Corrosion resistance of robust optical and electrical thin film coatings on polymeric substrates

Thin SiO2 films (ca. 130 nm) were deposited via magnetron sputtering as part of a multi-layer system onto polymeric substrates. By varying the deposition conditions for the SiO2 films, samples with varying residual film stress were obtained. The corrosion resistance of the combined multi-layer system was investigated by electrochemical analysis and salt spray tests. In this study it is reported that the corrosion resistance of a multi-layer system containing SiO2 is improved (at least a 10-fold increase) through deliberate control of the total residual stress of the multi-layer coating, thus influencing the SiO2 structure.

► Prepared plastic-based reflective devices using PVD.
► Improved corrosion resistance by increasing compressive stress of SiO2.
► Related resistance improvement to the decreased interfacial area.
► Seven-fold increase of corrosion resistance.