Hi Ralph -

Just a few quick comments:

In general, ever since the origins of "popcorning" were determined, both the
assembly and components industry have taken the approach to keep the parts dry
and dehumidified.  There have been many published reports on the phenomena.

There are a number of grades of plastics, which have varying periods of
"floor life" during which they can safely withstand reflow temperatures.
"Floor life" being that period before the plastic has absorbed sufficient
moisture to be at risk.

The objective is to avoid "popcorning" not let it crack and then keep stuff
out of the cracks.  Their logic for this decision would seem very questionable.

Have your folks considered the issues of attempting to conformal coat over no
clean residues?  (Particularly with some of the low VOC coatings, which don't
tend to take some of the lower grade process residues into solution.)

By the way, the Motorola folks have quite a number of pubs available on the
care and feeding of their parts relative to this subject.

Well, that's all for the moment.  I'm sure the others will have a great deal
to add.

Good luck - Kelly

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