The present invention concerns a process for the deposition of a solder-through polymer coating on an uncoated printed circuit board which comprises the use of an average low power and low pressure plasma polymerisation in a polymerisation chamber of an organosilane precursor monomer which is introduced into said polymerisation chamber by means of a carrier gas, said organosilane being of the Formula Y1-X—Y2 (I) or —[Si(CH3)2-X-]n- (II), wherein: X is O or NH; Y1 is —Si(Y3)(Y4)Y5; Y2 is Si(Y3′)(Y4′)Y5′; Y3, Y4, Y5, Y3′, Y4′, and Y5′ are each independently H or an alkyl group of up to 10 carbon atoms; the monomer of formula (II) is cyclic wherein n is 2 to 10, and wherein at most one of Y3, Y4 and Y5 is hydrogen, at most one of Y3′, Y4′ and Y5′ is hydrogen and the total number of carbon atoms is not more than 20.