Laser drilled 0.1mm microvias are OK, they do not suck significant amounts of solder.
If you have 0.2mm drill available at your fab you are using, that's usually OK as well, but maybe a bit iffy.
Particularly on lead-free, which flows much more slowly than leaded solder. I've seen QFN pads that didn't wick with this combination, 0.3mm even. (Some vias do wick visibly, and moreso the larger the hole. It's not a perfectly repeatable thing, sometimes none do, sometimes a few...)
By the way, do not use tented vias, in an effort to block the flow of solder into the hole -- this backfires, quite literally: the solder flux (and other residues from PCB fab) outgasses through the open end, causing voids in your solder joint. Either leave the via open both sides, or tent/cap it both sides.
A tented via
touching a pad, however, will neither void the solder joint, nor steal solder. This can help squeeze out precious fractions of a mm in a design.
Copper-filled holes are ultimate, but expensive. The pads look completely normal and flat. No solder sucking, and massively good electrical and thermal conductivity. They conduct a lot of heat during soldering, though, which you must take into account, balancing the pads.
Yup. There's also filled and capped vias. Expensive -- there are additional steps to mask, paste and plate only the target holes, by hand as I understand it. The result is fantastic, not as conductive as copper-filled of course, but the vias are completely flat and no solder wicks away.
Speaking of laser drilled, they often plate shut anyway. You might see a little dimple on the board, not planar like filled-and-capped, but hardly anything to worry about. HDI has this between every layer pair, so you don't have vias blocking traces or components on the opposite side, it's a routing free-for-all! You can easily route fine pitch BGAs.
Tim