Fixed Abrasive Diamond Wire Saw Slicing of Single-Crystal Silicon Carbide Wafers

This article investigates the slicing of single-crystal silicon carbide (SiC) with a fixed abrasive diamond wire. A spool-to-spool rocking motion diamond wire saw machine using a 0.22 mm nominal diameter diamond wire with 20 µm average size diamond grit was used. The effect of wire downfeed speed on wafer surface roughness and subsurface damage was first investigated. The surface marks generated by loose diamond grit and stagnation of the wire during the change of the wire-cutting direction were studied. The use of scanning acoustic microscopy (SAcM) as a nondestructive evaluation method to identify the subsurface damage was explored. Effects of using a new diamond wire on cutting forces and surface roughness were also investigated. Scanning electron microscopy has been used to examine the machined surfaces and wire wear. This study demonstrated the feasibility of fixed abrasive diamond wire cutting of SiC wafers and the usage of a SAcM to examine the subsurface damage.