I am having a board made and talking with pcbcart about plugged vias. They've tried to help me, but I'm still not really clear on what is possible or normal.
I have several QFN/MLF devices and I want to put vias in the central pad to improve grounding and dissipate heat. To prevent solder paste from draining away during reflow, I want to plug those vias.
But when I ask pcbcart how to do this they describe what looks to me like plugged and tented vias. They want me to have the solder mask over the vias. In other words, my "stop-mask" over the central QFN pad would have holes in it.
But I don't really want that since the solder mask would prevent the solder paste from adhering to the via's annulus (ring) during reflow. I believe what I want is a normal via (which has a solder mask opening) that is just filled with something to prevent draining.
Does this make sense or am I asking for something unusual?