研究了以次磷酸钠作还原剂的化学镀铜体系,添加剂2,2′-联吡啶对化学镀铜沉积速率、次磷酸钠阳极氧化和铜离子阴极还原、以及镀层形貌、结构和组分存在状态的影响.结果表明,2,2′-联吡啶对化学沉积起阻化作用.电化学线性伏安扫描实验显示,镀液中加入2,2′-联吡啶,次磷酸钠的氧化峰电势有所负移,但峰电流减小;铜离子的还原峰电势负移,但峰电流逐渐增大.扫描电子显微镜(SEM)、能量色散谱(EDS)、X射线衍射(XRD)及X射线光电子能谱(XPS)等实验分别表明,添加剂使镀层致密和光亮、镍含量降低;镀层为Cu-Ni合金,呈面心立方结构,无明显晶面择优取向现象;镀层中铜和镍以金属态存在,磷的质量含量小于0.05%.

In the bath of the electroless copper plating using sodium hypophosphite as reductant,the effects of 2,2′-dipyridine on the deposition rate,anodic oxidation of sodium hypophosphite,cathodic reduction of copper ions,surface morphologies,structure and the existing status of the deposit components were examined.The results showed that,2,2′-dipyridine hindered the electroless deposition.Experiments of liner sweep voltammetry(LSV) indicated that,as the addition of 2,2′-dipyridine to the electrolyte,the oxidation peak potential of sodium hypophosphite shifted to a more negative value but the peak current decreased;the reducing peak potential of copper ions moved to a more negative value whereas the peak current increased.Scanning electron microscope(SEM)、energy dispersive spectroscopy(EDS)、X-ray diffraction(XRD) and X-ray photoelectron spectroscopic(XPS) experiments displayed that,the additive caused the deposit in the compacter,brighter and lower nickel content.the deposit was Cu-Ni alloy in face-centered cubic structure without obvious crystal face preferred orientation.the copper and nickel in the deposit were in metal state,and the weight content of phosphorus was less than 0.05%.