medical device;

ii) an alumina insulator residing at least partially within the inner ferrule surface, wherein the insulator comprises an outer insulator surface extending from a first insulator end surface disposed adjacent to the first ferrule end surface to an opposed second insulator end surface disposed adjacent to the second ferrule end surface;

iii) a first metallization contacting at least a portion of the outer surface of the insulator;

iv) an electrically conductive material hermetically sealing the ferrule sidewall to the first metallization contacting the outer surface of the insulator;

v) at least one via hole extending through the alumina insulator from the first insulator end surface to the second end surface;

vi) a platinum insert residing in the via hole and comprising an insert sidewall extending from a first insert end to a second insert end, wherein at least the first insert end extends outwardly beyond the first insulator end surface and the second insert end is disposed at or adjacent to the second insulator end surface; and

vii) a platinum fill residing in the at least one via hole in contact with the platinum insert sidewall, the platinum fill extending from a first fill end disposed at or adjacent to the first insulator end surface to a second fill end disposed at or adjacent to the second insulator end surface,

viii) wherein the platinum fill is in a hermetically sealed relationship with both the insulator at the at least one via hole and the platinum insert sidewall so that the platinum insert provides as electrically conductive pathway extending through the alumina insulator to or adjacent to the first insulator end surface and to or adjacent to the second insulator end surface;

b) at least one monolithic chip capacitor disposed adjacent to the circuit board substrate, wherein the chip capacitor comprises:

i) a chip capacitor dielectric supporting at least one active chip electrode plate interleaved in a capacitive relationship with at least one ground chip electrode plate;

ii) an active chip end metallization electrically connected to the at least one active chip electrode plate at an active end of the chip capacitor dielectric, and a ground chip end metallization electrically connected to the at least one ground chip electrode plate at a ground end of the chip capacitor dielectric, wherein the active end is spaced from the ground end of the chip capacitor dielectric; and

c) a first electrically conductive material physically contacting and electrically coupling the active chip metallization to the first insert end extending outwardly beyond the first insulator end surface to thereby electrically connect the at least one active chip electrode plate to the platinum insert; and

d) a second electrically conductive material physically contacting and electrically coupling the ground chip metallization to the ferrule.

36. A hermetically sealed feedthrough for attachment to an active implantable medical device (AIMD), 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 to a second ferrule end surface, and wherein the ferrule is configured to be attachable to an opening in a housing of an active implantable medical device;

b) an insulator residing at least partially within the inner ferrule surface, wherein the insulator comprises an outer insulator surface extending from a first insulator end surface disposed adjacent to the first ferrule end surface to an opposed second insulator end surface disposed adjacent to the second ferrule end surface;

c) a first metallization contacting at least a portion of the outer surface of the insulator;

d) an electrically conductive material hermetically sealing the ferrule sidewall to the first metallization contacting the outer surface of the insulator;

e) at least one via hole extending through the insulator from the first insulator end surface to the second insulator end surface;

f) an electrically conductive insert extending along a longitudinal axis in the via hole, the insert comprising an insert sidewall spaced from the longitudinal axis and extending from a first insert end to a second insert end, wherein the first insert end is disposed at or adjacent to the first insulator end surface and the second insert end is disposed at or adjacent to the second insulator end surface; and

g) a conductive fill residing in the at least one via hole in contact with the insert sidewall, the conductive fill being spaced from the longitudinal axis of the conductive insert and extending from a first fill end disposed at or adjacent to the first insulator end surface to a second fill end disposed at or adjacent to the second insulator end surface,

h) wherein the conductive fill is in a hermetically sealed relationship with both the insulator at the at least one via hole and the insert sidewall so that the conductive insert provides an electrically conductive pathway extending through the insulator to or adjacent to the first insulator end surface and to or adjacent to the second insulator end surface.