Capacitive filtered feedthrough array for an implantable medical device

A filtered feedthrough assembly adapted to be fitted into an opening of a case of an electronic device, the feedthrough assembly having an internally disposed portion configured to be disposed inside the case and an externally disposed portion configured to be disposed outside the case, the assembly comprising:

• an electrically conductive ferrule having a ferrule wall adapted to be fitted into the case opening with an inner wall surface defining a centrally disposed ferrule opening and extending between opposed internally and externally facing ferrule sides;
• a multi-layer, co-fired metal-ceramic substrate having opposed internally facing and externally facing substrate surfaces joined by a common substrate edge, the metal-ceramic substrate further comprising:
• a plurality of metal-ceramic substrate layers each having internally and externally facing layer surfaces;
• a plurality of substrate conductive paths extending through the co-fired metal-ceramic substrate between the internally and externally facing layer surfaces and electrically isolated from one another;
• and
• a further plurality of substrate ground paths extending through the co-fired metal-ceramic substrate between the internally and externally facing layer surfaces and electrically isolated from the substrate conductive paths;
• means for hermetically sealing the common substrate edge to the ferrule inner wall within the centrally disposed ferrule opening and electrically coupling the plurality of substrate ground paths to the ferrule;
• a discoidal capacitive filter array formed of a ceramic capacitive filter substrate having an internally facing filter substrate side and an externally facing filter substrate side joined by a common filter substrate edge, the capacitive filter array substrate further comprising:
• a plurality of filter array conductive paths electrically isolated from one another and extending between the internally facing filter substrate side and the externally facing filter substrate side;
• and
• a plurality of discoidal capacitor filters each comprising at least one capacitor active electrode formed within the filter substrate and extending outward from a filter array conductive path and a common capacitor ground electrode;
• means for mechanically joining the externally facing filter substrate side to the internally facing substrate side and electrically joining each filter array conductive path to a substrate conductive path;
• and
• means for electrically coupling the common capacitor ground electrode of the discoidal capacitor filters to the plurality of substrate ground paths;
• whereby the filtered feedthrough assembly provides a plurality of miniaturized, electrically isolated, and capacitively filtered, feedthrough conductive paths with low inductance each comprising a substrate conductive path joined to a filter array conductive path and extending between the internally disposed portion and the externally disposed portion when the feedthrough assembly is affixed into an opening in the case of the electronic device.