化学镀镍浸金和化学镀镍镀钯浸金表面处理工艺概述及发展趋势

Current status and development prospect of ENIG and ENEPIG

当今电子信息产品便携小巧、功能多样的发展趋势,推动了其所需PCB产品向轻薄、信号传送速度更快的方向发展,这对PCB表面处理工艺的稳定性、可靠性提出了新的挑战。另一方面,欧盟在2003年制定的RoHS、WEEE等规范都旨在消除电子产品中铅、汞等有害的物质,推动了PCB表面处理技术向绿色无铅化方向发展。化学镀镍浸金(简称ENIG)和在其基础上发展的化学镀镍镀钯浸金(简称ENEPIG)表面处理技术可以适应PCB精细线路多类型元件的无铅焊接装配要求。上述两种表面处理技术克服了由无铅工艺带来的诸多问题,但其自身也面临如何进一步降低成本和技术难度,提高工艺可靠性等一系列问题。

The miniaturization and multiple functions of electronic devices require the development of thinner PCB with higher speed of signal transmission. Accordingly, these developments lead to challenges for surface ifnishes of PCB. On the other hand, legislations, such as RoHS and WEEE, restrict the use of hazardous materials containing lead (Pb) and mercury (Hg) in the manufacture of various type of electronic products, which calls for surface ifnishes compatible to lead-free solder. Both electroless nickel immersion gold ifnish (ENIG) and electroless nickel electroless palladium immersion gold finish (ENEPIG) can be adapted to lead-free soldering. Beneifts of ENIG include excellent electric contacting surface, stable performance and so on. The technique details, applications and comparison of ENIG and ENEPIG are presented, and their development prospect is also discussed.