可折叠OLED屏幕的弯折应力仿真

柔性OLED屏幕在弯折的过程中,容易出现器件损伤、胶层剥离等现象。调整显示层的应力中性层位置和光学透明胶(OCA)胶层的应变是解决该问题的主要途径。本文通过建立柔性OLED屏幕的弯折仿真模型,分析了不同堆叠结构、保护盖板刚度、OCA胶层厚度、背板厚度和弯折半径对弯折后显示层应力中性层位置和OCA胶层应变的影响。结果表明,不同堆叠结构对显示层的应力中性层位置有很大影响,保护盖板刚度与OCA胶层厚度均对显示层的应力中性层位置无影响,背板厚度的增大使显示层应力中性层位置向下移动,弯折半径增大使结构应力下降,保护盖板刚度降低、OCA胶层厚度增大、背板厚度减小均对OCA胶层应变降低有利。仿真结果为柔性OLED的屏幕结构设计、材料选用以及解决弯折过程中出现的力学问题提供了参考。

Stress simulation of foldable OLED screen bending

Flexible OLED screens are prone to produce the phenomenon such as optical device damage, OCA peeling during the folding problem. The position of the stress neutral layer in the display layers should be carefully adjusted and the strain of the OCA layers should be reduced to solve this issue. In this paper, a simulation model for the foldable OLED screen is established. The influence of stack structures, cover window stiffness, OCA thickness, back plate thickness and bend radius on the position of stress neutral layer and the strain of OCA layers are analyzed. The results show that different stack structures have great influence on the position of stress neutral layer in the display layer, but cover window stiffness and OCA thickness have no effect on it, thicker back plate makes the stress neutral layer in the display layer move downward, lager bend radius makes the stress of whole panel reduced, meanwhile, lower cover window stiffness, thicker OCA layer and thinner back plate are beneficial to the strain reduction of the OCA layers. The simulation results provide a reference for the design of flexible OLED screen structure, material selection and solving the problems occurred in the folding process.