Optical inspection is an important part of the quality process in manufacturing. It can range from quick, subjective inspection by a person to automated quantitative inspection by a machine. It can be performed off-line, where the part is removed from the manufacturing process and brought to the inspection station; on-line, where the part is inspected without removing it from the manufacturing , Automated optical inspection (AOI) is an automated visual inspection of printed circuit board (PCB) (or LCD, transistor) manufacture where a camera autonomously scans the device under test for both catastrophic failure (e.g. missing component) and quality defects (e.g. fillet size or shape or component skew)., Automated Optical Inspection (AOI) is a high-tech way to check if products are good. It uses cool machines and computer programs to find problems and make sure the products are great., , , .