cleaning PCB

Thread Starter


Joined Jul 26, 2010
Hello, I have just put together my first PCB but the copper tracks have greasy finger marks on them. Shall I just use a small amount of dishwashing detergent, water and a clean rag to wipe them off ?



Joined Aug 12, 2011
Never had any trouble cleaning assembled PCBs with 99% Isopropyl alcohol. I blow off the solvent with compressed air to make sure everything is fully dry before applying power.

I've read of people cleaning assembled PCBs with water and reporting no issue. I haven't done that myself.

It also depends on what's mounted on the PCB. For example, I would avoid getting something like an LCD display wet. They're usually not in sealed packages like other electronic components. I mount that stuff last and fully clean the board beforehand.


Joined Nov 1, 2006
I've used a mixture of water & industrial detergent on PC boards that are covered with grease & dirt from being used in factory environments [particularly where fan-cooled]. After washing & rinsing thoroughly we placed the boards in front of a fan for a day before we tested them & they always survived. I, too, wouldn't treat an LCD like this, however.

For cleaning boards before [re]soldering new components I use acetone-based nail polish remover & toothbrush or nylon parts cleaning brush followed by denatured or 90% or stronger isopropyl alcohol. All remove rosin soldering flux but the rosin-solvent mixture leaves a film, I've found, making the second cleanup necessary. Neither of these solvents seem to affect the fiberglass-epoxy boards nor the masking layer [when used].