Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

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Wavesolder for a second PASS

Hany A. Salam

#18524

Wavesolder for a second PASS | 31 December, 2001

Dear all :

We are suffering a severe curvature in our boards when coming out of the wave solder m/c. An Engineer suggested to enter them again for a second pass in the m/c expecting board were thermally mistreated just after the W.S.

Can this really help ? Can it harm the boards knowing that each one has two BGA�s on ?.

How to avoid the curvature problem in the future?.

Regards. Hany.

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Don Adams

#18527

Wavesolder for a second PASS | 31 December, 2001

The second pass in the wave is pretty extreme and will probably aggravate the conditions which caused warpage in the first place. Areas to look for problems,

The lay up of the boards at fabrication or the materials used can lead to warpage. Work with your fabricator.

Is the design a balanced constrution from a copper and dielectric standpoint?

Is your profile too hot? If you need a hot profile for wick up look at thermal reliefs or Higher Tg materials.

Is the board correctly supported in the process? A wave pallet may help.

How are the boards handled after soldering while they cool? I have seen wrinkles added to boards from racking before they cool.

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