Slurry Sawing of Multicrystalline Silicon with Low-Viscosity Carrier Liquid

The wafering of crystalline silicon is industrially realized by wire sawing with loose abrasive particles dispersed in a carrier medium (slurry process) or by fixed diamond particles embedded on the wire (diamond wire sawing - DWS). DWS demonstrates cost advantages by the usage of a cheap cooling fluid, which consists of water with about 2% of additives. In the slurry process, SiC particles are used as abrasive typically dispersed in polyethylene glycol (PEG200) as carrier liquid. A cost reduction of this process by saving electrical energy can be achieved by the usage of a lower-viscosity carrier liquid. In this contribution, PEG200 is substituted by the lower-viscosity organic substance propylene carbonate. In four consecutive sawing processes on multicrystalline silicon bricks, the cutting performance of this liquid was tested. The results are compared with the standard sawing process using PEG200. It was found that the average power of the wire saw main drive can be reduced by about 60%.