# Effectiveness of Electrode Design Methodologies for Fast EDM Slotting of Thick Silicon Wafers
## 1 Introduction
As there is no mechanical contact between the workpiece and tool during this process, it provides advantages over other contact-based conventional and non-conventional machining methods [2]. However, the main bottleneck of machining silicon using EDM is the slow material removal rate. Extensive research has been conducted to improve the removal rate of material during EDM using different approaches, which range from parametric optimization, improving the flushing rate, material of the electrode, or shape of the electrode, and reducing contact resistance to hybrid machining. Many research studies have focused on improving the material removal rate and machining performance by optimizing the process parameters for EDM. [PERSON] et al. [11] investigated the effects of the peak current, pulse on time, dielectric pressure, and tool size on the material removal rate and tool wear rate and carried out parametric optimization to increase the material removal rate (MRR) and decrease the tool wear rate (TWR) during EDM of EN-31 using copper electrodes. Using the analysis of variance, it was found that the MRR was influenced by the peak current by far the most, which accounted for almost 97%, followed by the pulse on time and size of the tool. The pulse on time, however, produced the greatest impact on the TWR, followed by the tool size. [PERSON] et al. [12] also investigated the optimization of process parameters for an increased material removal rate and reduced surface roughness for EDM of 55 NiCrMoV7 using EDM-3 POCO graphite electrodes. It was found that the peak current had a dominant influence on the MRR and surface roughness, followed by the pulse on time. The pulse off time had a negligible effect on the output parameters, but played a vital role in stabilizing the EDM process. [PERSON] et al. [PERSON] et al. (2018) examined a carbon composite as a workpiece, which is a 2 mm rectangular plate, and electrolytic cylindrical copper as a tool electrode with a diameter of 1.6 mm. It was found that the gap voltage had the most significant effect in both cases on the material removal rate and tool wear ratio, followed by the pulse current and pulse on time. [PERSON] et al. [PERSON] et al. (2018) analyzed the influence of open voltage, servo voltage, pulse on time (Ton), pulse off time (Toff), and wire tension for slicing the monocrystalline silicon using WEDM in terms of the material removal rate, slicing rate, and surface roughness. The Taguchi methodology and Grey Relational Analysis were utilized to analyze the experimental data. The output parameters primarily depended on the pulse on time, with the wire tension and open voltage coming in second and third. In parametric optimization, the pulse off time had the least impact. The surface roughness and material removal rate were both enhanced by reduced wire tension. [PERSON] et al. [PERSON] et al. (2018) further investigated the effects of the peak current, pulse on time, pulse off time, wire tension, and feed rate on the slicing rate and surface roughness during wire EDM of silicon. From the experiments, the maximum slicing rate was obtained at a higher value of pulse on time and peak current, and to obtain the least possible surface roughness, the pulse on time and peak current need to be the smallest. [PERSON] et al. [PERSON] et al. (2018) investigated the effects of process parameters on the EDM performance and carried out the optimization of parameters for slicing silicon ingots using wire EDM. The response surface methodology was used to optimize the process parameters. It was found that the kerf width increased with the increase in the peak current and wire diameter. The duty cycle and workpiece height have a negligible influence on the kerf width. The wire diameter has the maximum effect on the kerf width. The current was the most dominant factor in increasing the slicing rate. The slicing speed increased by 3.5 times when the value of the current changed from 1 A to 5 A. The height of the workpiece had a significant negative effect on the slicing rate. [PERSON] et al.