Multi-hardness hybrid silicone pad to laminate the bended cover window in a flexible OLED display

Abstract

According to the evolving requirements of smartphone consumers, the form of smartphone displays is becoming more advanced and diversified. In particular, the shape of the cover window of smartphones is changing from a conventional flat rigid shape to a bended shape with multiple curvatures. However, a relatively advanced lamination process is required to bond the flexible OLED panel to the bended cover window. To overcome this limitation, in this study, a hybrid structured silicone pad with multi-hardness was developed as a pad to be used for the lamination. Hybrid silicone pads were modeled in various shapes, considering the stress points and spreading characteristics of the pad pertaining to the vertical, horizontal, and center orientations during compression in the lamination process. In addition, the compression strength of the proposed pad was evaluated through simulation, and the compression results and reliability of the pad were validated through lamination process experiments performed using an optically clear adhesive.