【作者】 刘琼；

【导师】 李宁；

【作者基本信息】 哈尔滨工业大学 ， 化学工程与技术， 2007， 硕士

【摘要】 低磷化学镀镍因其优异的可焊性而被广泛的应用在电子领域。因此,研究低磷化学镀镍工艺有重大的实际意义和推广价值。本文分别对乳酸丙酸体系、柠檬酸乙酸体系、丁二酸苹果酸体系三个化学镀镍络合体系进行了研究。分别采用增重法、X射线荧光光谱仪(XRF)、贴滤纸法、挂锡法研究了不同体系对镀速、磷含量、孔隙率、可焊性的影响,并通过体视显微镜和原子力显微镜(AFM)对不同体系的镀层进行表面形貌的观察。通过上述比较确定了乳酸丙酸体系作为低磷化学镀镍的基础体系。将乳酸丙酸体系作为低磷化学镀镍的基础体系,研究了镀液中各成分以及工艺条件对化学镀镍镀速和磷含量的影响,发现提高Ni2+/H2PO2―、增加络合剂和醋酸钠浓度、提高pH值都有利于得到低磷镀层,并确定了各工艺参数的用量范围。通过正交试验,得到了磷含量较低的化学镀镍工艺。这种工艺得到的镀层磷含量为2.46mass%。在上述低磷化学镀镍工艺的基础上,分别研究了三乙醇胺、丙二酸、丁二酸、苹果酸以及乙二胺对镀层外观、镀液稳定性、孔隙率、可焊性、镀速磷含量、微观形貌的影响,从而确定了丁二酸适合作为低磷化学镀镍的络合剂。并通过周期试验检验了镀液的性能和寿命。通过测定添加不同络合剂条件下的阳极极化曲线和阴极极化曲线,发现三乙醇胺加入可以使次亚磷酸钠的氧化速度先增大后减小,丁二酸则使得氧化速度增大;三乙醇胺和丁二酸的加入均使得镍还原电位正移,还原电流增大,但三乙醇胺会使还原电流逐渐增大,而丁二酸会使还原电流先减小后增大。更多还原

【Abstract】 Electroless nickel of low-phosphorous coatings have been widely applied in electronic fields because of its great solderability. Therefore, the study of electroless nickel plating technics of low-phosphorous is of great practical significance and value.In this paper, lactic acid and propionic acid system , citric acid and acetic acid, succinic acid and malic acid system which are the complexing agent systems were researched. The deposition rate is measured through weighing by electro-balance; the P content is analyzed by X-ray fluorescence spectrum(XRF); the porosity is determined by GB5935-86; surface morphology is observed by stereomicroscope and atom force microscope(AFM); the solderability is tested by immersion tin. Through compared the different complexing agent systems, lactic acid and propionic acid system is determined as the electroless nickel of low- phosphorous based system.After determined the based system, the effect of composition in the electrole nickel plating solution and process condition on deposition rate and P content is discussed. Through the research obtained that increase Ni2+/H2PO2― , the concentration of complexing agent and sodium acetate and pH is propitious to low-phosphorous coatings. At the same time the scale of process condition is confirmed. Through orthogonal test, gets the best formula of electroless nickel of low-phosphorous. The P content of the coating obtained from the satisfactory electroless nickel plating is 2.46 mass%.Based on the satisfactory electroless nickel plating technic of low-phosphorous, then study the effect of Triethanolamine, Propandioic, Succinic acid, Malic acid and Ethylene diamine on coating appearance, bath stability, porosity, deposition rate, P content and the surface microtopography. Through these research obtain that Succinic acid is suitable for the complexing agent of electroless nickel of low-phosphorous. The turnover test is made to detect the bath life and the performance of the bath. Then, LVC is applied to study the effect of complexing agent on the cathode polarization curves and anodic polarization curves, The results show that the Triethanolamine can cause sodium hypophosphite oxidation rate increase and then decrease,succinic acid can make sodium hypophosphite oxidation rate increase; triethanolamine and succinic acid can cause the nickel reduction potential is positively shifted and reducing current increased. But triethanolamine can make nickel reduction rate increase, succinic acid cause nickel reduction rate decrease and then increase.更多还原