The benefits of online AOI detector after solder paste printing
Why use online AOI inspection after solder paste printing? What are the benefits of using an AOI detector after solder paste printing? Next, we will analyze and decompose them one by one for the reference of those who pay attention to the quality of SMT production.
The products before solder paste printing include bare PCB boards, and tin has partial materials. In order to perfectly combine the two, perfect technical means are required, at least one automatic solder paste printing machine with a speed of more than 900 rpm The thawed solder paste is completely stirred and defoamed. After evenly stirring, the tin has good viscosity and no foaming. It is more perfect printed on the tin printing machine, and the combination with the PCB board is also perfect. For this reason, the detection pass rate after solder paste printing is very high, which lays a good foundation for the subsequent patch assembly.
The benefits of using an online AOI detector after tin has printing
If the solder paste printing process meets the requirements, the number of defects found during the ICT function inspection can be greatly reduced. If the solder paste printing process fails to meet the requirements, there will be many quality problems in the subsequent process.
Typical printing defects include the following:
—: Insufficient solder on the pad.
Two: Too much solder on the pad.
3: The solder has poor coincidence with the pad. Four: Solder bridge between pads.
On ICT, the probability of defects relative to these situations is directly proportional to the severity of the situation. Slight tin deficiency rarely results in defects, while severe cases, such as no tin at all, almost always cause defects in ICT. Insufficient solder can be a cause of missing components or open solder joints. Nonetheless, deciding where to place an AOI requires recognizing that component loss may occur for other reasons that must be included in the inspection plan. Inspection of this location most directly supports process tracking and characterization. Quantitative process control data at this stage includes print offset and solder volume information, while qualitative information about the print solder is also generated.
In this process, using AOI optical detector is the best control method. Usually, the best control method for SMT patch quality is to use an online AOI quality detector after solder paste printing. The quality of the printing, how many, whether there are defects, after this level of quality control, to the next process of the placement process of the placement machine, the quality problem is at least well controlled, and then placed behind the placement machine and before the reflow soldering. An online AOI optical detector performs secondary quality control, which controls the placement quality of the placement machine, so that the quality of the reflow soldering process is further controlled, and the quality problems after reflow soldering are much less. , and then install an online or offline AOlI optical inspection equipment in the reflow oven. Such SMT processing quality is almost perfect.