Low impedance oxide resistant grounded capacitor for an AIMD

A hermetically sealed filtered feedthrough assembly for an implantable medical device, the filtered feedthrough assembly comprising:

• a) a ferrule of an electrically conductive material, the ferrule comprising a ferrule sidewall defining a ferrule opening, wherein the ferrule comprises a ferrule extension partially extending into the ferrule opening;
• b) an insulator of electrically non-conductive material, the insulator comprising an outer insulator surface extending longitudinally from a first insulator end to a second insulator end, wherein the insulator is hermetically sealed to the conductive ferrule sidewall in the ferrule opening, and wherein the insulator has at least a first insulator bore extending there through to the first and second insulator ends;
• c) a filter capacitor, comprising:
• i) a dielectric comprising an outer dielectric surface extending longitudinally from a first dielectric end to a second dielectric end, wherein the second dielectric end is longitudinally disposed adjacent to the first insulator end;
• ii) at least one active electrode plate supported by the dielectric in an interleaved, partially overlapping relationship with at least one ground electrode plate;
• and
• iii) at least a first and a second dielectric bores extending through the dielectric to the first and second dielectric ends;
• d) a first metallization electrically contacted to the at least one active electrode plate in the first dielectric bore;
• e) a conductor comprising an electrically conductive material hermetically sealed and disposed through the first insulator bore, wherein the conductor is in a non-conductive relation with the conductive ferrule and extends through the dielectric bore so that a first conductor end is spaced from the first dielectric end and a second conductor end is spaced from the second insulator end;
• f) a first electrically conductive material coupling the conductor in the dielectric bore to the first metallization coupled to the active electrode plate;
• g) a second metallization electrically contacted to the ground electrode plate at at least a portion of the outer dielectric surface;
• and
• h) a ground conductor extending through the dielectric in a non-conductive relation with the active and ground electrode plates, wherein the ground conductor has a first ground conductor end spaced from a second ground conductor end, and wherein the second ground conductor end is electrically and physically coupled to the ferrule extension;
• and
• i) an oxide-resistant metal addition electrically and physically coupling from the second metallization contacted to the ground electrode plate at the outer dielectric surface to a location on the ground conductor spaced from the second ground conductor end coupled to the ferrule extension,
• j) wherein a grounding pathway is defined from the second metallization, through the oxide-resistant metal addition and to the ferrule extension, wherein a total resistance of the grounding pathway is less than 5 milliohm and wherein a total inductance of the grounding pathway is less than 10 nanohenries.

A hermetically sealed filtered feedthrough assembly for an implantable medical device, the filtered feedthrough assembly comprising:

• a) a ferrule of an electrically conductive material, the ferrule comprising a ferrule side all defining a ferrule opening, wherein the ferrule comprises a ferrule extension partially extending into the ferrule opening;
• b) an insulator of electrically non-conductive material, the insulator comprising an outer insulator surface extending longitudinally from a first insulator end to a second insulator end, wherein the insulator is hermetically sealed to the conductive ferrule sidewall in the ferrule opening, and wherein the insulator has at least a first insulator bore extending there through to the first and second insulator ends;
• c) a filter capacitor, comprising:
• i) a dielectric comprising an outer dielectric surface extending longitudinally from a first dielectric end to a second dielectric end, wherein the second dielectric end is longitudinally disposed adjacent to the first insulator end;
• ii) at least one active electrode plate supported by the dielectric in an interleaved, partially overlapping relationship with at least one ground electrode plate;
• and
• iii) at least a first and a second dielectric bores extending through the dielectric to the first and second dielectric ends;
• d) a first metallization electrically contacted to the at least one active electrode plate in the first dielectric bore;
• e) a conductor comprising an electrically conductive material hermetically sealed and disposed through the first insulator bore, wherein the conductor is in a non-conductive relation with the conductive ferrule and extends through the dielectric bore so that a first conductor end is spaced from the first dielectric end and a second conductor end is spaced from the second insulator end;
• f) a first electrically conductive material coupling the conductor in the dielectric bore to the first metallization coupled to the active electrode plate;
• g) a second metallization electrically contacted to the ground electrode plate at at least a portion of the outer dielectric surface;
• and
• h) a ground conductor extending through the dielectric in a non-conductive relation with the active and ground electrode plates, wherein the ground conductor has a first ground conductor end spaced from a second ground conductor end, and wherein the second ground conductor end is electrically and physically coupled to the ferrule extension;
• and
• i) an oxide-resistant metal addition electrically and physically coupling from the second metallization contacted to the ground electrode plate at the outer dielectric surface to a location on the ground conductor spaced from the second ground conductor end coupled to the ferrule extension;
• j) a second electrically conductive material coupling the oxide-resistant metal addition to the second metallization contacted to the ground electrode plate by;
• and
• k) a third electrically conductive material coupling the oxide-resistant metal addition to the ground conductor,
• l) wherein a grounding pathway is defined from the second metallization, the second electrically conductive material, through the oxide-resistant metal addition, to the ferrule extension then the third electrically conductive material and the ground conductor.

A hermetically sealed filtered feedthrough assembly for an implantable medical device, the filtered feedthrough assembly comprising:

• a) a ferrule of an electrically conductive material, the ferrule comprising a ferrule sidewall defining a ferrule opening, wherein the ferrule comprises a ferrule extension partially extending into the ferrule opening;
• b) an insulator of electrically non-conductive material, the insulator comprising an outer insulator surface extending longitudinally from a first insulator end to a second insulator end, wherein the insulator is hermetically sealed to the conductive ferrule sidewall in the ferrule opening, and wherein the insulator has at least a first insulator bore extending there through to the first and second insulator ends;
• c) a filter capacitor, comprising:
• i) a dielectric comprising an outer dielectric surface extending longitudinally from a first dielectric end to a second dielectric end, wherein the second dielectric end is longitudinally disposed adjacent to the first insulator end;
• ii) at least one active electrode plate supported by the dielectric in an interleaved, partially overlapping relationship with at least one ground electrode plate;
• and
• iii) at least a first and a second dielectric bores extending through the dielectric to the first and second dielectric ends;
• d) a first metallization electrically contacted to the at least one active electrode plate in the first dielectric bore;
• e) a conductor comprising an electrically conductive material hermetically sealed and disposed through the first insulator bore, wherein the conductor is in a non-conductive relation with the conductive ferrule and extends through the dielectric bore so that a first conductor end is adjacent to the first dielectric end and a second conductor end is adjacent to the second insulator end;
• f) a first electrically conductive material coupling the conductor in the dielectric bore to the first metallization coupled to the active electrode plate;
• g) a second metallization electrically contacted to the ground electrode plate at at least a portion of the outer dielectric surface;
• and
• h) a ground conductor extending through the dielectric in a non-conductive relation with the active and ground electrode plates, wherein the ground conductor has a first ground conductor end spaced from a second ground conductor end, and wherein the second ground conductor end is electrically and physically coupled to the ferrule extension;
• and
• i) an oxide-resistant metal addition electrically and physically coupling from the second metallization contacted to the ground electrode plate at the outer dielectric surface to the ferrule electrically connected to the ground conductor.