Defect detection method of CMOS image sensor

Abstract

The invention discloses a defect detection method of a CMOS image sensor. The defect detection method of the CMOS image sensor comprises the following steps that a grey chip image is collected by using an industrial camera containing the CMOS image sensor; the grey chip image is preprocessed to obtain a gray scale image; data shift processing is carried out on pixel values in the gray scale imageto obtain a low-order image; the pixel values in the low-order image are averaged to obtain an image average value; absolute value calculation is carried out on the pixel values in the low-order imageand the image average values separately to obtain a difference image; standard deviation calculation is carried out on the pixel values in the difference image; when the obtained standard deviation is greater than a preset standard deviation threshold value, it is judged that a CMOS image sensor chip has the defect that the low-order image ground noise exceeds the standard. The defect detection method of the CMOS image sensor can well meet the testing requirement for the high-precision image sensor.

Description

technical field [0001] The invention relates to the technical field of semiconductor testing, and more particularly, to a method for detecting defects of a CMOS image sensor used for machine vision. Background technique [0002] In recent years, CMOS image sensors have been widely used in the field of digital images because of their low power consumption, high speed, strong anti-interference ability and high integration. Gradually, CMOS image sensors began to replace traditional film and CCD sensors in the field of machine vision and scientific research for high-precision image acquisition. [0003] However, CMOS image sensors still have many deficiencies, and sometimes cannot meet the high-precision requirements in the field of machine vision. For example, if the CMOS image sensor chip has defects of low bit and high noise floor, it cannot reflect the high precision of image acquisition well. [0004] Therefore, how to test the performance of CMOS image sensors used in fi...

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Problems solved by technology

[0003] However, CMOS image sensors still have many deficiencies, and sometimes cannot meet the high-precision requirements in the field of machine vision

For example, if the CMOS image sensor chip has defects of low bit and large noise floor, it cannot reflect the high precision of image acquisition.

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