Author : M.M. Hanon

This paper presents a comparison between the behavior of two different laser drilling processes, The first is a practical drilling application of the alumina ceramic with thickness (2.2 mm) using Nd:YAG laser whereas the other is a simulation of the transient heat transfer using COMSOL Multiphysics 3.5a for drilling PMMA substrate of thicknesses of (2.5 mm). For the practical work, Effects of the laser peak power, pulse duration and repetition rate, have been determined using optical images taken from the inlet and outlet of the samples. Different laser beam parameters have been used for the laser drilling process of alumina ceramic such as various peak powers increased consecutively by 2 kW from 2-6 kW, various pulse durations increased from 1-5 ms with 1ms increments and various repetition rates increased from 5-25 Hz with 5 Hz increments. Concerning the simulation, the beam parameters used for this study are selected to simulate drilling process using CW Diode laser of 1064nm wavelength. It has been used various output powers (0.96 W, 1.82 W, 2.45 W and 3 W) and various exposure times (2 s, 3 s, 4 s and 5 s) and a spot size with a 0.5mm beam radius. Effects of laser output power and exposure time have been carried out via the studying of the temperature distribution on the cross section of the substrate to determine the optimum conditions obtained from the combination of parameters that improves hole quality. It has been indicated that the results behavior of the practical and simulation of this work are in good agreement when compared to each other.

Keywords: Simulation of drilling, Laser Drilling, Alumina ceramic, PMMA, Modeling using COMSOL.

Article published in International Journal of Current  Engineering  and Technology, Vol.4,No.4 (Aug- 2014)