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

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Wet PCB Assemblies

Bill Graf

#23048

Wet PCB Assemblies | 16 January, 2003

I have received a few boxes of fully assembled boards that have damaged packaging boxes due to rain water. There is visible moisture inside the ESD bag. I have no idea how long these boards have been exposed to moisture. Does anyone have a procedure for drying out the boards without causing conponent damage or latent failures.

Bill G.

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#23071

Wet PCB Assemblies | 19 January, 2003

For laminated FR4 PCB, we bake between 6 and 24 hours at 100�C. [Search for other bake recipes in the fine SMTnet Archives.] Alot of the determination of baking time is a function of: * Amount of moisture absorbed. * Amount of moisture you need to remove for down stream operations. * Amount of reduction of the solderability of pads you can accept / deal with.

I'd trash the ESD bags prior to baking. They'll be tough to recover and they're cheap.

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