CHIP EVACUATION OF PCB MICRO-DRILLING AND HIGH-SPEED PHOTOGRAPHY

Zihao Ding, Lixin Huang

Abstract: Chip evacuation is one of the essential indicators reflecting the quality of drilling of printed circuit board (PCB). Thrust force variation shows the chip evacuation condition as drilling depth increases. This paper aims to describe the chip evacuation, thrust force and force generation mechanism. The goal is to provide thrust characteristics which can reflect chip evacuation performance. The chip evacuation is observed and recorded through high-speed photography technology. The thrust force of single and multiple drilling procedures of two materials is gauged with dynamometer. Curling is main deformation of copper and aluminium chips. The main evacuation form of chips is spiralling up along the flute. Maximum thrust force appears when drilling top copper foil. When the thrust force of multiple hole drilling is stable, the hole accuracy meets the requirement of production. This paper analyses chip evacuation in PCB micro-drilling. The process of chip evacuation is captured by high-speed camera. The relationship between hole accuracy and thrust force is illustrated.

Keywords: DRILLING , PHOTOGRAPHY

DOI: https://doi.org/10.15623/ijret.2018.0709021