BULK CAPACITOR AND METHOD
A bulk capacitor includes a first electrode formed of a metal foil and a semi-conductive porous ceramic body formed on the metal foil. A dielectric layer is formed on the porous ceramic body for example by oxidation. A conductive medium is deposited on the porous ceramic body filling the pores of the porous ceramic body and forming a second electrode. The capacitor can then be encapsulated with various layers and can include conventional electrical terminations. A method of manufacturing a bulk capacitor includes forming a conductive porous ceramic body on a first electrode formed of a metal foil, oxidizing to form a dielectric layer and filling the porous body with a conductive medium to form a second electrode. A thin semi-conductive ceramic layer can also be disposed between the metal foil and the porous ceramic body.
1 . A bulk capacitor, comprising:
a first electrode formed of a metal foil,
a semi-conductive porous ceramic body deposited on the metal foil,
a dielectric layer formed on the porous ceramic body, and
a conductive medium filling at least a portion of porous ceramic body forming a second electrode.
2 . The bulk capacitor of claim 1 further comprising a conductive metal layer encapsulating the porous ceramic body.
3 . The bulk capacitor of claim 2 wherein the conductive metal layer comprises silver.
4 . The bulk capacitor of claim 1 further comprising a semi-conductive ceramic layer disposed between the metal foil and the porous ceramic body.
5 . The bulk capacitor of claim 1 wherein the metal foil has a geometric profile.
6 . The bulk capacitor of claim 1 wherein the conductive medium comprises a conductive polymer.
7 . The bulk capacitor of claim 1 wherein the dielectric layer is formed on a free surface of the porous ceramic body.
8 . The bulk capacitor of claim 1 wherein the dielectric layer is formed on porous ceramic body and on the metal foil.
9 . The bulk capacitor of claim 1 further comprising a first electrical lead coupled to the first electrode and a second electrical lead coupled to the second electrode, wherein the first electrical lead and second electrical lead are configured to mate with first and second conductive pads located on a mounting substrate.
10 . The bulk capacitor of claim 9 wherein the first and second electrode are joined to the first and second conductive pads via a conductive adhesive.
11 . The bulk capacitor of claim 10 further comprising a non-conductive adhesive disposed between the first and second electrical leads.
12 . A method of manufacturing a bulk capacitor, the method comprising:
forming a conductive porous ceramic body on a first electrode comprising a metal foil,
oxidizing the porous ceramic body to form a dielectric layer, and
filling the porous ceramic body with a conductive medium forming a second electrode.
13 . The method of claim 12 comprising encapsulating the porous ceramic body with a conductive metal layer.
14 . The method of claim 13 wherein the conductive metal layer comprises silver.
15 . The method of claim 12 further comprising forming a semi-conductive ceramic layer between the metal foil and the porous ceramic body.
16 . The method of claim 12 comprising forming a geometric profile in the metal foil,
17 . The method of claim 12 wherein the oxidizing is performed thermally.
18 . The method of claim 12 wherein the oxidizing is performed electrochemically.
19 . The method of claim 12 wherein the conductive medium comprises a conductive polymer.
20 . The method of claim 12 wherein the dielectric layer is formed on porous ceramic body and on the metal foil.
21 . The method of claim 12 wherein a first electrical lead is coupled to the first electrode and a second electrical lead is coupled to the second electrode, wherein the first electrical lead and second electrical lead are configured to mate with first and second conductive pads located on a mounting substrate.
22 . The method of claim 21 wherein the first and second electrode are joined to the first and second conductive pads via a conductive adhesive.
23 . The method of claim 22 wherein a non-conductive adhesive is disposed between the first and second electrical leads.