This project shows the creation of a large array of UV LEDs. They are used to expose a presensititised blank circuit board. Another common method is to use UV Tubes. He used to make the isolation box: 54 UV leds buyed from E-bay for about 15 $ 18 resistors 68ohms, 1/4Watt for 0,60 $ 1 two pole connector for about 0,85 $ 1 Electrolitic capacitor of 2200uF and 30v recover from a F.A. 1 Eurocard presensibilized PCB of 160×100mm. Leds ohms will go in groups series of 3 with their polarising resistance of 68. The the plate of LEDs is powered by 12V.