Challenge to Development of Functional Multi-Wire EDM Slicing Method Using Wire Electrode with Track-Shaped Section

Abstract

Brittle materials, such as silicon, silicon carbide and sapphire have been conventionally sliced for wafers by a multi-wire saw method with slurry in industrial fields. Recently, the multi-wire saw method with a fixed diamond abrasive wire has been available as a commercial product at acceptable cost, and the high slicing performance is expected compared with the normal multi-wire saw method with slurry. However, there still remain some problems such as bad working environment with abrasives, cleaning cost of sliced wafers, crack generation on the sliced surface and a large kerf loss against a wafer thickness. On the other hand, the developed multi-wire EDM slicing method would accomplish the high performance slicing of silicon and silicon carbide with a narrow kerf width under a clean process environment. However, the thinner wire is challenging process with a normal round shape wire electrode. Therefore, the new wire electrode with track-shaped section was proposed in order to satisfy both the narrow kerf width and the high wire tension even in the case of thin wire electrode. In this study, the running control of wire electrode with a track-shaped section was experimentally investigated, and the possibility of proposed process was discussed.