AOI is a technology that can be used to inspect all components, including welding and mounting, in SMT manufacturing.

Main Applications of AOI

The AOI is used primarily in component inspection, solder paste printing inspection and after-welding inspection.

1. Stencil Printing

AOI is a key component of the SMT print process. AOI can be used to detect and verify that the solder paste is in the correct position, uniformity and quality.

AOI's high-resolution imaging can identify excessive or insufficient solder to ensure the proper distribution of the PCB.

2. Component Placement

AOI can be used during the placement process to ensure that all components have been placed correctly. It can determine the component's orientation, position, and polarity in order to verify that it meets the design drawings.

AOI can also detect potential errors in printed circuit board assembly, such as components that are tilted or offset, and missing components to avoid these issues leading to more serious quality problems.

3. Reflow Soldering

During welding, the AOI System inspects solder joints for quality and connectivity. It can detect if the solder joints insufficient or excessive and if there are any problems such as cold joints, short-circuits or open circuits.

AOI's real-time analysis of images can identify welds that are not qualified and alert operators to repair PCBs to ensure final welding quality.

4. After-Solder Inspection

AOI is still used in the post-welding process. It can detect problems with solder joints and components.

The AOI system can help to identify potential quality issues and ensure that the product meets required standards of quality before moving on to the next stage of circuit card production.

5. Final Inspection

AOI is also used to perform a comprehensive final inspection at the SMT terminal detection stage.

The circuit card is checked for component placement, solder joints, component alignment, and orientation.

Terminal inspection is the final check to make sure that the PCBs are designed according to the specifications. AOI achieves the goal of efficient automated inspection.

The Advantages and Challenges of AOI

The application of AOI to SMT processes has many benefits, including:

Increase inspection efficiency: AOI detects defects automatically and efficiently, saving time on manual inspection.

Increase detection accuracy: The AOI uses image recognition technology to accurately detect subtle defects.

Reduce production cost: By using AOI, you can reduce your PCB manufacturing costs and the rate of PCB rework.

There are also some challenges that AOI faces, such as:

High investment costs: The introduction of an AOI requires an initial investment, and then maintenance. This increases the cost to circuit board manufacturers.

Cannot replace manual inspection: Although automated optical inspection systems can efficiently detect many problems,It still can't replace manual inspections, particularly when it comes to complex defects.

PCB manufacturers should consider these advantages to improve the quality of SMT production.