稀土在金属表面处理工艺中的应用技术(3)——稀土对提高酸性亮铜镀层低区走位和抗变色能力的影响

Application Technology for Rare Earths in Surface Treatment of Metals Ⅲ——Effect on Low-Region Coating and Tarnishing Resistance of Bright Copper Plating from Acidic Bath

介绍了稀土在光亮酸性镀铜中应用的工艺配方和工艺条件以及镀液中各成分对工艺规范的影响;分析了不同的故障现象和相对应的原因,以便及时调整处理,着重介绍了在酸性光亮镀铜工艺中使用稀土添加剂后的三个优点:(1)能提高光亮镀铜层的抗变色性,从而提高整体镀层的结合力和抗蚀能力;(2)能扩大光亮镀铜层的光亮范围和低区走位能力;(3)提高镀液对杂质和容忍能力的稳定性,延长镀液使用时间,减少大处理的次数和成本。

An introduction is provided of the formulations and plating conditions for bright acidic copper plating in the presence of rare earths as additives.The effects of various ingredients in the plating bath on the plating process and criterion are analyzed well.Moreover,the reasons leading to failure in bright Cu plating are discussed,aiming at providing guidance to timely adjustment of the plating bath and parameters.The advantages of the rare earth additives for bright Cu plating are highlighted.Namely,the rare earth additives are able to improve the tarnishing resistance of the bright Cu coating and hence improve the adhesion to substrate and corrosion resistance of the coating.The rare earth additives help to broaden the bright plating range of the Cu coating and improve the low-region plating ability.Besides,they contribute to increase the stability of the plating bath and its endurance to impurities,extending the service life of the bath and reducing maintenance and cost as well.