Causes of virtual soldering in SMT patch processing

  Recently, in the front-end consultation of PCBA processing, we have summarized some issues that everyone is very concerned about in SMT patch processing. It is found that everyone is the most concerned about the problem of virtual soldering. Next, Shenzhen PCBA manufacturers will share with you the SMT patch processing results. Causes of false welding.

1. Welding caused by SMT process factors

（1）The solder paste is missing;

（2） The amount of solder paste is insufficiently applied;

（3） The steel mesh is aging and has poor leaks.

2. Virtual soldering caused by PCB factors

（1） PCB pads are oxidized and have poor solderability;

（2） There are via holes on the pads.

3. Welding caused by component factors

（1） Deformation of component pins;

（2） Oxidation of component pins;

4. Welding caused by SMT equipment factors

（1） The placement machine moves too fast in the PCB transmission and positioning, and the inertia is too large to cause the displacement of heavier components;

（2） The SPI solder paste detector and AOI testing equipment did not detect the related solder paste coating and placement problems in time.

5. Virtual soldering caused by PCB design factors

（1） The size of the pad and the component pin does not match;

（2） Virtual soldering caused by metallized holes on the pad.

6. false welding caused by operator factors

（1） Abnormal operation during PCB baking and transfer, causing PCB deformation;

（2） Illegal operations in the assembly and transfer of finished products.

Basically, there are so many reasons for the false soldering of the finished product in PCBA processing in SMT chip manufacturers, and the probability of false soldering in different links is different, and even only exists in theory, but the actual low-level errors are generally not Will appear. If there is something imperfect or incorrect, please call to communicate.