Cleaning PCBs, particularly ionic residue

[gbyleveldt]

I use SWAS prior to repairing water damaged automotive electronics. Basically, I clean off the worst of it with a short bristle brush dipped in SWAS and then remove under water. Once the debris is removed from the board, I dip the boards into an ultrasonic bath of SWAS (I don't heat the solution up) running it for 2 minutes both sides. This cleans up all contaminants in hard to reach places and cleans out the many vias as well. Hot air works well to dry the board and once the repair is complete it goes for another round of cleaning in the ultrasonic bath and then water.

SWAS does appear to be conductive, so it must be cleaned with water afterwards and dried properly. At least, that's my experience. It smells very similar to window cleaner.

[Bud]

ULTRASONIC TOOTHBRUSH with firm bristle + FORMULA 409 all purpose cleaner, then a normal flux off cycle after that.

Where do you buy this stuff, it seems not available in Canada.

[cdev]

He probably means "Sonicare" (available everywhere in US so probably Canada too)  You can use the handsets and brushes for PCB cleaning when they wear out for regular tooth-brushing.  (MAKE SURE TO MARK CLEARLY)

[Bryan]

Think Bud meant that 409 is not available in Canada.

[BrianHG]

Think Bud meant that 409 is not available in Canada.

My mistake, the cleaner was 'Spray Nine', sold here:
http://www.canadiantire.ca/en/pdp/spray-9-marine-multi-purpose-cleaner-946-ml-0790120p.html#

[Bud]

Thanks, will give it a try.

[Bryan]

Think Bud meant that 409 is not available in Canada.

My mistake, the cleaner was 'Spray Nine', sold here:
http://www.canadiantire.ca/en/pdp/spray-9-marine-multi-purpose-cleaner-946-ml-0790120p.html#

Thanks for the tip, picked a bottle up today and it is excellent. Although haven't tried it on a PCB it worked like magic cleaning off baked on grease grease and hardened sticker residue on some equipment.

[Bud]

I found it in Wallmart in automotive section. Tried on a piece of PCB against clean-free flux and it seemed to work. I used a regular toothbrush though, not an ultrasonic one. My concern was the white residue which you get when cleaning with IPA for example. But the board came very clean, no any white residue  under the microscope inspection. Seems to be good stuff. Thanks for the tip. It may be a bit expensive though per volume, compare to Alconox which I have not tried yet but am planning to.