Parametric optimization of hole taper control in ultraviolet nanosecond laser micro-drilling of copper foil

While hole taper is inevitably formed in the laser micro-drilling of through micro-holes, the formation propensity is largely determined by the interaction between laser processing parameters. In the present work, we perform numerical simulations and experiments to investigate the ultraviolet nanosecond laser micro-drilling of 1 mm diameter through micro-holes on copper foil with a thickness of 280 & mu;m, with an emphasis on the coupled influence of laser processing parameters on both the hole taper and circularity. Firstly, the characteristics of formed micro-hole quality are experimentally characterized, and the formation mechanisms of hole taper are further revealed by finite element simulations of multi-pulse laser ablation. Then, the relational degree of individual laser processing parameters in determining the hole taper and circularity is discovered by experimental investigation based on the gray relational analysis model. Finally, the coupled effect between significant parameters of laser power and repeat scanning number on the hole taper and circularity is further investigated by utilizing the response surface methodology, which derives the optimum laser processing parameters for manufacturing 1 mm diameter through micro-hole with a taper degree of 2.556 degrees and a circularity of 0.992 on the copper foil.

Automated summary

In this study, numerical simulations and experiments were performed to investigate the ultraviolet nanosecond laser micro-drilling of 1 mm diameter through micro-holes on copper foil. The relationship between laser processing parameters and hole taper and circularity was explored. The study provided insights into the formation mechanisms of hole taper and revealed the optimal laser processing parameters for manufacturing 1 mm diameter through micro-holes on copper foil.