de-panelizing scored PCBs

One can get PCBs manufactured as one big board that contains multiple copies
of the intended product, eg an NxM array of little PCBs. The separation can
either be by a v-score, or by tab-routing.

With tab-routing, it's easy to bust the individual pieces out by hand, but
one is left with non-straight edges because of the spots where the tabs
connect. This is fine in some applications, but a problem in applications
where the board needs to *** up against eg an enclosure edge.

With v-scoring, it seems that it is physically a bit challenging to separate
the boards without applying a lot of stress to the board, something I'm
reluctant to do after the parts have all been soldered on.

How is separation of v-scored boards done, in commercial practice? Is there
some trick to it, such as warming the board first, or using some sort of
clamp?


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