Application of USM to micromachining by on-the-machine tool fabrication

Most machining methods have difficulties in machining hard, brittle materials such as glass, ceramics, and silicon. Ultrasonic machining(USM) is a unique method from this point of view, because it easily machines these materials. However, USM has limitation in its application to micromachining because them are problems in fixing microtools to the machine and maintaining high precision. In this paper we propose a technique of micro-USM by applying on-the-machine tool. fabrication by wire electrodischarge grinding (WEDG). As a result, we were able to make microholes as small as 20pm in diameter on a silicon plate. Additional experiments revealed the possibility of wide application.