RELATIONSHIPS BETWEEN STRUCTURAL-PROPERTIES OF VAPOR-DEPOSITED METALLIC-FILMS ON TO POLYMER AND THEIR RELEVANT ADHESIVE PERFORMANCE

The use of ultrasonic vibrations to characterize the adhesion of ultra-thin metal layers on polymer films is reported. The aim of the study was to analyse and relate the microstructural characteristics of the metallic film to the ultimate practical adhesive properties of the metal-polymer system as measured by an ultrasonic test. The sample studied was formed by thermal deposition of an aluminium layer on to a poly(ethylene terephthalate) film: Al/PET. The adhesive strength of Al/PET laminates was studied in relation with the deposition rate of the metal, its thickness, the structure of the grains and the amount of metal oxide formed at the interface, as probed by transmission electron microscopy (TEM) and secondary ion mass spectroscopy (SIMS). From these results, a correlation between the microstructure of the interface, the bulk morphology of the metallic layer and the overall adhesive performance of the (Al/PET) laminates is proposed.