Mechanical simulation for the bending process of the AMOLED panel pad

Abstract

Panel pad bending is a critical process to improve the screen-to-body ratio of an active-matrix organic light-emitting diode (AMOLED) panel. The failure analysis of the metal wirings is the key to ensure the reliability of signal transmission when the pad be bent to the back of the panel. In the present work, the sub-modeling technique combined with the periodic boundary condition was used to simulate the stress distribution of the bending area of the pad. The progressive failure of bent metal wirings was investigated by the extended finite element method. It is proved to be rational to prevent the wirings damage if the interlayer dielectric is replaced by an organic layer. In order to reduce stress of metal wirings, it is a measure to replace the original ultraviolet (UV) curable adhesive with a higher-modulus UV adhesive. The simulated results also show that rectangular perforations can avoid the stress concentration caused by the holes compared with circular perforations. For better stress distribution of metal wirings, it is necessary to increase the lengths of the rectangular holes and decrease the widths of that to a certain extent, which is helpful for restraining crack propagation by means of low-stress zones and holes.

Keywords

• Narrow bezel
• AMOLED panel
• pad bending
• mechanical simulation