大家好，

向各位请教一个问题，因为有一个元件的特殊封装（QFP mix QFN）水洗工艺过程中很难洗干净QFN下散热Pad的Flux残留。我们的提议是更改PCB设计，改动单个大的散热焊盘为多个小焊盘并从PCB反面增加非电镀通孔以便水洗时溶液容易通过，因为散热焊盘面积的缩小会导致散热效率不同，我们需要提供给客户一份散热分析报告以证明这样更改的可行性，不知如何来做这个散热分析？
目前不能改成免洗工艺原因是测试点的Flux残留会影响到测试的可靠性。

WenWei
Flextroncis Suzhou

  
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