Epoxy filled thermal vias in D2PAK drain pad

[ocset]

We have a D2PAK FET  thats dissipating 12W. It’s a linear regulator usage.
The D2PAK rests on a  4 layer FR4 PCB which sits on thermal rubber pad which rests on an earthed heatsink.
We need to have thermal vias under the D2PAK, actually in the drain pad… but we cannot have too many, due to the potential for solder wicking. Therefore, we wish to use epoxy filled thermal vias in the D2PAK drain pad…….to stop wicking..then we believe we will be able to have  a good number of 0.4mm diameter thermal vias in the D2PAK drain pad….do you agree?

[filssavi]

There are specific processes and products that can be silk screened upon the pcb and after curing they can be put through the reflow process, they have also some thermal conductivity(still nothing compared to copper so the more VIAs  the better) but 0.4 mm is too small, the producer of the paste I looked at (Peters) recommends 0.8mm

The best process though is still plugged vias