P‐5.13: Wrinkle‐free stack‐up design of watch display with 3D spherical glass by FEM simulation

Abstract

The use of 3D glass as a cover will significantly improve the stylish sense of the product and provide a wider display interface. However flexible film are notoriously difficult to fully conform to non‐developable surface such as spheres. The greatest challenge when trying to attaching flexible display to 3D spherical glass is avoiding wrinkling phenomenon at the edge of flexible display. In this paper the finite element method is used to study the optimization of the stack‐up to avoid obvious wrinkling phenomenon. We confirm that the modulus and thickness of Optical Clear Adhesive(OCA) between flexible modulus and 3D glass cover have decisive impact on the formation of wrinkles. A wrinkle‐free watch product was successfully fabricated by replacing the low‐modulus OCA with high‐modulus OCA or by reducing the thickness of low‐modulus OCA to 50μm.