Optical detecting system and method thereof

Abstract

The invention discloses an optical detecting system and a method thereof. Raised flaws on a tested object of a solar cell are detected by shadow, the gray scale value of the tested object is measuredby irradiating the tested objected with slant light; a shadow region is distinguished by comparing gray scale value variation of the tested object; the gray scale variation rate of the shadow region gray scale value and the tested object gray scale value is calculated to capture corresponding height value from the self-prestored corresponding relationship of the gray scale variation rate; the corresponding relationship is correspondence of the gray scale variation rate and the height value; and finally, when the captured height value exceeds a preset threshold, the position of the shadow region, which corresponds to the tested object, is the raised flaw. Thus, the invention can quickly compare and judge the raised flow without precise height calculation and conforms to rapid test requirements of a production line.

Description

technical field [0001] The present invention relates to an optical inspection system and method, in particular to an optical inspection system and method for inspecting defects of solar cells. Background technique [0002] Today, as the earth's energy is gradually depleted, solar cells have become the new favorite of the new generation of energy products. At present, silicon solar cells still have the best conversion efficiency. For silicon solar cells, the structure of the solar cell includes a layered photosensitive layer and an adhesive substrate. The visible surface of the photosensitive layer is a colored silicon crystal and wires printed on the surface of the silicon crystal. [0003] Since the crystal lattice of silicon crystal is not easy to control, especially polysilicon is more complex, it may appear mottled and different shades of the same color from the appearance. When using Automated Optical Inspection (AOI) to detect defects, the traditional front light is u...

AI Technical Summary

Problems solved by technology

When using Automated Optical Inspection (AOI) to detect defects, the traditional front light is used to irradiate, and then the image sensor receives the reflected light to measure the grayscale value of the object to be tested; The grid is complex and confusing, so the flaws cannot be detected, especially the raised flaws on the surface of the solar cell, which are often not noticed when illuminated by frontal light, and this problem cannot be solved in the existing automatic optical inspection

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