Full-range image detecting system and method thereof

Abstract

A full-range image detecting system including a planar light source, an image capturing device, a light sensing device, a processing unit and a measuring module is provided. The planar light source projects a photo image with periodical variations onto an object to be detected. The image capturing device captures a reflective photo image reflected from the object. The light sensing device detects the coordinates of at least three measuring points on the object for fitting a plane. The processing unit calculates a phase variation of the reflective photo image after phase shift, a relative altitude of the surface profile of the object according to the phase variation, and an absolute altitude of the surface profile of the object with respect to the plane to obtain information of absolute coordinate. The measuring module detects the surface of the object according to the information of absolute coordinate of the object.

Description

technical field [0001] The invention relates to a detection system, in particular to a global image detection system and a detection method thereof. Background technique [0002] With the trend of wafer thinning, wafer warpage can reach millimeter (mm) level. Also due to the increase in the amount of warping, when the focus range of the general automatic optical inspection (AOI) system is not large enough and the focus speed is not fast enough, it will make it difficult for the automatic optical measurement system to focus and prolong the detection time. The detection effect is not good, which affects the subsequent process. [0003] In the prior art, the main focusing methods are divided into active focusing and passive focusing. Among them, the passive focusing uses two stages of coarse adjustment and fine adjustment to find the focus, and the active focusing uses the light generated by the light source to pass through the focusing grating. The projection is projected on...

AI Technical Summary

Problems solved by technology

Also due to the increase in the amount of warping, when the focus range of the general automatic optical inspection (AOI) system is not large enough and the focus speed is not fast enough, it will make it difficult for the automatic optical measurement system to focus and prolong the detection time. The detection effect is not good, which affects the subsequent process

[0003] In the prior art, the main focusing methods are divided into active focusing and passive focusing. Among them, the passive focusing uses two stages of coarse adjustment and fine adjustment to find the focus, and the active focusing uses the light generated by the light source to pass through the focusing grating. The projection is projected onto the surface of the object through the objective lens, and the grating image reflected by the object surface is compared with the original grating image to improve the focusing speed. However, the cost of active focusing is relatively high

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