Tantalum capacitor

About: Tantalum capacitor is a research topic. Over the lifetime, 2432 publications have been published within this topic receiving 26709 citations.

Solid electrolytic capacitor and improved method for manufacturing a solid electrolytic capacitor

Abstract: An improved process for forming a capacitor, and improved capacitor formed thereby is described. The process includes: providing an anode comprising a dielectric thereon; applying a first layer of an intrinsically conducting polymer on the dielectric to form a capacitor precursor; applying at least one subsequent layer of an intrinsically conducting polymer on the first layer from a dispersion; and treating the capacitor precursor at a temperature of at least 50°C no more than 200°C at a relative humidity of at least 25 % up to 100%, or fusing the layered structure by swelling the layered structure with a liquid and at least partially removing the liquid.

Failure Mechanism of Solid Tantalum Capacitors

Abstract: It has been suggested that failure of solid tantalum capacitors is due to thermal migration of impurities from the tantalum anode to flaws in the oxide layer. This implies, however, that leakage current gradually increases under normal operating conditions, an effect which has not been observed. An alternative hypothesis advanced here is that failure is due to crystallization of tantalum oxide under the influence of the electric field. Scanning electron microscopy of specially cleaned anodized tantalum sheet on which thin gold electrodes have been deposited clearly shows the occurrence of crystallization after 17 hours at an applied voltage of 75 V and a temperature of 65℃. Results of accelerated life tests on solid tantalum capacitors at temperatures of 85℃ and 125℃, and at up to 2,5 times rated voltage also accord better with a field crystallization hypothesis than with a thermal migration failure hypothesis.

Solid electrolytic capacitor element, solid electrolytic capacitor, and manufacturing method therefor

Abstract: The objective of the current invention is to provide a solid electrolytic capacitor element with low equivalent series resistance. In this solid electrolytic capacitor element, an anode including a porous sintered body, and a dielectric layer are sequentially formed on an anode lead so as to cover a portion of the anode lead. An intermediate layer including polyethylene glycol is formed on the dielectric layer so as to cover an area around the dielectric layer. An electrolyte layer that includes polypyrrole is formed on the intermediate layer so as to cover an area around the intermediate layer. A cathode that includes: a first electrically conductive layer mainly including graphite particles and a second electrically conductive layer mainly including silver particles is formed on the electrolyte layer so as to cover an area surrounding the electrolyte layer.