What is AOI?
AOI is a system that takes pictures of PCBs. It uses technology to compare these pictures to a database. The purpose is to find any problems or mistakes.
AOI enables complete and rapid in-line inspection that replaces slow and inefficient human visual inspection. The systems can detect microscopic defects and inconsistencies in electronic components and PCB assemblies.
How does AOI work?
AOI machines consist of advanced cameras, precision optics, lighting systems, and software algorithms. The PCB moves through the AOI machine on a conveyor belt or transport mechanism while the cameras capture images from multiple angles.
The images are processed by algorithms that compare them to an ideal image in the database. Any discrepancies in component placement, solder joints, or board features are flagged as defects.
Some AOI systems also use 3D scanning, machine learning, and artificial intelligence for enhanced defect detection. The results are immediately sent to the operator to take appropriate action.
What are the benefits of using AOI?
Using AOI machines provides several advantages:
- Increased product quality – AOI detects microscopic flaws in assembly and soldering that human inspectors cannot spot. This results in lower defect rates and improved quality.
- Reduced manufacturing costs – The automated inspection process is faster and more efficient than manual methods. Scrap and rework costs are decreased.
- Improved productivity – AOI performs inspection in seconds, allowing high-volume manufacturing. The systems can operate 24/7 with no downtime.
- Reduced product recalls – Early detection of defects means fewer faulty products shipped to customers, reducing recall occurrences.
Types of AOI Machines
There are three main types of AOI systems – single-sided, double-sided, and 3D AOI machines.
Single-sided AOI machines These entry-level systems inspect only the top side of the PCB. They are ideal for simple boards with low component densities.
Double-sided AOI machines inspect both the top and bottom of the PCB. They provide a complete inspection and have a higher defect detection rate than single-sided units.
3D AOI machines use laser scanning and 3D modeling to create a complete 3-dimensional image of the PCB. This allows detecting defects on surfaces as well as scanning component heights and solder joint profiles. 3D AOI provides the most detailed inspection.