On the mechanics of laser peeling for ultra-thin glasses

Laser peeling is a surface defect removal process involving irradiating laser pulses on edges of ultra-thin glasses. Mechanical- or laser-cutting induced edge defects on glass edges are removed by peeling off a thin layer containing the cutting defects. The new edge-surfaces of the glasses are defect-free and much less prone to cracking failure. In this paper the mechanism of this material removal process is investigated. From experimental observations and theoretical calculations, it is shown that the laser glass peeling is a brittle fracture process driven by residual stress associated to glass surface phase change phenomenon, as opposed to the typical laser ablation material removal. A quantitative fracture mechanics model that simulates the laser induced glass peeling process is also presented.