AOI inspection for coating
AOI (Automated Optical Inspection) for coating is an advanced inspection method used to automatically check the quality, coverage, and consistency of Conforme coating on PCBs. It is widely used in modern PCB-assemblage en SMT-assemblage lines to ensure high accuracy, repeatability, and efficiency in quality control.

How AOI inspection works
In coating inspection, AOI systems use high-resolution cameras, lighting (often including UV light), and image-processing software to analyze the PCB surface. The system compares captured images with predefined standards or CAD data to determine whether the Conforme coating has been applied correctly.
In many Turnkey PCB-assemblage processes, AOI is integrated inline, allowing real-time inspection immediately after coating.
What AOI checks in conformal coating
AOI inspection can detect a wide range of coating-related issues:
- Missing coating areas (insufficient coverage)
- Excess coating (over-application on connectors or pads)
- Uneven distribution
- Shadowing under components
- Bubbles, voids, or contamination
- Incorrect coating boundaries
This makes AOI especially valuable in high-density SMT-assemblage, where manual inspection may not be sufficient.
Advantages of AOI inspection
- High accuracy and consistency → eliminates human error
- Fast inspection speed → suitable for high-volume production
- Automated process → reduces labor costs
- Data recording and traceability → useful for quality tracking
- Inline integration → immediate feedback for process control
In large-scale PCB-assemblage, AOI significantly improves defect detection and overall yield.
AOI vs UV inspection
- UV inspection
- Simple and low cost
- Relies on human visual checking
- Good for basic coverage verification
- AOI-inspectie
- Fully automated and more precise
- Can quantify defects and compare against standards
- Better for complex and high-reliability applications
In many Turnkey PCB-assemblage lines, both methods are used together for optimal results.
Limitations of AOI inspection
- Higher equipment cost
- Requires programming and setup for each PCB design
- May struggle with very complex 3D geometries or hidden areas
Despite these limitations, AOI remains one of the most effective inspection tools in advanced SMT-assemblage.
Conclusie
AOI inspection for coating is a powerful automated solution for ensuring proper Conforme coating application. By detecting defects quickly and accurately, it enhances quality control in PCB-assemblage, SMT-assemblage, en Turnkey PCB-assemblage, helping manufacturers deliver reliable and consistent electronic products.
Vraag een offerte aan voor conforme coating
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