Introduction
Leveling in acid copper plating is a nebulous parameter for quantification. Most techniques require the tester to make subjective determinations based on visual inspections. As the art has matured, it has become necessary to develop techniques that can determine small, incremental improvements in leveling so that comparison of systems can be done objectively. Further, as small changes to leveler molecular structure can greatly impact charge distribution and hence leveling effectiveness, some metric must be put into place to allow differentiation. To this end, a test vehicle has been developed to compare and contrast systems as well as additives within a system. This testing matrix requires cyclic voltammetry, a reproducible substrate, profilometry and an easy visual presentation of the data.