Main Effects of Additives on Copper Electroplating at High Current Density

This study investigates the changes in the surface characteristic, electrical and mechanical properties of copper foils electrodeposited in electrolytes with added various additives (Janus Green B (JGB), 3–mercapto–1–propane sulfonic acid (MPSA), Polyethylene glycol (PEG) and Chloride ion) under high current density. The main effect of additives on these properties was analyzed. In the group with added JGB, the crystal size on the surface became finer, and a homogeneous surface was observed. However, dented areas were observed, which decreased with an increase in chloride ions. When 100 ppm of PEG and 10 ppm of JGB were added, the fine dents on the surface increased. When a certain amount or more of additives were added, defects on the surface occurred due to competition between additives. The addition of JGB induced crystal growth in the direction of the (111) plane. Copper foils with excellent yield strength, tensile strength, and elongation could be obtained with an appropriate crystal size. The addition of JGB mainly affected crystal size and the direction of crystal growth, which is an important factor for controlling mechanical properties. PEG mainly affected elongation, and chloride ions had a primary effect on surface roughness, resistivity, and corrosion rate. Therefore, controlling additives is an effective way to significantly affect the manufacture of copper foil and produce various suitable properties in high demand.