Automatic Optical Inspection equipment provides image based verification of populated circuit boards after placement, after reflow, or at selected stages of mixed assembly. This category includes SAKI, Koh Young, Mirtec, PARMI, DCEN, VCTA, TRI, and other two dimensional or three dimensional AOI platforms. The range allows factories to compare inspection approaches for different board sizes, process locations, and quality objectives. AOI can check component presence, polarity, orientation, offset, markings, solder appearance, bridges, lifted leads, and other visible conditions according to the programmed criteria. Three dimensional systems add height or surface information that can improve analysis of components and solder joints. The inspection result is only as useful as the program, lighting, defect thresholds, review method, and feedback process established by the production team. Selection should consider whether the machine will inspect after paste printing, placement, reflow, or THT assembly. Board dimensions, component density, line speed, camera resolution, lighting arrangements, conveyor setup, programming time, false call control, review station, traceability, and data export are all relevant. A factory should also decide how defects will be confirmed and how recurring findings will be communicated to printing, placement, or soldering teams. Automatic Optical Inspection is used in automotive electronics, industrial controls, communication products, consumer devices, power electronics, medical manufacturing, and high mix contract assembly. Some lines need rapid screening at volume, while others need detailed analysis of complex boards. AOI can reduce manual inspection pressure, but it does not replace process knowledge or every specialized test. Hidden joints may still require X ray inspection, and electrical performance requires separate testing. WenZhan recommends providing sample boards, defect priorities, inspection stage, output target, line direction, board range, and reporting requirements. For each listed AOI model, confirm the exact camera, software, options, computer, and condition. A sample program or defect study can help establish realistic acceptance criteria. Matching the inspection platform to the product and review workflow allows AOI data to support defect containment, process correction, and traceable quality decisions rather than becoming an isolated pass or fail station.
