Automated Optical Inspection or AOI is an automated visual inspection used in the cases of manufacturing printed circuit boards. Here, in this system, a camera scans the test device. It is used for both catastrophic failure and quality defects. Catastrophic failure includes missing components, while quality defects comprise fillet size, shape, or component skew.
A printed circuit board is known as PCB. It is also named LCD or translator. Different types of inline solder paste inspection, including 3D automated optical inspection and 2D AOI, are used for manufacturing processes majorly. As it is a non-contact test method, it is implemented through many stages in the manufacturing process. The stages are bare board inspection, solder paste inspection, pre-reflow, and post reflow. Well, there are other significant stages as well.
According to the records, the primary position for AOI systems has always been after the “post-production” stage, which is also known as solder reflow. It is placed in such a way that post-reflow AOI systems can inspect for diverse types of defects, including solder shorts, component misplacement, missing solder, and so on. Once the problem is found, the boards with defects are repaired, and the other boards are sent to the next process stage.
Some More Details about AOI
The major factors that are addressed in an automated optical inspection are- area defects, billboarding, component offset and polarity, component skew, flipped component, height defects, lifted leads, insufficient paste around leads, lifted leads, no population tests, tombstoning, volume defects, paste registration, solder bridging, and so on.
If you are using AOIfor bare PCB inspection, it may detect certain features including line width violations, spacing violations, excess copper, short circuit, gold finger damage, hole breakage, wrong mounting components, etc. According to the experts, the inspection is more trustworthy and effective than any manual visual inspection. Anyways, smaller circuit boards drive up the demand for automated optical inspection vs. in-circuit testing.
Wrapping it up
So, it was all about automated optical inspection and its different aspects. Undoubtedly, it is one of the most effective scientific inventions. Do you have any more questions regarding it? Let us know.
