Investigation on micro-milling of micro-grooves with high aspect ratio and laser deburring

Abstract

High aspect ratio micro-grooves are critical structures in the micro-electromechanical system. However, problems like rapid tool wear, low processing efficiency, and inferior machined quality in micro-milling of high aspect ratio micro-grooves by length–diameter ratio tools are particularly significant. In this work, a combined micro-milling method based on water-free alcohol as the cutting fluid and laser deburring is proposed to investigate the high aspect ratio micro-groove generation of oxygen-free high-conductivity copper TU1. Parametric experiments and high aspect ratio micro-groove experiments were conducted to investigate the surface quality, cutting forces, and tool wear. The water-free alcohol was employed to improve the tool life and machined surface quality. In the case of the oxygen-free high-conductivity copper TU1 material, a satisfactory high aspect ratio micro-groove (groove-width = 0.2 μm and aspect ratio = 2.5) with a nanoscale surface roughness ( Ra = 68 nm) was obtained under the preferred machining conditions. Furthermore, the deburring process of the high aspect ratio micro-groove by the laser technology was conducted to achieve ideal machined quality of the top surfaces.