Abstract
This paper describes a mechanism of deep hole drilling of covalent bond-ceramics using a pulsed YAG laser. The deep hole drilling process was simulated by the newly developed analysis method. It was combined the ray tracing method for a laser power intensity distribution analysis and difference method for a thermal analysis. It assumed that laser beam energy was delivered by reflection from the internal wall surface of a hole in the ray tracing model. Sublimation process of silicon nitride was considered during the thermal analysis. The deep drilling hole was processed mainly by energy reflected from the internal wall surface of the hole. In this process laser power intensity became higher in the center of the hole since the laser beam was focused by the wall-reflecting effect.
