Plated holes
Holes can be drilled with diameters 0.25 mm, 0.3 mm, 0.4 mm, 0.5 mm etc. up to 6.2 mm. Holes larger than 6.2 mm are drilled or routed. Minimum hole size is dependent on board thickness.

Unplated holes
If possible, avoid using unplated holes. Unplated holes require additional steps in the manufacturing process and thereby lengthening the manufacturing time.

Copper features must be kept at least 10% of the hole diameter away from the edge of the undplated hole. If your CAD software restricts holes with pads, chose a pad diameter which is smaller then the hole diameter.

Thickness Min. hole
<= 1.6 mm 0.25 mm
> 1.6 mm, <= 2.4 mm 0.4 mm
> 2.4 mm 0.5mm

Blind and buried via holes
Elprint can produce blind via holes in cases where the hole goes between the outer layer and the first inner layer when using specific stackups (e.g. 4063 and 6036).
Contact your local sale soffice for additional information.