PURPOSE: To improve high temperature durability by specifying a ratio of oxygen permeability of a sheathing base material for sheathing a capacitor element in which part of electrodes for holding a dielectric material is polypyrrole to an average thickness.
CONSTITUTION: A capacitor element 1 in which at least part of electrodes for holding a dielectric material is polypyrrole, and a sheathing base material 2 for sheathing the element 1 are provided. In this case, the material 2 has 0.2 or less of P/t, where P (unit, 10-10cm3.cm/cm2.sec.cmHg) is oxygen permeability at 105°C of the base material and t (unit, cm) is average thickness from the surface of the sheath to the element 1. Thus, the permeability of the material and the thickness of the material are controlled to suppress influence of oxygen to the polypyrrole for forming at least part of the electrodes. Accordingly, excellent high frequency characteristic and high temperature durability are improved.
TANAKA YUKIOMI
IMANISHI KUNIHIKO
YASUDA YUTAKA
