Research on laser-induced asymmetric low-damage thermal cleavage cutting technology for glass

The demand for precise glass segmentation in high-end displays and flexible electronics highlights the potential of laser-induced thermal cracking (LITC), owing to its low damage characteristics and controllable thermal stress. However, challenges like microcrack propagation, thermal influence control, and unstable crack guidance under complex/asymmetric paths limit its engineering application. This study addresses crack control in asymmetric, low-damage LITC of glass through theoretical and numerical analysis of thermo-mechanically coupled crack evolution. A path control method based on a reverse heating strategy is proposed. A volumetric heat source model for 1064 nm laser absorption in glass, based on the Beer–Lambert law, was integrated with Fourier heat conduction and thermoelastic equations to establish a 3D transient model for temperature and stress fields. The extended finite element method then simulated crack-tip stress evolution and propagation paths under three precrack conditions: side precrack heating, co-directional heating, and reverse heating. Trajectory deviation caused by thermal input in asymmetric geometries was analyzed. The results demonstrate that the reverse heating method achieved the highest Pearson correlation coefficient (0.9948) between the ideal and actual cutting paths under asymmetric conditions, indicating superior performance in minimizing path deviation and enhancing consistency. Other heating methods showed weaker guidance precision and path stability. These findings provide a theoretical and modeling basis for low-damage laser segmentation of closed curves, complex contours, and high-precision glass components, with significant implications for optical device manufacturing.