Abstract
An addition of selenic acid to copper electrolyte increases the exchanging current density (i0) and the cathodic change transfer coefficient (ac) . Change transfer resistance decreases and current distribution appears to be determined mainly by the ohmic drop of the electrolyte. The addition of 200 and 1000 g/m3 of selenic acid, decreases the Wa (Wagner) number less than by one. This causes non-uniform current distribution which causes humps on the bump surroundings. Bumps with different surrounding hump heights have been electrodeposited with the selenic acid additive. The trapped conductive particles on the bump with different hump heights are counted after COG (Chip on Glass) interconnection with ACF (Anisotropic Conductive Film) . Bumps with 8 to 11μm hump heights trap four times more conductive particles when compared to the flat shaped bumps.
