Hermetically sealed filtered feedthrough assembly having a capacitor with an oxide resistant electrical connection to an active implantable medical device housing

Patent metadata

Field	Value
Publication number	US-2018304084-A1
Application number	US-201816004569-A
Country	US
Kind code	A1
Filing date	Jun 11, 2018
Priority date	Mar 1, 2011
Publication date	Oct 25, 2018
Grant date	—

Abstract

A hermetically sealed filtered feedthrough assembly attachable to an AIMD includes an insulator hermetically sealing a ferrule opening of an electrically conductive ferrule with a gold braze. A co-fired and electrically conductive sintered paste is disposed within and hermetically seals at least one via hole extending in the insulator. At least one capacitor is disposed on the device side. An active electrical connection electrically connects a capacitor active metallization and the sintered paste. A ground electrical connection electrically connects the gold braze to a capacitor ground metallization, wherein at least a portion of the ground electrical connection physically contacts the gold braze. The dielectric of the capacitor may be less than 1000 k. The ferrule may include an integrally formed peninsula portion extending into the ferrule opening spatially aligned with a ground passageway and metallization of an internally grounded feedthrough capacitor. The sintered paste may be of substantially pure platinum.

First claim

What is claimed is:

1 . A hermetically sealed filtered feedthrough assembly attachable to an active implantable medical device, the filtered feedthrough assembly comprising:
a) a hermetic feedthrough, comprising:
i) a metallic and electrically conductive ferrule configured to be installed in an opening of a housing of the active implantable medical device, the ferrule separating a body fluid side opposite a device side, and the ferrule comprising a ferrule opening extending from the body fluid side to the device side;
ii) an insulator disposed at least partially within the ferrule opening;
iii) at least one via hole in the insulator extending from the body fluid side to the device side;
iv) an electrically conductive sintered paste disposed within and hermetically sealing the at least one via hole, wherein the electrically conductive sintered paste and the insulator are co-fired; and
v) a gold braze hermetically sealing the insulator to the ferrule;
b) at least one capacitor disposed on the device side, comprising:
i) a capacitor dielectric body having a dielectric constant, k, less than 1000;
ii) at least one active electrode plate and at least one ground electrode plate disposed within the capacitor dielectric body in spaced and interleaved relation with each other;
iii) a capacitor active metallization attached to the capacitor dielectric body and electrically connected to the at least one active electrode plate; and
iv) a capacitor ground metallization attached to the capacitor dielectric body and electrically connected to the at least one ground electrode plate; and
c) an active electrical connection electrically connecting the electrically conductive sintered paste to the capacitor active metallization; and d) a ground electrical connection electrically connecting the capacitor ground metallization to the gold braze, wherein at least a portion of the ground electrical connection physically contacts the gold braze.

2 . The filtered feedthrough assembly of claim 1 , including an insulator metallization at least partially disposed on the insulator, wherein the gold braze is disposed between the ferrule and the insulator metallization.

3 . The filtered feedthrough assembly of claim 2 , wherein the insulator metallization comprises an adhesion layer and a wetting layer, wherein the adhesion layer is disposed on the insulator and the wetting layer is disposed on the adhesion layer, wherein the adhesion layer is titanium and the wetting layer is molybdenum or niobium.

4 . The filtered feedthrough assembly of claim 1 , wherein the at least one capacitor is a multilayer ceramic chip capacitor, a monolithic ceramic capacitor, a flat-thru capacitor or an X2Y attenuator.

5 . The filtered feedthrough assembly of claim 1 , wherein the at least one capacitor is a feedthrough capacitor, wherein the capacitor ground metallization is disposed on at least a portion of an outside perimeter surface of the capacitor dielectric body.

6 . The filtered feedthrough assembly of claim 1 , wherein the at least one capacitor is an internally grounded feedthrough capacitor, wherein the capacitor active metallization is disposed within a first passageway extending through the feedthrough capacitor, and wherein the capacitor ground metallization is disposed within a second passageway extending through the feedthrough capacitor.

7 . The filtered feedthrough assembly of claim 6 , wherein the internally grounded feedthrough capacitor has no outside perimeter metallization.

8 . The filtered feedthrough assembly of claim 6 , wherein the internally grounded feedthrough capacitor is a hybrid internally grounded feedthrough capacitor including at least a portion of the capacitor perimeter having at least a second ground metallization disposed on an outside surface of the capacitor dielectric body, wherein the second ground metallization is electrically connected to the at least one ground electrode plate.

9 . The filtered feedthrough assembly of claim 8 , including a second ground electrical connection electrically connecting the second ground metallization to the gold braze, wherein at least a portion of the second ground electrical connection physically contacts at least a portion of the gold braze.

10 . The filtered feedthrough assembly of claim 9 , wherein a portion of the gold braze is spatially aligned with the second passageway and the capacitor ground metallization of the internally grounded feedthrough capacitor.

11 . The filtered feedthrough assembly of claim 9 , wherein the ferrule comprises an integrally formed peninsula portion extending into the ferrule opening, wherein the insulator comprises a cutout matching the shape of the peninsula portion, wherein a portion of the gold braze along the peninsula portion is spatially aligned with the second passageway and the capacitor ground metallization of the internally grounded feedthrough capacitor.

12 . The filtered feedthrough assembly of claim 6 , wherein a portion of the gold braze is spatially aligned with the second passageway and the capacitor ground metallization of the internally grounded feedthrough capacitor.

13 . The filtered feedthrough assembly of claim 6 , wherein the ferrule comprises an integrally formed peninsula portion extending into the ferrule opening, wherein the insulator comprises a cutout matching the shape of the peninsula portion, wherein a portion of the gold braze along the peninsula portion is spatially aligned with the second passageway and the capacitor ground metallization of the internally grounded feedthrough capacitor.

14 . The filtered feedthrough assembly of claim 1 , wherein the insulator comprises at least 96% alumina.

15 . The filtered feedthrough assembly of claim 1 , wherein the electrically conductive sintered paste comprises substantially pure platinum.

16 . The filtered feedthrough assembly of claim 15 , wherein the hermetically sealed relationship between the platinum sintered paste and the insulator comprises a tortuous and mutually conformal knitline.

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

18 . The filtered feedthrough assembly of claim 1 , wherein the active electrical connection comprises a solder, a braze, an electrically conductive adhesive or a thermal-setting conductive material.

19 . The filtered feedthrough assembly of claim 1 , wherein the active electrical connection comprises a solder bump or a ball grid array.

20 . The filtered feedthrough assembly of claim 1 , wherein the ground electrical connection comprises a solder or a thermal-setting conductive material.

21 . The filtered feedthrough assembly of claim 1 , wherein the ferrule is formed as a contiguous part of the housing of the active implantable medical device.

22 . A hermetically sealed filtered feedthrough assembly attachable to an active implantable medical device, the filtered feedthrough assembly comprising:
a) a hermetic feedthrough, comprising:
i) a metallic and electrically conductive ferrule configured to be installed in an opening of a housing of the active implantable medical device, the ferrule separating a body fluid side opposite a device side, the ferrule comprising a ferrule opening extending from the body fluid side to the device side, and the ferrule comprising an integrally formed peninsula portion extending into the ferrule opening;
ii) an insulator disposed at least partially wit

Assignees

• Greatbatch Ltd

Inventors

• Stevenson Robert A
• Frysz Christine A
• Seitz Keith W
• Marzano Thomas
• Martino Marc Gregory

Classifications

• B22F1/10

  Metallic powder containing lubricating or binding agents; Metallic powder containing organic material · CPC title

• A61N1/05

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

• H01G4/005

  Electrodes · CPC title

• H01R43/00

  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 title

• B22F7/08

  with one or more parts not made from powder {(B22F7/062 takes precedence)} · CPC title