A project log for DIY UV Exposure 'oven' for PCB etching and masks

Converting a towel warmer to a UV exposure 'oven' for making PCBs

fl@C@fl@C@ 03/09/2015 at 10:160 Comments

So, I haven't been updating this (or my other) project(s) on a daily basis for a while.. I'm going to make an effort to do that... I don't think I will include logs for every single effort I make and every success and failure...instead, I think I'll keep a log (maybe weekly) of how it's going... and update the project to reflect where it stands.. And in the end, the project page will show a method to produce your own.. I just can't do all the work and update daily... I'd be typing all the time and not working.. :)

So, I will say...I have tried a couple methods for the UV Oven so far and don't like the first two efforts I made... First I tried some 3watt 365nm UV LEDs, buck converters all driven by a nice boost converter that fell short of my expectations... Ultimately it had a serial port that made it seem like you could control it from a MCU, but when I got it and tried playing around with it....the serial protocol has literally ZERO documentation.... I don't have time to weed it out and hack it out... I tried hooking a protocol analyzer up and saw that it transmits some pretty understandable stuff when it powers up, but time...

Onto trial two... I skipped the 3watt LEDs mainly because they didn't live up to my expectations in brightness and coverage consistency.... so I moved on to try 200 5mm UV LEDs... Nope... too much work again creating the PCBs and so on to get them arranged properly, etc...

So, my new effort is directed at UV LED tape... I bought a spool of 300 or so UV LEDs on a few meters of flexible PCB tape similar to what you'd see WS2812s connected up to.. I'm going to try arranging them so there is nice coverage over the internal surface and maintaining as much of the reflective stainless steel inside as possible....I'm still waiting for them to arrive, hopefully this week...

I went back and forth a hundred times on which processor to use for this project.... I hate arduino's.. But I have a few laying around because they came with various things I've bought and replaced them... and this project doesn't have huge requirements for an MCU.... and everyone has access to I guess I'll start off with one.. I tried an UNO first because it's cheap and easy....turns out that it doesn't actually have enough memory for what I want to do...Next up: 2560... Seems to be holding up ok... It'll be driving a display, keypad, the leds on a four channel msofet board, and possibly the power supply and a few relays.. The display and interface are what's going to take most of the processing power.. :)

So, I'll start posting some pictures when I get the LEDs, etc.. Keep an eye out!