Research on fracture behaviour of the adhesive sealant based on energy failure criterion for TFT-LCD

Abstract

The adhesive sealant is a crucial structure connecting color filters and thin film transistors in liquid crystal panels. Research on the fracture progress of the connection structure is heavily needed in reliability evaluation engineering. In this work, three types of adhesive sealants with different widths were tested by the uniaxial tensile experiment to obtain their fracture process curves, which conformed to the brittle fracture characteristics described by the bilinear cohesion zone model. Then, according to the theory of engineering fracture mechanics, the Dugdale-Barenblatt plastic zone model was employed to analyze the adhesive sealant with hole defects, and it was simplified to mode ? fracture mechanics problem. Calculating with finite element numerical simulation, the numerical relationship between the stress field of the internal defect and the external stress of the material was obtained, and the brittle fracture behavior model was deduced as related to the defect size. Applying the model to the adhesive sealant, the average error of the model value after the correction was reduced from 7.98-12.13% to 6.84-7.53%, and the overall error was only within 15%. The model includes the material’s basic characteristics and the defect’s size that affect the fracture process, provides a theoretical basis for predicting the fracture of the sealant and improving the strength of bonded joints, thus is of great significance for material application and fracture analysis in engineering.