Electronic – How to prevent blue oxidation / corrosion from growing back

corrosionpcbrepair

I've got a PCB for an old console. It had some blue corrosion which I cleaned off using some diluted vinegar and isopropyl. Its not the typical brown rust when it has been exposed to water or white drying residu.

I've noticed that after a while the oxidation grows back, without the PCB having been used. How can I prevent this from happening?

Do I need to apply some sealer after cleaning?
Did I not clean the PCB properly?

Best Answer

Industrially, stuff called "conformal coating" is applied to PCBs for a variety of reasons, but it will keep moisture out and generally massively extend the time over which oxidation residue forms.

For hobbyists, clear nail polish works, though you might want to be careful so as not to allow the acetone in the nail polish to dissolve the silkscreen patterns on the PCB.

If the oxidation is not causing functional problems, you might just let it go.