Filtered feedthrough assembly having a capacitor ground metallization electrically connected to the gold braze portion sealing a ferrule peninsula to a matching insulator cutout

Patent metadata

Field	Value
Publication number	US-11344734-B2
Application number	US-201916589752-A
Country	US
Kind code	B2
Filing date	Oct 1, 2019
Priority date	Mar 1, 2011
Publication date	May 31, 2022
Grant date	May 31, 2022

Abstract

A hermetically sealed filtered feedthrough assembly attachable to an AIMD includes an insulator hermetically sealing the opening of a ferrule with a gold braze. The ferrule includes a peninsula extending into the ferrule opening and the insulator has a cutout matching the peninsula. A sintered platinum-containing paste hermetically seals at least one via hole extending through the insulator. At least one capacitor is disposed on the device side. An active electrical connection electrically connects the capacitor active metallization to the sintered paste. A ground electrical connection electrically connects the capacitor ground metallization disposed within a capacitor ground passageway to the portion of the gold braze along the ferrule peninsula. The dielectric of the capacitor may be less than 1,000 k.

First claim

What is claimed is:

1. A hermetically sealed filtered feedthrough assembly attachable to an active implantable medical device (AIMD), 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 an AIMD, the ferrule separating a ferrule first side opposite a ferrule second side and comprising a ferrule opening extending to the ferrule first and second sides, wherein the ferrule comprises a peninsula extending into the ferrule opening;
ii) an insulator disposed at least partially within the ferrule opening, the insulator comprising an insulator first side corresponding to the ferrule first side and opposite an insulator second side corresponding to the ferrule second side, the insulator having a cutout matching the shape of the peninsula of the ferrule;
iii) at least one active via hole extending through the insulator to or adjacent to the insulator first and second sides;
iv) an electrically conductive material disposed within and hermetically sealing the at least one active via hole; and
v) a gold braze hermetically sealing the insulator to the ferrule including the ferrule peninsula received in the insulator cutout;

b) at least one internally grounded feedthrough capacitor disposed on or adjacent to the ferrule and insulator first sides, the internally grounded feedthrough capacitor comprising:
i) a capacitor dielectric body;
ii) at least one active electrode plate and at least one ground electrode plate disposed in a capacitive relationship within the capacitor dielectric body;
iii) a first passageway and a second passageway, both passageways extending through the capacitor dielectric body;
iv) a capacitor active metallization disposed within the first passageway and being electrically connected to the at least one active electrode plate; and
v) a capacitor ground metallization disposed within the second passageway and being electrically connected to the at least one ground electrode plate,
vi) wherein a portion of the gold braze along a perimeter of the peninsula of the ferrule and the cutout of the insulator is spatially aligned directly under the capacitor ground metallization disposed within the second passageway of the internally ground feedthrough capacitor; and

c) an active electrical connection electrically connecting the electrically conductive material disposed in the at least one active via hole extending through the insulator to the capacitor active metallization; and
d) a ground electrical connection directly contacting both the spatially aligned portion of the gold braze along the perimeter of the peninsula of the ferrule and the capacitor ground metallization disposed within the second passageway of the internally grounded feedthrough capacitor.

2. The filtered feedthrough assembly of claim 1 , wherein the electrically conductive material disposed within and hermetically sealing the at least one active via hole in the insulator is an electrically conductive sintered paste.

3. The filtered feedthrough assembly of claim 2 , wherein the electrically conductive sintered paste and the insulator are characterized as having been co-fired.

4. The filtered feedthrough assembly of claim 1 , wherein the electrically conductive material is a platinum-containing conductive pathway disposed within and hermetically sealing the at least one active via hole in the insulator.

5. The filtered feedthrough assembly of claim 4 , wherein the platinum-containing conductive pathway disposed within and hermetically sealing the at least one active via hole is substantially flush with the insulator first side adjacent to the capacitor.

6. The filtered feedthrough assembly of claim 1 , wherein the capacitor dielectric substrate does not have an outer perimeter metallization.

7. The filtered feedthrough assembly of claim 1 , wherein the internally grounded feedthrough capacitor is a hybrid internally grounded feedthrough capacitor comprising at least a capacitor second ground metallization disposed on an outer surface of the capacitor dielectric substrate, wherein the capacitor second ground metallization is electrically connected to the at least one ground electrode plate, and wherein a second ground electrical connection electrically and physically connects at least a portion of the capacitor second ground metallization to the gold braze hermetically sealing the insulator to the ferrule.

8. The filtered feedthrough assembly of claim 1 , wherein the platinum-containing conductive pathway disposed within the at least one active via hole comprises a nail-headed electrically conductive member with the nail head one of:
i) facing the internally grounded feedthrough capacitor,
ii) facing the outwardly adjacent to the ferrule and insulator second sides, or
iii) facing both the internally grounded feedthrough capacitor and outwardly adjacent to the ferrule and insulator second sides, and
wherein the nail headed member is hermetically sealed in the at least one active via hole extending through the insulator by an electrically conductive platinum-containing material comprising the electrically conductive material in the active via hole.

9. The filtered feedthrough assembly of claim 1 , wherein the platinum-containing conductive pathway disposed within the at least one active via hole in the insulator comprises a crimp post.

10. The filtered feedthrough assembly of claim 1 , comprising an insulator metallization disposed on an outer surface of the insulator, wherein the gold braze contacts the ferrule and the insulator metallization.

11. The filtered feedthrough assembly of claim 10 , wherein the insulator metallization comprises an adhesion layer disposed on the outer surface of the insulator and a gold braze wetting layer disposed on the adhesion layer.

12. The filtered feedthrough assembly of claim 11 , wherein the adhesion layer is titanium and the wetting layer is molybdenum or niobium.

13. The filtered feedthrough assembly of claim 1 , wherein the active electrical connection is selected from the group of a solder, a braze, an electrically conductive adhesive, and a thermal-setting conductive material.

14. The filtered feedthrough assembly of claim 13 , wherein the active electrical connection is selected from a solder dot, a solder bump, a dot of thermal-setting conductive adhesive or epoxy, a bump of thermal-setting conductive adhesive or epoxy, and a ball grid array.

15. The filtered feedthrough assembly of claim 1 , wherein the ground electrical connection is selected from the group of a solder, and a thermal-setting conductive material.

16. The filtered feedthrough assembly of claim 1 , wherein the electrically conductive material disposed in the at least one active via hole extending through the insulator comprises a substantially pure platinum or a ceramic reinforced metal composite (CRMC) in a hermetically sealed relationship with the insulator.

17. The filtered feedthrough assembly of claim 16 , wherein the hermetically sealed relationship between the substantially pure platinum or CRMC and the insulator comprises a tortuous and mutually conformal knitline having a glass that is at least about 60% silica.

18. The filtered feedthrough assembly of claim 1 , wherein the ferrule comprises titanium.

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

20. The filtered feedthrough assembly of claim 1 , wherein the ferrule is formed a

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

• A61N1/3754 Primary

  Feedthroughs · CPC title

• H01R4/022

  comprising preapplied solder · CPC title

• A61N1/375

  Constructional arrangements, e.g. casings · CPC title

• H01G4/12

  Ceramic dielectrics {(H01G4/085 takes precedence)} · CPC title