測定バーによるラッピング定盤の表面形状解析

抄録

In high-precision lapping process, it is required to measure accurately the surface shape of the lapping plate because the flatness of the workpiece such as Si-wafer is affected significantly by the surface shape of the lapping plate. This paper describes the flatness measuring system which is composed of a measuring bar equipped with several displacement sensors and a microcomputer. The measuring bar is set above the rotating lapping plate and then signals obtained by the sensors are delivered to the microcomputer to process and display the flatness of the surface as the 3-D image. In this case, unavoidable error motion of rotating axis and inclined plane error should be occurred. To avoid these errors, a geometrical method in which the sensors are set at the intersections of the measuring lines is proposed. An experimental result shows that the measuring accuracy approximates to the resolution of the sensors. It is recognized that this measuring method is useful for the surface analysis of the lapping plate.