甲基磺酸亚光纯锡电镀添加剂的研究

Methylsulfonate Additive for Matt Pure Tin Electroplating

锡铅合金因其优良的可焊性和耐晶须性能广泛应用于电子工业中。但世界各国正在不断颁布严格的法规限制电子产品中铅的使用,在这样的背景下,国内外都在积极开发无铅电镀工艺,其中电镀纯锡工艺得到电子厂商的普遍认可。运用电化学和化学方法开发了一种亚光纯锡电镀添加剂。通过HullCell试验和电镀模拟试验确定了工艺:150～210g/L甲基磺酸,12～18g/LSn2+,温度15～25℃,电流密度0.5～2.0A/dm2,10～80mL/L添加剂BSn-2004,并测定了镀液和镀层的性能。结果表明,该添加剂工艺稳定性好,且镀层可焊性优良、抗变色能力强,可取代高污染的锡铅电镀工艺。

Tin-lead alloy electroplating has been widely applied in electronic industry for its excellent solderability and free whisker. But most strict laws for banning lead in electronic products were been legislating gradually in some countries or organizations. Some lead-free electroplating processes have been developed at home and abroad. In these processes, electroplating pure tin finishes on electronic components are a leading contender to replace the industry standard tin-lead. An additive for matt pure tin electroplating was developed by electrochemical and chemical methods. The process conditions such as methylsulfonic acid, bivalent tin ion, temperature, current density and additive were determined by Hull Cell test and electroplating analogue test. The properties of electroplating bath and deposit were also measured. The result proves that the process has advantages of high stabilization, excellent solderability and antitarnishing, which may replace high-pollution tin-lead electroplating technology.