摘要 |
A wafer imaging system is provided in which a camera is mounted at a known position in relation to an open front of a cassette to view the cassette and its entire stack of wafer contents. The camera can be mounted on a robot or on a tool. An image of the set of wafers is captured and is image processed to provide information on the position and alignment of each wafer in the cassette. The image can be processed to provide data on separation of the wafers within the cassette, any cross slotting of wafers, and the center point of each of the wafers. Image analysis and processing is employed to determine the edge of each of the wafers. One image scan provides a determination of all information on the X, Y and Z position of the wafers in relation to the camera reference position.
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