Abstract
In this paper, we describe the results of our study of precision micro-Electro-Discharge Machining. Micro-EDM had been developed and mainly used for making holes in nozzle plates within the inkjet printer field. Smaller-diameter hole boring and burr minimization are required in the manufacture of aperture disks for electron beam equipment such as SEM and FIB. Specifically, this study focuses on the measurement of the floating stray capacitance of a relaxation pulse-type electro- discharge generator, the investigation of the effect of the waveform of pulse discharged current, and the resulting surface roughness of the machined area as they relate to each element of the discharge circuit including the pulse generator and equipment. Additionally, it is confirmed that the use of a low gap voltage achieves a smoother surface finish. This is the result of the diameter of each single crater generated on the surface by a single pulse discharge being smaller than 1.2μm, which is 50% smaller than that for conventional micro-EDM equipment.
