Multi-Wire Electrical Discharge Slicing for Silicon Carbide Part 2: Improvement on Manufacturing Wafers by Forty-Wire EDS

Abstract

In this paper, a machining energy control slicing method for cylindrical shaped ingots and forty-wire electrical discharge slicing (EDS) technology are investigated. Our recent study in [4], ten-wire EDS was applied to 100 mm-square polycrystalline SiC material. Applying this technology to ingot slicing, an appropriate process technology for cylindrical shaped SiC materials which are the same as an actual ingot is required. The slicing of cylindrical shaped SiC using conventional multi-wire EDS causes the increase of sori, or wire break with unstable machining process since wasteful machining power is not controlled as a function of machining length. To resolve this problem, we applied the machining energy control method which varies machining power with machining position. Using proposed method, ten-simultaneous slicing of cylindrical shaped SiC material is obtained with 80 μm/min in machining speed. The sori of machined surface is 34 μm, and TV5 is 28 μm as a result. Moreover, forty-wire EDS technology is applied to SiC slicing for improving wafer productivity. We successfully verified forty-simultaneous slicing of 100 mm-square poly-crystal SiC material without wire break. The sliced 39 thin plates are obtained 385 μm in average thickness, and 16 μm in maximum thickness variation.

Enhancing Cutting Rates in Multi-Channel HSWEDM of Metal Materials with a Novel Decoupling Circuit

“…The wire is then fed in the same direction to allow the multi-wire cutting of workpiece [9]. Itokazu et al successfully developed the 10-channel WEDM technology to process silicon carbide blocks at a speed of 56 µm/min [10], and the 40-channel WEDM technology at a speed of 80 µm/min [11]. Okamoto [9] employed a wire electrode with a track-shaped section in multi-channel WEDM to enhance the operational stability of the electrode wire and improve the quality of the kerf shape of SiC.…”