| 摘要 |
PROBLEM TO BE SOLVED: To solve the problems of flat formability inhibition, decrease in breakdown voltage characteristics, and operation sound during ripple current, by preventing occurrence of voids, wrinkles and distortion of a metalization film wound body in a capacitor element having ellipticity of 0.6 or more.SOLUTION: A composite film wound body 6 is configured by further winding an exterior film 5 on the outer periphery of a metalization film wound body 4 configured by winding a metalization film 3, and then winding and fixing by thermal welding. A flat columnar body 9 is configured by pressing the composite film wound body 6, and metal electrodes 10 are formed at both ends in the axial direction thereof. In a capacitor element having an oblateness of 0.6 or more from the point of view of volumetric efficiency up, the winding and fixing of the exterior film 5 is thermal welding at a part of self overlap, and performed at a plurality of points distributed in the circumferential direction, and the ratio of the entire outer peripheral surface occupied by the total thermal welding area is set to 30% or less. |
