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-11198014-B2
Application number	US-201816004569-A
Country	US
Kind code	B2
Filing date	Jun 11, 2018
Priority date	Mar 1, 2011
Publication date	Dec 14, 2021
Grant date	Dec 14, 2021

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. An active implantable medical device (AIMD), comprising:
a) a ferrule formed as a contiguous part of a device housing, the housing ferrule having an opening defined by a ferrule opening perimeter, wherein the device housing contains electronic circuits;
b) a hermetic feedthrough, comprising:
i) an insulator comprising an insulator perimeter surface extending to an insulator body fluid side opposite an insulator device side, wherein the insulator perimeter surface supports an insulator perimeter metallization;
ii) at least one insulator active via hole extending to the insulator body fluid and device sides;
iii) an adhered and agglomerated body of platinum particles disposed in and hermetically sealing the at least one insulator active via hole, wherein closed pores reside between the platinum particles in the adhered and agglomerated body; and
iv) a gold braze hermetically sealing the insulator perimeter metallization to the ferrule opening perimeter so that the insulator body fluid and device sides reside outside and inside the device housing, respectively;

c) at least one capacitor disposed adjacent to the insulator device side, the capacitor comprising:
i) at least one capacitor active electrode plate and at least one capacitor ground electrode plate disposed in a spaced and interleaved relationship within a capacitor dielectric body, wherein the capacitor ground electrode plate extends to an outer perimeter surface of the capacitor dielectric body;
ii) a capacitor active passageway extending through the capacitor dielectric body; and
iii) a capacitor active metallization disposed in the capacitor active passageway and being electrically connected to the at least one capacitor active electrode plate; and

d) an active electrical connection electrically connecting the capacitor active metallization in the capacitor active passageway electrically connected to the at least one capacitor active electrode plate to the adhered and agglomerated body of platinum particles in the insulator active via hole and to the electronic circuits contained in the device housing; and
e) a ground electrical connection electrically connecting the capacitor ground metallization electrically connected to the at least one capacitor ground electrode plate at the outer perimeter surface of the capacitor dielectric body to the gold braze hermetically sealing the insulator perimeter metallization to the housing ferrule.

2. The AIMD of claim 1 , wherein the capacitor dielectric body has a dielectric constant, k, that is greater than zero but less than 1000.

3. The AIMD of claim 1 , wherein the insulator perimeter metallization comprises a titanium adhesion layer disposed on the insulator perimeter surface and a molybdenum or niobium wetting layer disposed on the adhesion layer.

4. The AIMD of claim 1 , wherein the at least one capacitor is selected from the group of a multilayer ceramic chip capacitor, a monolithic ceramic capacitor, a flat-thru capacitor, and an X2Y attenuator.

5. The AIMD of claim 1 , wherein the opening perimeter of the housing ferrule has an L-shaped bend.

6. The AIMD of claim 1 , wherein the opening perimeter of the housing ferrule has a first width and the insulator perimeter surface has a second width greater than the first width, and wherein the insulator device side is supported on a body fluid side of the housing ferrule with the insulator perimeter metallization being hermetically sealed to the housing ferrule by the gold braze.

7. The AIMD of claim 1 , wherein the adhered and agglomerated body of platinum particles hermetically sealing the at least one insulator active via hole is selected from the group of substantially pure particles of platinum, and a mixture of platinum and alumina, and wherein the adhered and agglomerated body of platinum particles is characterized as having been sintered with the insulator to thereby hermetically seal the at least one insulator active via hole.

8. The AIMD of claim 1 , wherein the adhered and agglomerated body of platinum particles hermetically sealing the at least one insulator active via hole comprises a paste containing substantially pure platinum, and wherein the paste is characterized as having been sintered with the insulator to thereby provide the adhered and agglomerated body of platinum particles as a platinum-containing sintered material hermetically sealing the at least one insulator active via hole.

9. The AIMD of claim 8 , wherein the hermetically sealed relationship between the platinum-containing sintered material and the insulator comprises a tortuous and mutually conformal knitline.

10. The AIMD of claim 9 , wherein the knitline comprises a glass that is at least about 60% silica.

11. The AIMD of claim 1 , wherein the adhered and agglomerated body of platinum particles disposed in the at least one insulator active via hole is substantially flush with the insulator device side.

12. The AIMD of claim 11 , wherein an insulator washer is disposed between the insulator and the capacitor, the insulator washer having at least one active hole aligned with the insulator active via hole and the capacitor active passageway, and
wherein the active electrical connection is disposed at least partially in the insulator washer active hole to electrically connect the capacitor active metallization in the capacitor active passageway electrically connected to the at least one capacitor active electrode plate to the adhered and agglomerated body of platinum particles in the insulator active via hole and to the electronic circuits contained in the device housing.

13. The AIMD of claim 1 , wherein the insulator comprises at least 96% alumina.

14. The AIMD of claim 1 , wherein the active electrical connection is selected from the group of a solder, a solder bump, a braze, an electrically conductive adhesive, a thermal-setting conductive material, and a ball grid array.

15. The AIMD of claim 1 , wherein the adhered and agglomerated body of platinum particles has a density that is less than 100%.

16. The AIMD of claim 1 , wherein at least some of the closed pores residing in the adhered and agglomerated body of platinum particles are not contiguous.

17. An active implantable medical device (AIMD), comprising:
a) a device housing having an opening defined by an opening perimeter of the housing, wherein the device housing contains electronic circuits;
b) a hermetic feedthrough, comprising:
i) an insulator comprising an insulator perimeter surface extending to an insulator body fluid side opposite an insulator device side, wherein the insulator perimeter surface supports an insulator perimeter metallization;
ii) at least one insulator active via hole extending to the insulator body fluid and device sides;
iii) an adhered and agglomerated body of platinum particles hermetically sealing the at least one insulator active via hole, wherein closed pores reside between the platinum particles in the adhered and agglomerated body, and wherein the adhered and agglomerated body of platinum particles hermetically sealing the at least one insulator active via hole is selected from the group of substantially pure particles of platinum, and a mixture of platinum and alumina, and wherein the adhered and agglomerated body of platinum particles is substantially flush with the insulator device side and is characterized as having been sintered with the insulator to thereby hermetically seal the at least one insulator active via hole;
iv) a gold braze hermetically sealing the insulator perimeter metallization to the opening perimeter o

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

• Y10T156/1052

  with cutting, punching, tearing or severing · CPC title

• H01R4/022

  comprising preapplied solder · CPC title

• H01G4/30

  Stacked capacitors (H01G4/33 takes precedence) · CPC title

• B22F7/08

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