Investigating Electrode Design Methodology for Improving Machining Performance in Silicon Using Die Sinking EDM

Abstract

Abstract Silicon is the material that is most frequently utilized in the electronic industries because of its distinctive properties which encompasses from age resistance to high temperature stability. However, it is extremely challenging to machine silicon using conventional machining processes that employs traditional cutting force. As a result, non-conventional machining techniques have gained popularity and Electrical Discharge Machining (EDM) is one of the non-conventional machining techniques that has enormous potential in terms of machining silicon. However, the slow rate of material removal is the major drawback of machining silicon using EDM. This study seeks to investigate unique electrode designs and explore their efficacy in terms of improving material removal rate (MRR), reducing electrode or tool wear rate (TWR), and improving quality of the features machined by those electrodes. In this study, graphite electrodes with different arrays (1 × 4, 2 × 4 and 3 × 4) and leg heights (0.2” and 0.3” of electrode legs) were made using milling machine and were used in the die sinking EDM process to investigate the effects of heights and arrays on the material removal rate, tool wear rate and dimensional accuracy of the fabricated features keeping the EDM parameters constant. It has been observed that the increase of arrays of electrode legs results in shorter machining times per leg due to improve flushing conditions for both cases of electrode height. For lower arrays of electrode legs, smaller height (0.2″) performs better in terms of material removal rate. At 3 × 4 arrays of electrode, both cases of height of electrode show almost identical material removal rate. In case of dimensional accuracy, the quality of features improved with increased arrays of electrode legs for both leg heights (0.2” and 0.3″) of electrode. However, for overall accuracy of the features, height does not have significant effect as both performs quite similar. In this study, electrode wear rate is found negative due to carbon deposition on the graphite electrode. With the increased arrays of electrode legs, there is a decrease in carbon deposition per legs of electrode for both cases of electrode height. In terms of the effects of electrode leg height, each case of arrays performs quite alike.