硫酸铈铵对甲烷磺酸浸镀银结晶过程的影响  

Effect of Ceric Ammonium Sulfate Sulphate on Crystallization Process of Immersion Silver Plating in Methane Sulfonic Acid System

作　　者：吴道新[1] 杨荣华[1] 肖忠良[1] 王毅玮 姚文娟 周光华 王伟业 WU Dao-xin;YANG Rong-hua;XIAO Zhong-liang;WANG Yi-wei;YAO Wen-juan;ZHOU Guang-hua;WANG Wei-ye(School of Chemistry and Biological Engineering,Changsha University of Science and Technology,Changsha 410114,China;Aoshikang Technology Co.,Ltd,Yiyang 413000,China)

机构地区：[1]长沙理工大学化学与生物工程学院,长沙410114 [2]奥士康科技股份有限公司,湖南益阳413000

出　　处：《表面技术》2019年第9期266-272,共7页Surface Technology

基　　金：国家自然科学基金(51604042,51774051,31527803,21275022,21545010&21501015);中国科学院环境监测STS项目(KFJ-SW-STS-173);湖南省科技计划项目(2015GK1046);湖南省战略性新兴产业科技攻关与重大成果转化项目(No.2015GK1046);国家工业信息化部、财经部绿色制造系统集成项目;长沙市科技计划项目(kq1701077,kq1706063)~~

摘　　要：目的探究添加剂硫酸铈铵对铜基材上进行置换镀银的影响,提高对置换镀异相成核机理的认识。方法应用循环伏安(CV)、塔菲尔曲线、交流阻抗(EIS)、电化学噪声(EPN)等电化学方法及扫描电子显微镜(SEM)技术对不同浓度的硫酸铈铵镀银液环境进行研究。结果随着硫酸铈铵浓度的增加,Ag[(NH3)2]^+络合物量增加,导致阴极还原阻力增大,同时Ce^4+吸附在铜表面,阻碍了铜的氧化反应和银离子的还原反应,阳极与阴极交换电流密度分别下降33.9%和13.4%。当硫酸铈铵的质量浓度达到6mg/L时,EIS中频区容抗弧直径显著增大,硫酸铈铵对置换镀银阳极的影响大于阴极。电化学噪声时域信号与SEM图像结合比较显示,具有大电位漂移的结晶EN对应于银沉积物松散且不均匀的结构,而具有小电位漂移的EN对应于致密层。基于小波变换的电化学噪声能量分布图(EDP)表明,随着硫酸铈铵浓度的增加,B、C区累积的相对能量减小,区域A的能量增加。结论硫酸铈铵镀银液中,Ce^4+在凹凸不平的铜层表面吸附,形成不同厚度的吸附层,来实现银层结构的致密性与平整性。由于硫酸铈铵对镀银阴极与阳极的阻碍作用,使得银沉积系统控制步骤为“扩散控制—混合控制—活化控制”逐步转变。The work aims to study the effect of the additive ammonium cerium sulfate on displacement silver plating on copper substrate and improve the understanding of the heterogeneous nucleation mechanism during displacement plating.The ammonium cerium sulphate of different concentrations for silver plating was studied by cyclic voltammetry (CV),Tafel curve, electrochemical impedance spectroscopy (EIS),electrochemical noise (EPN) and scanning electron microscope (SEM).As the concentration of ceric ammonium sulfate increased,the amount of Ag[(NH3)2]^+ increased,thus resulting in larger resistance in cathode reduction.The adsorption of Ce^4+ on the copper surface hindered the oxidation reaction of copper and the reduction reaction of silver ions.The exchange current density of anode and cathode were decreased by 33.9% and 13.4%,respectively. When the concentration of ceric ammonium sulfate reached 6 mg/L,the capacitive reactance arc in the middle of the EIS was significantly increased,so the effect of ceric ammonium sulfate on the anode was greater than that of the cathode.Electrochemical noise time-domain signal and SEM image displayed that the crystalline EN with large potential drift corresponded to the loose and uneven structure of silver deposit,while EN with small potential drift corresponded to the dense layer.The energy distribution plot (EDP) based on wavelet transformation showed that the accumulated relative energy in region B and C decreased,while the energy of region A increased significantly with the increase of ceric ammonium sulfate concentration.Ce^4+ can realize dense and flat silver layer structure by forming adsorption layer of different thickness at the pit sites and protrusion sites in silver-plating bath with ceric ammonium sulfate.The ceric ammonium sulfate can inhibit the cathode and anode in the process of silver plating,so the control step of silver deposition system changes from diffusion-control through mixing control to activation control.

关 键 词：置换镀银 塔菲尔 交流阻抗 成核机理 电化学噪声 印制电路板 

分 类 号：TG153.1[金属学及工艺—热处理]