exposed pad in EQFP package

I have done this before on the same chip using vias. I forgot how large they were... > 20 for sure. To solder it correctly, flood the vias with flux and then add solder until it sinks into the vias. As mentioned above, if you do not connect that pad, you will have serious issues - if your chip runs flaky until you press hard on it, your pad is not connected. The height did not seem to matter in my case. The better way to do it is of course through solder paste...