Method for resuming operation of wire saw and wire saw

Abstract

The present invention is a method for resuming the operation of a wire saw in the case where after cutting of a workpiece has been temporarily interrupted halfway, the cutting is resumed. The method is characterized by comprising: a step for cutting the workpiece while the direction and travel speed of the back-and-forth travel of a wire are detected and recorded on a time-series basis; and a step for controlling the direction of the back-and-forth travel of the wire and the travel time in the direction on the basis of the travel history of the wire recorded before the interruption of the cutting of the workpiece so that the back-and-forth cycle of the wire maintains continuity between before the interruption of and after the resumption of the cutting of the workpiece when the cutting of the workpiece is resumed. Consequently, even when cutting of a workpiece is interrupted halfway due to the breaking of a wire or the like in the cutting of the workpiece by a wire saw, it is possible to reliably suppress the deterioration of the nanotopography of a processed wafer and complete the cutting.

Description

Technical field [0001] The present invention relates to a wire saw that presses a workpiece such as a semiconductor ingot to perform cutting while supplying slurry to a steel wire, and more particularly to a method for restarting the operation of the wire saw when the cutting is interrupted, and the wire saw. Background technique [0002] Conventionally, as an apparatus for cutting a workpiece such as a semiconductor ingot into a wafer shape, a wire saw is known. In this wire saw, the cutting steel wire is wound around two or more grooved drums many times to form a steel wire array. The cutting steel wire is driven at high speed in the axial direction, and the slurry is appropriately supplied. The workpiece is cut and fed with respect to the steel wire row, and thereby the workpiece is simultaneously cut at each steel wire position. [0003] In addition, the steel wire of the wire saw adopts a wear-resistant, tension-resistant and high-hardness wire, such as piano wire, etc.; in a...

AI Technical Summary

Problems solved by technology

[0006] When the time required from the start of the restoration work of the steel wire to the cutting of the workpiece again is extremely short, for example, when the breakage of the steel wire does not occur at the place where the grooved roller fits, the The steel wires are connected to each other, and the steel wire treatment can be completed; however, in addition, in the case where the steel wire repair process takes a long time (more than 1 hour), due to the bearing part of the grooved roller and the steel wire, etc. Due to frictional heat, the grooved roller that was originally thermally expanding will cool and contract. Since the distance between the steel wire rows will be narrower than the original state of cutting, if the cutting of the workpiece is started again in this state, it will be cut again. The cut surface of the wafer may have problems such as uneven steps that cannot be corrected

Images