SMT/THT混装回流焊工艺技术研究

摘要

含有大量表面贴装元件和少量通孔插装元件的高密度混装型印制板是电子装联技术的主要类型，这种SMT/THT混装型印制板采用传统的回流焊接无法一次完成印制板的组装。采用波峰焊或手工焊接会增加工序而且可能使印制板翘曲变形，采用SMT/THT混装回流焊则可以较好的解决问题。通过选用可用于回流焊的表面贴装和通孔元件制作样件，对通孔元件的焊膏印刷模板的合理设计，导入SMT/THT混装回流焊工艺，完成试验板的组装和焊接，焊点质量满足要求。%High density and mixed-mounting printed circuit boards, which contain lots of surface mount devices and a few of through hole components, is the main type of electronic assembly category. Traditional reflow soldering couldn’t finish mounting SMT/THT mixed PCBs in one process. Otherwise, wave soldering or hand soldering may add extra processes and induce wrapping to PCBs. These problems could be resolved using SMT/THT mixed reflow soldering process. In this process, firstly, all of SMCs and THCs are pre-prepared, then designed reasonable solder printing stencil for THCs, finally adopted SMT/THT mixed reflow soldering process. The mixed-mounting PCBs were completed, the quality of soldering joints are up to demands.