Stuff you can learn in this section:
What’s UV etching?
The method is normally called “UV etching” or “Ultraviolet etching”, though that’s a misnomer. Because you’re not actually etching using ultraviolet light. The PCB etching part is still done through a chemical agent (acid or ferric chloride). What’s done through ultraviolet light is the part prior to the acid: where you put your design on the raw copper board. If we want to be more precise, we should call it “UV transfer”, but, let’s not split hairs here.
In UV etching, you take a plastic film that’s sensitive to ultraviolet light, block out the parts you want the acid to eat away, and expose it. The ultraviolet light hardens the film where it hits it and makes it stick to the copper board. Then you put the board into a developer solution, that sets the hardened parts and dissolves the soft parts of the film.
And you end up with a board that’s ready for an acid bath, and that has amazing precision on the traces.
The big problem with UV etching: how to do it?
One of the biggest hurdles I found for doing ultraviolet PCB etching is that there was very little documentation on the Internet about how to do it. There were a lot of separate sources, saying different things, and nobody was really clear on the details. So I started diving into manufacturer’s websites, poking around in technical manuals, and simply trying stuff out to see what the best recipe for UV etching was.
And then, I put it all here. Mainly so I wouldn’t forget what I learned… I don’t etch PCBs that often to know the whole procedure by heart. So it’s nice to have these notes to work by.
And well, they’re here so you can use them too. If you’re having a hard time learning UV etching, here’s a couple of years’ worth of experience and errors to help you along.