Printed circuit board (PCB) composed of glass fiber reinforcement plastic and copper foil is a kind of typical composite material. The cutting process of fiber reinforcement plastic materials such as carbon fiber or glass fiber reinforcement plastic materials have been studied for many years, but the drilling process of printed circuit board using microdrill is more complicated than common carbon fiber reinforcement plastic materials. It is event that the cutting force changed when drill different material. The variation of drilling force may cause some problems such as drill break, board delamination. So it is important to study the drilling force in PCB drilling. The precision dy-namometer was used in experiments and cutting process was analyzed in this paper. The drilling process of PCB experience six stages and the drill will meet aluminum board, glass fiber reinforce-ment plastic (GFRP) and base strip. According to the drilling force in one circle, the peak force ap-peared at the moment of drilling copper foil and another smaller peak force appeared at the moment of drilling aluminum board and base board. The experiment results show that thrust force increased with federate and decreased with rotational speed.
