SMT Technology: Reasons for Displacement of Components in SMT

The main purpose of SMT is to accurately install the surface assembled components to the fixed position of PCB. During  SMT, there are sometimes some process problems that affect the chip quality, such as the displacement of components, tin connection, missing welding and other process problems in SMT. No matter what causes the problem, we should pay attention to it.

For the components displacement, the reason can be found from the following aspects:

1. The use time of the solder paste is limited. After the use period is exceeded, the flux in it will deteriorate and the soldering will be poor.
2. The solder paste itself is not sticky enough, and the components vibrate and shake during handling, resulting in the displacement of components.
3. The flux content in the solder paste is too high, and the excessive flux flow during the reflow soldering process causes the displacement of the components.
4. During the handling of components after printing and pasting, the components are displaced due to vibration or incorrect handling methods.
5. During patch processing, the air pressure of the suction nozzle was not adjusted well, and the pressure was not enough, resulting in the displacement of components.
6. The mechanical problems of the placement machine have caused the wrong placement of the components.

Once the component shift occurs in smt, it will affect the performance of the circuit board. Therefore, it is necessary to understand the reason for the component shift during the processing and solve it in a targeted manner.