BGA无铅焊点零空洞缺陷控制研究

在无铅BGA封装工艺过程中,通过不同组分的BGA焊球合金与焊膏合金组合焊接、焊膏助焊剂活性剂不同配比及其不同再流焊接条件等实验,对焊料合金和助焊剂配比、再流焊接峰值温度、再流保温时间等参数变化,以降低BGA焊点空洞缺陷进行了研究。结果表明选用相同或相似的BGA焊球和焊膏合金组合焊接、选用活性强的焊膏、选择焊接保温时间较长均有助于降低BGA焊点空洞缺陷产生的几率和空洞面积,BGA焊点最佳再流焊接峰值温度为240℃,当峰值温度设置为250℃时,BGA焊点产生空洞缺陷几率会比240℃高出25%～30%。

Study of Zero Voids Control of BGA Lead-Free Solder Joint

To realize effectively zero defects of the BGA solder joint voids,optimizing the solder alloy,scaling powder composition formula,the setting temperature of solder peak reflow,the time of flow holding and other parameters in the unleaded BGA packages process were researched,which have been done by the experiment that the different components of BGA soldered ball alloys,solder paste alloys mix soldering,the formulations of different active agents in scaling powder and the parameters are controlled in reflow,etc.The results show that the same or similar BGA solder ball and solder paste alloys,strong active solder paste,long time of the weld holding,which will help to reduce the rate of defects of BGA solder joint voids and the voids area.Optimal peak reflow temperature of BGA solder joints is 240 ℃,When the peak temperature is 250 ℃,the rate of defects of BGA solder joint voids is 25%-30% higher than that at240 ℃.