Automated vision inspection
Automated optical inspection (AOI) is an automated visual inspection of a wide range of products, such as printed circuit boards (PCBs), LCDs, transistors, automotive parts, lids and labels on product packages. In case of PCB-inspection, a camera autonomously scans the device under test for variety of surface feature defects such as scratches and stains, open circuits, short circuits, thinning of the solder as well as missing components, incorrect components, and incorrectly placed components.

Manual vision inspection
Manual vision inspection with usage of the stereo microscope is often used to study the surfaces of solid specimens or to carry out close work such as small circuit board manufacture or inspection.

X-Ray Inspection
X-ray inspection is a technology based on the same principles as optical inspection. It uses X-rays as its source, instead of visible light, to inspect features, which are typically hidden from view.
The increasing usage of ICs with packages such as BGAs where the connections are underneath the chip and not visible, means that ordinary optical inspection is impossible. Because the connections are underneath the chip package there is a greater need to ensure that the manufacturing process is able to accommodate these chips correctly. Additionally the chips that use BGA packages tend to be the larger ones with many connections. Therefore it is essential that all the connections are made correctly.