sales@brightlx.com
Views: 0 Author: Site Editor Publish Time: 2026-10-19 Origin: Site
AOI (Automated Optical Inspection) is a non-contact visual inspection equipment widely used in SMT assembly. It acts as a critical quality checkpoint for PCBA manufacturing. It catches visual defects at early production stages to avoid defective boards flowing into downstream processes and reduce rework cost.
AOI workflow includes image capture, algorithm comparison, defect marking and data reporting. Multi-direction lighting clearly shapes components and solder joints. Software checks every part and solder joint. Any feature outside tolerance will trigger an alarm. AOI is commonly deployed at two stations: post-placement (before reflow) to check missing, shifted or reversed components; post-reflow to verify soldering quality.
AOI identifies 3 major categories of visual defects in SMT production: component mounting defects, soldering defects and PCB surface defects.
· Component mounting defects: missing components, offset & shifted parts, reversed polarity, wrong component model
· Soldering defects (key inspection items): excess solder, insufficient solder, open solder, cold solder, solder bridging and other soldering failures
· PCB surface defects: scratches, stains, foreign particles and substrate damage
AOI is a powerful inline visual quality control solution widely used in SMT assembly, bringing multiple core benefits for PCBA mass production.
l High inspection speed, suitable for mass production
l Consistent inspection results and minimized human deviation
l Detect multiple types of defects on components, solder joints and PCB surfaces
l Traceable inspection data for closed-loop quality management
l Early defect interception to reduce downstream costs
AOI requires program setup based on PCB files before mass production.
· Define inspection windows for resistors, IC pins and BGA pads
· Optimize multi-angle lighting to reduce reflection and false calls
· Set tolerance threshold for component offset and solder volume
· Validate program with golden boards and defective samples, minimize false alarms.
Note: Program quality directly determines detection accuracy. Well-tuned programs balance detection rate and false alarms.
AOI records full inspection data for every PCBA: defect location, type and quantity, and generates quality reports automatically. Quality engineers analyze reports to trace upstream root causes. For example, frequent tombstoning will trigger adjustments for stencil printing and component placement, forming a closed-loop quality improvement.
BRIGHTLX SMT workshop is equipped with AOI systems. All PCBA after SMT placement go through 100% in-line AOI inspection and delivering precise inspection for fine-pitch IC, QFN and BGA high-density assemblies. Inspection logs are preserved for full traceability.
AOI automated optical inspection is indispensable on modern SMT production lines. It reliably catches placement and solder joint defects. At BRIGHTLX, AOI works together with stencil design and solder paste control to guarantee PCBA yield from printing to final assembly. Contact us to discuss your PCBA inspection requirements.
