| dc.description.abstract | The microhole machining of quartz wafers depends on photolithography techniques akin to those used in semiconductor fabrication. These methods present challenges due to high equipment setup costs, large space requirements, and environmental pollution risk. This research applies ultrasonic vibration assistance in electrochemical discharge machining to create an array of microholes on quartz wafers. In the experiments, a self-prepared tungsten carbide micro electrode array served as the tool electrode. This electrode was a 2 × 2 square array, with needles measuring 30 × 30 μm. A series of experiments was conducted to investigate the effects of various machining parameters including working voltage, feed rate, duration time, duty factor, and ultrasonic power level on the characteristics of the microholes array. The characteristics included average hole diameter, through-hole surface morphology, and average fillet radius of the electrode needles. The experimental objective was to achieve a through-hole diameter of 80 μm with accuracy of ±8 μm.
During the electrochemical discharge machining, suitable ultrasonic vibrations can thin the insulating gas film coating on the electrode surface, resulting in a more uniform gas film. As the insulating gas film’s thickness decreased, so did the critical voltage needed for the electrochemical discharge machining , reducing the hole’s diameter expansion. The ultrasonic vibration assistance can enable the satisfaction of the dimensional accuracy requirement. The experimental results indicate that the ultrasonic vibration assistance can effectively improve the processing capacity and reduce the sample fragmentation. A working voltage of 44 V, feed rate of 1 μm/6 s, duration time 30 μs, duty factor 30%, and ultrasonic power level of 1 resulted in better inlet and outlet surface morphology, without outlet fragmentation. Moreover, the average diameters of the inlet and outlet were roughly 80 μm while meeting the through-hole diameter of 80 μm with accuracy of ±8 μm. | en_US |