摘要 |
PURPOSE: An edge grip type pre-aligner for simultaneously processing two wafers is provided to improve processing efficiency by shortening processing time. CONSTITUTION: A lower lifter(4) receives a first wafer from a transfer robot. An upper lifter(5) receives a second wafer from the transfer robot. A lower clam lever(6) is connected to a first rotation driving unit to rotate the first wafer. An upper clam lever(7) is connected to a second rotation driving unit to rotate the second wafer. A detector includes a second light emitting sensor and a second light receiving sensor. |