68‐2: Optimization Analysis of Rollable Shape and Stack Design for Rollable AMOLED Display by Finite‐Element Analysis

Abstract

The finite element analysis method (FEA) is used to study the optimization of the rolling shape and stack design. The rollable simulation model is established to compare the three rolling shapes for single‐roll, double‐roll and S‐roll. Simulation results and experiments show that single‐roll is the best rollable shape among them. The effect of optical clear adhesive (OCA) on the design of rolling stack is analyzed. The results show that, the similar OCA can significantly reduce the strain of the functional layer in the outer‐roll crimping stack, and the strain of the functional layer tends to be stable after the first round of rolling, regardless of the number of turns. Increasing the OCA1 modulus (it is recommended to be high modulus) will help reduce the strain of OCA and functional layer. Optimized stack design not only could improve the rollable ability but also could provide larger space for the design of terminal products. A 12.3‐inch prototype rollable AMOLED display has been successfully rolled up more than 100,000 cycles in dynamic at 5mm outer‐rolling radius without damages.