Circuit board mounted filtered feedthrough assembly having a composite conductive lead for an AIMD

A circuit board mounted filtered feedthrough assembly having a composite conductive lead for an active implantable medical device (AIMD), the circuit board mounted filtered feedthrough assembly comprising:

• a) a ferrule comprising a ferrule opening, wherein the ferrule is configured to be attachable to an opening in a housing of an AIMD;
• 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, and wherein an internal metallization is disposed on an inner surface of each of the plurality of insulator passageways;
• c) a plurality of first leadwires, each comprising a first leadwire first end spaced from a first leadwire second end, wherein a first leadwire first end resides in each of the plurality of insulator passageways;
• d) a plurality of second leadwires which are not of the same material as the first leadwires, the plurality of second leadwires each comprising a second leadwire first end spaced from a second leadwire second end, wherein a second leadwire first end resides in each of the plurality of insulator passageways and is positioned at or adjacent to a respective first leadwire first end, and wherein the plurality of second leadwire second ends extend outwardly beyond the insulator second end surface;
• e) a plurality of second gold brazes, a respective second gold braze contacting the first leadwire first end, the second leadwire first end and the internal metallization to thereby form a hermetic seal separating the insulator first end surface from the insulator second end surface in each of the plurality of insulator passageways;
• and
• f) 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;
• g) a plurality of circuit board active via holes extending through the circuit board, wherein at least a portion of a respective one of the plurality of second leadwire second ends extending outwardly beyond the insulator second end surface resides in one of the circuit board active via holes, and wherein the circuit board comprises a plurality of circuit board active circuit traces that are electrically connectable to electronic circuits housed in the AIMD;
• 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 an active metallization is electrically connected to the at least one active electrode plate, and a ground metallization is electrically connected to the at least one ground electrode plate of each of the plurality of two-terminal MLCC chip capacitors,
• i) wherein an active electrical path extends from each of the first leadwires to a respective one the second leadwires and then to the active metallization of a respective one of the plurality of two-terminal MLCC chip capacitors and to a respective one of the circuit board active circuit traces, and
• j) wherein a ground electrical path extends from the ground metallization of a respective one of the plurality of two-terminal MLCC chip capacitors to the circuit board ground metallization and then to the ferrule.

A circuit board mounted filtered feedthrough assembly having a composite conductive lead for an active implantable medical device (AIMD), the circuit board mounted filtered feedthrough assembly comprising:

• a) a ferrule comprising a ferrule opening, wherein the ferrule is configured to be attachable to an opening in a housing of an AIMD, and wherein a ground pin is conductively and mechanically connected to the ferrule;
• 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, and wherein an internal metallization is disposed on an inner surface of each of the plurality of insulator passageways;
• c) a plurality of first leadwires, each comprising a first leadwire first end spaced from a first leadwire second end, wherein a first leadwire first end resides in each of the plurality of insulator passageways;
• d) a plurality of second leadwires which are not of the same material as the first leadwires, the plurality of second leadwires each comprising a second leadwire first end spaced from a second leadwire second end, wherein a second leadwire first end resides in each of the plurality of insulator passageways and is positioned at or adjacent to a respective first leadwire first end, and wherein the plurality of second leadwire second ends extend outwardly beyond the insulator second end surface;
• e) a plurality of second gold brazes, a respective second gold braze contacting the first leadwire first end, the second leadwire first end and the internal metallization to thereby form a hermetic seal separating the insulator first end surface from the insulator second end surface in each of the plurality of insulator passageways;
• f) 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 an active metallization is electrically connected to the at least one active electrode plate, and a ground metallization is electrically connected to the at least one ground electrode plate of each of the plurality of two-terminal MLCC chip capacitors;
• g) 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, and wherein there is at least one internal circuit board ground circuit trace;
• h) a plurality of circuit board active via holes extending through the circuit board, wherein at least a portion of a respective one of the second leadwire second ends extending outwardly beyond the insulator second end surface resides in one of the circuit board active via holes, and wherein the circuit board comprises a plurality of circuit board active circuit traces that are electrically connectable to electronic circuits housed in the AIMD;
• and
• i) a plurality of circuit board ground via holes extending through the circuit board, wherein a ground metallization resides on an inner surface of each of the plurality ground via holes in the circuit board, and wherein the at least one internal circuit board ground circuit trace is electrically connected to the ground pin and to the plurality of circuit board ground metallizations,
• j) wherein an active electrical path extends from each of the first leadwires to a respective one the second leadwires and then to the active metallization of a respective one of the plurality of two-terminal MLCC chip capacitors and to a respective one of the circuit board active circuit traces, and
• k) wherein a ground electrical path extends from the ground metallization of a respective one of the plurality of two-terminal MLCC chip capacitors to the ground metallization residing in a respective one of the plurality of ground via holes in the circuit board, the ground metallization being electrically connected to the internal circuit board ground circuit trace electrically connected to the ground pin and to the ferrule.