Microelectroplating of nickel by direct and pulse current with one-dimension step-moving of anode

• Main Authors: Yu Shun-Po, 游絢博
• Other Authors: Lin Jing-Chie
• Format: Others
• Language: zh-TW
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/69843112320238852003

碩士 === 國立中央大學 === 機械工程研究所 === 88 === Localized electroplating of nickel on copper substrate was conducted in a watts bath to obtain a nickel column. This electroplating was carried out by means of a specially designed anode, that is a platinum wire(diameter 125μm) moving vertically in micro-steps. Direct and pulse current are used as the power source. The results for the direct current electroplating indicated (1) a nickel column can be obtain when the bias of the electrodes is controlled at 5-7V. The higher the bias, the better the localization, and the more coarse of the deposit. (2) The gap between the electrodes affects the microstructure of the nickel column. In the gap ranging from 5 to 100μm, the greater the gap, the more dense and refined grain of the nickel column, but the worse localization. (3) An additive of 1mM saccharin sodium added in the bath results in grain-refining and surface leveling of the nickel column. The results for the pulse current electroplating indicated (1) pulse plating is better than dc plating to obtain a dense and smooth nickel column. (2) modified pulse current is better than the common pulse current to obtain a good nickel column. The microstructure of the nickel column was examined through scanning electron microcopy at the initial stage in the process of electroplating. In addition to the microstructural examination, the study of cyclic cathodic potentiodynamic provides useful informations for the mechanism elucidation of the localized electroplating.