工艺条件对硫脲-酒石酸-柠檬酸三配位体系化学镀锡沉积速度的影响  

Effect of Process Conditions on Deposition Rate of Electroless Tin Coating in Thiourea-Tartaric Acid-Citric Acid Tri-Ligand System

作　　者：杨余芳[1] 文朝晖[2] 邓斌[1] 周费亮[1] 

机构地区：[1]湘南学院化学与生命科学系,湖南郴州423000 [2]湘南学院图书馆,湖南郴州423000

出　　处：《材料保护》2011年第4期34-37,7,共4页Materials Protection

基　　金：湖南省科技厅资助课题(2007FJ3028)

摘　　要：为了提高硫脲、酒石酸、柠檬酸三配位体系化学镀锡的沉积速度和镀液稳定性,考察了硫脲单配位体系、硫脲-酒石酸及硫脲-柠檬酸双配位体系、硫脲-酒石酸-柠檬酸三配位体系镀锡液中配位剂浓度对沉积速度的影响,并研究了三配位体系主盐浓度、还原剂浓度、镀液温度、pH值、沉积时间对沉积速度的影响,优化了工艺条件,探讨了最优工艺制备的镀层的性能。结果表明:三配位体系的沉积速度大于硫脲-酒石酸、硫脲-柠檬酸双配位体系和硫脲单配位体系的沉积速度;随着硫脲、酒石酸、柠檬酸、次磷酸钠、SnCl2.2H2O浓度以及温度、pH值、沉积时间的增加,沉积速度均先升高后降低;最佳工艺条件为20 g/L硫脲,40 g/L柠檬酸,40 g/L酒石酸,20 g/L次磷酸钠,40 g/L SnCl2.2H2O,2 g/L对苯二酚,镀液温度80℃,pH值0.72,沉积30 min;最佳工艺条件下镀液稳定,沉积速度达到3.12μm/h,镀层耐蚀,结合力、可焊性良好,结晶均匀致密。The effect of complexing agent concentration of thiourea mono ligand,thiourea-tartaric acid and thiourea-citric acid bicomponent ligand,and thiourea-tartaric acid-citric acid tricomponent ligand on the deposition rate of electroless Sn plating was investigated.The effects of major salt concentration,reducing agent concentration,plating bath temperature,pH value and deposition time of tri-ligand system on the deposition rate were examined,and the plating parameters were optimized.The properties of the coating obtained under the optimized plating condition were analyzed.Results indicated that the plating rate in the tri-ligand system was greater than those in the dual-ligand and mono-ligand systems.The plating rate initially increased and then decreased with the increase of concentration of thiourea,tartaric acid,citric acid,sodium hypophosphite and SnCl2·2H2O as well as the rise of temperature and pH value.The optimized bath was composed of 20 g/L thiourea,40 g/L citric acid,40 g/L tartaric acid,20 g/L sodium hypophosphite,40 g/L SnCl2·2H2O and 2 g/L hydroquinone.The optimized plating parameters were suggested as bath temperature of 80 ℃,pH value of 0.72 and deposition time of 30 min.Under the optimized conditions,the plating bath had good stability,and the deposition rate of Sn coating was as much as 3.12 μm/ h.Resultant Sn coating was composed of uniform and compact crystals and possessed good corrosion resistance,adhesion to substrate and solderability.

关 键 词：化学镀锡 硫脲 酒石酸 柠檬酸 配位剂 沉积速度 

分 类 号：TQ153.1[化学工程—电化学工业]