Theoretical approach to estimate laser process parameters for drilling in crystalline silicon

This paper presents a simple method for estimating the ablation rate during drilling processes in crystalline silicon wafers. Using data from literature, the physical process of material heating, melting, and ejection can be estimated on a time scale and leads to a temporal separation of the pulse duration in two parts. The latter one offers a theoretical determination of the expected average ablation rate. The results of this approximation coincide with experimental values and offer solutions to increase drilling efficiency. The experiments were done with a q-switched solid-state laser emitting at 1064 nm wavelength at pulse durations between 810 ns and 1440 ns. Copyright (C) 2010 John Wiley & Sons, Ltd.