PCB News - Introduction to the problems of AOI detection in MT patch processing

Introduction to the problems of AOI detection in MT patch processing

In SMT patch processing and production, AOI inspection is the result of image acquisition and analysis processing, which is more efficient than manual visual inspection. Because the related technology of image analysis and processing has not reached the level of human brain after all, there will be some misjudgments and missed judgments of AOI in SMT patch processing. This is because AOI will exist in the detection after SMT patch is completed. A few questions:

1. There is a detection problem of the screen, shielding cover, and shielding point.

2. It is impossible to detect the invisible solder joints of BGA, FC and other flip-chip components.

3. Most AOIs have ambiguities in their understanding of virtual welding, causing evasiveness.

4. The difference in the accuracy of the polarity judgment caused by the different character processing methods is large.

5. The capacitance value is different but the size and color are the same, which is easy to cause missed judgment.

6. The process requirements of SMT patch with more tin, less tin, offset, and skew are defined differently, which may easily lead to misjudgment.

7. Some AOIs with lower scores cannot do OCR character recognition testing.

8. The detection speed of most AOI products is slow, and a few AOUIs that use scanning methods are faster, but the rate of misjudgment is higher.

9. Most AOI programming is complicated, cumbersome and long adjustment time, not suitable for scientific research units, small OEM factories, production units of multi-specification and small-batch products.

In response to the above-identified problems, SMT processing plants need to increase quality inspection personnel as well as auxiliary equipment. AOI not only has online AOI, but also offline AOI equipment, so we need to pay great attention to quality control.

The above-mentioned timely AOI will have problems in the inspection after the SMT patch processing is completed. In order to improve this situation, do not increase the number of quality inspection personnel but also add auxiliary equipment (including online AOI and offline AOI equipment). Only the quality control link can guarantee the quality of the product. Good products make good brands, and circuit board manufacturers look forward to cooperating with you!

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