| 摘要 |
PURPOSE:To enhance the flatness accuracy of a cut surface due to the grindstone of an inner peripheral blade by footing at least one through-hole allowing one end surface and other end surface of the grindstone of the inner peripheral blade to communicate with each other to a ring-shaped core or a cutting part. CONSTITUTION:Since the upper and rear surfaces U, D of an inner peripheral blade 20 are allowed to communicate with each other by the through-hole 23 formed to the core 21 of the blade 20, air or a coolant flows through the through-hole 23 and, since the through-hole 23 develops the function of the vent hole of air or the coolant, differential pressure is rapidly eliminated. Since no differential pressure is generated between the upper and rear surfaces U, D of the inner peripheral blade 20, the core 21 and cutting part 22 of the inner peripheral blade 20 are not vibrated up and down. As a result, the cutting position of the cutting part 22 in the inner peripheral blade 20 is not displaced or changed and a thin-walled wafer having a flat cutting surface can be smoothly sliced from a silicon ingot W and the flatness accuracy of the cut surface is markedly enhanced. Further, kerf loss is reduced and yield is improved. |
