Pretreatment and Cleaning of the Web Substrate

By means of ion bombardment and the concurrent UV radiation, functional groups on the surface of the substrate are activated. This increases the polar portion of the surface energy, thereby improving the adhesion of the evaporated layer to the substrate (Fig. 8.4) [5]. 

Excessive pretreatment destroys the polymer surface and therefore reduces adhesion. In addition to the adhesion, the surface of the substrate affects the growth, and thus the structure, resistance, and barrier properties, of the metal layer. 

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