Research on fixture hole drilling quality of printed circuit board

Abstract

Printed circuit board (PCB) fixture hole is used for installing PCB board or fixing PCB board during drilling process. The drilling quality parameters involve burr size, hole wall roughness et al. In order to improve drilling quality, proper drilling parameters and tool geometries are important especially the tool geometries. In this study, the drilling machinability of PCB fixture hole is studied, effects of drilling parameters on thrust force, drilling temperature and quality are discussed. The experimental results show that resin will be melted during the drilling process. The increase in spindle speed will lead to drilling temperature rise. The fuzzing and spalling of glass fibers result in the generation of hole wall roughness. The exit burrs and enter burrs are generated from drilling copper foils which located in the upper and lower surfaces. The heights of exit burrs are increased with the elevated feed. Drilling experiments are carried out with 9 drill bits which have different point angles, helix angles and length of chisel edges. Analysis of variance (ANOVA) is carried out for hole quality parameters. Desirability function method is used in multiple response optimization to obtain the optimal tool geometry parameters.