Wear characteristics of micro-drill during ultra-high speed drilling multi-layer PCB consisting of copper foil and ceramic particle filled GFRPs

Abstract

As a typical difficult-to-machine composite material, the microfabrication process of printed circuit board (PCB) is widely studied, especially the micro-hole drilling. However, multi-layer PCBs composed of flat glass fiber reinforced polymer and high-hardness ceramic particle fillers exhibit different tool wear behavior during the micro-hole drilling. The results showed that the abrasive wear on the chisel edge and main cutting edge are observed in the drilling of multi-layer PCB, while fracture of the main cutting edge only occurred in the drilling of ceramic particle filled GFRPs. Increasing the feed rate or spindle speed could effectively reduce tool wear. The cold air auxiliary drilling can effectively reduce the flank wear of the micro-drill, especially in the drilling of multi-layer PCBs.