This is the basic construction of the "SP-Cap". It uses an etched aluminum foil to increase the surface area of the capacitor, thereby increasing the capacitance value. The foil is oxidized to form the dielectric alumina or Al2O3. Alumina has very stable dielectric characteristics, which provides the "SP-Cap" with stable capacitance properties for temperature, DC and AC voltage bias. Conductive polymer, carbon and silver are added to the dielectric to form the cathode. "SP-Cap" family has a planar structure. One to fifteen aluminum layers or capacitor elements may be stacked depending on the desired package size, capacitance, voltage, ESR and ripple current. The planar structure is basically a multi anode structure, which helps to provide very low ESRs and excellent high frequency properties.