The main purpose of SMT placement processing is to use the pick and place machine to accurately install the surface assembly components to the fixed position of the PCB. But in the process of SMD processing sometimes there will be some process problems, affecting the quality of SMD, such as the displacement of components, SMT processing in the appearance of even tin, leakage of solder and other various process problems.
For the reasons of no device shift, can be found from the following aspects:.
1. The use of solder paste is limited, beyond the use period, resulting in the deterioration of the flux therein, poor soldering.
2. The solder paste itself is not sticky enough, the components in the handling of oscillation, shaking and other problems caused by the components shift.
3. Solder paste in the flux content is too high, in the reflow oven soldering process too much flux flow led to the displacement of components.
4. Components in the printing, SMD after the handling process due to vibration or incorrect handling caused by the displacement of components.
5. Patch processing, SMT nozzle air pressure is not well adjusted, the pressure is not enough, resulting in the displacement of components.
6. The placement machine itself mechanical problems caused by the placement of components in the wrong position.
Once the SMT placement processing components shift, it will affect the performance of the circuit board, so in the processing process need to understand the causes of component displacement, and targeted solutions.
