Evaluation method for the machining accuracy of diamond wire squaring mono-crystalline silicon and its application in comparison of reciprocating wire and endless wire

Square wire sawing (squaring) is the preceding process of silicon ingot grinding and slicing for solar wafer manufacturing. The machining accuracy will affect the machining efficiency of the grinding process, and affect the quality of slicing. At present, extreme difference (ED) method is used for the evaluation of squaring accuracy, which cannot fully reflect the squaring accuracy. Novel evaluation method of straightness difference (SD) and flatness difference (FD) of squaring were proposed. The evaluation process was compared with ED method. The results show that the novel method can solve the defects that cannot be sufficiently evaluated by ED method. In addition, the profile errors of the cross sections along and perpendicular to longitudinal direction and the surface contour errors on the symmetric surface were evaluated. The relationship between the error distributions along the longitudinal direction and the processing parameters was also found, which provides help for optimizing the process.