甲醛法化学镀铜的电化学研究

Electrochemical Study on Electroless Copper Plating Using Formaldehyde as Reductant

研究甲醛化学镀铜的电化学机理可以为开发化学镀铜工艺提供指导。应用线性扫描伏安法(LSV)分析了温度、pH值和添加剂浓度对镀液体系阳极氧化和阴极还原的影响。在优化化学镀铜工艺后进行石墨粉化学镀铜,并对石墨及镀铜石墨的物相、形貌及成分进行分析。结果表明:升高温度能同时增大镀液体系阳极氧化和阴极还原的反应速率;p H值增大加快了阳极氧化的反应速率,抑制了Cu(Ⅰ)的歧化反应,促进了阴极铜离子还原;添加剂对阴、阳极反应均有一定抑制作用,但可配位Cu(Ⅰ),抑制歧化反应;较优的化学镀铜工艺参数(10 mg/L2,2’-联吡啶,5 mg/L亚铁氰化钾,镀液温度为50℃和p H=13)下进行化学镀铜得到的镀铜层与石墨结合紧密,包覆完整。

Studying the electrochemical mechanism of electroless copper plating used formaldehyde as reductant can guide the electroless copper plating process. Linear scanning voltammetry( LSV) was used to analyze the influence of temperature,p H value and additive concentration on the anodic oxidation and the cathodic reduction of the plating bath in the electroless copper plating process. After optimizing the electroless copper plating process,the graphite powder was plated with copper. The phase,morphology and composition of graphite and copper coated graphite were analyzed. Results showed that the reaction rates of anodic oxidation and cathode reduction could be increased by elevating the temperature. The increase of p H value increased the rate of the anodic oxidation reaction and inhibited Cu( Ⅰ) disproportionation reaction,promoting the cathode copper ions reduction. Additives to cathode and anode reaction all had certain inhibitory effect,but could complex Cu( Ⅰ) to inhibit the disproportionation reaction. Under the better process parameters of electroless copper plating( 10 mg/L,2,2’-dipyridine,5 mg/L K4 Fe( CN)6,bath temperature of 50 ℃ and p H= 13),the copper plating layer obtained by electroless copper plating was tightly bound to graphite and completely coated.