Solid electrolytic capacitor and method of fabricating the same

Abstract

A solid electrolytic capacitor comprising an anode body, a dielectric layer placed on the surface of the anode body, a conductive polymer layer placed on the surface of the dielectric layer, and a housing accommodating at least the anode body, the dielectric layer and the conductive polymer layer, wherein a water-retaining layer having higher water absorption than that of the housing is placed between the conductive polymer layer and the housing.

1 . A solid electrolytic capacitor comprising:
 an anode body,   a dielectric layer placed on a surface of said anode body,   a conductive polymer layer placed on a surface of said dielectric layer, and   a housing accommodating at least said anode body, said dielectric layer and said conductive polymer layer,   wherein a water-retaining layer having higher water absorption than that of said housing is placed between said conductive polymer layer and said housing.   
   
   
       2 . The solid electrolytic capacitor according to  claim 1 , wherein the water absorption of said housing is 0.04% or less. 
   
   
       3 . The solid electrolytic capacitor according to  claim 1 , wherein at least a part of said water-retaining layer is in contact with said conductive polymer layer. 
   
   
       4 . The solid electrolytic capacitor according to  claim 1 , wherein an epoxy resin is used as said water-retaining layer. 
   
   
       5 . The solid electrolytic capacitor according to  claim 1 , wherein a porous body of valve metal is used as said anode body. 
   
   
       6 . A method of fabricating a solid electrolytic capacitor, comprising the steps of:
 forming a dielectric layer on the surface of an anode body;   forming a conductive polymer layer on a surface of said dielectric layer;   applying a material for a water-retaining layer in such a way that at least a part of said water-retaining layer is in contact with said conductive polymer layer, and then curing the material to form said water-retaining layer;   allowing said water-retaining layer to absorb water; and   forming a housing so as to accommodate at least said anode body, said dielectric layer, said conductive polymer layer and said water-retaining layer.   
   
   
       7 . The solid electrolytic capacitor according to  claim 2 , wherein at least a part of said water-retaining layer is in contact with said conductive polymer layer. 
   
   
       8 . The solid electrolytic capacitor according to  claim 2 , wherein an epoxy resin is used as said water-retaining layer. 
   
   
       9 . The solid electrolytic capacitor according to  claim 2 , wherein a porous body of a valve metal is used as said anode body. 
   
   
       10 . The solid electrolytic capacitor according to  claim 3 , wherein an epoxy resin is used as said water-retaining layer. 
   
   
       11 . The solid electrolytic capacitor according to  claim 3 , wherein a porous body of a valve metal is used as said anode body. 
   
   
       12 . The solid electrolytic capacitor according to  claim 4 , wherein a porous body of a valve metal is used as said anode body.