Other common soldering defects and causes in PCBA processing
It is not good to eat tin on PCB pads or to eat tin on component leads.
Causes: Component leads/PCB pads have been oxidized/contaminated; too low reflow temperature; poor solder paste quality results in poor wettability and severe soldering in severe cases. RADIO FREQUENCY BOARD.
2, the amount of tin is very small:
The performance is that the solder joint is not full, and the monthly curved surface at the root of the IC pin is small.
Cause: The printing template window is small; the wick phenomenon (poor temperature curve); the solder paste metal content is low. One of the above reasons will result in a small amount of tin and insufficient solder joint strength. ENIPIG HDI manufacturer china.
3. Pin damage:
The performance of the device pins is not good or curved, which directly affects the quality of the solder.
Cause: In case of damage during transportation/handling, care should be taken to store components, especially FQFP
4. Contaminants cover the pad:
It happens from time to time during production.
Cause: Paper from the scene; foreign matter from the tape; hand touch PCB pads or components; the character map is not in the right position. Attention should be paid to the cleaning of the production site during production, and the process should be standardized. RIGID-FLEXIBLE BOARD supplier.
5, the amount of solder paste is insufficient:
It is also a phenomenon that often occurs in production.
Cause: The first PCB printing / printing after the machine stops; the printing process parameters change; the steel plate window is blocked; the quality of the solder paste is deteriorated.
6, the solder paste is angular:
It often occurs in production and is difficult to find. In severe cases, it will be welded.
Cause: The speed of the printing machine is too fast; the wall of the template hole is not smooth, and the solder paste is easy to make the ingot shape.
Knowing other common welding defects and causes in PCBA processing, we can prevent evasion in the actual production process.