Automated Optical Inspection( AOI ) is a method that uses optics to capture PCB images to see whether components are missing and in the correct position or not to identify defects and ensure the quality of the board manufacturing process. That’s to say, AOI is not only able to check components of all sizes such as 0201 and 0402, but also package like BGA, CSP, LGA, PoP and QFN, etc.
Apart from that, the application of AOI also enabled the real-time inspection function. With the advent of high-speed and high-volume production lines, an incorrect machine setup, incorrect placement of components on the PCB, or alignment issues can all lead to a large number of manufacturing defects and subsequent rework in a short period of time. The primitive AOI machines were able to perform two-dimensional measurements, such as inspecting board features and component features to determine X and Y coordinates and measurements. However, when 3D system is extended in 2D, adding the height dimension to the equation to provide X, Y, and Z coordinates and measurements.
Note: Some AOI systems do not actually "measure" the height of components.
In addition, AOI is able to find board errors in the early manufacturing process, which guarantees the quality of the Assembly technology before the board is moved to the next manufacturing step. What’s more, AOI also helps increase production by providing feedback to the production line and providing historical data and production statistics. Furthermore, ensuring that quality is controlled throughout the process saves time and money because of material waste, repair and rework, increased manufacturing labor, time and expenses, not to mention the cost of all equipment failures.
3 Key Purpose Of AOI Machines
1. Detect any errors on the production line and immediately feedback the information to upstream to avoid repeated errors.
2. Adapt to the high-speed function consistent with the tact time so that corrective measures can be taken in time.
3. Fast, easy to program and operate, the detection can be completed in real time, and the detection result is reliable.
