Lighting device for testing substrate

Abstract

A lighting apparatus is provided to simplify the movement structure of the lighting apparatus by lighting the wide area of a substrate through the use of plural lightings. A lighting apparatus comprises a plurality of mirrors(130,140) for reflecting the light beams generated from a plurality of light sources(110,120); and first and second Fresnel lens(200,210) for focusing the diffused light beams reflected from each of the mirrors to a single focusing point, and radiating the focused light beams to a substrate(100) mounted on a stage. The light beams radiated to the substrate from the first Fresnel lens and the second Fresnel lens are partially overlapped.

Description

technical field [0001] The present invention relates to an illumination device for directing light onto a large substrate for visual inspection of defects. Background technique [0002] Usually, a visual inspection, that is, an inspection with the naked eye, is carried out in order to find out that the substrates of semiconductor wafers or LCD (Liquid Crystal Display), PDP (Plasma Display), or EL (Electroluminescent) substrates are left during the production process. defects, such as foreign matter or spots. In this case, in order to easily find defects, the entire substrate is uniformly illuminated with one illuminating device, and spots and defects on the substrate can be easily found by utilizing the light reflected on the substrate. [0003] A light-focusing illumination device using a Fresnel lens in the prior art transmits light from a light source through the Fresnel lens and directs (irradiates) the light onto a substrate so as to uniformly illuminate the substrate....

AI Technical Summary

Problems solved by technology

[0016] First, referring to FIGS. 3A and 3B , the method for inspecting a large-sized substrate by moving the lighting device in left / right or up / down directions is inconvenient for inspection when moving the lighting device to multiple parts of the substrate. , because the illumination device can only illuminate a limited portion of the substrate

Since the entire substrate is not inspected at the same time, but is inspected piece by piece according to the area that can be illuminated by the lighting device, it takes a long time to inspect the entire large-sized substrate, and the accuracy is poor

In addition, referring to Fig. 3A, this method has the inconvenience that when the focus of the operator changes from 'S' to 'S', the operator also needs to move with the focus in order to inspect the substrate

[0017] Second, referring to Figures 4A and 4B, while methods for inspecting large areas of a substrate using more than one illuminator work well in terms of accuracy for the temporal and spatial issues discussed in Figures 3A and 3B, the 4B shows that there is a dark area between the two lighting fixtures that are not illuminated by light, causing the problem that the dark area cannot be inspected

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