Yoshihiko Saiki

Neocapacitor. New Tantalum Capacitor with Conducting Polymer

Publisher Summary In the past decade, portable electronic equipment has been miniaturized and its energy consumption has been lowered remarkably. This requires much lower noise on the power-supply line of electronic equipment and lower equivalent series resistance (ESR) on capacitors in the line. To meet this demand, NEC has recently developed a new tantalum capacitor, NeoCapacitor, which uses polypyrrole (PPy) as its electrolyte. Because of much higher electrical conductivity than that of MnO 2 , which is used in conventional tantalum capacitors, PPy provides lower ESR to NeoCapacitor. Moreover, thermally degrading property at over 300 °C provides healing function to the new capacitor. If a micro defect exists on the dielectric, the current flows at this point. This current generates heat and the heat degrades PPy at the point. Therefore, insulated polymer stops current flow and prevents the capacitor from short-circuiting. A decrease in leakage current in load life tests has been observed for the new capacitor. This is one of the examples of the healing function of conducting polymer. This chapter provides ripple current loading tests and the gas chromatography–mass spectrometry (GC–MS) analysis of the polymer.