Paper Title
High Efficiency Laser Square Hole Drilling of Si3n4 Substrates

Abstract
In this paper, we propose efficient laser drilling technology by optimization laser parameters, such as scanning speed, pulse repetition rate, overlapping rate, and repetition of process. We demonstrate how laser parameters obtain high ablation rate for laser hole drilling. The efficiency of laser ablation of Si3N4 is investigated using the femtosecond laser. Initially, the laser beam characteristics, such as focused laser beam diameter and averaged power are measured. The maximum pulse energy can be helpful in obtaining greater ablation depth. The optimal pulse overlapping rate, which is related to the scanning speed and pulse repetition rate, is predicted to be approximately 97% in Si3N4 material. The high aspect ratio drilling is controlled with process times, for which the optimal value is predicted to be approximately 40 times. Keywords- Ablation rate, Drilling, Femtosecond, Hole, Laser