Minimizing Burrs and Defects on Microstructures with Laser Assisted Micromachining Technology

Molding technology is widely used to manufacture optical components because of its high efficiency. Along with the quick development of miniaturization in industry, the detrimental effects of previously negligible burrs and defects on mold surfaces have become significant to the performance of components, so these problems should be minimized. In this study, a laser assisted micromachining method was developed to solve this problem during the fabrication of periodic microstructures on a molding material of electroless nickel-phosphorus (NiP) plating. The transient temperature distributions of the workpiece under laser irradiation and the change in the maximum shear stress during the laser assisted micromachining process were simulated to set appropriate experimental conditions. Then, periodic micropyramid structures were fabricated by both conventional cutting and the laser assisted cutting processes. Results show that defects largely decreased on machined structures with the assistance of laser irradiation. The decrease in specific cutting force and the change of chips’ morphology were also utilized to analyze the reasons for this improvement.