The development of a real-time image guided micro electroplating system

A real-time image guided continuous micro-electroplating system equipped with four elements, such as a Charge-coupled Device camera (CCD camera), a magnifier lens, a micro-stepper motor controller, and micro-electroplating device, is proposed in this paper. To maintain the electroplating quality, the system continuously controls the micro-stepper motor and keeps constant gap distance between the micro-anode and copper specimen. In the process of electroplating, chemical reactions would generate oxygen bubbles automatically thus to deteriorate captured images. To solve the bubble issue, a real-time image of the distance between the copper column tip and the anode captured by a CCD camera is used to determine and adjust the cathode position. Besides, four statistic judging criterions are used and compared to determine the bubble-free images. Based on the processing time and accurate rate, the algorithm using entropy index is proposed in this paper for real-time control. From the experiment results, a real-time image guided micro electroplating system does produce better structure, better uniformity and better finishing surface of the specimens compared to those by previous intermittent electroplating setup.