Tailored-edge laser glass cleaving supported by thermal separation

Abstract

A two-step laser-based concept is presented for cleaving glass substrates with tailored edges. In a first step beam shaped ultrashort laser pulses are used to modify the transparent material along chamfered or C-shaped edges. Secondly, thermal stress is applied close to the modified area by absorbing the radiation from CO₂ laser. The tensile stress thus induced on the upper side of the glass leads to the actual release. The efficacy of our approach is demonstrated by presenting selected samples with tailored shaped edges and discussing corresponding edge qualities.