In the manufacturing process of PCBA, due to some reasons during the SMT process, some undesirable phenomena such as solder beads may be left on the PCB, which is a common situation. Solder beads refer to small spherical or point shaped solder that appears on the solder pad or back metal layer after SMT circuit board assembly. If these solder beads are not treated, it can lead to equipment failure and the lifespan of the circuit board. In this article, we will discuss what to do when solder beads are generated on the PCB surface after SMT welding.
reason
The formation of solder beads is caused by some factors during the SMT production process. There are several common reasons:
1. Induction deposition
When using induction heating on a circuit board, solder balls may form on the PCB. This is caused by the instability of the melt pool and the temperature inconsistency of the circuit board. When the induction heating in the circuit board is too high, it can reduce the melting point of the solder pad or back metal layer, leading to the formation of solder beads.
2. Involvement
During circuit board assembly, sometimes the PCB board may experience deformation or misalignment, leading to solder entering the wrong position. This can cause the formation of solder beads.
3. Welding repair
Circuit boards often require welding and repair during SMT processing. If repaired improperly, it can cause solder beads to appear on the solder pad.