The University of British Columbia

This paper reports on advances in the throughput of micro-electro-discharge machining (micro-EDM) technology by increasing the spatial and temporal multiplicity of discharge pulses. Lithographically fabricated electrode arrays are used in conjunction with various pulse generation schemes, resulting in > 10(2)x improvement in throughput compared to single electrodes. Increasing the number of pulse generation circuits distributed across electrode arrays increases the machining rate several fold, but compromises surface smoothness. A modified pulse generation scheme that exploits the parasitic capacitance of the interconnect offers similarly high machining rates and is more amenable to integration. Stainless steel workpieces of 100 mum thickness were machined by 100 mum x 100 mum square cross section electrodes using in 85 s using an 80 V power supply. Surface smoothness was unaffected by electrode multiplicity. Using electrode arrays with four circuits, batch production of 36 WC-Co gears with 300 pm outside diameter and 70 mum thickness in 15 min. is demonstrated.