Modeling and optimization of pulsed green laser dicing of sapphire using response surface methodology

Laser dicing of single-crystalline sapphire substrate (α-Al2O3) with a pulsed Nd:YAG green (λ=532 nm) is investigated. The Box–Behnken Design (BBD) technique based response surface methodology (RSM) is employed to plan the experiment, then empirical models are developed to determine the correlation between responses and input variables, and finally multi-response optimization and quality testing are performed to obtain the optimum operating conditions. In the design of experiment (DOE), processing parameters, such as the pulse laser energy, scanning velocity and scanning times, are considered as the input independent variables, and the groove depth and width as the targeted responses. Results identify the most predominant parameters on the responses, provide insight into the interactions of these parameters, and obtain the optimized operating conditions. The specific combination-pulse laser energy of 150 μJ, scanning velocity of 0.55 mm/s, scanning times of three, can obtain a deep groove depth of 148 μm, narrow groove width of 19 μm with good dicing quality.

► Pulsed green laser dicing of sapphire is investigated by the RSM method.
► The process parameters are optimized to use the desirability function approach.
► A deep and narrow groove with good dicing quality is obtained.