September 30, 2022
The use of automated optical inspection (AOI) has become increasingly important in the manufacturing process. In this article, we will discuss some of the key benefits that AOI can offer to a manufacturing process such as improved quality, eliminating defects or “escapes”, eliminating the reliance on human inspection, cost savings, and enhanced customer satisfaction.

What is Automated Optical Inspection (AOI)?
Automated optical inspection (AOI) is a methodology used primarily to test for defects in printed circuit board assemblies (PCBAs). AOI uses multiple high-resolution cameras to capture images of the PCBA and compares these images to what the PCB data expects to see on the board. The data “knows” what component should be in each location and the AOI equipment quickly validates that. If any discrepancies are found, the AOI system will flag the defective component for repair or replacement.
AOI is a critical quality control step in the PCB assembly process as it can identify defects that may not be visible to the naked eye. This allows for corrective action to be taken before the assembly is shipped to the customer, saving time and money.
2D AOI System VS. 3D AOI System
There are two main types of AOI systems: 2D and 3D. 2D systems capture images from a top-down perspective and are typically used for simple inspections, such as checking for missing components or shorts. 3D systems capture images from multiple perspectives (angles) and can be used for more complex inspections, such as verifying the correct component orientation and 3D systems can also perform solder joint analysis which is more difficult as component terminations get smaller and smaller.
3D AOI systems offer several advantages over their 2D counterparts. First, they provide a more complete view of the object being inspected. This allows for more accurate inspection, as all sides of the object can be examined. Second, 3D AOI systems can inspect objects at different angles, which can be helpful in identifying defects that may not be visible from a single perspective. Finally, 3D AOI systems are typically faster than 2D systems, as they can capture and process images more quickly. With PCB’s becoming more densely populated and components becoming smaller 3D AOII using multiple camera angles provide the most effective way to do high speed inspection and not rely on operators.
Overall, 3D AOI systems offer a more comprehensive and efficient inspection solution than 2D systems. If your manufacturing process requires more accurate and/or complex inspection, then a 3D AOI system is likely the best option for you.
AOI Inspection Speeds
AOI systems are generally classified by their inspection speed, with high-speed systems being able to inspect hundreds of PCBAs per hour. Lower-speed systems may be used for more complicated inspections or when throughput is not as critical. AOI systems can be used in conjunction with other quality control methods, such as automated test equipment (ATE) or X-ray inspection, to provide a complete picture of the assembly process.
Benefits of Using an Automated Optical Inspection System

AOI Reduces Cost
One of the key benefits of using AOI is that it can reduce costs. This is because AOI can help identify defects which would otherwise go unnoticed. By identifying these defects early, the manufacturing process can avoid the need to perform additional rework or testing.

AOI Speeds Up the Manufacturing Process
AOI can also help speed up the manufacturing process. This is because it can help identify defects that are preventing the production line from running smoothly. By addressing these defects early, the manufacturing process can avoid potential delays and disruptions.

AOI Improve Quality

AOI also leads to improved quality. This is because it helps ensure that products are free of defects and meets customer expectations. By using AOI, manufacturers can ensure that their products are of high quality and meet customer demands. AOI also provides a digital record of all PCB’s produced so if there is a field failure it can be traced back to the inspection data using serial numbers to get an understanding of why that particular PCB passed initial inspection.

AOI Can Increase Productivity

AOI can also lead to increased productivity. This is because it can help speed up the manufacturing process and reduce delays. By addressing defects early, the manufacturing process can avoid potential disruptions and disruptions. Also, manufacturers of PCB’s can no longer rely on operators to inspect PCB’s. The components are too small and there are far too many defect “escapes” using operators.

AOI Can Detect Problems Early and Avoid Defects
AOI also helps detect problems early. This is because it can help identify defects that are preventing the production line from running smoothly. By addressing these defects early, the manufacturing process can avoid potential delays and disruptions.
AOI had been a luxury that only the largest PCB manufacturers were able to afford but it is now an integral part of any manufacturing line. 

Overall, the use of AOI can offer significant benefits to a manufacturing process. By automating the inspection process, AOI can help to speed up the inspection process, improve product quality, and reduce costs. These benefits can help to improve the overall efficiency of the manufacturing process. Automated optical inspection is an essential component in any manufacturing process. It provides numerous benefits to operators, manufacturers and customers.