Patent ID: 7329334

Claim:
A method of electroplating an article in an acidic copper electroplating bath comprising the steps of: (a) suspending said article in the acidic copper electroplating bath; (b) plating said article for a period of time with a pulse-reverse current profile to produce a desired thickness of copper on the surface of said article; wherein the hardness of the plated copper is controlled to a level between about 89 and 208 HV 50 by controlling the ratio of cathodic pulse time to anodic pulse time or cathodic pulse current density to anodic pulse current density, wherein the acidic copper electroplating bath comprises a hardening agent comprising a sulfur (II) compound, and a Polyalkylene glycol and wherein the plated copper is softer than copper plated from the same electroplating bath under direct current plating.