| 摘要 |
PURPOSE:To improve the alignment precision of laser lights to a link while accelerating the speed thereof by a method wherein a peculiar-shaped pattern of the link is detected after identifying a wafer pattern to align the laser light position with the peculiar pattern. CONSTITUTION:An optical system 13 with low magnification forms the image of patterns contained in relatively wide range on a CCD 19. A controller (pattern identification circuit) 25 identifies the patterns by signals from the CCD 19; locates the existing position of wafer by processing; calculates the displacement of coordinates from reference positions of an objective link 2; shifts an XY table 11; and sets up the link 2 on a position near the optical axis of another optical system 14 with high magnification. When a shutter 23 on the low magnification side is closed and another shutter 24 on the high magnification side is opened, the controller 25 detects a peculiar pattern in a link judging circuit 28 in terms of the pattern with high magnification and the data in case of low magnification; shifts the XY table 11 to the central position of optical axis to actuate a laser source 21. Finally the link 2 may be irradiated with the laser light to be cut off. |
