Solid electrolytic capacitor and manufacturing method thereof

Abstract

The invention relates to a coil type solid electrolytic capacitor containing solid organic polymer with high electrical conductivity as electrolyte and its manufacturing method. In the invention, such processes as oxidation, carbonization, immersing, chemical oxypolymerization, and so on are fully disclosed. The solid electrolytic capacitor of the invention has a pretty low equivalent series resistance (ESR), good impedance frequency properties, so can be used at a frequency above 1 MHz. And it has a high anti-ripple current capacity, wide applicable range of temperature, good temperature properties, large capacity, long life, and reliable performance, therefore can be widely applied in the fields of modern communication, computer, and high performance civilian and military electronic products.

1 . A solid electrolytic capacitor comprising:
 an anode foil having a metal foil made of valve metal and a dielectric oxide film formed on the surface of said metal foil;   a cathode foil made of metal aluminum;   a separate sheet set between said anode foil and said cathode foil;   an anode lead wire electrically connected to said anode foil;   a cathode lead wire electrically connected to said cathode foil   an aluminum casing; and   a seal member;   wherein said separate sheet is covered with solid conductive material, and said separate sheet, said anode foil and said cathode foil are coiled together to form a core of a coil type capacitor which is cased in said aluminum casing, and the opening of said casing is sealed with said seal member.   
   
   
       2 . The solid electrolytic capacitor of  claim 1 , wherein said valve metal is metal aluminum. 
   
   
       3 . The solid electrolytic capacitor of  claim 1 , wherein said separate sheet is made of electrolytic paper containing Manila hemp, or nonwoven of polyester, or compound of polyvinyl alcohol and nylon. 
   
   
       4 . The solid electrolytic capacitor of  claim 3 , wherein the density of said separate sheet ranges from 0.2 to 0.7 g/cm 3 , and the thickness of said separate sheet ranges from 30 μm to 70 μm. 
   
   
       5 . The solid electrolytic capacitor of  claim 1 , wherein said solid conductive material is organic polymer with high electrical conductivity. 
   
   
       6 . The solid electrolytic capacitor of  claim 5 , wherein said organic polymer with high electrical conductivity is made from organic monomer and oxidant via chemical oxypolymerization. 
   
   
       7 . The solid electrolytic capacitor of  claim 6 , wherein said organic monomer comprises at least one of pyrrole, thiophen and aniline. 
   
   
       8 . The solid electrolytic capacitor of  claim 6 , wherein said organic monomer is a mixture comprising two or above of pyrrole, thiophen, and aniline pro rata. 
   
   
       9 . The solid electrolytic capacitor of  claim 6 , wherein said oxidant comprises at least one of ferric salt, persulphate and bichromate. 
   
   
       10 . The solid electrolytic capacitor of  claim 6 , wherein said oxidant is a mixture comprising two or above of ferric salt, persulphate and bichromate pro rata. 
   
   
       11 . The solid electrolytic capacitor of  claim 1 , wherein said seal member is made of ethoxyline rubber, ethylene-propylene rubber, or butyl rubber.