UV LED Exposure Box
Warning - this is a work in progress! You won't be able to just follow these steps and get something that works. Don't follow these instructions.
This article is the first in my series on building a box for making PCBs from UV-sensitised copper-clad boards. Eventually I’ll cover everything from construction through to developing, etching and preparing for assembly.
All the files are available on GitHub.
To make a UV exposure unit suitable for home PCB manufacture, an LED-based solution is ideal. They use less power, you don’t have to worry about bulbs blowing and needing replacing, and you’re not messing about with 240V AC power.
- LED illumination – low power, reliable, cheap, safe.
- Timer – a timer of some sort to control the exposure time.
- Two-sided – to expose both sides of a double-sided PCB at the same time.
A common PCB size is in the region of 10cm x 20cm, and I figure that’s pretty much the upper bound of anything I’m likely to need, so that’s the area I’m going to illuminate.
To do that, I’m creating two panels of 84 LEDs, giving a total of 168! That’s going to take a bit of care, both in construction and power management.