废旧BGA器件二次利用的焊接强度研究

BGA器件首先经历2 000 h的温循老化以接近废旧状态, 再以自重跌落, 然后用锡膏印刷的方法完成焊锡球的修复, 最后利用Dage4000测试机对不同状态的器件进行焊锡球推拉力测试。结果发现, 随着温循老化的时间增加, 失效模式逐渐由韧性失效主导转向脆性失效主导。当焊锡球被修复后, 失效模式变为混合模式。通过强度对比可以发现, 器件的焊接强度随着温循老化时间的增加而降低。当焊锡球被修复后, 焊接强度可以恢复到初始状态的80%左右。修复的焊锡球产生的再生金属间化合物可能是造成焊接强度变化的主要原因。The BGA went through 2 000 h thermal aging to reach the waste package condition, then the waste BGA were broken up and repaired by falling weight and solder paste printing processes. Finally, the solder ball shear & pull tests were performed to measure the soldering strength by using Dage4000 tester. Results show that with the increasing aging time, the dominant failure mode turns from ductile to brittle. After solder joints repairing, the dominant failure mode is mixed modes. From the strength comparison, it is found that with the increasing aging time, the soldering strength decreases.After solder joints repairing, the soldering strength can recover to about 80% of original condition. The difference of soldering strength may be induced by the re-born inter metallic compound during the solder joints repairing.