| 摘要 |
PROBLEM TO BE SOLVED: To surely prevent the breakage of wafers when carried. SOLUTION: A number of wafers 15 are stored to be laminated in an up-and- down movable wafer cassette 13, a carrying arm 18 is inserted in the carried wafers 15 at their lower sides and held to be set in and out of the wafer cassette 13. Sensors 16, 17 provided at a preset height from the wafer cassette 13 are used to detect the wafer 15 in a n-order to be carried and the wafers 15 in (n-1) and (n+1) orders located up and down to the wafer 15 in an n-order at their flexible centers and at their peripheral edges to be inserted into a slot groove 14 in the wafer cassette 13, so that the flexibility amount of the wafers 15 can be found in accordance with these positional information to judge whether the carrying arm 18 is inserted or not in the wafer in an n-order carried at its lower side and the wafer at an n-order lifted or not at a wafer attracting stroke. |
