Evaluation of machinability in the micro end milling of printed circuit boards

Abstract

Printed circuit boards (PCBs) have slots and holes that aid in the assembly of electronic devices. To produce these shapes, advances in manufacturing methods have been made in processes including machining, laser, plasma, and punching. In this study, to evaluate the capability of a micro end mill in the machining of PCBs, cutting forces were measured using a dynamometer under various cutting speed and feed per tooth conditions. Copper-clad laminate (CCL), which is a PCB raw material, was selected as the workpiece to evaluate the machining capabilities of the PCB end mill. The cross-section of a machined slot in a workpiece was observed under a microscope, and the burr height of the cross-section was measured. Finally, the relationship between cutting force and burr height was determined. The cutting force increased with increasing feed per tooth, and the burr height decreased with increasing feed per tooth; thus, it was inversely proportional to the cutting force.