Fraunhofer Institute for Mechanics of Materials IWM
Minimizing kerf loss during wire sawing of silicon wafers
Industrially, multi-wire saws are used for the separation of silicon ingots. A steel wire is drawn over pulleys whose indentations guarantee a constant spacing of the wires. The sawing process is achieved by pressing the silicon ingot against the wire mesh, which is moistened with abrasive slurry. The slurry typically consists of polyethylene glycol and angular SiC grains. The challenge is to simultaneously minimize silicon kerf loss while maximizing sawing efficiency. At the Fraunhofer IWM, particle based simulations have been implemented for the sawing process which is difficult to access experimentally; these provide insights into interactions within the carrier fluid, abrasive grains and silicon surfaces and show optimization options for both sawing waste and sawing efficiency.
