| 摘要 |
PROBLEM TO BE SOLVED: To provide aluminum alloy foil for electrolytic capacitors which can meet the high capacity requirement of the electrostatic capacity in an electrolytic etching treatment and its production method.SOLUTION: In aluminum alloy foil for electrolytic capacitors, the foil body other than the part from the surface of the foil to the depth of 300 nm has an Al content of 99.98 mass% or higher and contains 5-30 ppm of Si, 5-30 ppm of Fe and 40-150 ppm of Cu, and the outermost surface layer from the surface of the foil to the depth of 20 nm contains 10-3,000 ppm of Pb and 1-5,000 ppm of Sn. The copper concentration in the front layer part from the foil surface to a depth of 20-60 nm is twice to four times the copper concentration of the foil body. In the outermost surface layer, the content ratio Sn/Pb is 0.3-10. |
