UV Box For PCB Exposure

uv box

Hack-A-Day reader [Mindaugasu] built this box for exposing copper boards to ultraviolet light before etching them. It has two banks of four 20W UV lamps. The box is lined with reflective foil. The banks can be controlled separately and the exposure time is set by an Atmel AT90. You can change the time using button panel and LCD. He’s got some example boards in his ARM development section.

16 thoughts on “UV Box For PCB Exposure

  1. I built my own using a normal flourescent light (while it was in my ceiling), a ladder, a cardboard box, some tape, and a transparency with the circuit on it. It works quite nicely if you don’t accidently move it during exposure.

  2. You do not really need this if you live in a “sunny” area on this planet. During Summer in Taiwan, you need at least 15 and better not more than 45 seconds exposure – thanks to our sun. OK, you can not work at night and when it is raining, but in most cases you should be fine. I did this with layouts down to 0.2mm track width…

  3. Does this thing really need a microcontroller? What happened to a 555 timer & variable resistor?

    I built my PCB exposure unit using UV LEDs, because they were cheaper than fluorescent tubes. It pretty much works but the diffusion/polka dot issue is a hassle. I use a couple of layers of tracing paper spaced at different heights away from the LEDs in order to spread it out. I do think fluorescent tubes would probably be easier to work with.

  4. Bah, if you buy the right presensitized PCBs, you don’t even need a special UV exposure lamp. Look here:


    These photo resist pre-sensitized boards are so highly sensitive to UV that you can expose them to regular fluorescent bulbs and have them fully developed in 8 minutes or so. Plus, they are really cheap too!

    You can buy a regular fluorescent lamp fixture and bulbs for less than probably $20 down at Wal-Mart.

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