View Full Version : Cleaning Printed Circuit Boards

July 10th, 2005, 07:13 PM
Hi all,

I've seen a few posts about cleaning pc boards, I'd like to relate how I do it.

I work in a food processing plant where the electronic devices can get rather nasty. Hot and cold temperature cycles and very high humidity promote mold and mildew inside closed cabinets. Breader (flour) dust infiltrates every nook and cranny. And of course the condensation on the boards leads to erratic machines.

What do I use to clean this mess? Soap and water, believe it or not. The boards are usually easily removed, and hot water, soap and a toothbrush is just the ticket. After the bath, I lay some paper towels on a hard surface and tap the edges of the board on it to drive the water out from under the components. A few judicious shots of aerosol contact cleaner for the really stubborn water droplets and then a good session with a hair dryer and the board is good as new.

When a replacement circuit board can cost upwards of $5,000 US we do what we can to keep what we have going. I can think of only one failure in 10 years and that was because I sprayed a board with contact cleaner under power. :roll: It had a bipolar 15vdc supply so I thought it was safe. Guess I was wrong. Although, it was kinda cool to watch a $150 load cell pre-amp actually go up in flames. :twisted: I didn't tell the manager how cool it was, though, just that I would have to replace the pre-amp.


July 11th, 2005, 12:47 AM
On many occasions I have used high presure water from a car cleaner to clean up dusty and dirty boards for vintage computers. You have to be careful of surface mount components, but high presure water is much better for the equipment than "A toothbrush" I feel, and usually somewhat more effective. Coming from an electronics production background, I have seen highpresure water used to clean assemblies comanly. The only problems occur when you have components that water may penitrate. Buzzers and relays are the most coman of these.

You will have to make sure there are NO bateries on the Board of course.

As for drying the PBA, I use an oven set to 50 deg celcius. I have not run into any problems with this, but you might want to make sure there is no plastics on the board that would be effected by temperature, though I have dried several once dirty Keyboards this way and had no problems.


Kaptain Skitzo
July 11th, 2005, 03:28 PM
That's a pretty interesting way of doing it...I usually use a q-tip with rubbing alcohol(70% or higher), and only use a toothbrush if there is a pretty heavy encrustation...and for that, I use an "Extra Soft" brush VERY gently.
This, of course, is assuming that compressed air won't do the job.