CONTINUOUS WIRE SAW LOOP AND METHOD FOR MANUFACTURE THEREOF

摘要

A closed loop wire saw loop (12), a method for making the closed wire saw loop (12), and an apparatus and method for slicing a work piece, in particular, a polysilicon or single crystal silicon ingot (14), utilizing a closed loop of diamond impregnated wire (40) in which the work piece (40) is rotated about its longitudinal axis as the diamond wire (40) is driven orthogonally to it and advanced from a position adjoining the outer diameter ("OD") of the ingot (40) towards its inner diameter ("ID"). In this manner, the diamond wire (40) cuts through the work piece at a substantially tangential point to the circumference of the cut instead of through up to the entire diameter of the piece and single crystal silicon ingots of 300mm to 400mm or more may be sliced into wafers relatively quickly, with minimal "kerf" loss and less extensive follow-on lapping operations. The closed wire saw loop (12) is made by squaring and welding the wire ends together and then twice heat treating the weld at about 1500 F.