Abstract: An improved electrolyte composition and process for electrodepositing bright, level and ductile copper deposits on a substrate enabling use of conventional electroplating equipment for high-speed copper plating employing average cathode current densities substantially higher than heretofore feasible. The electrolyte contains an additive system comprising carefully controlled relative concentrations of:(a) a bath soluble polyether compound;(b) a bath soluble organic divalent sulfur compound;(c) a bath soluble adduct of a tertiary alkyl amine with epichlorohydrin; and(d) a bath soluble reaction product of polyethyleneimine and an alkylating agent.

Abstract: A composition and method for electrodepositing ductile, bright, level copper deposits from an aqueous acidic copper plating electrolyte particularly suited for plating electronic circuit boards containing a brightening and leveling amount of a brightening and leveling system comprising (a) a bath soluble substituted phthalocyanine radical, (b) a bath soluble adduct of a tertiary alkyl amine with polyepichlorohydrin, (c) a bath soluble organic divalent sulfur compound, and (d) a bath soluble reaction product of polyethyleneimine and an alkylating agent which will alkylate the nitrogen on the polyethyleneimine to produce a quaternary nitrogen. The electrolyte optionally also contains bath soluble polyether compounds as a supplemental brightening agent.