1, Check the defect samples under microscope, The solder on the PCB PAD is sufficient compare with the OK Pins and can fully melt , but the solder on PIN of component can’t fully melt which coursed the part of solder can not joint with solder pad, so the non-wetting happened
2, Check reflow profile, per the below IR Reflow profile, it is noted that 205-230degree Max IR/C convection reflow Temp was used at XXX reflow process, check the profile every shift, the reflow Temp not out of control
3, Since the devices XXX are the RoHS 6/6 (lead free) design, and the melting point of the solder is 227degree ( Sn99.5Cu0.50 )
4, Per the IPC standard on the lead free part(RoHS 6/6), the IR reflow soldering Temp should be 245 degree above, whereas XXX run tin lead process ,the reflow Temp of Max 205-230 degree can’t meet the lead free component's soldering Temp requirement
作者: 肥仔超 时间: 2011-10-30 02:15
我看都看不懂，但是帮你顶上去吧，版主扣我分也认了，谁让我这么热心呢！作者: 阿J 时间: 2011-10-30 02:15
XXXX换锡膏一试XXXX作者: 清风瘦马 时间: 2011-10-30 02:15
LS的是高手呀。。。
