Drying oven

[martinw]

Dear All,

Does anybody have a link to a quick and easy DIY assembled board drying oven?

Our PCBs are assembled, and we clean off flux residues in an ultrasonic bath using an aqueous solvent, rinse them in tap water, and then with de-ionised water. We then need to dry them in an oven. Commercially, ovens run at up to 100C, for a few minutes (5?) but that makes me nervous. I would be happy for something that blows a load of air around them at 55C for a few hours.

Using stuff available, I was thinking of making a box from MDF with a massive 300mm diameter fan to wizz the air about over the boards. Light bulbs hooked up to a PID controller would be the heat source, and excess moisture would be vented to the outside of the oven using some kind of crude inlet/ outlet damper.

It might work, but if someone has been down this road before, I would be grateful for their advice.

Thank-you,

Best wishes,

Martin

[dertsap]

Originally Posted by martinw Using stuff available, I was thinking of making a box from MDF with a massive 300mm diameter fan to wizz the air about over the boards. Light bulbs hooked up to a PID controller would be the heat source,

I haven't been down that road but I could see that working quite well , my daughter can whip me up a cake in her easy bake oven in no time so the same type of thing should work well for drying
200watt bulbs throw off a lot of heat , when I lived north guys would put them into dog houses to keep them heated for the pooch

[RomanLini]

Hi Martin, there is a closed loop temperature controller I designed as part of the open-source Shift1LCD project, this is ideal for your drying oven and will allow adjustment in 1 degree steps and show the set temperature and actual temperature on the LCD. A number of them have been built and are in service for low temp drying and curing ovens etc.

Main Shift1LCD open-source projects page

Here is a complete drying oven controller I whipped up in a couple of hours;
Shift1LCD drying oven controller

If you don't want to make your own PCB there are simple kits with nice quality PCB available from James, he can pre-program the PIC for you too;

Buy Shift1LCD kit $12

[johnohara]

Desktop computers generally run at the temperatures you are describing. They move air around pretty well too. You could probably turn an old case into a solution just by adding a portable ceramic heater to the front and a couple of fans to the back.

Just another starting point idea.

~John