Analysis of sawing characteristics of fine diamond wire slicing multicrystalline silicon

Abstract

At present, the diamond wire sawing technology has been widely used in the slicing of photovoltaic multi-crystal silicon (mc-Si). The diameter of diamond saw wire becomes smaller and smaller, and the surface abrasive density and sawing process parameters affect the sawing characteristics of mc-Si wafer. In this paper, the sawing experiment of photovoltaic mc-Si with fine diameter electroplated diamond saw wire was carried out, and the effects of abrasive density and sawing process parameters on the sawing characteristics were analyzed. The results show that the cutting ability and sawing efficiency of diamond wire increase with the increase of surface abrasive density. However, too large surface abrasive density is easy to cause the accumulation of abrasives and the reduction of chip holding space. The core wire diameter is 60 μm and the surface fixed abrasives size is 8–10 μm, when the surface abrasive density is 200–300 grit/mm, the saw wire has relatively good sawing characteristics. The area formed by the material ductile removal domain accounts for a large proportion of the sawn surface, and the surface roughness and subsurface microcrack damage depth (SSD) of silicon wafer are lower. The surface quality of as-sawn wafer can be improved by decreasing the feed speed of workpiece and increasing the wire speed. The research results can provide a reference for the optimization of diamond wire sawing process of photovoltaic mc-Si cells.