processes and measurements as in example 1 table ii oxalic adipate adipate citrate phosphate capacitance df esr leakage capacitance df esr leakage lot u03bcf ohms u03bca u03bcf ohms u03bca 1 14 04 1 235 0 0357 0 0687 13 73 0 941 0 0318 0 093 2 14 11 0 866 0 0351 0 103 13 71 0 856 0 0346 0 1674 3 13 75 0 822 0 0347 0 0488 13 22 0 785 0 0334 0 0931 4 13 77 0 771 0 0295 0 0734 12 90 0 796 0 0339 0 1466 5 13 97 0 766 0 0304 0 0785 13 34 0 744 0 0355 0 1218 avg 13 93 0 892 0 0331 0 07448 13 38 0 824 0 0338 0 12438 when oxalic acid anodization followed by ammonium adipate formation was used in the process the average capacitance was 4 1 higher and the average leakage was 40 less than with the edge formation process of ammonium citrate followed by ammonium phosphate however df was 8 higher with the oxalic acid ammonium adipate process in addition one of the batches processed in oxalic acid and ammonium adipate had visible signs of hydration in the weld zone after standing for several days none of the batches processed in ammonium citrate and ammonium phosphate showed hydration etched.