Wire width / Isolation gap

  Our customers often ask how thick copper can they use on their boards. For us, as a PCB manufacturer would be best to produce two different boards: one for signal part and second for power part of the design. For the signal part we could use thinner copper foil and for power part thicker. But this is usually not the case and brings the question how thick copper should I use so the board is producible. It is necessary to understand how PCBs are made and what the risks when using thick copper foil are. It is not only under-etching of the wire, but also about total balance of design with regards to galvanic process. It is impossible for any galvanic process to plate well boards that have large copper areas on one side and fine micro wires on second side.

Thickness of Cu foil Wire width, annular ring ( driller / pad) Isolation gap Under-etching
9µm 0,10mm 0,10mm 20µm
18µm 0,12mm 0,12mm 30µm
35µm 0,20mm 0,15mm 40µm
50µm 0,25mm 0,20mm 50µm
70µm 0,30mm 0,20mm 70µm
105µm 0,35mm 0,20mm 105µm

- values in table are the lowest possible. The higher the values are, the better.

Other possibilities can be consulted with our technicians.


- for the inner layers of multilayer printed circuit board is important to keep a minimum distance from the edge of the hole to the first object nearest 0.3 mm !! (Drill diameter is 0.1 mm larger than the hole in the final design of the system)

  company adress :
Žateckých 1532/7
140 00 Praha 4, Česká republika

  place of business :
Technologický park Běchovice
190 11 Praha 9, Česká republika

tel: + 420 222 729 257, + 420 222 590 402
fax: + 420 222 724 032