| 摘要 |
PROBLEM TO BE SOLVED: To ensure the shape of a surface plate required for wafers whose shape characteristic is good and to easily judge the timing of the correction of the surface plate by using the wafers which are pasted in such a way that a pressure-sensitive sheet which is divided into a plurality of pressure measuring regions is sandwiched between them. SOLUTION: Two wafers 1, 2 are pasted in such a way that a pressure- sensitive sheet 3 is sandwiched between them. As the sheet 3, e.g. a polyester sheet on which a pressurization conductive ink is printed is used, and the sheet is divided into a plurality of pressure measuring regions 4 in an X-Y matrix. By using the wafers for the measurement of a pressure distribution, pieces of pressure information detected in the regions 4 are fetched to the outside via a signal line 5, and the distribution of pressures applied to the wafers 1, 2 is found on the basis of the information. Then, on the basis of the distribution of the pressures, a place to which a deviated pressure is applied and the existence of the deviated pressure are checked, and the shape of a surface plate is corrected easily and quickly. In addition, when the distribution of the pressures inside the face of the wafers is measured at a prescribed cycle, the timing of the correction of the surface plate can be known. |
