Highly-reliable feed through/filter capacitor and method for making same

A method for making a capacitor from a canister having first and second mutually insulated electrically conductive interior surfaces and from a capacitive structure having a plurality of pairs of spaced apart electrically conductive plates, a first electrically conductive bus connecting one plate of each pair together to the exclusion of the other plate of each pair, and a second electrically conductive bus connecting the other plate of each pair together to the exclusion of the one plate, the method comprising the steps of:

• placing the capacitive structure in the canister so the first bus lies adjacent to the first surface of the canister to define a first gap therebetween and the second bus lies adjacent to the second surface of the canister to define a second gap therebetween;
• injecting into the first and second gaps uncured thermosetting material loaded with electrically conductive particles;
• and
• curing the thermosetting material.

A method for making a capacitor from a canister having first and second mutually insulated electrically conductive interior surfaces, an open end, and an insulative closed end surface opposite the open end, and from a capacitive structure having a plurality of pairs of spaced apart electrically conductive plates, a first electrically conductive bus connecting one plate of each pair together to the exclusion of the other plate of each pair, and a second electrically conductive bus connecting the other plate of each pair together to the exclusion of the one plate of each pair, the method comprising in the order recited the steps of:

• placing the capacitive structure in the canister so the first bus lies adjacent to the first surface of the canister to define therewith and the closed end surface of the canister a first cavity in communication with the open end of the canister so the second bus lies adjacent to the second surface of the canister to define therewith and the closed end surface of the canister a second cavity in communication with the open end of the canister, the first and second cavities being out of direct communication with each other;
• introducing into the open end of the canister a connecting material comprising a non-conductive solidifiable fluid and solid conductive particles of higher density insolubly mixed with the fluid;
• rotating the canister about a center of rotation toward which its open end faces to induce by centrifugal force flow of the fluidic connecting material into the first and second cavities;
• and
• solidifying the connecting material.

A capacitor comprising:

• a canister having first and second mutually insulated electrically conductive interior surfaces;
• a capacitive structure having a plurality of pairs of spaced apart electrically conductive plates, a first electrically conductive bus connecting one plate of each pair together to the exclusion of the other plate of each pair, and a second electrically conductive bus connecting the other plate of each pair together to the exclusion of the one plate, the capacitive structure lying in the canister to define a first gap therebetween and so the second bus is adjacent to the second surface of the canister to define a second gap therebetween;
• a first mass of connecting material bridging the first gap, the first mass comprising a cured thermoset and conductive particles suspended in the thermoset in sufficient concentration to establish an electrical connection between the first bus and the first surface;
• and
• a second mass of connecting material bridging the second gap, the second mass comprising a cured thermoset and conductive particles suspended in the thermoset in sufficient concentration to establish an electrical connection between the second bus and the second surface, the first and second masses being insulated from each other, at least one mass having an uneven concentration of conductive particles in the connecting material.