re why circuit boards are green kuusama kaarne cs tut fi kuusama juha vtt writes not that the question is anything important but i am still curious why is that almost all printed circuit boards are green i have seen a few blue ones but no red yellow company logo etc is there a technical reason or could it be that the marketing geniuses have not tought about it yet the green layer is a solder mask and is used to make a finished board look neat and to avoid solder bridges especially when using wave soldering or any other mechanized approach i ve seen red mask but most that i ve seen are green a bakelite board will look brown in colour and if the solder mask is put on looks like a brown board with green paint on either side or just one side of the board a fibreglass board will look green from the side because the green solder mask makes the board appear that colour if you got a fibreglass board with no mask it would be a whitish grey colour teflon boards do exist as well but i m not sure about that one i d guess the stuff they invented for solder mask was green so they re not about to change also any change in any chemical probably requires a better than normal cleaning of the machines that make boards a lot of companies do not make their own boards they ship them to a real boardhouse
