| 摘要 |
PURPOSE:To provide easy floating of wafer on reducing the vacuum pressure of a vacuum chuck, by installing a gas nozzle for helping wafers floating. CONSTITUTION:A wafer 3 drawn out of a carrier is sucked into a vacuum chuck 2 and simultaneously floats by gas 9 blown off from a gas nozzle between a fixed plate 7 and the wafer 3 to be chucked by the chuck 2. In other words, when the gas 9 is blown between the wafers 3 and fixed plate 7, vacuum strength F1 and gas pressure F2 act on the front and back surface, becoming resultant to make the wafer 3 float. When the wafer 3 is chucked, the clearance between the fixed plate 7 and wafer 3 becomes larger to reduce F2 acting on the wafer 3 with almost only F1 imposed on the wafers 3. Therefore, the reduction of F1 provides easyfloating of the wafers 3 without breaking in chucking. |
