As many of you, I have been concerned and questioned voiding %
and volume plus all the rest. However, I keep coming back to
one thing haunting. What's in the voids?

In other times, I found horrific problems with residual flux
entrapped in the voids. This often was effected by solder
termination area contamination. The flux remained in the joint
trying to do what was intended - fight the infection. Often,
this resulted in failures as the solder joint continued to fail
as it was "erroded" away.

Certainly, X-Ray points the way to what is to be X-Sectioned.
Beyond that, some type chemical analysis technique needs to
examine the residue left in the void. I have graphic evidence
of this phenomonom as, probably, do most of you. Does this
continue to be an issue in the BGA world as it did/does in the
PLCC/QFP arena?

Earl Moon

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