Maybe I should know better than to ask two questions in the same email, but
they're related...
I got into a discussion about the hole fill requirement for some large
through-hole power devices and connectors. The supplier is worried about
using a "percentage" hole fill measurement, because he says that even if
the hole is 75% full (or whatever percentage we want to use) the hole wall
will not be WETTED 75%. He maintains that the cold solder can extend up
farther than the actual portion that makes a good joint. So he is looking
at the TOP PAD WETTING for verification of a good solder joint, even though
we don't require it.

Q1) It seems like an inspection procedure looking for WETTING instead of
HOLE FILL is not what is intended in IPC, but does he have a point? The
hole fill problem is with Selective Soldering, not Reflow

Q2) Wanting to provide bare board designs using good DFM practices, I would
be willing to reduce my thermal spoke widths so the solder will flow
better, but I can't find a calculation that would tell me what I need for
something like 10A. There is nothing about this in the IPC-2152 Current
Carrying standard. Is there a rough guideline I can use for current through
planes using thermal relief??

thanks
Jack


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