Low frequency noise measurements as an early indicator of degradation for devices on plastic substrates subjected to mechanical stress

We report on experiments performed in order to verify the ability of low frequency noise measurements to serve as a sensitive tool for the characterization of the degradation of electron devices on flexible substrates as a consequence of mechanical stress. We designed and build a dedicated stress chamber for performing stress (repeated bending) in controlled environmental conditions. Test devices are copper resistance onto plastic substrates. We observe that, whenever the flicker noise produced by the resistances is clearly detectable, the level of flicker noise increases as the mechanical stress increases. In some cases noise increment of 100 % are observed when the change in the DC resistance of the sample is as low as 0.1%.