I'm thinking of making my own UV exsposure box for making PCB's. How many watts of bulb per square cm should i have ?
I think it is normal for the light to be purple, I used to work for a printers as a press operator and often made my own plates (ie when I wanted them to be more accurate that the bosses so called accurate +-5mm ) and the UV exsposure unit had a 2 KW uv lamp, this was actuaslly quite a visible purple light, while it was obviosly not 2 Kw worth of visible light, the visible component was perhaps equivalent to 60 WI've observed that all the "UV" LEDs that I buy glow what looks like purple to me. Is this me, or are they not actually UV? They don't actually confess what their wavelength is; what is the typical wavelength of LEDs that claim to be UV?
And the money question: Are they the ones you would use for PCB exposure? (e.g. GC Chemicals cat No 660 etc.)