Investigation on the Uniformity of Electroplating with Fountain Bath

• Main Authors: Hsu,Wen-Chung, 徐文忠
• Other Authors: Jr.-Ming Miao
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/98279911758319768859

碩士 === 國防大學中正理工學院 === 兵器系統工程研究所 === 95 === Electroplating is a type of oxidation-reduction reaction and generally composed of an anode and a cathode within a suitable solution. By applying electric current with specific flow rate of solution for certain period of time, the cathode is coated with a thin layer of metal, which usually has properties of abrasion and wear resistance, corrosion protection, etc. Also, electroplating has characteristics of low cost, high resolution and good capacity; therefore, it is widely used in Microelectromechanical Systems (MEMS) and semiconductor industry. A desirable coating has to be uniform, which implies the flow velocity washing the cathode must be small enough to let the process of deposition occur. Hence, the purpose of this paper is to discover this phenomenon with experimental and numerial methods developing . A fountain-type plating tank is used, where anodic plate is placed on several locations(i.e. 1.27cm, 3.5cm, 5.0cm) from the bottom to change the flow field. The coated wafer is regarded as cathode and is located at the top of tank. By setting pH value, temperature and current to be immobile, the experiments are performed at specific flow speed of 0.58m/s. The effect of flow speed ranging from 0.29m/s to 0.87m/s on the uniformity of coating layer is also investigated. Two types of hole’s shape on the anode plate are implemented to find out the optimum geometry in present tank. By comparing experimental data and numerical results, the best uniformity of coated layer can be achieved with flow speed of 0.58m/s and distance of 1.27cm in all runs.