Many Years ago (2014 to be precise) there was a thread 'Conformal coating for Sulphur environments'

There was also a paper presented at SMTA in 2016 on the effectiveness of conformal coatings in preventing silver sulphide corrosion

I am interested in what further research/findings have occurred in the industry since then. There is definitely an increase of failures instances in areas where there is high concentrations of fossil fuel usage (the countries are obvious!). From my information research it seems that the resistor suppliers (it seems they are most affected) now supply a range of sulphide resistant types, but that comes with an expense for the supply chain in both actual cost and change over cost, along with actually identifying whether all the resistors are at risk on the board or is it just certain construction in parts of the circuit (i.e. thick film for measurement)

Another way is to conformal coat the board, the research says NOT to use silicone based as it absorbs the sulphur, so my question is about those coatings:

  1.  There are nano coatings listed, have there been additional research into their effectiveness?
  2.  What coatings are preferred due to EU legislation in the future

Many thanks in advance

Paul Taylor
GE Grid Solutions