抄録
We have performed EDM of reverse-tapered microholes with a diameter of less than 100μm and a high rate of taper. Two methods have been tested for drilling a hole in a 50-μm-thick copper sheet using tungsten electrodes: one uses an electrode moving in planetary motion with planetary-motion diameter gradually increasing; the other employs an electrode bent at a high angle to its original axis. A hole 35μm in entrance diameter and 42μm in exit diameter was drilled by the former method and a hole 50μm in entrance diameter and 115μm in exit diameter was fabricated by the latter.
