TFT Parameter Test And Structure Simulation Optimization Of A Foldable AMOLED Panel

Flexible AMOLED(Active-matrix organic light-emitting diode)panels have become the focus of extensive research in the display industry.Its thin,bendable and other characteristics make it popular with people.The current research on popular folding screen mobile phones especially requires flexible display panels with high performance.However,during the bending process,due to the greater bending stress in some areas,it is likely to cause failure to inner parts or defects in the panel.Therefore,the mechanical properties of flexible AMOLED panels are very important,especially bending and impact resistance.This paper uses the finite element simulation method to explore the mechanical properties of different TFT(Thin Film Transistor)structures in the flexible AMOLED panel array layer.The main contents include:(1)The physical parameters of the thin film materials in the flexible AMOLED panel were measured and researched,and the test method of the elastic modulus of the new thin film materials was explored.Use nanoindentation equipment to measure the hardness of each layer of the film in the panel structure.According to the test principle of the indentation experiment and the initial measurement results,the hardness is calculated as the elastic modulus,and the required material performance library is established to provide simulation analysis.More accurate physical parameters.(2)The finite element method is used to realize the comparative analysis of complex structures.According to the TFT stack structure in the AMOLED panel,a TFT unit cell model is established.Apply reasonable boundary conditions and Global to local simulation algorithm to compare the stress difference of the two structures with and without opening.The results show that appropriate openings in the TFT structure have a certain effect on reducing thermal stress and bending stress,and can effectively improve the stress concentration around OLED electronic devices.(3)Based on the simulation results of the opening structure,the basic structure is optimized.The influences of the size of holes and the position of holes on the bending stress of the TFT structures are compared.Openings on the upper and lower sides of the OLED devices and larger-sized holes have a better effect on reducing stress.In addition,the influences of adding the PV layer,the SD layer and the hole-punching design in layer GE were also studied.TFT structures with more excellent mechanical properties were obtained.In this paper,the mechanical differences of different flexible AMOLED display structures are analyzed by simulation.The conclusions provide reference for product structure design and process optimization,screening of existing structure schemes,and also provide a characterization method of mechanical properties of thin-film materials.