Scott:

The concern, to our experience, is more in the moisture absorption than the 
other two (oxidation and contamination). We require boards to be baked prior to 
assembly processes if their storage time is over 1 year. Failing to bake runs a 
risk of delamination at SMT reflow and blow holes at wave soldering. Oxidation 
(and/or intermetallics growth) usually would not be an issue for HASL finish if 
sufficient thickness is coated. Neither is contamination if boards are properly 
wrapped. For OSP finish, however, oxidation could be a problem too.

Regards,
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