Dielectric properties of aluminium solid electrolytic capacitor using conduction polymer

Digitalization in electronic systems is required with capacitors which are large capacitance with small size, low impedance at high frequency, and high reliability. The fabrication and properties of aluminium solid electrolytic capacitors are investigated. Employing a conducting polymer film such as, polypyrrole as solid electrolyte, solid type aluminium electrolytic capacitors were made. The surface of insulating oxide is covered with conducting polymer layer prepared by chemical oxidative polymerization. Thereafter this conducting layer is covered with conducting polymer prepared by electrochemical polymerization. The dielectric properties of these capacitors were also measured and discussed. Regarding the frequency characteristics of the trial capacitor, impedance and ESR at high frequency is lower than those of the stacked type film capacitor. It is also confirmed that the temperature coefficient of capacitance and dissipation factor of the capacitor is lower than that of the film capacitor and liquid type aluminium electrolytic capacitor