I've been down this road many times and have convinced "black magic"
engineering folks that holes directly in SMT pads are not necessary.
Using DFM neck down features works just fine with a little engineer
stuff "tweaking".

You can contact Mahesh Bett at SSE Telecommunications in Fremont, CA to
get more evidence. He was the quality persone caught in the middle of my
consulting efforts and top management pushing poor engineering types to
run the experiments.

If you do have to place holes in SMT termination areas, you can either
place expensive micro vias or conventional vias that are "capped" in the
relamination and surface plating process. Both have been done by me,
Multek, and Praegetzer, as examples

It's not easy getting to first base, but it's a whole lot easier to do
it right at the design level than watching solder going down the "tubes"
during reflow. Also, expensive rework, not repair (because you always
end up cracking the devices you touch up), is always ready for you just
to get close to acceptalbe solder joints. If you'd like to talk off
forum, contact me at the address below or the one in this message's
heading.

Good Luck,

Earl Moon ([log in to unmask])

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