Could you tell me how fast you can drill holes in boards?
This depends on variables like material type, thickness, copper weight, layer count, drill machine type, etc. Using a standard FR4 six layer panel, .060” thick with .5oz cores and a 20mil drill as a baseline a newer machine with linear drive motors will drill around 300-325 holes per minute. An older machine with leadscrews will drill around 175 holes per minute.
How does that change per diameter?
Smaller and larger diameters need to run slower. Smaller to maintain accuracy/registration and larger to avoid damaging the panel.
Per # drill changes (is that due to death of bit or diameter changes?)
Each material/board type is tied to a diameter page that controls spindle speed, infeed & retract rates and hit counts. A 20mil bit drilling a standard FR4 panel will go around 1200 hits but this dops to 200 when drilling a ceramic filled PTFE. It’s important not to overuse the bits as it will create all sorts of quality issues. With all the material sets now in use along with mixed constructions it’s also important to have a software system controlling the drill room. The one we use pulls the stack-up information then automatically loads the drill program with the correct diameter page for that construction into the machines. This eliminates operator error and provides traceability.
What about with laser drills?
The laser is all about using a specific amount of energy to ablate/vaporize a specific amount of material. Again this depends on the machine and hole density but typically drilling a 6mil via through 9um foil and 3mils of dielectric will run around 2000 holes per minute.
So is 20mil the optimum for your process? Or is there a range like 20mil-50mil that are all roughly equivalent?