Relationship between Slurry Actions in Slicing Groove and Slicing Characteristics at Multi-Wire Saw

The multi-wire saw is one of the methods used to slice large-sized silicon ingots. This slicing method uses a working fluid mixed abrasive grains, which is called slurry. In the case of a multi-wire saw of the workpiece descent-type, this slurry is supplied on the wire and carried to the processing area. As the workpiece is processed by slurry which enters between the wire and the workpiece, the slurry action is very important to the slicing efficiency and the accuracy of silicon wafers. In this study, the slurry actions on the periphery of the wire and inside the slicing groove are observed by a high-speed video camera. The slicing characteristics were studied under a series of slicing conditions using the workpiece descent-type multi-wire saw. From this study, the followings have become evident: (1) The slicing grooves are filled by the slurry, and the wire running brings about the slurry flow to the slicing grooves. (2) Air enters into the slicing grooves by the wire running, and some bubbles and air layer can be observed in the slurry of the slicing grooves. These are factors which contribute to lower slicing efficiency and accuracy.