【摘要】 无铅化进程给电子组装带来了一系列的新问题。主要阐述了气氛对无铅回流焊工艺和性能的影响。与锡铅焊料相比,无铅焊料的熔点高、润湿性差和工艺窗口窄等一系列问题给无铅回流焊带来了新的挑战。焊接时以氮气作为保护气氛对提高可焊性有明显的效果,惰性气体保护可以明显改善无铅焊料的润湿性,适当降低焊接温度,减少工艺缺陷,形成良好的焊点;此外,还原性气氛(如氢气)也能显著改善无铅回流焊焊点质量。更多还原

【Abstract】 The transition from traditional tin-lead to lead-free has brought great challenge to present electronic assembly technology.The effect of reflow atmosphere on lead-free reflow process is introduced.Compared with Sn-Pb eutectic solder,lead-free solders have a high melting point and poor wettability.It has been reported in recent years that soldering in inerting gas of nitrogen can widen the reflow process window,improve the wettability,reduce soldering temperature and improve the reliability of solder joints.Furthermore,reducing atmosphere such as hydrogen atmosphere could also improve the reflow quality of the solder joints.更多还原