AOI Automatic Optical Inspection System Function Selection

1. Resolution Selection

The resolution of an AOI automatic optical inspection system should be determined based on the size of the pixels, i.e., spatial resolution. The size of the pixels is not the standard for evaluating the detection capability of an AOI automatic optical inspection system. More accurately, the size of the pixels determines the size of the pixels per unit area. If the area per unit is different, even a higher pixel count is not comparable. For example, if an AOI automatic optical inspection system has a field of view (FOV) of 12 x 16 millimetres and uses a 300,000-pixel camera, its resolution is only 25 micrometres, meaning it can only detect components with a package size of 0402 or larger. However, if the AOI uses a 2-megapixel camera, its resolution becomes 10 micrometres, enabling it to detect components with package sizes of 01005 or larger. Conversely, if the AOI uses a 2-megapixel camera with a FOV of 24×32 micrometres, its resolution is only 20 micrometres, meaning it can only detect components with package sizes of 0402 or larger despite having a higher pixel count. Generally speaking, for PCBA boards with component package sizes of 0402 or larger, the required resolution of the AOI automatic optical inspection system must be at least 20 microns. For PCBA boards with components of 0201 or larger package sizes, the required resolution of the AOI automatic optical inspection system must be at least 15 microns. For PCBA boards with components of 01005 or larger package sizes, the required resolution of the AOI system must be at least 10 microns.

2. Selection of Special Functions

If you need to inspect multi-board PCBA, you must select an AOI automatic optical inspection system with a jump board function, i.e., an AOI automatic optical inspection system with a region selection function.

If you plan to use the AOI system for quality process control, you must select an AOI system with RPC functionality, i.e., one with real-time process control capabilities.

3. CAD Selection

Most AOI systems now have CAD data import functionality, but this feature is not very efficient for PCBA boards with few components. However, it can significantly improve efficiency for PCBA boards with a large number of components.