| 摘要 |
<p>An apparatus for precisely positioning semiconductor wafers (12) on a flat bed (14) comprises a precision motor (16) coupled to the bed (14) for driving the bed in the X and Y directions under control of a computer (30) which also determines the operation of a motor (60) operating to rotate the bed (14). A video camera (40) fixed relative to the bed (14) views the wafers (12) and provides corresponding signals to a monitor (42) and to a pattern recognition unit (44) coupled to the computer (30). The apparatus is used in a method in which the camera (40) is focussed upon a selected distinctive portion of a die (10) on the wafer (12), tests are conducted to verify the distinctiveness of the selected portion in comparison to adjacent portions, and comparisons are made with the aid of the pattern recognition unit (44) between a stored representation of the selected distinctive portion and corresponding portions of other dies (10) brought into the field of view of the camera (40) by operation of the precision X-Y motor (16). These comparisons enable the rotary disposition of the wafer (12) to be sensed and any necessary adjustments made by means of motor (60). By this means, for example, complex semiconductor devices arrayed upon a substrate wafer can be accurately probed regardless of any misalignment of the devices in the array.</p> |
