The ionic contamination of the boards themselves, even before the printed circuits that they support are contaminated, is due to a set of polluting agents that remain after the production processes of the circuit itself: generic salts, organic and inorganic acids, ethanolamines, flux activators, and chemical agents derived from the processes of metal plating, human sweat.
You can find more details on the following link:
https://albapcb.com/reduce-the-ionic-contamination-of-pcbs/
You can find more details on the following link:
https://albapcb.com/reduce-the-ionic-contamination-of-pcbs/
