With more and more advanced electronic equipment, the wiring on the PCB (printed circuit board) has become finer, the components have become smaller and the high density of assembly has also been improved. Now the visual inspection does not meet the requirements of SMT assembly quality inspection. Therefore, AOI (Automatic Optical Inspection Electronic Equipment), as a key method for detecting the performance of solder joints formed in the surface assembly process, has been more and more widely used in surface assembly. At present, the AOI system, as a detection method for surface mount assembly, is moving towards intelligence.

AOI is used in 3 different situations:

1. AOI can use PCB bare board to detect whether the PCB board has broken wires, scratches, pinholes, line spacing, rough edges and large-area defects.

2. AOI can be printed with solder paste, and the printing thickness and printing edge collapse can be detected by matching the AOI system.

3. AOI can use SMT components and solder joints. Mainly check whether the components are missing, misplaced, component placement direction, component quantity, solder joint quality, etc.