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假焊不良怎么办?

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1#
发表于 2011-10-30 02:15:22 | 只看该作者 回帖奖励 |倒序浏览 |阅读模式


Defect rate: 1%
无铅料用在有铅制程中(230度max),该料表面成分是Sn99.5Cu0.50 ,熔点是227度


下面内容摘自邮件我的分析:

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
2#
发表于 2011-10-30 02:15:27 | 只看该作者
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!
3#
发表于 2011-10-30 02:15:33 | 只看该作者
XXXX换锡膏一试XXXX
4#
 楼主| 发表于 2011-10-30 02:15:39 | 只看该作者
LS的是高手呀。。。
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