Principles and Advantages of AOI Detection in SMT

In SMT industry, AOI inspection is essential. What is AOI testing? AOI stands for Automatic Optical Detector. It is a new device that has only become popular in recent years. It can automatically patrol, automatically alarm, display abnormalities, and fully realize automation. I will introduce the principles and advantages of AOI detection in SMT.

1. Principle of AOI Detection

Principle: Use the optical principle to scan the PCB with the camera on the device, collect images, and compare the collected solder joint data with the qualified data in the machine database, and after image processing, mark the PCB soldering status.

2. Advantages of AOI Detection

As some electronic products are becoming smaller and smaller, PCB circuit boards are becoming more and more sophisticated, and the difficulty of manual inspection of PCB boards is increasing. The inspection speed is slower than that of machines. Long-term inspections are also prone to eye fatigue and missed inspections. In order to increase work efficiency, AOI can reflect its excellence.

The advantages of AOI are as follows:

• Save manpower and reduce labor costs.
• Increase production efficiency and increase production capacity.
• Unified testing standards, no difference due to different line types.
• Timely feedback and statistics of production problems.
• Collect testing data, provide process analysis, and strengthen process capabilities.
• Increase the rate of warehousing yields.

3. The Location of AOI Inspection in SMT Production Line

• Use after the placement machine: it can effectively prevent the missing, polarity, displacement, tombstone, reverse, etc. of the components.
• Use after reflow soldering: Located at the end of the production line, the inspection system can check for missing, offset and skewed components, the correctness of solder joints and insufficient solder paste, solder short circuits, and defects in tilt and polarity.

Although AOI detection has great advantages over manual inspection, AOI detection is not a panacea, and there will be technical blind spots, resulting in misjudgment, and then manual judgment is required to ensure product quality.