Homebrew PCBs

Stefan,

By chance do you happen to know what process the board MFGs use to 
remove the excess copper? (as in etching boards the way we do to leave 
only the traces)

 I am guessing it is a chemical etching of some sort, but have no idea 
beyond a guess.

Chris


 
> it makes no sense to coat the PCBs with something that prevents 
coating  
> with resist, intentionally or by accident.
> The manufacturer could not sell the material so he can not produce 
it.
> If it was coated with some "mystery material" it must have been by  
> accident later on, or maybe a silly person "preventing corrosion".
> 
> In PCB houses the boards are cleaned by motorised scrubbers and 
water  
> only, usually, i'm told.
> 
> ST
>