Bending Stress Analysis of Laminated Foldable Touch Panel

Abstract The touch panel technology has been developed in recent years, and the foldable touch panel is one of the newly attractive characteristics. This article focuses on the bending stress analysis of foldable touch panel, composed of plastic substrate PET, adhesive layer, plastic layer PI, organic layer and conductive layer ITO to form a seven-layer laminated structure. By applying four-point bending, the stress distribution of the touch panel under different radius of curvature was analyzed. The results show that the maximum von Mises stress occurred in the ITO layer and the maximum von Mises stress increased from 0.497 GPa to 1.242 GPa with decreasing radius of curvature. The region near the center of the touch panel has higher von Mises stress, and the relation between the radius of curvature and the maximum von Mises stress exhibits a non-linear feature.

[1]  B. Sammakia,et al.  Bending Fatigue Study of Sputtered ITO on Flexible Substrate , 2011, Journal of Display Technology.

[2]  Gregory P. Crawford,et al.  Flexible flat panel displays , 2005 .

[3]  Wang Huaqing,et al.  The bending properties of flexible ITO films , 2007, 2007 Asia Optical Fiber Communication and Optoelectronics Conference.

[4]  Darran R. Cairns,et al.  Stress–corrosion cracking of indium tin oxide coated polyethylene terephthalate for flexible optoelectronic devices , 2009 .

[5]  Y. H. Lo,et al.  Durability under mechanical bending of the indium tin oxide films deposited on polymer substrate by thermionically enhanced sputtering , 2010 .

[6]  L. Xu,et al.  Reliability study of flexible display module by experiments , 2008, 2008 International Conference on Electronic Packaging Technology & High Density Packaging.

[7]  Yves Leterrier,et al.  Mechanical properties of transparent funcional thin films for flexible displays , 2003 .

[8]  Darran R. Cairns,et al.  The Mechanical Reliability of Sputter-Coated Indium Tin Oxide Polyester Substrates for Flexible Display and Touchscreen Applications , 2001 .

[9]  Leon Xu,et al.  Thermal analysis based on the environmental tests of STN display , 2009, EuroSimE 2009 - 10th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems.

[10]  L. Segerlind.  Applied Finite Element Analysis , 1976 .

[11]  R. Cook,et al.  Concepts and Applications of Finite Element Analysis , 1974 .

[12]  Young-Rae Cho,et al.  Failure Mechanism of Patterned ITO Electrodes on Flexible Substrate under Static and Dynamic Mechanical Stresses , 2007 .

[13]  Myeongkyu Lee,et al.  Highly enhanced mechanical stability of indium tin oxide film with a thin Al buffer layer deposited on plastic substrate , 2009 .