High-voltage filtered feedthrough assembly having a filter capacitor grounded to a gold pad nested in a ferrule pocket of the feedthrough for an active implantable medical device (AIMD)

A filtered feedthrough assembly that is attachable to an active implantable medical device (AIMD), the filtered feedthrough assembly comprising:

• a) a feedthrough, comprising;
• i) An electrically conductive ferrule comprising:
• A) a ferrule sidewall defining a ferrule opening, the ferrule sidewall having a ferrule height extending to a ferrule body fluid side surface spaced from a ferrule device side surface;
• B) at least one recessed pocket having a depth extending from the ferrule device side surface part-way through the height of the ferrule toward the ferrule body fluid side surface;
• and
• C) a gold pocket-pad nested in the at least one recessed pocket so that the gold pocket-pad is electrically connected to the ferrule;
• and
• ii) an insulator hermetically sealed to the ferrule in the ferrule opening, the insulator extending to an insulator body fluid side spaced from an insulator device side, wherein, when the ferrule hermetically sealed to the insulator is attached to an opening in a housing of an AIMD, the ferrule body fluid side adjacent to the insulator body fluid side, and the ferrule device side adjacent to the insulator device side reside outside and inside the AIMD, respectively;
• and
• iii) at least a first terminal pin hermetically sealed to the insulator in a first via hole by a first braze, wherein the first terminal pin extends outwardly beyond at least the insulator device side;
• and
• b) a filter capacitor, comprising:
• i) a dielectric substrate having a dielectric substrate peripheral surface extending to a dielectric substrate first end surface and an opposed dielectric substrate second end surface that is spaced above the ferrule device side surface, wherein the dielectric substrate supports at least one active electrode plate interleaved in a capacitive relationship with at least one ground electrode plate extending to the dielectric substrate peripheral surface, and wherein the dielectric substrate first end surface is adjacent to the insulator and the ferrule device sides;
• and
• ii) at least a first passageway extending through the dielectric substrate to the dielectric substrate first and second end surfaces, wherein the first terminal pin extends through the first passageway and outwardly beyond the dielectric substrate second end surface, the first terminal pin being electrically connected to the at least one active electrode plate in the first passageway;
• c) an external ground metallization contacting the at least one ground electrode plate at the peripheral surface;
• d) an electrical connection material connecting from the external ground metallization to the gold pocket-pad Connected to the ferrule;
• e) a first polymeric insulating material contacted to the dielectric substrate second end surface and the external ground metallization at the dielectric substrate peripheral surface, wherein the polymeric insulating material comprises insulating nanoparticles, wherein the first polymeric insulating material also contacts the gold pocket-pad nested in the at least one recessed pocket of the ferrule;
• and
• f) a second polymeric insulating material as a second washer positioned between the insulator device side and the dielectric substrate first end surface, wherein the second polymeric washer has at least a washer first opening through which the first terminal pin extends, and wherein the second polymeric insulating material comprises insulating nanoparticles.