DEFECT INSPECTION SYSTEM AND METHOD

摘要

A defect inspection system is provided for inspection of defects in the surface of a sample. An array of light sources is used, with different light sources providing light to the sample from different directions. A main direction of illumination is defined with highest intensity, and this direction evolves over time. By providing varying directional illumination instead of blanket illumination, it becomes easier to detect defects.

主权项

1. A defect inspection system for manual visual inspection of surface defects in a sample, comprising:
a lighting system for illuminating the sample surface, comprising an array of light sources formed within a plane, wherein the array of light sources defines a range of illumination directions towards the sample within the plane, which range covers at least 90 degrees; and a controller for controlling the light sources in the array to gradually vary the intensity of the output of the light sources, wherein at respective points in time within a sequence each light source has a greater intensity than the others such that each point of the sample is illuminated, at the respective points in time within the sequence, with a light distribution having a maximum light source intensity in a single incident direction, and over time the direction in which the maximum light source intensity is provided changes to cover said range.