Development and Experimental Study of Milling Electrochemical Spark Micromachining (M-ECSMM) of Silicon

Milling Electrochemical Spark Micromachining (M-ECSMM) is hybrid micromachining process which is used to create microfeatures in non-conducting materials. Silicon is one of the abundantly used material in microelectronics and micro-industry as base material for developing the user end products. In present paper, authors attempt to create the microchannels using M-ECSMM in the silicon wafer using tungsten carbide microtool (500 µm) in the presence of a hybrid electrolyte (NaOH + KOH). One-factor-at-a-time (OFAT) approach has been used to study the variation of material removal rate (MRR) and surface roughness (R a ) with change in parameters such as voltage, pulse on-time, electrolyte concentration, and rpm in multipass micromilling. It has been observed in experimentation that micromilling cannot be carried out on higher speed for silicon workpiece because tool stick around the bottom causing plastic adhesion on the workpiece. Similarly, MRR rises with increase in value of voltage above critical voltage and maximum roughness is achieved at 5.5 M of electrolyte. The experiments result for silicon are compared with machining of borosilicate glass coverslip on same parameters and similar results are seen where glass develops cracks or breaks at higher rpm.