PURPOSE: To reduce rejection ratio of capacitors, and to contrive improvement in reliability by a method wherein a manganese nitrate solution is impregnated into a porous anode member, and a heat treatment process to be conducted in a high temperature and high humidity atmosphere and a heat decomposition treatment, to be performed in the atmospheric air, are provided.
CONSTITUTION: A porous anode body 12, consisting of a tantalum of 96mg in weight having a buried lead wire 11 consisting of valve-action metal, is chemically formed at 24V, and a dielectric oxide film is formed on the surface of the anode body 12. Subsequently, a manganese nitrate solution of 1.35 in specific gravity is impregnated, and a thermal decomposition operation is conducted at 250°C for 10 minutes using a hot-air circulation thermal decomposition device. Besides, a manganese nitrate of 1.93 in specific gravity is impregnated, and after a heat treatment has been conducted in the atmosphere of the temperature of 140°C and the humidity of 50%, a thermal decomposition operation is conducted at 250°C for 10 minutes using a hot-air circulation thermal decomposition device, and a manganese dioxide layer 13 is formed. As a result, a highly reliable solid electrolytic capacitor, having a low reject percentage in manufacturing process, can be obtained.
KOBASHI YASUHIRO
KAJIKAWA TAKAO
