Adhesion behavior of PVD coatings on ECR plasma and ion beam treated polymer films
In a great many cases the well-adhering coating of plastic films requires a purposive pretreatment. For the in-line treatment prior to physical vapor deposition processes, plasma and ion beam techniques will be the method of choice. The success of the pretreatment does not only depend on the polymer type concerned but, in a highly sensitive manner, also on the intensity and type of processing. Exemplified by polyester films, acrylate-coated polyester films and films made of oriented polypropylene the effects a plasma or ion-beam pretreatment exerts on the adhesion strength of sputtered and evaporated copper layers are discussed. In order to make the results transferable, Langmuir probe and retarding field analyzer measurements were conducted to assess the ion-current dose of the plasma and the ion-beam treatment, respectively. Since the layer adhesion often reaches a maximum at extremely low doses of pretreatment, the application of available plasma and ion sources allows one to implement web speeds in a range of some meters per second.