EMI filtered co-connected hermetic feedthrough, feedthrough capacitor and leadwire assembly for an active implantable medical device

Patent metadata

Field	Value
Publication number	US-9352150-B2
Application number	US-201514864959-A
Country	US
Kind code	B2
Filing date	Sep 25, 2015
Priority date	Jan 16, 2012
Publication date	May 31, 2016
Grant date	May 31, 2016

Abstract

A co-connected hermetic feedthrough, feedthrough capacitor, and leadwire assembly includes a dielectric substrate with a via hole disposed through the dielectric substrate from a body fluid side to a device side. A conductive fill is disposed within the via forming a hermetic seal and is electrically conductive between the body fluid side and the device side. A feedthrough capacitor is attached to the dielectric substrate and includes a capacitor dielectric substrate, an unfilled capacitor via hole including an inner metallization, a set of capacitor active electrode plates electrically coupled to the inner metallization, an outer metallization disposed and a set of capacitor ground electrode plates electrically coupled to the outer metallization. A conductive leadwire is disposed within the unfilled capacitor via hole. An electrical joint connects the conductive fill, the capacitor inner metallization along with the capacitor active electrode plates and the conductive leadwire.

First claim

What is claimed is:

1. A filter feedthrough assembly, comprising:
a) a hermetic feedthrough, comprising:
i) an insulator of electrically non-conductive material defined by an insulator sidewall having an outer insulator surface extending along a first length from a first insulator end to a second insulator end;
ii) at least one insulator via defined by an insulator bore extending along a second length that is less than the first length, wherein the insulator via extends from a first via end spaced from the first insulator end to a second via end at the second insulator end;
iii) an internal circuit trace extending from the insulator bore to the outer insulator surface, wherein the circuit trace is spaced from the first and second insulator ends;
iv) a conductive fill disposed within the insulator via, wherein the conductive fill forms both a hermetic seal with the insulator bore and an electrically conductive path extending from the internal circuit trace to a second conductive fill end at the second insulator end; and
v) a ferrule of an electrically conductive material comprising a ferrule opening defined by a surrounding ferrule sidewall having an inner ferrule surface, wherein the insulator is hermetically sealed in the ferrule opening;

b) a feedthrough capacitor, comprising:
i) a dielectric body defined by a dielectric sidewall having an outer dielectric surface extending from a first dielectric end to a second dielectric end;
ii) at least one active electrode plate and at least one ground electrode plate supported in the dielectric body in spaced relation with each other;
iii) at least one dielectric via defined by a dielectric bore extending through the dielectric body to the first and second dielectric ends;
iv) an inner metallization disposed on the dielectric bore in electrical contact with the at least one active electrode plate; and
v) an outer metallization disposed on an outer surface of the dielectric body in electrical contact with the at least one ground electrode plate;

c) a conductive leadwire extending from a first leadwire portion having a first leadwire end to a second leadwire end, wherein the first leadwire portion is disposed within the dielectric via with the first leadwire end located in contact with or adjacent to the second conductive fill end;
d) an electrically conductive material at least partially filled in the dielectric via to physically and electrically connect:
i) the first leadwire portion to the inner metallization electrically connected to the at least one active electrode plate; and
ii) the first leadwire end to the second conductive fill end; and

e) an outer ground conductive material electrically connecting the outer metallization in electrical contact with the at least one ground plate at the outer dielectric surface to the ferrule.

2. The filter feedthrough assembly of claim 1 , wherein the electrically conductive material at least partially filled in the dielectric via is selected from the group consisting of a solder, an epoxy, a low temperature braze, a conductive glass frit, and a weld.

3. The filter feedthrough assembly of claim 1 , wherein the hermetic seal formed by the conductive fill contacting the insulator bore has a leak rate no greater than 1×10 −7 std cc He/sec.

4. The filter feedthrough assembly of claim 1 , wherein the conductive fill disposed in the insulator via comprises a substantially closed pore and fritless platinum fill.

5. The filter feedthrough assembly of claim 4 , wherein the hermetic seal formed by the conductive fill contacting the insulator bore is a tortuous and mutually conformal knitline between the insulator and the platinum fill.

6. The filter feedthrough assembly of claim 5 , wherein the knitline comprises a glass that is at least about 60% silica.

7. The filter feedthrough assembly of claim 1 , wherein the dielectric body comprises at least 96% alumina.

8. The filter feedthrough assembly of claim 1 , wherein the dielectric body comprises at least 99% alumina.

9. The filter feedthrough assembly of claim 1 , wherein the outer metallization comprises an adhesion metallization disposed on the outer surface of the dielectric body.

10. The filter feedthrough assembly of claim 9 , wherein the outer metallization comprises a wetting metallization disposed on the adhesion metallization.

11. The filter feedthrough assembly of claim 1 , including a gold braze hermetically sealing the outer insulator surface to the ferrule.

12. The filter feedthrough assembly of claim 11 , wherein the gold braze hermetically sealing the outer insulator surface to the ferrule has a leak rate no greater than 1×10 −7 std cc He/sec.

13. The filter feedthrough assembly of claim 1 , wherein an insulative washer is disposed between the insulator of the hermetic feedthrough and the dielectric body of the feedthrough capacitor.

14. The filter feedthrough assembly of claim 1 , wherein the dielectric via extending through the dielectric body to the first and second dielectric ends is staggered.

15. The filter feedthrough assembly of claim 1 , wherein the insulator comprises an elevated insulator portion extending outwardly from the ferrule opposite the feedthrough capacitor, and wherein a leadwire contact is electrically coupled to the circuit trace at the outer insulator surface, but spaced from the ferrule, the contact being configured for direct electrical connection to a leadwire.

16. The filter feedthrough assembly of claim 15 , wherein the leadwire contact comprises a wire bond pad.

17. The filter feedthrough assembly of claim 15 , including a braze preform physically and electrically coupling the leadwire contact to the circuit trace.

18. A hermetic feedthrough, comprising:
a) an insulator of electrically non-conductive material defined by an insulator sidewall having an outer insulator surface extending along a first length from a first insulator end to a second insulator end;
b) at least one insulator via defined by an insulator bore extending along a second length that is less than the first length, wherein the insulator via extends from a first via end spaced from the first insulator end to a second via end at the second insulator end;
c) an internal circuit trace extending from the insulator bore to the outer insulator surface, wherein the circuit trace is spaced from the first and second insulator ends;
d) a conductive fill disposed within the insulator via, wherein the conductive fill forms both a hermetic seal with the insulator bore and an electrically conductive path extending from the internal circuit trace to a second conductive fill end at the second insulator end; and
e) a ferrule of an electrically conductive material comprising a ferrule opening defined by a surrounding ferrule sidewall having an inner ferrule surface, wherein the insulator is hermetically sealed in the ferrule opening.

19. A filter feedthrough assembly, comprising:
a) a hermetic feedthrough, comprising:
i) an insulator of electrically non-conductive material defined by an insulator sidewall having an outer insulator surface extending along a first length from a first insulator end to a second insulator end;
ii) at least one active insulator via defined by an active insulator bore extending along a second length that is less than the first length, wherein the active insulator via extends from a first active via end spaced from the first insulator end to a second active via end at the second insulator end;
iii) an internal circuit trace extending from the active insulator bore to

Assignees

• Greatbatch Ltd

Inventors

• Stevenson Robert A
• Marzano Thomas
• Seitz Keith W
• Winn Steven W
• Frysz Christine A
• Brendel Richard L
• Woods Jason
• Frustaci Dominick J
• Tang Xiaohong
• Thiebolt William C

Classifications

• A61N1/375

  Constructional arrangements, e.g. casings · CPC title

• A61N1/37512

  Pacemakers · CPC title

• A61N1/05

  for implantation or insertion into the body, e.g. heart electrode (A61N1/06 takes precedence) · CPC title

• A61N1/3754 Primary

  Feedthroughs · CPC title

• H01G4/35

  Feed-through capacitors or anti-noise capacitors · CPC title