Surface characteristics and wire wear of electroplated diamond wire saw slicing photovoltaic polycrystalline silicon

The surface characteristics of photovoltaic (PV) polycrystalline silicon cut by electroplated diamond wire saw affects the fracture strength and the subsequent texture process of wafers. The experiment of electroplated diamond wire sawing PV polycrystalline silicon was conducted in order to analyze the sliced wafer surface characteristics, investigate the influence of sawing parameters on the sawn surface characteristics and reveal the wire saw wear mechanism. The results show that there are shallow ductile scratches and deep grooves formed by ductile shear micro-cutting of diamond abrasives, and fracture micro-pits left by brittle removal of materials on the sawn polysilicon surface. The relative proportion of materials brittle removal to ductile removal varies with the change of process parameters combination. Increasing the feed rate of crystals and decreasing the wire speed, the surface roughness of sliced wafer increases and the sawn surface topography gradually changes from ductile grooves to fracture micro-pits. The wear forms of electroplated diamond saw wire fabricated by nickel-coated (metallized) diamond abrasives are as follows: abrasive flattening is the main wear form in steady wear stage, and abrasives-pulled out and coating wear are the main wear forms in late-use period.