HIGH SPEED OPTICAL INSPECTION SYSTEM WITH ADAPTIVE FOCUSING

摘要

An optical inspection system (41, 42, 43, 44, 45) for inspecting a substrate (10) is provided. The system (41, 42, 43, 44, 45) includes an array (4) of cameras (2A-2H) configured to acquire a plurality of sets of images as the substrate (10) and the array (4) undergo relative motion with respect to each other. At least one focus actuator (9A-9H) is operably coupled to each camera (2A-2H) of the array (4) of cameras (2A-2H) to cause displacement of at least a portion of each camera (2A-2H) that affects focus. A substrate range calculator (16) is configured to receive at least portions of images from the array (4) and to calculate range between the array (4) of cameras (2A-2H) and the substrate (10). A controller (80) is coupled to the array (4) of cameras (2A-2H) and to the range calculator (16). The controller (80) is configured to provide a control signal to each of the at least one focus actuator (9A-9H) to adaptively focus each camera (2A-2H) of the array (4) during the relative motion.