According to the preparation method of the
solid tantalum capacitor, the
solid tantalum capacitor is composed of a
tantalum block, a medium
oxide layer with gradient thickness, a
cathode layer, a
transition layer, a silver layer and a
plastic packaging layer, and the thickness of the medium
oxide layer is in gradient nonlinear decrease from the outer surface of the tantalum block to the body center of the tantalum block; the preparation method of the
solid tantalum capacitor comprises the following steps of pressing and
sintering, energizing, heat treatment, complementary forming,
coating,
graphite silver paste,
plastic packaging and multiple times of aging. The environment of the aging process is as follows: the
relative humidity is 60-90%, the aging temperature is 60-125 DEG C, and the aging
voltage is 0.6-1.5 times of rated
voltage; according to the method, secondary energizing and multiple humidifying and aging processes are matched, so that the thickness of the
dielectric oxide layer of the solid
tantalum capacitor has the structural characteristic of gradually reducing from outside to inside, the capacity contribution degree has the trend of gradually increasing from outside to inside, the short-plate effect of the external
dielectric oxide layer is supplemented, and the performance of the solid
tantalum capacitor is improved. Therefore, the overall
voltage endurance capability of the tantalum
capacitor is improved, and the capacity of the tantalum capacitor is not sacrificed.