Roughening Treatment of the Polishing Surface of Oxygen Free Copper Using NaCl-Electrolytic Oxidizing Water

—The Effects of Ultrasonic Agitation—

Abstract

This paper discusses the surface modification processing of polished surface of oxygen free copper using NaCl-electrolytic oxidizing water (hereinafter to as EO water). First, the unheated polished surface test pieces were roughened by immersion with and without ultrasonic using NaCl EO water while comparing with the HCl solution. The surface of test pieces after roughening treatment was observed by FE-SEM and measured by AFM. The results showed that NaCl EO water has a stronger roughening effect than HCl solution, and becomes stronger when with ultrasonic. When with ultrasonic, the surface roughness can be controlled by the immersing time into NaCl EO water. Next, the residual abrasive material (Al₂O₃) and chlorine contamination on the surface of the test pieces after treatment were quantitatively evaluated based on EDS analysis results. The results showed that compared with Na₂SO₄ EO water, using NaCl EO water gives the following. Without ultrasonic, the amount of residual abrasive material (Al₂O₃) is similar, and the amount of chlorine contamination is considerably large. With ultrasonic, the amount of residual abrasive material (Al₂O₃) is dramatically reduced, and the amount of chlorine contamination is the same. By this study, we received the suggestion that NaCl EO water could be applied to the surface roughening treatment of polished surface of oxygen free copper.