Mechanism Research Of Rollers Peeling Process For The Multi-Layer Flexible Device

Flexible electronic packaging needs to transfer the devices from the flexible donor substrate to the receptor package substrate. It is important to improve the efficiency and reliability of the transfer process of the large-area flexible electronic devices. The roller peeling process in the flexible electronics composite equipment can achieve a continuous, efficient peeling and transfer, causing a widespread concern in the field of the electronics manufacturing. The thesis carries out theoretical modeling, fracturing simulation and experimental test of the interfacial energy release rate, ensuring the successful peeling. The prime work can be summarized as follows:The conformal bending of devices with different stiffness on a peeling roller is discussed. The contact condition of the substrate layer and peeling cylinder is simplified as: complete contact and partial contact. According to the two cases, the device-substrate interface mechanics model is established with nonlinear beam theory. The interfacial stress and energy release rate(ERR) of the device-substrate layer are calculated under different bending radius and load.The interfacial stress and ERR of large-area multilayer flexible structure in the process of the peeling is simulated using cohesive element in ABAQUS. The virtual crack closure technique(VCCT) is introduced to calculate the interfacial delamination ERR in different states, revealing the relationship between the ERR and the peeling radius, device layer thickness and elastic modulus. The results of simulation are compared with the theory model to testify the correction of theoretical calculations.A peeling test device is designed to measure the interfacial fracture energy of the multilayer structure and a reference value for the interfacial delamination. Furthermore, the thesis analyzes the impact of peel angle and rolling speed to the interfacial fracture energy and the peel force, providing a method to estimate the interfacial energy under different roller radius and rolling speeds.In summary, the thesis provides a theoretical model of the roller peeling process, setting up a criterion for the peeling of multilayer flexible devices, providing a theoretical basis of the design of peeling roller(roller radius) and process optimization(substrate tension and rolling speed), laying the foundation for efficient, continuous peeling of flexible electronics.