Abstract Subsurface microcrack damage depth (SSD) in silicon wafer processed by diamond wire sawing has a great influence on the subsequent processing process and fracture strength of silicon wafer. Based on the indentation fracture mechanics, a new numerical model for predicting the SSD of silicon wafer on the basis of half-penny crack system is proposed in this paper. In this model, effect of the random distribution characteristics of size, position and tip half angle of abrasives and different material removal modes to the contour of workpiece cutting groove are all considered. Median cracks and radial cracks are regarded that propagating into one body, that is half-penny crack system. Validity of this model is verified by comparing with experimental results in the literature. From this model, the relationship between SSD and feed rate, wire speed, size of abrasives and density of abrasives on the surface of saw wire is analyzed, the critical speed ratio of feed rate to wire speed that can achieve pure ductile processing is discussed as well. The results show that using the maximum extended length of half-penny crack system as the SSD of silicon wafer is more reasonable than using the maximum extended length of median cracks as the SSD of silicon wafer. As wire speed increases, feed rate decreases, or density of abrasives on the surface of saw wire increases, the SSD will decrease. Keeping other parameters of saw wire unchanged, the size of abrasives has no significant effect on the change of SSD. Keeping the ratio of feed rate to wire speed unchanged, the SSD varies within a small range. When the speed ratio is in the range of 10.43–16, the slice surface tends to be formed by pure ductile removal of material. The results can be used to guide the optimization of diamond wire sawing process.

中文翻译：

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金刚石线锯硅晶次表面微裂纹损伤深度的解析预测

摘要 金刚石线锯加工硅片的次表面微裂纹损伤深度(SSD)对后续加工工艺和硅片断裂强度有很大影响。本文基于压痕断裂力学，提出了一种基于半便士裂纹系统预测硅片SSD的新数值模型。该模型综合考虑了磨料的尺寸、位置和尖端半角的随机分布特性以及不同的材料去除方式对工件切槽轮廓的影响。中间裂纹和径向裂纹被认为是传播为一个整体，即半便士裂纹系统。通过与文献中的实验结果进行比较，验证了该模型的有效性。从这个模型，SSD和进给率之间的关系，分析了锯线的线速、磨料粒度和磨料密度，讨论了可实现纯延性加工的进给速度与线速的临界速度比。结果表明，采用半分状裂纹最大延伸长度作为硅片SSD比采用中间裂纹最大延伸长度作为硅片SSD更为合理。随着线速增加、进给速度降低或锯线表面磨料密度增加，SSD 会降低。在保持锯线其他参数不变的情况下，磨料的大小对SSD的变化没有显着影响。保持进给速度与线速之比不变，SSD在小范围内变化。当速比在10.43-16范围内时，切片表面往往是通过材料的纯延展性去除而形成的。研究结果可用于指导金刚石线锯工艺的优化。