2,2′-联吡啶在化学镀铜中的作用研究

Research of 2,2′-dipyridine on Electroless Copper Plating Using Sodium Hypophosphite as Reductant

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 vohammetry （LSV） indicated that, as the addition of 2,2＇-dipyfidine 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%.