电路板激光钎焊系统

Laser solder welding system of PCB

摘要: 采用激光作为热源对电路板端子进行焊接，在激光聚焦头与电路板之间添加自动送丝机构,对电路板焊盘处进行自动送丝处理。阐述了设备总体结构、自动送丝机构、钎焊工艺流程及实际焊接效果。其中，钎焊工艺流程包括电路板预热处理、自动送丝、锡丝形成液滴、锡滴冷却和形成钎焊接头的过程；重点比较研究了预热和非预热处理的钎焊效果。结果表明，经预热处理焊锡液滴刚好覆盖焊盘，焊点圆滑饱满，无明显缺口，无脱落现象，效果更好。

Abstract: The laser was used as heat source to weld the terminal of PCB. The automatic tin wire feeding system was mounted between the focus head of laser and PCB. Before the laser welding, the laser was used to preheat the PCB, then the tin wire was fed to the underneath of the focus head of laser. The tin wire was melted into droplet by high power laser, transferred to the PCB, and formed the tin welding spot.