> >> A friend got burned by poor plating a long time ago, and on his
> >> protos, insists on filling the vias with solder- just in case the
> >> plating was poor. Valid, but I haven't seen a bad via on my boards
> in
> >> years- if the vias are that bad, there probably are other problems.
> >
> >That would be either a very long time ago while the process was
> getting well sorted, or it was a manufacturer just setting up PTH
> process, and not yet familiar with the process control requirements. If
> one has a problem with via quality these days then the manufacturer
> should be shouted at very loudly.
>=20
> You may want to solder-fill vias to help in high current or high
> thermal load situations, on flow-soldered PCBs,  although relying on it
> would probably mean you'd want to inspect to make sure they got filled.

When doing space flight qualified PCBs there are two options, don't fill th=
e via at all, or fully fill it. This follows some research that IBM did som=
e years ago when researching thermal cycling problems with PTH PCBs.=20

AIUI there is no preference either way, and for all our boards we go with u=
nfilled vias unless there is a specific thermal or current carrying capacit=
y requirement, or inspection of the soldering work shows that a via has had=
 solder start to fill a via.
--=20
Scanned by iCritical.

--=20
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