| 摘要 |
PURPOSE:To obtain wafers with small dispersion in thickness and as well as with excellent parallelism by a structure wherein a holding body is coupled through a spherical beaing structure with a fulcrum shaft in order to apply a constant load to the wafers at all times so as to uniformly lap the wafers. CONSTITUTION:The semiconductor wafers 3 are held on the circular disc shape holding body 4 supported by the fulcrum shaft 5. A coupling body 10 with a flange 9 is fixed to the lower end of the fulcrum shaft 5. The coupling body 10 and the holding body 4 compose the spherical bearing structure by interposing a steel ball 13 between the lower surface center of the coupling body 10 and the upper surface center of the holding body 4. Owing to the structure as described above, the load W applied to the holding body 4 is rendered to be smaller at the peripheral edge of the holding body 4 than at the center of the holding body 4, resulting in applying a constant load to the wafers by cancelling with the lapping resistance applied by a lapping machine. |
