I'm looking at the various options for tenting/plugging/capping vias in IPC-4761 (Via Protection Guidelines). None of the options seem to address the thermal vias in power pads. We are trying to 1) have a solderable pad, apply paste on that side (of course) 2) prevent solder from creating bumps on the heatsink side (of course) 3) avoid the cost of plugging/capping IPC-4671 states that all forms of one-sided via protection are NOT RECOMMENDED. So here's the question - I know I have seen a picture of a thermal pad in an IPC document where I could see vias with green mask material in them on the paste side (the component side), but the green stuff was only in the holes, which left the thermal pad exposed for soldering. I don't think this would be called TENTING because there's no mask on the pad. but is this an acceptable practice? Can I instruct a bare board fabricator to put mask in holes from the top side, but keep the pad clear? (I can't remember where I saw the picture!) If that's NOT an accepted practice, is there a way to design the hole big enough to plate but small enough to prevent solder flowing through the other side of the board? I couldn't find a discussion of that in the TechNet Archives thanks, Jack