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Warpage of Flexible OLED under High Temperature Reliability Test
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 Title & Authors
Warpage of Flexible OLED under High Temperature Reliability Test
Lee, Mi-Kyoung; Suh, Il-Woong; Jung, Hoon-Sun; Lee, Jung-Hoon; Choa, Sung-Hoon;
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Flexible organic light-emitting diode (OLED) devices consist of multi-stacked thin films or layers comprising organic and inorganic materials. Due to thermal coefficient mismatch of the multi-layer films, warpage of the flexible OLED is generated during high temperature process of each layer. This warpage will create the critical issues for next production process, consequently lowering the production yield and reliability of the flexible OLED. In this study, we investigate the warpage behavior of the flexible OLED for each bonding process step of the multi-layer films using the experimental and numerical analysis. It is found that the polarizer film and barrier film show significant impact on warpage of flexible OLED, while the impact of the OCA film on warpage is negligible. The material that has the most dominant impact on the warpage is a plastic cover. In order to minimize the warpage of the flexible OLED, we estimate the optimal material properties of the plastic cover using design of experiment. It is found that the warpage of the flexible OLED is reduced to less than 1 mm using a cover plastic of optimized properties which are the elastic modulus of 4.2 GPa and thermal expansion coefficient of .
flexible organic light-emitting diode;multi-layer;warpage;numerical simulation;
 Cited by
G. P. Crawford, Editor, "Flexible flat panel displays", Wiley, Chichester (2005).

J. H. Ahn, H. Lee, and S. H. Choa, "Technology of flexible semiconductor/memory device", J. Microelectron. Packag. Soc., 20(2), 1 (2013).

Y. Zhang and P. L. P. Rau "Playing with multiple wearable devices: exploring the influence of display, motion and gender", Computers in Human Behavior, 50, 148 (2015). crossref(new window)

J. H. Kim and J. W. Park, "Improving the flexibility of largearea transparent conductive oxide electrodes on polymer substrates for flexible organic light emitting diodes by introducing surface roughness", Organic Electronics, 14(12), 3444 (2013). crossref(new window)

A. W. J. Gielen, M. Barink, J. van den Brand, and A. M. B. van Mol, "The electro-thermal-mechanical performance of an OLED: a multi-physics model study", 10th. Int. Conf. on Thermal, Mechanical and Multiphysics Simulation and Experiments in Micro-Electronics and Micro-Systems, Euro-SimE, 1 (2009).

C. G. Kim, H. S. Choi, M. S. Kim, and T. S. Kim, "Packaging substrate bending prediction due to residual stress", J. Microelectron. Packag. Soc., 20(1), 21 (2013). crossref(new window)

T. Mizutani, T. Ikeda, K. Miyake, and N. Miyazaki, "Warpage analysis of an LCD panel under thermo-mechanical and hygro-mechanical stress", Electronic Materials and Packaging, EMAP 2007. International Conference, 1 (2007).

M. K. Yeh, L. Y. Chang, and M. R. Lu, "Bending stress analysis of flexible touch panel", Microsyst Technol, 20 (8), 1641 (2014). crossref(new window)

C. J. Chiang, C. Winscom, S. Bull, and A. Monkman, "Mechanical modeling of flexible OLED devices", Organic Electronics, 10(7), 1268 (2009). crossref(new window)

H. Y. Low, and S. J. Chua, "Mechanical properties of organic light-emitting thin films deposited on polymer-based barrier substrate: potential for flexible organic light-emitting displays", Mater. Lett., 53(4), 227 (2002). crossref(new window)

G. G. Stoney, "The tension of metallic films deposited by electrolysis", Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character, 82(553), 172 (1909).

K. Roll, "Analysis of stress and strain distribution in thin films and substrates", J Appl Phys, 47, 3224 (1974).

C. C. Lee, Y. S. Shih, C. S. Wu, C. H. Tsai, S. T. Yeh, Y. H. Peng, and K. J. Chen, "Development of robust flexible OLED encapsulations using simulated estimations and experimental validations", J. Phys. D: Appl. Phys. 45(27), 275102 (2012).

N. Murata, "Adhesives for optical devices", Electronic Components and Technology Conference, 1178 (1998).

Y. Wang and P. Hassell, "On-line measurement of thermally induced warpage of BGAs with high sensitivity shadow moire", The International Journal of Microcircuits and Electronic Packaging, 21(2), 191 (1998).

W. Lin and M. W. Lee, "PoP/CSP warpage evaluation and viscoelastic modeling", Electronic Components and Technology Conference, 1576 (2008).