PRE-Reflow Aoi

In general, pre-reflow AOI systems are typically two to three times faster than 3-D systems and range in inspection speed between 10 and 40cm /sec. The prices of 2-D component and solder paste placement automated inspection systems are typically somewhat less than those of the 3-D solder paste systems with the fastest inspection speed capabihty. 

Pre-reflow AOI systems also have the ability to inspect 2-D solder paste however, this ability is utihzed only to inspect a small percentage of the solder paste deposits combined with the component misalignment measurements. Component misalignment measurements cover the passive components, whereas the solder paste measurements cover deposits for BGA, CSP, or fine-pitch QFP devices. Therefore, these systems are placed within production lines after the pick-and-place systems for passive devices but before the pick-and-place systems for the larger area-array and leaded devices. These systems serve the same purpose as those only meant for component placement measurement, both detecting defects and monitoring measurements within control limits to discover process drift as early as possible. 

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