EEG signals typically have high source impedance. Amplifiers in the EEG circuits have high input impedance too. The signal is DC-coupled to the amplifier.
One problem is that leakages across the surface of the board can distort the signal. Guard rings help prevent that. Contamination on the PCB increase leakages. So, I would like to clean the contamination. Could anyone recommend a procedure for that and what solvents to use?
The board is FR4 with solder mask and silk screen. SMT components.
Cleaning will be done in an industrial facility, which is equipped for handling and disposing solvents. We have fume hoods.
UPDATE: Just added a bounty to this question. What I'd like to get is a fairly detailed procedure. Just throwing names of chemicals at this question will not count.
UPDATE: Bounty period had expired. Still looking for the procedure. Didn't get answers I could award the bounty to.
The tips which got posted so far might be useful for somebody in the future. More tips about board cleaning here (parallel thread on another forum).