| 摘要 |
<p>PROBLEM TO BE SOLVED: To precisely detect a circuit surface to be detected by previously storing the position of an area to be detected in the direction of depth by classifications of semiconductor wafers, and placing the focal point of an image pickup means on the stored position to detect the required position of the semiconductor wafer. SOLUTION: An image pickup means includes a storage means for storing the focal point position D of a semiconductor wafer 10 by coordinates on a Z-axis, and has a function of automatically matching a focal point with the stored focal point position D. Before alighment, the position on the Z-axis is previously set in the storage means. A console panel of a dicing device is operated to numerically input the position on the Z-axis of a circuit surface 11 and store the same. In the case where the surface of a chuck table 21 is taken as the origin on the Z-axis, the relative distance D from the origin is set as the focal distance D in the storage means. When light including infrared rays is radiated to the wafer 10, an objective lens 29 is moved up and down, and the focal point of an image pickup element is matched with the stored focal distance D on the Z-axis, the circuit surface having a target is displayed on a monitor.</p> |
