rupertlssmith
Junior Member level 1
Hi,
I etched a circuit board last week, it was a great fun and something I have not done since I was at school 20 years ago. I am (re)learning electronics.
I bought some ready treated photo resist coated boards from RS components, on FR4 base. The surface of these boards is not completely smooth, there is a noticable grain in one direction.
I think I got a reasonable exposure of the resist with a UV unit using several layers of laser printed film, 3 minutes exposure. When I put it in the developer, the exposed resist does not disappear. I had to rub it with my gloved finger quite hard in places to get the exposed areas off. Even then, due to the grain on the board there must have been fine traces left on, since little fingers of copper were left at the end of the etching, where there should be none.
Is it normal to have to scrub exposed resist off? or should the developer clean it easily away? Do I need a longer UV exposure?
Can anybody recommend some ready made boards that are smoother, no grain? Is it better to spray the resist on yourself? I suppose I can make sure I buy one made by a different manufacturer next time and see if that is any better.
Thanks for your advice.
I etched a circuit board last week, it was a great fun and something I have not done since I was at school 20 years ago. I am (re)learning electronics.
I bought some ready treated photo resist coated boards from RS components, on FR4 base. The surface of these boards is not completely smooth, there is a noticable grain in one direction.
I think I got a reasonable exposure of the resist with a UV unit using several layers of laser printed film, 3 minutes exposure. When I put it in the developer, the exposed resist does not disappear. I had to rub it with my gloved finger quite hard in places to get the exposed areas off. Even then, due to the grain on the board there must have been fine traces left on, since little fingers of copper were left at the end of the etching, where there should be none.
Is it normal to have to scrub exposed resist off? or should the developer clean it easily away? Do I need a longer UV exposure?
Can anybody recommend some ready made boards that are smoother, no grain? Is it better to spray the resist on yourself? I suppose I can make sure I buy one made by a different manufacturer next time and see if that is any better.
Thanks for your advice.