Flat capacitor having an active case

The present invention concerns implantable medical devices, such as defibrillators and cardioverters, and more specifically to a method of manufacturing a capacitor for an implantable heart monitor. A capacitor comprising an aluminum case; a capacitor stack mounted within the aluminum case, the capacitor stack comprising one or more anodes and one or more cathodes, one of the one or more anodes and one or more anodes attached to the aluminum case; wherein the case is adapted to be an active capacitor element. In one aspect, a capacitor includes a case having an etched inner surface, the inner surface including an etched upper inner surface and an etched lower inner surface. The capacitor further includes a capacitor stack disposed within the case, where the capacitor stack includes a plurality of cathode stacks and a plurality of anode stacks, and the cathode stacks are electrically coupled with the etched inner surface. The plurality of anode stacks include a first anode stack disposed adjacent to the upper inner surface. In one aspect, a capacitor assembly includes at least one anode stack having one or more anode conductive layers and an anode separator, and at least one cathode stack having one or more cathode conductive layers and a cathode separator. The capacitor assembly further includes at least one separator disposed between the anode stack and the cathode stack, where each at least one anode stack stacked with the cathode stack to form a capacitor stack, and a capacitor case sized to receive therein the capacitor stack. The capacitor case includes a conductive surface therein, and one or more of the anode conductive layers is electrically coupled with the conductive surface of the capacitor case.