The definition of AOI detection misidentification and the existence of original difficulties, the definition of detection mispositives and the existence of original difficulties, the definition of detection mispositives and the existence of original difficulties and the causes of false positives can be divided into the following points:

1. Components and solder joints originally have a tendency to occur, but they are within the acceptable range. If the component was originally offset, but within the allowable range; This kind of misjudgment is mainly caused by the threshold setting too strictly, or it may be between the bad and good standards, AOI and MV (manual visual inspection) confirmation caused by the deviation, such misjudgment can be reduced by adjusting and coordinating the standards with MV.

2. There is no bad tendency of components and solder joints, but because DFM design does not consider the measurability of AOI, it is difficult to determine whether AOI is good or not, in order to ensure the detection effect, some misjudgments will be introduced. If the pad design is too narrow or too short, it is difficult to make a very accurate determination when AOI is inspected, and it is difficult to eliminate false positives caused by such situations, unless DFM is improved or the solder joint defect detection of such components is abandoned.

3. Because AOI relies on reflected light for analysis and judgment, sometimes it will be interfered by some random factors and cause misjudgment. For example, the component solder end is dirty, or part of the printed wire on the pad side is not fully coated and partially exposed, resulting in poor search, etc. And the more detections there are, the more false positives may be caused. Such false positives are random and cannot be eliminated.

Based on this, there is a general consensus in the AOI industry that AOI false positives are inevitable but can be reduced. Under industry-recognized ideals, false tests can be accepted within 3000PPM.

Now the development of artificial intelligence, machine vision has introduced deep learning algorithms, will reduce AOI detection false judgment, later we will exchange with you artificial intelligence new technology AOI equipment, intelligent image analysis technology deep learning algorithms.

Automated Optical Inspection (AOI) for PCB Assembly 

AOI PCB Machine - Automatic Optical Inspection

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