Drilling hole and Finish hole

Seeed Services Fusion PCB/ PCBA Services
#1

Hi,

On the DRC list on the Fusion service page it lists “Drilling Hole (Mechanical)” as being a minimum diameter of 0.3mm (11.81th) and “Finish Hole (Mechanical)” as being 0.8mm (31th) and I am wondering what the difference between these are. Is a drilling hole not through-hole plated and a finish hole is through-hole plated? I am doing a very small board for a project and I need the smallest possible vias to save space, can someone recommend the smallest allowed via hole size? Thanks very much!

#2

I would like to echo OP’s question. The Fusion Eagle DRC file allows for the smaller vias (12mil), but I would like to know the difference between Finish and Drilling Holes. I would think a via would be a ‘Finish Hole’, i’e’ finished with plating in order to make an electrical connection between the top and bottom layers.