Thermal Stress Cleaving of Si-Wafer: Investigation of Fracture Initiation during laser Beam Irradiation

摘要

This paper investigates the fracture initiation at the vicinity of a micro-groove caused by thermal stress through computational and experimental studies. Fracture initiation time has been determined by analyzing the stress intensity factor. Stress distribution was examined by using a finite element method, and the fracture toughness of the material was determined by using a Vickers indentation technique. The fracture initiation process was verified experimentally by monitoring the acoustic emission signals, while the temperature of the laser spot was also measured using two-color pyrometer. The result shows that stress intensity factor was increased with the increase in micro-groove sizes. Consequently, fracture initiation was attained faster. The simulation results show a good agreement with the experimental results in examining the fracture initiation and recognizing the ideal micro-groove parameters for laser cleaving process.