摘 要 本研究主要在探討銅箔基板在35℃雙氧水及硫酸混合溶液中浸泡後之微蝕行為。微蝕之程度以表面平坦度、表面平均粗糙度(Ra)來評估。若混合溶液中雙氧水及硫酸的濃度改變，銅箔基板上之微蝕程度不同，因而造成平均粗糙度的差異，本系統最佳之微蝕結果為其平均粗糙度介於0.2~0.3μm。本論文藉由改變混合溶液中雙氧水及硫酸的濃度，來監測系統中開路電位(Open Circuit Potential,OCP)，嘗試建立銅箔微蝕程度與系統溶液電位之關係圖，期望藉由此關係圖運用於微蝕製程中，作為製程自動控制及監控設計參考之用。對此ㄧ35℃雙氧水及硫酸混合浸泡液而言，系統的開路電位隨雙氧水濃度增加而上升，銅箔之蝕刻速率亦隨之增加；反之，開路電位隨硫酸濃度增加而下降，但不影響銅箔之蝕刻速率。適量添加雙氧水使其維持穩定之電位為控制微蝕速率之要件。 關鍵字：硫酸、雙氧水、銅箔基板、開路電位、粗糙度 Abstract Printed circuit boards (PCBs) were immersed in a 35℃mixed solution of hydrogen peroxide and sulfuric acid to investigate the micro-etching on the copper substrate in this work. The degree of micro-etching on the copper surface was estimated by measuring the flatness and roughness. The average roughness (Ra) was of the most interest and it would depend on the concentration of hydrogen peroxide and sulfuric acid. The satisfactory micro-etching on the copper substrate revealed Ra in the range from 0.2 to 0.3μm. In the micro-etching process, the concentration of hydrogen peroxide and sulfuric acid was varied to explore its effect on the etching rate by virtue of monitoring the open circuit potential (OCP) of the system. An attempt was made to construct a diagram which correlates the OCP with concentration of the components in the mixed solution. This diagram is useful in design a monitoring and control system for this process. In the system of 35℃mixed solution containing hydrogen peroxide and sulfuric acid, OCP predominately depend upon the concentration of hydrogen peroxide. The OCP increases with increasing the concentration of hydrogen peroxide. The etching rate on copper is enhanced with increasing the OCP. The measurement of OCP and its adjustment by controlling the concentration of hydrogen peroxide provide a key to control the etching rate in the micro-etching. Key words: mixed solution, micro-etching, average roughness, copper, hydrogen peroxide, sulfuric acid.
