An improved internally grounded feedthrough filter capacitor includes at least one conductive terminal pin, a feedthrough filter capacitor having first and second sets of electrode plates and a first passageway through which the terminal pin extends in conductive relation with the first set of electrode plates, and a conductive ferrule through which the terminal pin passes in non-conductive relation. The ferrule includes a conductive ground plane which substantially spans and supports an adjacent face of the feedthrough filter capacitor, and an integral grounded terminal pin which extends into a second passageway through the feedthrough filter capacitor in conductive relation with the second set of electrode plates. A washer electrically insulates the feedthrough filter capacitor from the conductive ferrule except for the conductive relation between the grounded terminal pin and the second set of electrode plates. In various illustrated embodiments, (1) the feedthrough filter capacitor may be asymmetrical as well as symmetrical about the ground lead, (2) the ground plane and grounded terminal pin may be machined in one piece as an integral part of a machine ferrule, (3) the terminal pin may be added by welding, brazing or the like to a plate of the ground plane, (4) the plate and grounded terminal pin of the ground plane may be co-formed by metal stamping, punching or similar operations, and (5) the ground plane may be alternatively deposited by sputter or equivalent metal deposition process to an insulator disposed within the ferrule, with the grounded terminal pin subsequently mechanically and electrically attached thereto.
