摘要 |
System and method provide for optical alignment of an upper film or substrate to a lower film or substrate. The upper film or substrate has an aperture and the lower film or substrate has a set of four apertures. A light is shone on the upper film or substrate at the point above the set of four apertures in the lower film or substrate. A photodetector, which is divided into four quadrants, is positioned beneath the lower film or substrate. Each quadrant of the photodetector detects the amount of light traveling through a different one of the four apertures. The position of the upper film is adjusted until each quadrant detects a substantially equal amount of light. When each quadrant detects a substantially equal amount of light, the aperture in the upper film or substrate is centered over the set of four apertures in the lower film or substrate, and the upper film or substrate is aligned with the lower film or substrate.
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