The laser beam drills by focusing {HEAD ~ the energy} of the laser onto {TAIL ~ the substrate material} 18 to vaporize or melt the substrate to form a blind hole, or well 
The laser beam drills by focusing { HEAD ~ the energy } of the laser onto { TAIL ~ the substrate material } 18 to vaporize or melt the substrate to form a blind hole , or well
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH