Double-sided PCBs
Standard

With overhead expenses

Basic copper Final copper (1)Min. ring (2)Basic copperFinal copper (1)Min. ring (2)
18µm43µm200µm/8mil70µm95µm300µm/12mil
35µm60µm200µm/8mil105µm130µm325µm/13mil

 

The min. thickness of the final copper is given in the above table.

 

 

1. Final copper

2. Min. ring

3. Final diameter of the hole after plating and soldering

4. Drill diameter

5. Pad diameter    

 

Plated through-hole microsection

 

 

The strength of the hole metal cylinder is less in holes with larger diameter. It is not recommended to use plated through holes with the diameter larger than 5 mm for electrical contacting between the layers.  The picture shows a possible solution with using plated through holes with smaller diameter, whose final conductivity is equal to that of the copper cylinder of a large diameter hole, if plated.