Ingot cutting method with wire saw

TL;DR: In this paper, the problem of reducing the warp of the wafer wafer was addressed by reducing the unevenness of the thickness of a wafer, increasing the yield of wafer per ingot, and reducing warp.

Abstract: PROBLEM TO BE SOLVED: To shorten the cutting time of an ingot, reduce the unevenness of the thickness of a wafer, increase the yield of the wafer per ingot and also reduce the warp of the wafer. SOLUTION: A feed amount per cycle of the go and return of a wire row 11 is made comparatively larger at the cutting start end and cutting final end of the ingot I and comparatively smaller at the cutting central part of the ingot I. As this result, total idle time of the cutting start end and final end with a short contact length to the ingot I an be shortened and the ingot cutting time is shortened. At the same time, the ingot can be cut smoothly with causing the run-out of lubrication of an abrasive liquid at the cutting central part with a long contact length. The unevenness of the thickness of the wafer W just after cutting can be reduced and the yield of the wafer production can be increased. The warp of the wafer W can be reduced and the break of the wafer W and wire disconnection at the lapping time can be prevented, too.