Organic Solid Tantalum Electrolytic Capacitor Cathode Materials And Device Characterization

In this paper, A new conductive polymer which can be applied for tantalum capacitor's cathode plate, PEDT(3,4—polyethylene dioxythiophene),has been discussed. The performance of PEDT such as conductivity and thermal stability was analyzed. In order to reduce solid electrolytic tantalum capacitor's ESR, it is a good route that the manganese dioxide was replaced by PEDT which was applied for solid electrolytic tantalum capacitor's cathode plate. we finally made the sample(10V/68μF)have low ESR(0.01—0.08Ω)in 100kHz.The primary works in this paper are below: 1) The PEDT film in conductive glass has been obtained by chemical method, the influence of the different process factors on the conductance and thermal stability of the PEDT has been studied. The different process includes polymerization temperature , content of accelerant, content of solvent, drying temperature and so on. 2) Through the analysis of the PEDT materials, we made the PEDT film as tantalum capacitor's cathode plate on a porous Ta2O5 .The influence of the process on the parameter of the PEDT tantalum capacitor also be analyzed, the capacitor's parameter includes capacitance, wastage, ESR, leakage current etc. 3) Different performances of PEDT tantalum capacitor were studied in this paper. Such as the temperature properties of capacitance, the temperature properties of ESR, the frequency properties of capacitance, the frequency properties of ESR etc. The some main performance of PEDT solid tantalum capacitor has been analyzed and compared with common solid tantalum capacitor which uses manganese dioxide as cathode plate. A method to produce high conductivity PEDT film has been found in this paper. The PEDT can be used to substitute for manganese dioxide as solid electrolytic tantalum capacitor's cathode plate. The analysis shows that the PEDT tantalum capacitor has the better frequency performance of capacitance and the frequency performance of ESR. The results would make it possible for electrolytic tantalum capacitor applying for higher frequency.