| 摘要 |
<p>PURPOSE:To eliminate the need for retract operation function for avoiding interference with a carrying arm and enable structure and control system of carrying and placement to be simplified by providing a wafer carrying arm for installing two or two pairs or more reflection mirrors for leading light which is radiated from an optic sensor for detecting wafer or from the emission side in a side surface direction of the wafer. CONSTITUTION:An elevator 1 is gradually lowered while detecting output of optic sensor light-receiving elements 17 and 18. While the output of the optic sensor light-receiving elements 17 and 18 stays at 'H' level, it is judged that no wafers exist and the elevator 1 descends. When a wafer 6 within a cassette 2 reaches a height of light paths 12 and 13, light of optic sensor light-emitting elements 7 and 8 is screened by the wafer 6, thus enabling the output to be at 'L' level. This signal allows the elevator 1 to stop at a proper position and allows a carrying arm 14 to be inserted into the cassette 2. Then, while suctioning air from vacuum holes 15 and 16, the elevator 1 is lowered, the wafer 6 is subjected to vacuum deposition onto the carrying arm 14, and at the same time the wafer 6 is lifted up, thus allowing the wafer 6 to be taken out of the cassette 2 in chucked state.</p> |
