Bulk capacitor and method

Abstract

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.