MLCC filter on an AIMD circuit board with direct connect to the gold braze hermetically sealing a feed through insulator to a ferrule

• US 10,099,051 B2
• Filed: 12/12/2016
• Issued: 10/16/2018
• Est. Priority Date: 03/20/2008
• Status: Active Grant

• Current Assignee: Greatbatch Limited (Greatbatch Incorporated)
• Original Assignee: Greatbatch Limited (Greatbatch Incorporated)
• Inventors: Stevenson, Robert A., Frysz, Christine A., Brendel, Richard L.
• Primary Examiner(s): Koharski, Christopher D
• Assistant Examiner(s): Bays, Pamela M
• Application Number:
  US15/375,315
• Publication Number:
  US 20170087356A1
• Time in Patent Office: 673 Days
• Field of Search: 607 36, 607 37
• CPC Class Codes: A61N 1/08 Arrangements or circuits for monitoring, protecting, controlling or indicating for external stimulators A61N1/3603; for implantable neurostimulators A61N1/36128; for heart stimulators A61N1/37; for defibrillators A61N1/3925
• CPC Class Codes: A61N 1/086 Magnetic resonance imaging [MRI] compatible leads
• CPC Class Codes: A61N 1/3718 Monitoring of or protection against external electromagnetic fields or currents
• CPC Class Codes: A61N 1/375 Constructional arrangements, e.g. casings
• CPC Class Codes: A61N 1/3754 Feedthroughs
• CPC Class Codes: H01G 4/06 Solid dielectrics
• CPC Class Codes: H01G 4/35 Feed-through capacitors or anti-noise capacitors
• CPC Class Codes: H01G 4/40 Structural combinations of fixed capacitors with other electric elements, the structure mainly consisting of a capacitor, e.g. RC combinations
• CPC Class Codes: H01R 13/7195 with planar filters with openings for contacts
• CPC Class Codes: H03H 1/0007 of radio frequency interference filters
• CPC Class Codes: H03H 2001/0042 Wound, ring or feed-through type capacitor
• CPC Class Codes: H03H 2001/0085 Multilayer, e.g. LTCC, HTCC, green sheets
• CPC Class Codes: H03H 7/1766 Parallel LC in series path H03H7/1783 takes precedence
• CPC Class Codes: H05K 1/181 associated with surface mounted components
• CPC Class Codes: H05K 2201/10015 Non-printed capacitor
• CPC Class Codes: H05K 5/0095 hermetically-sealed
• CPC Class Codes: H05K 9/00 Screening of apparatus or components against electric or magnetic fields devices for absorbing radiation from an antenna H01Q17/00

Abstract

An EMI/energy dissipating filter for an active implantable medical device (AIMD) is described. The filter comprises a first gold braze hermetically sealing the insulator to a ferrule that is configured to be mounted in an opening in a housing for the AIMD. A lead wire is hermetically sealed in a passageway through the insulator by a second gold braze. A circuit board substrate is disposed adjacent the insulator. A two-terminal chip capacitor disposed adjacent to the circuit board has an active end metallization that is electrically connected to the active electrode plates and a ground end metallization that is electrically connected to the at least one ground electrode plates of the capacitor. A ground path electrically extends between the ground end metallization of the chip capacitor and the ferrule. There is also an active path electrically extending between the active end metallization of the chip capacitor and the lead wire. The active path comprises at least a first electrical connection material connected directly to both the second gold braze and the lead wire, and the first electrical connection material is electrically connected to the active end metallization of the chip capacitor.

Claims

1. A filtered feedthrough assembly for an active implantable medical device, the filtered feedthrough assembly comprising:

a) an electrically conductive ferrule comprising a ferrule opening, wherein the ferrule is configured to be attachable to an opening in a housing of an active implantable medical device;

b) an insulator at least partially residing in the ferrule opening where a first gold braze hermetically seals the insulator to the ferrule, wherein at least an insulator first passageway extends through the insulator to an insulator first end surface and an insulator second end surface;

c) an electrically conductive lead wire residing in the insulator first passageway where a second gold braze hermetically seals the lead wire to the insulator, the lead wire extending from a lead wire first portion having a lead wire first end to a lead wire second portion having a lead wire second end, wherein the lead wire second portion extends outwardly beyond the insulator second end surface;

d) a circuit board comprising spaced apart circuit board first and second sides, wherein the circuit board first side is adjacent to the insulator second end surface;

e) a circuit board ground plate at least partially residing on the circuit board first side;

f) a circuit board ground via hole extending through the circuit board to the circuit board ground plate;

g) a circuit board active via hole being electrically isolated from the circuit board ground plate, wherein at least a portion of the lead wire second portion extends into the circuit board active via hole to adjacent to the circuit board second side;

h) a two-terminal MLCC chip capacitor comprising a chip capacitor dielectric supporting at least one active electrode plate interleaved in a capacitive relationship with at least one ground electrode plate, wherein an active metallization is conductively connected to the at least one active electrode plate, and a ground metallization is conductively connected to the at least one ground electrode plate of the two-terminal MLCC chip capacitor; and

i) wherein an active electrical path extends from the lead wire to the two-terminal MLCC chip capacitor, the active electrical path comprising a first electrically conductive material conductively connecting at least a portion of the lead wire second portion adjacent to the circuit board second side to the active metallization electrically connected to the active electrode plate of the two-terminal MLCC chip capacitor, and

j) wherein a ground electrical path extends from the two-terminal MLCC chip capacitor to the circuit board ground plate and then to the ferrule, the ground electrical path comprising a second electrically conductive material;

i) being conductively connected to the ground metallization electrically connected to the ground electrode plate of the two-terminal MLCC chip capacitor;

ii) at least partially residing in the circuit board ground via hole where the second electrically conductive material is conductively connected to the circuit board ground plate; and

iii) being conductively connected to the first gold braze hermetically sealing the insulator to the ferrule.

2. The filtered feedthrough assembly of claim 1, wherein the lead wire first and second ends extend outwardly beyond the respective insulator first and second end surfaces.

3. The filtered feedthrough assembly of claim 1, wherein the two-terminal MLCC chip capacitor is spaced closer to the insulator second end surface than the insulator first end surface.

4. The filtered feedthrough assembly of claim 1, wherein the lead wire second portion extending outwardly beyond the insulator second end surface and residing in the circuit board active via hole also extends outwardly beyond the circuit board second side.

5. The filtered feedthrough assembly of claim 1, including at least one telemetry antenna wire hermetically sealed within an insulator second passageway, wherein the telemetry antenna wire is not electrically connected to the two-terminal MLCC chip capacitor.

6. The filtered feedthrough assembly of claim 1, wherein the second electrically conductive material residing at least partially in the circuit board ground via hole comprises a metallization supported by at least a portion of the circuit board.

7. The filtered feedthrough assembly of claim 1, wherein the circuit board comprises a rigid section, and wherein the circuit board rigid section comprises at least one material selected from the group consisting of a ceramic, an alumina, a fiberglass, and an FR4 material.

8. The filtered feedthrough assembly of claim 1, wherein the circuit board comprises a flexible section, and wherein the circuit board flexible section comprises at least one material selected from the group consisting of a polyimide, a Kapton, and an acrylic material.

9. The filtered feedthrough assembly of claim 1, wherein the lead wire second end extends outwardly beyond the circuit board second side and the lead wire first end extends outwardly beyond the insulator first end surface.

10. The filtered feedthrough assembly of claim 1, wherein the second electrically conductive material is directly conductively connected to the circuit board ground plate supported on the circuit board first side.

11. A filtered feedthrough assembly for an active implantable medical device, the filtered feedthrough assembly comprising:

a) an electrically conductive ferrule comprising a ferrule opening, wherein the ferrule is configured to be attachable to an opening in a housing of an active implantable medical device;

b) an insulator at least partially residing in the ferrule opening where a first gold braze hermetically seals the insulator to the ferrule, wherein at least an insulator first passageway extends through the insulator to an insulator first end surface and an insulator second end surface;

c) an electrically conductive lead wire residing in the insulator first passageway where a second gold braze hermetically seals the lead wire to the insulator, the lead wire extending from a lead wire first portion having a lead wire first end to a lead wire second portion having a lead wire second end, wherein the lead wire second portion extends outwardly beyond the insulator second end surface;

d) a circuit board comprising spaced apart circuit board first and second sides, wherein the circuit board first side is adjacent to the insulator second end surface;

e) at least one circuit board first ground plate residing between the circuit board first and second sides;

f) a circuit board second ground plate at least partially residing on the circuit board first side;

g) a circuit board ground via extending through the circuit board to the circuit board first and second ground plates;

h) a circuit board active via hole being electrically isolated from the circuit board first and second ground plates, wherein at least a portion of the lead wire second portion extends into the circuit board active via hole to adjacent to the circuit board second side;

i) a two-terminal MLCC chip capacitor comprising a chip capacitor dielectric supporting at least one active electrode plate interleaved in a capacitive relationship with at least one ground electrode plate, wherein an active metallization is conductively connected to the at least one active electrode plate, and a ground metallization is conductively connected to the at least one ground electrode plate of the two-terminal MLCC chip capacitor; and

j) wherein an active electrical path extends from the lead wire to the two-terminal MLCC chip capacitor, the active electrical path comprising a first electrically conductive material conductively connecting at least a portion of the lead wire second portion adjacent to the circuit board second side to the active metallization electrically connected to the at least one active electrode plate of the two-terminal MLCC chip capacitor, and

k) wherein a ground electrical path extends from the two-terminal MLCC chip capacitor to the circuit board first and second ground plates and then to the ferrule, the ground electrical path comprising a second electrically conductive material;

i) being conductively connected to the ground metallization electrically connected to the ground electrode plate of the two-terminal MLCC chip capacitor;

ii) residing at least partially in the circuit board ground via hole where the second electrically conductive material is conductively connected to the circuit board first and second ground plates; and

iii) being conductively connected to the first gold braze hermetically sealing the insulator to the ferrule.

12. The filtered feedthrough assembly of claim 11, wherein the second electrically conductive material is directly conductively connected to the circuit board second ground plate supported on the circuit board first side.

13. The filtered feedthrough assembly of claim 11, wherein the lead wire first and second ends extend outwardly beyond the respective insulator first and second end surfaces.

14. The filtered feedthrough assembly of claim 11, wherein the two-terminal MLCC chip capacitor is spaced closer to the insulator second end surface than the insulator first end surface.

15. The filtered feedthrough assembly of claim 11, wherein the lead wire second portion extending outwardly beyond the insulator second end surface and residing in the circuit board active via also extends outwardly beyond the circuit board second side.

16. The filtered feedthrough assembly of claim 11, including at least one telemetry antenna wire hermetically sealed within an insulator second passageway, wherein the telemetry antenna wire is not electrically connected to the two-terminal MLCC chip capacitor.

17. The filtered feedthrough assembly of claim 11, wherein the second electrically conductive material at least partially residing in the circuit board ground via hole comprises a metallization supported by at least a portion of the circuit board.

18. The filtered feedthrough assembly of claim 11, wherein the circuit board comprises a rigid section, and wherein the circuit board rigid section comprises at least one material selected from the group consisting of a ceramic, an alumina, a fiberglass, and an FR4 material.

19. The filtered feedthrough assembly of claim 11, wherein the circuit board comprises a flexible section, and wherein the circuit board flexible section comprises at least one material selected from the group consisting of a polyimide, a Kapton, and an acrylic material.

20. The filtered feedthrough assembly of claim 11, wherein the lead wire second end extends outwardly beyond the circuit board second side and the lead wire first end extends outwardly beyond the insulator first end surface.

21. A filtered feedthrough assembly for an active implantable medical device, the filtered feedthrough assembly comprising:

a) an electrically conductive ferrule comprising a ferrule opening, wherein the ferrule is configured to be attachable to an opening in a housing of an active implantable medical device;

b) an insulator at least partially residing in the ferrule opening where a first gold braze hermetically seals the insulator to the ferrule, wherein a plurality of insulator passageways extend through the insulator to an insulator first end surface and an insulator second end surface;

c) a plurality of electrically conductive lead wires residing in respective ones of the insulator passageways where a respective second gold braze hermetically seals each of the lead wires to the insulator, each lead wire extending from a lead wire first portion having a lead wire first end to a lead wire second portion having a lead wire second end, wherein each lead wire second portion extends outwardly beyond the insulator second end surface;

d) a circuit board comprising circuit board first and second sides, wherein the circuit board first side is adjacent to the insulator second end surface;

e) a circuit board ground plate at least partially residing on the circuit board first side;

f) a plurality of circuit board ground via holes extending through the circuit board to the circuit board ground plate;

g) a plurality of circuit board active via holes being electrically isolated from the circuit board ground plate, wherein at least a portion of each of the plurality of the lead wire second portions extend into a respective one of the circuit board active via holes to adjacent to the circuit board second side; and

h) a plurality of two-terminal MLCC chip capacitors, each comprising a chip capacitor dielectric supporting at least one active electrode plate interleaved in a capacitive relationship with at least one ground electrode plate, wherein each two-terminal MLCC chip capacitor has an active metallization electrically connected to the at least one active electrode plate, and a ground metallization electrically connected to the at least one ground electrode plate,

i) wherein there are a plurality of active electrical paths, each active electrical path comprising a first electrically conductive material conductively connecting at least a portion of one of the lead wire second portions adjacent to a respective one of the circuit board active via holes to the active metallization electrically connected to the active electrode plate of a respective one of the two-terminal MLCC chip capacitors, and

j) wherein there are a plurality of ground electrical paths extending from the respective one of the two-terminal MLCC chip capacitors to the circuit board ground plate and then to the ferrule, each of the ground electrical paths comprising a second electrically conductive material;

i) being conductively connected to the ground metallization electrically connected to the ground electrode plate of the respective two-terminal MLCC chip capacitor;

ii) residing at least partially in the respective circuit board ground via hole where the second electrically conductive material is conductively connected to the circuit board ground plate; and

iii) being conductively connected to the first gold braze hermetically sealing the insulator to the ferrule.

22. The filtered feedthrough assembly of claim 21, wherein the second electrically conductive material is directly conductively connected to the circuit board ground plate supported on the circuit board first side.

23. A filtered feedthrough assembly for an active implantable medical device, the filtered feedthrough assembly comprising:

a) an electrically conductive ferrule comprising a ferrule opening, wherein the ferrule is configured to be attachable to an opening in a housing of an active implantable medical device;

b) an insulator at least partially residing in the ferrule opening where a first gold braze hermetically seals the insulator to the ferrule, wherein at least an insulator first passageway extends through the insulator to an insulator first end surface and an insulator second end surface;

c) an electrically conductive lead wire residing in the insulator first passageway where a second gold braze hermetically seals the lead wire to the insulator, the lead wire extending from a lead wire first portion having a lead wire first end to a lead wire second portion having a lead wire second end, wherein the lead wire second portion extends outwardly beyond the insulator second end surface;

d) a circuit board comprising spaced apart circuit board first and second sides, wherein the circuit board first side is adjacent to the insulator second end surface;

e) a circuit board ground plate at least partially residing on the circuit board first side;

f) a circuit board ground via hole extending through the circuit board to the circuit board ground plate;

g) a circuit board active via hole being electrically isolated from the circuit board ground plate, wherein at least a portion of the lead wire second portion extends into the circuit board active via hole to the circuit board second side;

h) a two-terminal MLCC chip capacitor comprising a chip capacitor dielectric supporting at least one active electrode plate interleaved in a capacitive relationship with at least one ground electrode plate, wherein an active metallization is conductively connected to the at least one active electrode plate, and a ground metallization is conductively connected to the at least one ground electrode plate of the two-terminal MLCC chip capacitor; and

i) wherein an active electrical path extends from the lead wire to the two-terminal MLCC chip capacitor, the active electrical path comprising a first electrically conductive material conductively connecting at least a portion of the lead wire second portion at the circuit board second side to the active metallization electrically connected to the active electrode plate of the two-terminal MLCC chip capacitor, and

j) wherein a ground electrical path extends from the two-terminal MLCC chip capacitor to the circuit board ground plate and then to the ferrule, the ground electrical path comprising a second electrically conductive material;

i) being conductively connected to the ground metallization electrically connected to the ground electrode plate of the two-terminal MLCC chip capacitor;

ii) at least partially residing in the circuit board ground via hole where the second electrically conductive material is conductively connected to the circuit board ground plate; and

iii) being conductively connected to the first gold braze hermetically sealing the insulator to the ferrule.