SPCC钢碱性无氰直接预镀铜工艺研究

目的提高LED支架的性价比,减少SPCC钢表面镀银预镀铜工艺的镀液污染,简化现有的预镀镍-镀铜施镀工艺,提高预镀层质量。方法采用HEDP碱性无氰直接预镀铜方法来简化工艺,用单因素实验法,系统研究了电流密度、镀液pH、电镀温度、HEDP/Cu~(2+)摩尔比、电镀时间等参数,对镀层镀速、孔隙率及镀层表面质量的影响,并表征镀层的微观组织及镀层结合力。结果在阴极电流密度为1.41 A/dm~2,pH值为9.5,温度为50℃,HEDP/Cu~(2+)摩尔比为3.75:1(Cu~(2+)为10 g/L),时间为11 min的条件下,可获得镀速约为1.7 mg/(cm~2·min)的预镀铜层,且镀层与基体的结合力良好,无孔隙,呈良好的光亮/半光亮状的细晶镀层。结论与钢铁表面氰化镀铜及镀银前预镀铜工艺相比,推荐的HEDP直接预镀铜工艺的镀层质量好,可满足直接镀铜和镀银前预镀铜工艺要求,可有效减少镀液污染和简化施镀工艺,对SPCC钢的镀铜工艺改善具有较好的推广价值。

Direct Copper Preplating Technique in Cyanide-free Alkaline Solution for SPCC Steel Substrate

The work aims to improve cost performance of LED support,reduce pollution of plating solution for silver plating + pre copper preplating process applied on SPCC steel surface,simplify current nickel preplating-copper plating techniques and improve quality of preplated coating.Technique was simplified by applying HEDP cyanide-free direct copper preplating.Effects of parameters including current density,solution pH,electroplating temperature,HEDP/Cu2+ mole ratio and plating time on coating plating velocity,porosity and surface quality were systematicly studied in the method of single factor experiment,and microstructure and binding force of the coating were also characterized.The preplated copper layer could be obtained at the plating velocity of nearly 1.7 mg/(cm2 · min) provided with cathode current density of 1.41 A/dm2,pH 9.5,temperature 50 ℃,HEDP/Cu2+ mole ratio 3.75∶1 (Cu2+ 10 g/L) and plating time 11 min.The fully-bright/semi-bright fine-grain and void-free plating exhibited excellent binding force.Compared with steel surface cyanide copper plating and silver plating pre copper plating techniques,the recommended HEDP direct copper preplating technique generates quality coating and meets the requirements of direct copper plating and silver plating copper preplating technique.Meanwhile,this method can effectively reduce pollution of plating solution and simplify plating process,and is of better promotion value for improving copper plating technique of SPCC steel.