Abstract
This paper describes the micro-drilling process of printed wiring boards (PWBs) containing high hardness and high thermal conductive fillers. When processing these PWBs, the drill tools undergo severe wear due to the high hardness of the filler. Therefore, we examined the characteristics of drill wear and derived practical formulas of drill wear from these results. These equations are similar to Taylor's tool life equation. Moreover, we investigated the effects of thermal conductivity on temperature during the drilling process. The temperature around the drill hole was shown to be a complex phenomenon according to increasing filler content of PWBs.
