Hi Peter,
You are correct. If you plate the barrel on the thin side and the hole
diameter is large, the hole wall will buckle [plastically deform] inwards. On
cooling this causes 'resin recession' or 'hole-wall pull-away,' and
inner-layer [post] separation on layers near the surface.
Most through-holes nowadays are however small-diameter vias, which are more
susceptible to barrel cracking.

Regards,
Werner

In a message dated 03/27/2003 19:27:43, [log in to unmask] writes:
>I heard stories in my last Company about barrels in holes for PTH
>components being "too small" or " too deformed' to permit components to be
>fitted. Turned out to be a combination of finished hole diameter not having
>sufficient component lead/solder clearance and barrel-crushing through
>board expansion/contraction. Maybe wrong choice of PCB materials as well,
>I don't know. It was remarked, however, that the effects would have been
>greatly mitigated if n.f. pads had been retained.

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