Patent ID: 6402924
Filing Date: 2002-06-11
Classification: C25D,H05K,Y10S

Abstract:
A method of enhancing the properties of a deposit obtained when electroplating metal onto a substrate, which method comprises applying a pulsed periodic reverse current comprising an uninterrupted, sequential forward to reverse, reverse to forward, continuously repeating pulsing sequence across the electrodes of a plating cell utilizing a peak reverse current density and a peak forward current density, and varying the ratio of the peak reverse current density to the peak forward current density in periodic cycles comprising first and second values of ratios of peak reverse current density to peak forward current density to provide a metal deposit of uniform appearance, fine grain structure and uniform thickness on the substrate, wherein the ratio of peak reverse current density to peak forward current density is varied sequentially during the cycle between a first value in a first time period and a second value which is different than the first value in a second time period.