With the continuous progress of production technology, Automated Optical Inspection system (AOI) has become an indispensable equipment for SMT line. Where is the Automated Optical Inspection installed in SMT line? According to different detection needs, we usually have 5 positions to choose.
1: Install automated optical inspection system behind the solder paste.
This is a good location for the AOI system because many defects are related to the amount of solder paste and print quality. What should such a system monitor? Only the X-Y size of the solder paste, including misprints or solder paste volume (X-Y-Z)? The solder paste volume measurement will be slower than the X-Y measurement, but provides more useful data. This is more critical than other applications in some applications. For example, for ceramic array packaging, the volume of solder paste is critical to achieving the desired solder joint quality.
2. Install automated optical inspection system directly behind the shooter.
Here, you can check for misplaced or misplaced small components, including resistors and capacitors, as well as the quality and volume of solder paste for BGA and fine pitch components, which are mounted on different placement machines after the in-line shooter. Using their visual capabilities, they usually have better precision for larger packages.
3.Install automated optical inspection system behind the fine pitch and BGA placement machine (before reflow)
Check for misplaced pins, BGAs, and other large components. This is a good location because most of the defects are related to the feet. These are the choices for those who prevent philosophy.
4.Install automated optical inspection system under reflow soldering
Look for solder joints of poor quality. This is a good way for companies that want to ensure unacceptable solder joints are found before shipping to the end user.
5. Install automated optical inspection system after each process step – solder paste printing, film shooter, BGA and foot mounting, and reflow soldering. This choice may not be affordable.