Research on Microhole Processing Technology Based on the Femtosecond-Laser Spiral Trepanning Method

Microholes have crucial applications in aerospace, the automotive industry, and other industries. In this study, the microhole processing technology based on the femtosecond-laser spiral trepanning method was investigated. By adjusting the spiral scanning path, laser power distribution, and defocusing amount to control laser energy distribution, an inverted cone hole, straight hole, and normal cone hole were obtained finally. The morphology and element of the microhole were investigated by scanning electron microscopy (SEM) equipped with energy-dispersive X-ray spectroscopy (EDX). The experimental results of the femtosecond-laser spiral trepanning method could achieve fewer impurities. Finally, the formation mechanisms of different microholes are explained in detail. The method is simpler and more efficient than the traditional microhole processing technology. The femtosecond-laser spiral trepanning method with controllable hole roundness, accuracy, and taper has important practical significance in microhole processing.