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PCBA Tech
Analysis of welding defects in PCBA manufacturing
PCBA Tech
Analysis of welding defects in PCBA manufacturing

Analysis of welding defects in PCBA manufacturing

2021-12-08
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Author:pcba

Ipcb has maintained long-term and stable cooperation with many well-known enterprises, and its products are widely used in communication, medical treatment, industrial control and other fields. The company has a number of high-end automatic mounting lines with complete testing equipment. It provides sample sheet and batch patch processing services to meet customer needs. At the same time, ipcb also provides excellent PCBA processing and manufacturing and electronic component procurement services. Ipcb's team has rich experience in electronic manufacturing and strong technical force.

PCBA

Diagnosis and analysis of poor welding during PCBA processing:

1. Pad peeling: it is mainly due to the peeling of the pad from the printed circuit board after being subjected to high temperature. This bad solder joint is easy to cause the fault of open circuit of components.


2. Asymmetric distribution of solder: it is mainly caused by poor quality of flux or solder or insufficient heating. The strength of the bad solder joint is not enough, and it is easy to cause the fault of open circuit of components under the action of external force.


3. White solder joint: uneven and dull. Generally, it is caused by too high temperature of electric soldering iron or too long heating time. The strength of the bad solder joint is not enough, and it is easy to cause the fault of open circuit of components under the action of external force. Sharpening: the main reason is that the electric soldering iron is withdrawn in the wrong direction, or the high temperature causes a large amount of sublimation of flux. This bad solder joint will cause a short circuit between components and wires.


4. Cold welding: the surface of the solder joint is in the shape of tofu slag. Mainly due to the insufficient temperature of the electric soldering iron or the jitter of the weldment before the solder solidification, the strength of the bad solder joint is not high and the conductivity is weak. It is easy to cause the fault of open circuit of components under the action of external force.


5. There are holes in the solder joint: the main reason is that the lead is poorly wetted or the gap between the lead and the jack is too large. The bad solder joint can be conducted temporarily, but the components are prone to open circuit fault over a long time. Excessive solder: mainly caused by untimely removal of welding wire.


6. Too little solder: it is mainly caused by the premature removal of the welding wire. The poor solder joint has insufficient strength and weak conductivity. It is easy to cause the fault of open circuit of components under the action of external force. Loose lead and movable weldment: it is mainly caused by the movement of lead before solder solidification or poor lead flux infiltration. This poor solder joint is easy to cause the components to fail to conduct.


7. There are holes on the surface of the solder joint: it is mainly caused by the excessive gap between the lead and the jack. The strength of the bad solder joint is not high, and the solder joint is easy to be corroded. In PCBA processing, poor welding materials, selection of welding temperature and length of welding time can affect the quality after welding.