Table of Contents Author Guidelines Submit a Manuscript
Advances in Materials Science and Engineering
Volume 2015, Article ID 106424, 16 pages
Research Article

Bending Characteristics of Foldable Touch Display Panel with a Protection Structure Design

1Department of Aerospace and Systems Engineering, Feng Chia University, Taichung 40724, Taiwan
2Department of Power Mechanical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
3Display Technology Center, Industrial Technology Research Institute, Chutung 31040, Taiwan

Received 22 September 2014; Revised 8 March 2015; Accepted 10 March 2015

Academic Editor: Zoe Barber

Copyright © 2015 Hsien-Chie Cheng et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The study proposes and demonstrates an enhancement of a touch display panel (TDP) through a polymer-based protection structure to achieve higher bendability and reliability. The bending performance of the TDP without or with the protection structure designs is addressed using three-dimensional geometry-nonlinear finite element analysis and mechanical testing. The elastic properties of the components in the TDP structure are derived from nanoindentation and uniaxial tensile/compressive testing. The calculated results are compared with each other and also against the experimental bending fatigue test data. At last, a design guideline and optimal factor setting for enhanced bending performance are sought through parametric FE analysis and Taguchi experimental design, respectively. The optimal design is compared with the original in terms of bending stress. The simulation results show that bending would create significant tensile and compressive bending stresses on the indium tin oxide/dielectric layers, which are the main cause of several commonly observed failures, such as thin film cracking and delamination, in a thin rigid film coating on a thick compliant substrate. It also turns out that a substrate with a lower stiffness has a better mechanical stability against bending stress.