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SMT electronics assembly manufacturing forum.


warped boards and cracked solder joints

#18024

warped boards and cracked solder joints | 29 October, 2001

We recently have received a lot of warped (bowed and/or twisted behond IPC 600 specs.) bare boards (some our fabricator's fault, some ours by design) and I can't help but figure that long term reliability will suffer when building product with them.

Can anyone point me to any trade pubs. or papers re: the affect of warp (and the associated stress on solder connections on installed assemblies) on reliability? Higher rate of fatigue cracks during accelerated stress testing of twisted boards vs. flat boards, for instance?

Thanks,

Steve

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#18026

warped boards and cracked solder joints | 29 October, 2001

DON'T do it!!! The two problems you'll have are: 1 Poor manufacturing process control, resulting in weak solder connections. 2 Weak solder connections are stressed, when the board is straightened upon installation in the "box".

There's several hits on ... warp ... in the SMTA [http://www.smta.org] "knowledgebase". Also consider looking in: * SMT magazine [http://smt.pennnet.com/home.cfm] * Circuits Assembly [http://www.cassembly.com/] * EP&P http://www.e-insite.net/epp/ * PC Fab http://www.pcfab.com/ * Etc

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#18030

warped boards and cracked solder joints | 30 October, 2001

Hey, Preacher, choir here.

Unfortunately I didn't get to make the call here (hot boards, new product, same ol' same ol'), but I dam* well am looking for future (print) backup to assist in persuading the bottom line guys that it's cheaper to wait for good boards. Thanks for validating my concerns, though. ;)

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