Using Laser-Based Thermal Stress Cleaving to Trim the Edges of Rectangular Glass Plates

摘要

When trying to trim the edges of a rectangular glass plate using thermal stress cleaving, the resulting crack path does not typically remain straight but will bend towards the nearby edge --- even though the path of the moving heat source lies parallel to the edge. This effect is brought about by the formation of a mode II stress singularity at the crack tip. Two dimensional finite element analysis of the transient thermal stress field shows that the mode II stress intensity factor varies according to the relative position of the heat source with respect to the cleaving line. Based on this analysis, three types of heat source profile are proposed to keep the cleaving path straight and parallel to the edge: a circular heat source, double circular heat sources, and a rectangular heat source.