Well, apparently heat generated from drilling a hole was enough to melt the protective plastic layer 2x the size of the drill hole…thereby ruining the stack of Keyfobs I was drilling.
Seriously…?
o dear, so how would you make a hole then in a sheet of carbon, low speed + coolant?
I have to drill very slowly to avoid melting the matrix
did the same with epoxy only set the other day…perfect!!! epoxy doest melt…figures since the rest of my day has been going along the same lines.
melt down time.
Use masking tape to top and bottom 
If you use a sharp drill it really helps. We make a part with about 60 holes and I need to sharpen the drills 50 or more times to get a good result. We also use carbide drills that want to be used at high speeds.