Through-Hole Filling by Copper Electroplating Using a Single Organic Additive

A copper electroplating process using a single organic additive was developed for filling through holes of printed circuit boards. The organic additive acted as an inhibitor of copper deposition in the presence of chloride ions and . This copper electroplating formula resulted in center-up filling, which differs from the bottom-up filling exhibited by blind microvias. The inhibiting strength of the organic additive and the filling capability of the plating solution strongly depended on the concentration of . The electrochemical behavior of the organic additive was characterized by electrochemical analyses and imaging of TH cross sections.