金属微细结构化学镀镍及镀液稳定性分析

化学镀镍技术是一种有效的表面微机械加工艺,为此介绍了碱性溶液中硅表面化学镀镍的工艺过程及其镀液稳定性测试方法.化学镀镍是一个表面自催化的氧化还原过程,基底表面的前处理十分关键,对整个实验过程有着决定性影响.半导体硅表面没有催化活性,施镀之前要对基底先进行活化处理,但在处理过程中不可避免引入的少量钯粒子以及从基底表面扩散到镀液中的镍粒子都具有很强的催化活性,使镀液在瞬时分解,析出海绵状镍,导致镀液失效.因此,应合理选择稳定剂以阻止自分解反应,使镀液稳定.实验结果表明,在相同施镀条件下镀液的稳定性随时间、装载比的变化而发生显著变化.

Electroless Nickel Deposition of Metal Microstructure and the Stability Evaluation

The process of electroless nickel deposition on silicon from ammoniacal bath and the stability evaluation of plating solution are investigated. Electroless nickel plating is a surface autocatalytic redox process. Pretreatment of the substrate surface has a decisive influence during the whole process. The silicon surface has no autocatalytic ability, so it entails an activation in advance of being plated. It can not be avoided that there are trace amount of palladium particles involved in the plating solution in the process. In addition, nickel particles by reversed diffusion from the plating substrate exist in the bath. Those tiny particles cause self-decomposition of the solution and produce a lot of fine nickel flakes. A proper stabilization system will prohibit the self-decomposition to enhance the solution stability. It is indicated that the solution stability in constant plating conditions changes dramatically with time and plating loading.