Effect of additives on the elongation and surface properties of copper foils

We report on the effects of additives on the mechanical properties of electrodeposited copper foils. Additives A (leveler), B (brightener) and C (Coll-A) are used in this study, and additive D is used as a Cl^- ion. The study results show that there are large differences in surface roughness and elongation, according to whether the additives are added singly or in combination. In the case of additive D, its addition exhibits a high tendency to grow crystals in a (220) direction, and leads to increased elongation; however, it also exhibits the disadvantage of increasing surface roughness. The addition of all four additives results in a low surface roughness of less than 1 um, and shows low tensile strengths and uniform grain sizes. Here, the elongation is 15.6%, which represents an increase in elongation by 34% when compared to that of not adding additives.