Parametric Study Of Hole Taper In Laser Micro-Drilling Of Copper Sheet

Laser beam machining is a thermal energy based non-contact type advanced material processing technique which can be applied for almost all materials. Nowadays there is an increasing trends towards miniaturization of various components used in different applications like MEMS, photonics, microelectronics, robotics, bio-medical devices, etc. which needs micro-machining. Use of laser microdrilling can be attributed to several advantages like high standard of finishing, high production rate, no mechanical damage or tool wear, low material wastage, low production cost, very small heat affected zone and ecologically clean technology. Copper is one of best light metals due to its excellent electrical and thermal conductivity, good strength and formability. It also has outstanding resistance to corrosion and fatigue. Due to these properties they are used in the field of micro-electronics, printed circuit board, robotics, bio-medical application, aerospace & aircraft industry, automobile industry, etc. In this present research work, copper sheet of 0.2 mm thickness is micro-drilled by Nd:YVO4 laser. Hole taper has been investigated with respect to the laser beam power, pulse frequency, scanning speed and number of passes. L9 Orthogonal array has been applied to minimize the No. of experiments. The results show that hole taper increases with the increase of laser beam power. Whereas hole taper increases initially but decreases again with the further increase of pulse frequency, scanning speed, and number of passes. ANOVA technique is applied to optimize the response and thereby selecting the optimum combination of process parameters. At last confirmation test has been performed to compare the predicted value with the experimental value.