In PCBA (Printed Circuit Board Assembly) manufacturing, automatic optical inspection (AOI) is a key link to ensure the quality of soldering. 2D AOI and 3D AOI are two mainstream technologies, and their core differences are as follows:
1. Detection principle
2D AOI: Based on the two-dimensional images captured by high-resolution cameras, defects (such as missing parts, offsets, and bridging) are identified by comparing them with the standard image library.
3D AOI: By combining laser triangulation or structured light technology, it acquires three-dimensional data such as the height and volume of solder joints, and can detect three-dimensional defects such as false soldering and insufficient solder that are difficult to identify with 2D.
2. Detection capability
2D AOI: It is good at detecting planar defects such as the presence, polarity, and marking printing of components, but has limited judgment on the quality of solder joints (such as solder paste thickness).
3D AOI: It can precisely measure the height of solder joints (±5μm) and the volume of solder paste, identify three-dimensional defects such as collapse and lifting, and is especially suitable for the detection of hidden solder joints such as BGA and QFN.
3. Efficiency and Cost
2D AOI: Fast speed (usually 0.5-2 seconds per board), low equipment cost, suitable for large quantities of simple boards.
3D AOI: The detection time is relatively long (2-5 seconds per board), and the equipment is expensive, but it can significantly reduce the missed detection rate and is suitable for high-reliability products (such as automotive electronics).
4. Industry applications
2D AOI: Cost-sensitive fields such as consumer electronics and LED lighting.
3D AOI: Scenarios with zero defect requirements such as automobiles, medical care, aerospace, etc.
