Flat capacitor for an implantable medical device
One aspect provides a capacitor feedthrough assembly having an electrically conductive member dimensioned to extend at least partially through a feedthrough hole of a case of the capacitor, the conductive member having a passage therethrough.
1. A process, comprising:
depositing a curable resin mask onto a foil;
curing the curable resin mask into a cured mask;
etching the foil, the cured mask restricting the etch;
removing the cured mask from the foil;
anodizing the foil;
assembling the foil into a flat capacitor stack; and
inserting the flat capacitor stack into a capacitor case.
2. The process of claim 1 , comprising:
connecting one or more electrically isolated conductors connected to the capacitor stack;
filling the capacitor case with an electrolyte; and
sealing the one or more electrically isolated conductors to the capacitor case such that the one or more electrically isolated conductors extend outside the capacitor case.
3. The process of claim 1 , wherein assembling the foil into a flat capacitor stack includes:
aligning a cutting tool to the foil using one or more visual alignment features printed onto the foil;
cutting the foil into shapes with a cutting tool; and
stacking the shapes into a capacitor stack, the cutting tool aligned using one or more features for visual alignment printed onto the foil.
4. The process of claim 1 , wherein assembling the foil into the capacitor stack includes:
layering a first anode foil with a first separator layer, the first separator layer including first separator holes positioned approximately over the unetched regions of the first anode foil;
layering a cathode foil over the first separator layer, the cathode foil having cathode holes positioned approximately over the first separator holes;
placing a conductive interconnect through each cathode hole and first separator hole to contact an unetched region of the first anode layer;
layering a second separator layer over the cathode layer, the second separator layer including second separator holes positioned approximately over the cathode holes; and
layering a second anode layer over the second separator layer, the second anode layer having its own unetched regions contacting the conductive interconnect.
5. The process of claim 4 , wherein the conductive interconnect is a metal plug.
6. The process of claim 4 , wherein the conductive interconnect has a cross section which is smaller than the cathode hole and the conductive interconnect is placed to avoid direct electrical contact with the cathode foil and wherein the first anode and the second anode are electrically connected through the conductive interconnect.
7. The process of claim 4 , wherein the first anode layer is substantially flat.
8. The process of claim 4 , wherein the conductive interconnect is aluminum.
9. The process of claim 4 , wherein the cross section is circular.
10. The process of claim 4 , wherein the conduction interconnect is ultrasonically welded to the first anode layer and the second anode layer.
11. The process of claim 4 , wherein the conduction interconnect is resistance welded to the first anode layer and the second anode layer.
12. The process of claim 4 , wherein the conductive interconnect mates to an unetched region of the first anode layer.
13. The process of claim 4 , wherein the conductive interconnect mates to an unformed region of the first anode layer.
14. The process of claim 4 , wherein the conductive interconnect includes a rivet.
15. The process of claim 4 , wherein the conductive interconnect includes a wire.
16. The process of claim 4 , wherein the conductive interconnect includes a conductive epoxy.
17. The process of claim 4 , wherein the conductive interconnect includes a conductive polymer.
18. The process of claim 4 , wherein the conductive interconnect includes a polyimide filled with aluminum.
19. The process of claim 4 , wherein the conductive interconnect includes a fused aluminum powder.