An electrical assembly which has a multi-layer conformal coating comprising three or more layers on at least one surface of the electrical assembly, wherein the lowest layer of the multi-layer conformal coating, which is in contact with the at least one surface of the electrical assembly, is obtainable by plasma deposition of a precursor mixture comprising (a) one or more organo-silicon compounds, (b) optionally O2, N2O, NO2, H2, NH3 and/or N2, and (c) optionally He, Ar and/or Kr; the uppermost layer of the multi-layer conformal coating is obtainable by plasma deposition of a precursor mixture comprising (a) one or more organosilicon compounds, (b) optionally O2, N2O, NO2, H2, NH3 and/or N2, and (c) optionally He, Ar and/or Kr; and the multi-layer coating comprises one or more layers which is obtainable by plasma deposition of a precursor mixture comprising (a) one or more hydrocarbon compounds of formula (A), (b) optionally NH3, N2O, N2, NO2, CH4, C2H6, C3H6 and/or C3H8, and (c) optionally He, Ar and/or Kr, Z1 represents C1-C3 alkyl or C2-C3 alkenyl; Z2 represents hydrogen, C1-C3 alkyl or C2-C3 alkenyl; Z3 represents hydrogen, C1-C3 alkyl or C2-C3 alkenyl; Z4 represents hydrogen, C1-C3 alkyl or C2-C3 alkenyl; Z5 represents hydrogen, C1-C3 alkyl or C2-C3 alkenyl; and Z6 represents hydrogen, C1-C3 alkyl or C2-C3 alkenyl.