Abstract: A solid electrolytic capacitor with improved ESR before and after mounting on a circuit board is obtained by forming a cathode on a dielectric layer using a conductive polymer, especially an intrinsically conductive polymer. The polymer is then coated with graphetized carbon by dipping in a suspension thereof. After drying, the carbon is infused and coated at least once with a second conductive polymer layer before a conductive paint such as “dipping silver” is applied and the capacitor encapsulated by a transfer molding process. The application of a second conductive polymer layer improves the ESR by filling voids in the carbon layer and improves adhesion of the carbon.

Abstract: A process for isolating flaw sites in the dielectric of solid electrolytic capacitor comprising immersing a conductive polymer impregnated capacitor in an electrolyte solution, and then alternately subjecting the conductive polymer impregnated capacitor to a high voltage and a low voltage; wherein the high voltage is between about 10 volts and 50 volts, and the low voltage is between about 0 volts and the voltage corresponding to 90% of the anodization voltage for pellets anodized at less than 20 volts, or the voltage at which the current drops to 50% of the peak voltage current for pellets anodized at voltages greater than or equal to 20 volts. The period of time at or above the anodization voltage is relatively short to prevent damaging the dielectric film.