三种铁基体上碱性镀铜工艺的比较

Comparison between three types of alkaline copper plating process on iron substrate

为了考察EDTA体系无氰碱性镀铜工艺的性能,在铁基体上获得结合力优良的镀铜层,作为后续镀铅工艺的中间层,从镀液性能(如阴极极化、电流效率、均镀能力、深镀能力、整平能力、沉积速率等)和镀层性能(如孔隙率、结合力、表面形貌等)两方面对氰化体系、柠檬酸–酒石酸体系和EDTA体系等3种镀铜工艺进行了比较。结果表明,传统氰化镀铜的综合性能优势明显,EDTA无氰碱性镀铜体系的性能优于柠檬酸–酒石酸体系,其较优的工艺条件为:Cu2(OH)2CO314g/L,Na2EDTA120～170g/L,C6H5O7K3·H2O25～40g/L,KNO34g/L,pH12～13,温度50～70°C,阴极电流密度0.5～3.5A/dm2。

To investigate the performance of cyanide-free alkaline copper plating process of EDTA system and obtain a copper coating with good adhesion on iron substrate, which can be used as an interlayer of the flowing lead plating, three kinds of copper plating bath, citrate-tartrate bath and processes including cyanide EDTA bath were compared from two aspects of bath properties （including cathodic polarization, current efficiency, throwing power, covering power, leveling ability and deposition rate） as well as coating properties （such as porosity, adhesion strength and surface morphology）. Test results indicated that the traditional cyanide system has the best comprehensive performance, and the EDTA system has better performance than the citrate- tartrate system. The optimal process conditions for EDTA system were obtained as follows： Cu2（OH）2CO3 14 g/L, Na2EDTA 120-170 g/L, C6HsO7K3·H20 25-40 g/L, KNO3 4 g/L, pH 12-13, temperature 50-70 ℃, and cathodic current density 0.5-3.5 A/dm^2.