Double-sided PCBs

This light-box frame can be easily built by anybody and lets you accurately align films on double-sided PCBs.Making your own PCBs is fairly straightforward when you make use of the readily available products on the market. When the board is single sided, its exposure is easy. But for double-sided boards the artwork films have to be aligned precisely on both sides of the board in order to make sure that the holes drilled will be neatly centred in the copper pads on both sides.Most light-boxes are provided with alignment crosses to aid lining up the films. In practise they were not found to be accurate enough.