Experimental research on semiconductor shaping by abrasive-spark hybrid machining

Abstract

In this study, the problem of poor precision and low efficiency in shape-cutting hard, brittle semiconductor materials with traditional fixed abrasive diamond wire sawing (DWS) is investigated experimentally and a novel approach, which combines electric discharge and diamond abrasive grinding into a single process, is proposed. Experiments with polycrystalline silicon materials are conducted to contrast abrasive-spark hybrid machining, diamond wire sawing, and wire electricaldischarge machining (WEDM). The results show that, under the same processing conditions, the shape accuracy of abrasive-spark hybrid machining is the highest and cylindricity error is as the lowest, at 11 μm. In comparison with WEDM, the damage-layer thickness of machined surfaces is reduced by 10 μm. Among three processing methods, hybrid machining has the minimum wire bending and wider kerf. The thickness of damage layer and the surface roughness of hybrid machining are in the middle. The surface topography is composed of shallow discharge pits and grinding areas, and there are few scratches on the cut surface compared to diamond wire-cut surfaces, such that this new machining method is found to be more suitable for shape-cutting hard and brittle semiconductor materials.