A Microcontroller-based Electrochemical Discharge Machining (ECDM) Equipment for Micro-drilling of Quartz Substrates

Electrochemical discharge machining (ECDM) is a hybrid micromachining technique used for micro-structuring quartz substrates. In the present work, we have built a microcontroller based ECDM setup for drilling quartz substrates. This setup can be effectively used to fabricate precise micro-holes using the constant velocity feed drilling technique. The tool can be moved along the Z-axis with the minimum and maximum speeds of 1 $mm/hr$ and 50 $mm/hr$ respectively. In order to study the effect of tool feed rate (TFR) on precision improvement, micro-holes were fabricated at different tool feed rates ranging from 0.3 $\mu m/\sec$ to 1.7 $\mu m/sec$. The optimum TFR for fabricating micro-holes with the least entrance diameter, central diameter and overcut was observed to be 0.8 $\mu m/sec$. The lower TFR values $(\lt 0.8\mu m/\sec)$ can be used for fabricating through-holes on the substrates. A through-hole having with an aspect ratio of 2.32 with entrance and exit diameters of 820 $\mu m$ and 677 $\mu m$ respectively was fabricated at a TFR of 0.6 $\mu m/sec$.