What is the recommended exposure time for presentisized positive photoresist board using UV light, fluorescent light, CFL bulb and (will it also work with LED light)?
How do we also determine if the resulting exposed board that failed is overexposed or underexposed like this?
You expose a test piece of PCB material, sliding a piece of, say, cardboard, along every 1 minute. Develop and etch it, and see which exposure time gives the best results. With high-intensity UV, the exposure time will be relatively short, and 1/2 minute intervals would be better. Over- and under-exposure will be obvious.
UV LEDs will work.
