Drills & Throughplating

Printed Circuit Board drill tool

A unique differentiation in your data between plated-through holes (PTH) and non plated- through holes (npth) is of fundamental importance!

This means that you must (additional to your Gerber data) output a separate drilling program for pth- and npth drill holes, e.g. as Excellon or Sieb&Meyer data. For multilayers, this also applies for blind  and buried vias. ODB++ data contain the necessary information automatically!

Component holes need the accurate hole diamater, vias may have a smaller final diameter due to electroplating (plated through) and PCB surface. Basically, we assume holes < 0.5mm are vias.


  • Please always specify the final hole diameter within the PCB data.
  • Hole diameter ≥ 0.5mm will be final diameters.
  • Component holes < 0.5mm need to be specified in the order!

Producible hole diameters

TypeSmallest ØLargest ØMax. aspect ratio
TypeDrill hole npthSmallest Ø200µmLargest Ø6,0mm (larger = milling)Max. aspect ratio1:10 (rfq 1:12)
TypeDrill hole pthSmallest Ø75µm*Largest Ø6,0mmMax. aspect ratio1:12
TypeBlind via**Smallest Ø75µm*Largest Ø0,4mmMax. aspect ratio1:1 (rfq 1:1,2)
TypeBuried viaSmallest Ø75µm*Largest Ø0,4mmMax. aspect ratio1:12

* Final diameter after surface finishing!
** Not possible with HAL surface!

Aspect ratio

The aspect ratio indicates the relationship between the technically producible final diameter depending on the material thickness. Multi-CB can produce aspect ratios up to a maximum of 1:12, for blind vias 1:1,2.

Sample aspect ratios

Material thicknessdrill-Ø minfinal-Ø min.*
Material thickness6,0mmdrill-Ø min600µmfinal-Ø min.*550µm
Material thickness3,0mmdrill-Ø min300µmfinal-Ø min.*250µm
Material thickness2,0mmdrill-Ø min200µmfinal-Ø min.*150µm

* Final diameter after through-plating

Tooling / assembly holes (npth)

Tooling or assembly holes (normally with diam. = 3.05mm) should be placed in the same drilling program as pth drill holes, by the customer. Thus, there are no additional tolerances for re-placement into the drill- / milling machine.

Component holes

It is normally advisable to select a hole diameter in the upper tolerance region of the corresponding part. You should design the annular rings as large as possible.

Please note:

  • Please specify component holes ≤ 0.5mm with your order!
  • Component holes ≤ 0.6mm must be manufactured with a chemical surface, otherwise these holes will be filled with tin during the HAL process!