Manufacturing technique of microelectrowinning of nickel on copper substrate by single-shaft micro-stepping motor.

• Main Authors: Cheng-Chih Chen, 陳承志
• Other Authors: Jing-Chie Lin
• Format: Others
• Language: zh-TW
• Published: 1999
• Online Access: http://ndltd.ncl.edu.tw/handle/54550114228201388678

碩士 === 國立中央大學 === 機械工程研究所 === 87 === This is the second year of a "Three-Dimensional Microwinning project". The object is Micro-winning of nickel on copper substrate and has been investigated to discuss the localized growth of the Ni-deposit and its microstructure. The localized growth was defined as a ratio of the deposit height to the deposit time and radius of deposit area. Nickel sulfamate and Watts solution was used as the electrolyte, and platinum wires in 125 μm diameter were the anode. The anode was controlled to have a micro-translation by a micro-stepping motor. When optimum potentials were applied, the deposit was built on the substrate by moving the anode in the electrolyte. The gap between the anode and the substrate was initially set at 1, 10, 100μm. The anode was controlled to translate at 1, 10 and 100μm per step. Next step translation was drived as the current for the previous step beyond 20 mA. The motion of the anode was controlled by a computer PC through an interphase coupled with a dedicated software. In the present work, the influence of electrode gap and plating voltage on the localized growth of the 3D-deposit was concerned. A faster deposition rate was obtained in this system, roughly three orders of magnitude greater than the traditional technique. The growth rate of the microdeposit was governed mainly by the electrode gap and the plating voltage. Localized growth of the deposits decreases with increasing the gap from 1 to 100μm. At a gap of 1μm , the localized growth increases with increasing the plating voltage from 5 to 8V. At a gap of 10 and 100μm, the localized growth increases to a maximum with increasing the voltage at 5~7V and then decreases gradually at 7~8V. A deposit with fined grains structure is better then that with coarse grains in mechanical properties. Examining the microdeposits through SEM, localized growth of the deposits was compensated by coarse grains structure. Moreover, the deposit obtained at a fixed gap indicated a variation of grain size with the deposit height: the grain size decreases with increasing the height of the deposit.