Development of numerical-computation program to predict thermal shock induced by fs laser processing of meatals

펨토초 레이저 금속 가공시 발생하는 열충격 수치계산 프로그램 개발

It has been recognized that laser dicing of wafers results in low mechanical strength compared to the conventional sawing techniques. Thermal shock generated by rapid thermal loading is responsible for this problem. This work presents a two-dimensional ultra-short thermo elastic model for numerical simulation of femtosecond laser ablation of metals in the high-fluence regime where the phase explosion is dominant. Laser-induced thermoelastic stress is analyzed for Ni. The results show that the laser-induced thermal shock is large enough to induce mechanical damages.