The idea of using Ultraviolet LEDs to expose photo-sensitive circuit board is not a new one but with this design I hope to provide a solution with consistent timed exposure using very simple circuit construction, downward exposure and using off-the-peg boxes to house the unit. In fact, everything has been designed with the home constructor in mind. The basic system consists of two circuit boards; the UV exposure circuit and the microcontroller timer circuit. The UV exposure board has 54 UV LEDs arranged in an offset matrix and the control Board is a simple PIC controller intended for mounting above the UV exposure board. It is programmed as an adjustable timer with a triple seven segment display, two timed outputs; one for single-sided PCB exposure and another for anyone wanting to extend the unit to include double-sided PCBs. Also, a sounder output is included to indicate when the selected exposure period is over: usually about 2.5 minutes.
Please see 'Other Files' below for a more detailed description of the project including images and descriptions displayed 'in context'.