Effects of Surface Morphology on Pit Nucleation and Growth of High Purity Aluminum Foil in Electrolytic Capacitors Used for DC Etching

摘要

The pit growth behavior of high purity aluminum foil in electrolytic capacitors used for DC elching in a hot HCI solution has been studied using grained foil. Hemispherical patterns with diameters of about 1-3μm and Cubic patterns with widths and lengths of 7-15μm were formed by electrolytic grainings in HNO_3 and HNO_3/HCI solutions, respectively. By using cubic or hemispherical patterns, uniform distributions of pits were obtained for a surface that was untreated and one that was pre-treated during the early stage of DC etching.