Part 9/10/11 - Drilling the PCB
Channel: Eurocircuits
Date: 2014-05-08

Now we drill the holes for leaded components and the via holes that link the copper layers together.  First we use an X-ray drill to locate  targets in the copper of the inner layers.  The machine drills registration holes to ensure that we will drill precisely through the center of the inner layer pads.

http://www.eurocircuits.com/index.php/making-a-pcb-eductional-movies/41-drilling-the-pcb