Capacitive filtered feedthrough array for an implantable medical device

Abstract

A capacitive filtered feedthrough assembly is formed in a solid state manner to employ highly miniaturized conductive paths each filtered by a discoid capacitive filter embedded in a capacitive filter array. A non-conductive, co-fired metal-ceramic substrate is formed from multiple layers that supports one or a plurality of substrate conductive paths and it is brazed to a conductive ferrule, adapted to be welded to a case, using a conductive, corrosion resistant braze material. The metal-ceramic substrate is attached to an internally disposed capacitive filter array that encloses one or a plurality of capacitive filter capacitor active electrodes each coupled to a filter array conductive path and at least one capacitor ground electrode. Each capacitive filter array conductive path is joined with a metal-ceramic conductive path to form a feedthrough conductive path. Bonding pads are attached to the internally disposed ends of each feedthrough conductive path, and corrosion resistant, conductive buttons are attached to and seal the externally disposed ends of each feedthrough conductive path. A plurality of conductive, substrate ground paths are formed extending through the co-fired metal-ceramic substrate between internally and externally facing layer surfaces thereof and electrically isolated from the substrate conductive paths. The capacitor ground electrodes are coupled electrically to the plurality of conductive, substrate ground paths and to the ferrule.