Overview of AOI

AOI, the full name of which is Automatic Optical Inspection, namely automatic optical inspection equipment, is an efficient intelligent device that simulates the human eye and operates machine vision technology to replace humans in the welding process production and detect common missing parts in PCBA.

As PCBS become increasingly complex and components become smaller and smaller, traditional ICT and functional testing are becoming more and more laborious and time-consuming. It is difficult to obtain the physical space for the test probes of closely spaced and fine-spaced plates by using bed-of-nails testing. For surface mount circuit boards (PCBA) responsible for high density, manual visual inspection is neither reliable nor economical. However, when it comes to tiny components such as Type 0402 and Type 01005, manual visual inspection has actually lost its significance. To overcome the obstacles mentioned above, AOI emerged as a powerful complement to online testing (ICT) and functional testing (F/T). It can help PCBA manufacturers increase the pass rate of ICT(F/T), reduce the labor cost of visual inspection and the production cost of ICT fixtures, prevent ICT from becoming a capacity bottleneck, shorten the capacity expansion cycle of new products, and effectively control product quality through statistics to improve product quality.

AOI technology can be applied to multiple positions of the PCBA production line. ALeader AOI can provide effective and high-quality quality inspection at the following five detection positions:

1. After solder paste printing: After the solder paste is printed on the printing machine, defects during the printing process can be detected. By inspecting the printed solder paste, defects in PCBA production before surface mount can be avoided, reducing the maintenance cost of the PCBA board.
2. Before reflow soldering: This position should be after the surface mount and before reflow soldering. This position can detect the quality of solder paste and surface mount, prevent defects in the PCBA before reflow soldering, and reduce the maintenance cost of the PCBA board.
3. After reflow soldering: This position is the most typical one and indispensable. The greatest advantage of using this position for detection is that the defects existing in the ownership process can be detected at this stage, so no defects will flow to the end customers.
4. Red adhesive inspection after reflow oven: The inspection at this position mainly focuses on the red adhesive board, which can effectively detect whether the red adhesive is okay or not, reduce the defects after passing through wave soldering, and effectively lower the labor visual inspection cost and maintenance cost.
5. After the wave soldering furnace: This position is mainly for wave soldering inspection, which includes the inspection of components and plug-ins. The inspection at this position is an effective supplement to the quality inspection and control throughout the wave soldering process.