I had the same idea about fixing the photoresist with a reprap today, which lead me here and to this post. I think using a small lens and an led would be perfect. I tried a lens from a cd player (high power lens) so the distance between the lens and the board is small but that's ok. I could make a very tiny spot of light on a surface using the lens and LED. These lenses are normally used to make spots the size of a bit on a cd so we know the points of light are small.
My previous experience with making circuit boards is spending lots of time and effort for poor quality transfers to the copper from wax paper or photo paper. I don't have experience with transparencies but I can guess it's not much better. With a printer and a very tiny spot of uv light, I think we could expect amazing board quality. I love the idea of not having to get out a marker or paint to touch up a transfer.
There is probably an opportunity to improve the top to bottom lineup of the board as well. Maybe even a head with a top and bottom light that is already aligned and you print both sides as you go. Just thinking outside the box.
I have yet to build my first reprap but I am sure I will by working on this topic when I finish my first one.
Eric
My previous experience with making circuit boards is spending lots of time and effort for poor quality transfers to the copper from wax paper or photo paper. I don't have experience with transparencies but I can guess it's not much better. With a printer and a very tiny spot of uv light, I think we could expect amazing board quality. I love the idea of not having to get out a marker or paint to touch up a transfer.
There is probably an opportunity to improve the top to bottom lineup of the board as well. Maybe even a head with a top and bottom light that is already aligned and you print both sides as you go. Just thinking outside the box.
I have yet to build my first reprap but I am sure I will by working on this topic when I finish my first one.
Eric