Coatings for waterproofing electronic components

A circuit board water-proofing coating composition, comprising:

• A) at least one dissolved and/or dispersed passivating agent containing a molecule comprising a thio-functional group and/or an azolic moiety, the passivating agent in a concentration greater than a solubility limit of the passivating agent in the binder component;
• B) a dissolved and/or dispersed binder component comprising one or more of the following types of binders:
• 1) an organic or inorganic film-forming polymer that is unreactive with (A);
• 2) an organic or inorganic film-forming polymer, which is capable of reacting with (A);
• 3) one or more polymer pre-cursors polymerizable on a substrate surface and unreactive to (A);
• 4) one or more polymer pre-cursors polymerizable on a substrate surface and capable of reacting with (A);
• and
• C) optionally, one or more dissolved and/or dispersed additive(s), selected from wax, adhesion promoter, leveling agent, flow modifier, wetting agent, rheology modifier, stabilizer, catalyst, pigment, photoinitiator, biocide and biostat;
• and
• D) optionally at least one organic solvent.