In a typical AOI setting, a top-mounted camera takes precisely measured photographs of finished circuit boards and compares the results to a highly detailed schematic file. Parameter differences that pass a certain threshold get flagged, and a human operator inspects the product in question.
The upshot of this process is that human operators no longer need to manually verify every parameter of a finished circuit board - for modern PCBs, that would take far too long. Now, a small team of operators can verify a very large volume of PCBs and pick out the defective ones with great accuracy.
3D AOI builds on this premise by using two cameras to develop a three-dimensional image of the PCB. This allows the AOI process to verify smaller components than ever before. In some cases, the addition of a side-mounted stereo camera set lets the optical image technology build a complete render of the PCB, allowing for unprecedented precision and quality control.
Who Uses 3D AOI for PCB Inspection?
As of mid-2017, this technology is almost exclusively used in the autonomous vehicles industry. The ability to quickly identify and measure panel defects when dealing with extremely small components is an important factor contributing towards making autonomous vehicles an everyday reality.