Study on mechanism of generation of nail-head caused by drilling through multi-layered printed wiring board

摘要

Electric devices have been smaller and more multi-functioned and so electric parts have. So it is required for printed wiring board (PWB) to be more compact. Drilling has been used for through-halls. But in using drills various problems have been pointed out. On this report we focus on “Nail-head” to solve one of problems. We evaluate nail-head by changing matrix of FRP and thickness of copper and show how much wear of drill affects the nail-head. On the other hands we respected relationship between cutting force and nail-head.