Implementation of anti-glare, low reflectance, anti-fingerprint functional hard coating for foldable cover window application

Abstract

Since the usage of flexible displays on commercial foldable devices, they have caught interest due to their unique portability and design. However, the cover window, which is the outmost part which users directly interact, still remains a challenge. This is due to the required mechanical properties are not suitable for traditional glass covers and its processing methods. Instead, flexible hard coatings with high hardness and decent flexibility are highlighted as alternatives. In order to form a complete foldable cover window, not only high strength hard coatings but also functional coatings that are implemented to enhance user experience are crucial. For example, anti-glare (AG), low reflectance (LR) coatings which can reduce external light glare and increase display visibility, or anti-fingerprint (AF) coatings that improve screen texture and scratch resistance can be implemented. In this thesis, a flexible coating with various improved optical and mechanical properties were fabricated through the inclusion of AG, LR, and AF coating layers. AG coatings were obtained via imprinting haze patterns or adding scattering agents, and LR coatings were formed by the addition of low refractive index hollow silica particles. Lastly, it was tested that with PFPE-based AF surface treatment, the combined multilayer coating could be used as a foldable cover window with high wear resistance.