液晶与显示, 2018, 33 (5): 427, 网络出版: 2018-07-31
OLED金属走线弯折过程裂纹扩展有限元分析
Finite element analysis of crack growth of metal line in bending process of OLED panel
摘要
针对OLED面板COF(Chip on Film)连接过渡区在弯折过程中易发生金属走线断裂的问题,本文对金属走线中裂纹的扩展机理以及抑制裂纹扩展的方法进行了研究。基于复合材料界面裂纹偏转与穿透理论分析了金属走线与有机光阻界面处的裂纹扩展方式,比较了两种金属走线结构在裂纹扩展过程中的应力强度因子变化。仿真结果表明,金属走线与有机光阻的裂纹倾向于沿垂直走线的方向扩展,裂纹沿着界面扩展的趋势很小。对比两种不同金属走线(环状与条状)的应力强度因子发现,环状金属走线内部靠近孔处的应力强度因子降低了95%,能有效抑制金属走线中的裂纹扩展。
Abstract
Aiming at the problem that the metal lines breakage easily occurs during the bending process of COF connection transition zone in the OLED panel, the mechanism of crack propagation and the way to inhibit the crack propagation in the metal line are studied. Based on the theory of interface crack deflection and penetration, the mode of crack growth at the interface between metal line and organic photoresist is analyzed. The change of stress intensity factor of the two metal line during crack growth is compared. The simulation results show that the main path of crack propagation in the pad bending area is perpendicular to the metal lines. The tendency of propagation along the interface between the metal traces and the organic photoresist is very small. Through the calculation of stress intensity factor of the two structures, it can be found that the stress intensity factor near the inner hole of the annular metal line is reduced by 95% with respect to that of striped metal line. Thus the hole of the annular metal line effectively suppresses crack propagation.
张博, 廖敦明, 刘正周, 滕子浩, 吴棣, 陈继峯, 林书如. OLED金属走线弯折过程裂纹扩展有限元分析[J]. 液晶与显示, 2018, 33(5): 427. ZHANG Bo, LIAO Dun-ming, LIU Zheng-zhou, TENG Zi-hao, WU Di, CHEN Ji-feng, LIN Shu-ru. Finite element analysis of crack growth of metal line in bending process of OLED panel[J]. Chinese Journal of Liquid Crystals and Displays, 2018, 33(5): 427.