Low damage silicon separation (wire sawing)

© Photo Fraunhofer IWM

When wire sawing silicon material for solar cell wafers, a considerable amount of the silicon that has already taken a lot of energy to clean and crystallize is lost in the form of non-recyclable silicon dust. A core topic is therefore the reduction of the sawing gap width and research into the fundamentals of material removal in the single saw gap process. The work involves experimental and numerical investigations on new wire, abrasive and substrate materials as well as material removal mechanisms and sawing parameters. Investigations cover the abrasion of wires and the mechanical properties of the subsequent surfaces in order to define promising wire-slurry systems for industrial 100 µm sawing process.