Hi,
How does a typical 2 layer PCB board with 4oz copper on both sides stack up look like? Does it have a typical 1.6mm thickness or it is thicker because it has 4oz copper instead of 1oz.
Standard copper thickness is 35um, which is quite thin. With 4oz it may well be 6*35 = 210 um thicker, so your PCB may become 1.8mm. However, PCB thickness is not regarded as an important measurement and tolerances are probably bigger than this difference.
Because of the way PCB’s are made, it’s unlikely that the core will be thinner. Usually the raw material has 17um copper on both sides, then the holes are drilled and made conductive, and then the holes are plated and the outside is thickened with copper by electrolysis. So the most logical step to put more copper on a PCB is to use the same stock, but put it in the electrolysis bath for a longer time. But who knows, a manufacturer that has a lot of such boards may choose a (for them) more cost effective method. Thickening copper with electrolysis is a relatively slow and thus expensive process.
Another, but much more important factor is that due to etching limits you have to use wider tracks and clearances. You have to look at your manufacturers website for what their limits are.
1 Like
You best bet is to query your boardhouse (or shop around). They will typically stock what is typically used: 1/2 oz at 0.6. Outside of the general purpose you need to live with whatever they have on order of their supply chain can get hold of.
Now if you want to pay a bit you can get almost whatever you like 
3 Likes
This topic was automatically closed 90 days after the last reply. New replies are no longer allowed.