Self-organized nanostructure of polymer films by linear ion beam irradiations for flexible devices

Nanostructured surfaces of flexible polymers have been required for enhancing optical transparency, electrode adhesion and anti-fouling of flexible devices. In spite of the pattern regularity of lithography and transfer methods, a production cost is a bottleneck for the industrialization of nanostructured polymer surface. An ion beam irradiation causes crosslinking and scission resulting in self-organized nanostructure. The size and repeatability could be controllable by modulating the irradiation conditions such as angle, energy, dose and species. And linear ion beams generated by closed drift type ion sources could be attractive alternatives for high speed web treatments. Recently our interests include flexible display, flexible copper clad laminates applying the self-organized nanostructure. For example, the irradiation of oxygen ion beam with several hundred electron volt makes spiky and fungoid geometry on hard coated PET. The structure enhances the optical transparency of polymer substrate up to 3 %. And argon ion beams with a few thousand electron volt are used to make ripples on the PET. It also improves the adhesion of metal electrode on the polymer film. Practical applications of the nanostructures applied to flexible products will be reported in presentation.