Metallurgically bonded gold pocket pad for grounding an EMI filter to a hermetic terminal for an active implantable medical device

Patent metadata

Field	Value
Publication number	US-10350421-B2
Application number	US-201815943998-A
Country	US
Kind code	B2
Filing date	Apr 3, 2018
Priority date	Jun 30, 2013
Publication date	Jul 16, 2019
Grant date	Jul 16, 2019

Abstract

A feedthrough subassembly for an active implantable medical device includes a metallic ferrule having a conductive ferrule body, at least one surface disposed on a device side, and a ferrule opening passing through the at least one surface. An insulator body hermetically seals the ferrule opening of the conductive ferrule body by at least one of a first gold braze ceramic seal, a glass seal or a glass-ceramic seal. At least one hermetically sealed conductive pathway is disposed through the insulator body. At least one pocket formed in the at least one surface has a gold pocket pad disposed within. When the first gold braze ceramic seal is present, the first gold braze ceramic seal and the gold pocket pad are not physically touching one another.

First claim

What is claimed is:

1. A filtered feedthrough that is attachable to an active implantable medical device (AIMD), the filtered feedthrough comprising:
a) a titanium ferrule configured to be installed in an opening of a housing of the AIMD, the ferrule comprising:
i) a conductive ferrule body separating a ferrule body fluid side end surface opposite a ferrule device side end surface, wherein, when the ferrule is installed in the opening of the AIMD housing, the ferrule body fluid side end surface and the ferrule device side end surface reside outside the housing and inside the housing, respectively;
ii) at least one surface disposed on the ferrule device side end surface;
iii) a ferrule opening passing through the at least one surface and extending to the ferrule body fluid side end surface and to the ferrule device side end surface; and
iv) at least one pocket provided in the at least one surface disposed on the ferrule device side end surface; and

b) an insulator hermetically sealed in the ferrule opening by a first gold braze, the insulator having at least one via hole extending through the insulator to an insulator body fluid side and to an insulator device side, wherein the insulator comprises alumina ceramic;
c) at least one conductive pathway disposed through and hermetically sealed to the insulator in the at least one via hole;
d) a gold pocket-pad disposed within the at least one pocket in the ferrule device side end surface;
e) wherein the first gold braze and gold pocket-pad do not physically touch one another; and
f) a filter capacitor disposed on the ferrule device side end surface, the filter capacitor comprising:
i) at least one active electrode plate disposed parallel and spaced from at least one ground electrode plate, wherein the active and ground electrode plates are disposed within a capacitor dielectric substrate;
ii) a first passageway disposed through the capacitor dielectric substrate;
iii) a capacitor active metallization disposed within the first passageway and being electrically connected to the at least one active electrode plate, but in a non-conductive relation with the at least one ground electrode plate; and
iv) a capacitor ground metallization disposed on an outer surface of the capacitor dielectric substrate and being electrically connected to the at least one ground electrode plate, but in a non-conductive relation with the at least one active electrode plate; and

g) wherein the at least one conductive pathway is electrically connected to the capacitor active metallization; and
h) an electrical connection material electrically connecting the capacitor ground metallization to the gold pocket-pad disposed within the at least one pocket of the ferrule device side end surface.

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

3. The filtered feedthrough of claim 1 , wherein the filter capacitor is selected from the group consisting of a feedthrough filter capacitor, a chip capacitor, an MLCC, an X2Y attenuator, an internally grounded feedthrough capacitor, a hybrid internally grounded feedthrough capacitor, and a chip capacitor, and wherein when the chip capacitor, the MLCC or the X2Y attenuator is mounted on a circuit board, the circuit board is disposed adjacent to at least one of the ferrule and the insulator.

4. The filtered feedthrough of claim 1 , wherein the insulator is selected from the group consisting of an alumina ceramic, a glass, and a glass-ceramic, and wherein the glass seal or the glass-ceramic seal comprises a fusion seal or a compression seal.

5. The filtered feedthrough of claim 1 , wherein:
a) a capacitor first perimeter surface of the filter capacitor extends outwardly beyond a ferrule first perimeter surface of the ferrule,
b) a capacitor second perimeter surface of the filter capacitor does not extend outwardly beyond a ferrule second perimeter surface of the ferrule,
c) the capacitor ground metallization is disposed on at least a portion of the capacitor second perimeter surface,
d) the at least one pocket is located adjacent to the ferrule second perimeter surface,
e) the capacitor first perimeter surface, the capacitor second perimeter surface, the ferrule first perimeter surface and the ferrule second perimeter surface are perpendicular to the at least one surface of the titanium ferrule,
f) the capacitor first perimeter surface is perpendicular to the capacitor second perimeter surface, and
g) the ferrule first perimeter surface is perpendicular to the ferrule second perimeter surface.

6. The filtered feedthrough of claim 1 , wherein the at least one conductive pathway comprises a solid through pin.

7. The filtered feedthrough of claim 1 , wherein the at least one conductive pathway comprises:
i) a first conductive leadwire having a first conductive leadwire first end disposed within the at least one via hole in the insulator and having a first conductive leadwire second end extending outwardly beyond the insulator body fluid side;
ii) a second conductive leadwire having a second conductive leadwire first end disposed within the at least one via hole in the insulator and having a second conductive leadwire second end extending outwardly beyond the insulator device side and being disposed within the first passageway of the filter capacitor;
iii) wherein the first conductive leadwire first end is in contact with or adjacent to the second conductive leadwire first end;
iv) wherein the first conductive leadwire is not the same material as the second conductive leadwire;
v) a second braze electrically connecting the first conductive leadwire first end to the second conductive leadwire first end;
vi) a third conductive leadwire having a third conductive leadwire first end disposed within the first passageway of the filter capacitor;
vii) wherein the third conductive leadwire first end is in contact with or adjacent to the second conductive leadwire second end;
viii) wherein a third conductive leadwire second end extends outwardly beyond the filter capacitor adjacent to the ferrule device side end surface and the insulator device side;
ix) wherein the third conductive leadwire is not the same material as the first conductive leadwire or the second conductive leadwire; and
x) a second electrical connection material electrically connecting the second conductive leadwire second end to the third conductive leadwire first end.

8. The filtered feedthrough of claim 1 , wherein the at least one conductive pathway comprises:
i) a first conductive leadwire disposed through the at least one via hole in the insulator and having a first conductive leadwire first end extending outwardly beyond the insulator device side and being disposed within the first passageway of the filter capacitor, and having a first conductive leadwire second end extending outwardly beyond the insulator body fluid side;
ii) a second conductive leadwire having a second conductive leadwire first end disposed within the first passageway of the filter capacitor and having a second conductive leadwire second end extending outwardly beyond the filter capacitor on the device side;
iii) wherein the first conductive leadwire first end is in contact with or adjacent to the second conductive leadwire first end;
iv) wherein the first conductive leadwire is not of the same material as the second conductive leadwire; and
v) a second electrical connection material electrically connecting the first conductive leadwire first end to the second conductive leadwire first end.

9. The filtered feedthrough of claim 1 , wherein the at least one conductive pathway comprises:
i) a first conductive leadwire ha

Assignees

• Greatbatch Ltd

Inventors

• Stevenson Robert A
• Frysz Christine A
• Woods Jason

Classifications

• H01R13/26

  Pin or blade contacts for sliding co-operation on one side only {(for modular jack type connectors H01R24/62)} · CPC title

• A61N1/378

  Electrical supply · CPC title

• H03H2001/0042

  Wound, ring or feed-through type capacitor · CPC title

• A61N1/3754 Primary

  Feedthroughs · CPC title

• H01R2201/12

  for medicine and surgery · CPC title