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: Single element and/or multiple element valve-metal, solid-electrolyte, surface-mount capacitors are manufactured using one or more materials taken from the following three categories of materials: graphitic carbon, highly-conductive metal-powder-filled paint, and metallic terminals. The resulting capacitors have lower equivalent series resistance (ESR) at 100 kHz than do similar capacitors manufactured with conventional materials and with conventional techniques. Moreover, not only do these devices possess lower “as-manufactured” ESR, but also their ESR is substantially more stable (less increase in ESR) when these devices are exposed to IR reflow temperatures, high humidity, thermal shock, 1000 hours at 150° C., and 1000 hours at 175° C.