In PCBA processing, the welding process primarily involves soldering PCB circuit boards and components. Common defects such as cold soldering and dry soldering can occur during this process. These issues can significantly affect product reliability and increase maintenance costs.
The causes of cold soldering and dry soldering defects in PCBA welding are varied, but they mainly arise when solder fails to adequately wet the pads and component pins, leading to incomplete solder joints. To address these issues during production, specific preventive measures can be taken as follows:
1. **Moisture-proof storage of components**
Components exposed to air for extended periods can absorb moisture and become oxidized. This oxidation can prevent proper soldering during the welding process, leading to defects such as cold soldering and dry soldering. To mitigate this, components with moisture should be baked before soldering, and oxidized components should be replaced. Typically, PCBA processing plants are equipped with ovens for baking moisture-laden components.
2. **Choose solder paste from reputable brands**
The quality of the solder paste plays a crucial role in preventing defects like cold soldering and dry soldering. An improperly configured alloy composition or flux in the solder paste can result in inadequate flux activation and poor infiltration of the solder paste into the pads. This leads to soldering defects. Therefore, opting for solder paste from well-known brands such as Senju, Alpha, and Victory is recommended.
3. Adjust printing parameters
The issues of insufficient and incorrect soldering are primarily due to inadequate tin application. During the printing process, adjust the squeegee pressure and select the appropriate steel mesh. Ensure the mesh opening is not too small to avoid insufficient tin application.
PCBA processing
4. Adjust the reflow soldering temperature curve
During the reflow soldering process, it’s essential to control the soldering time precisely. Insufficient time in the preheating zone may prevent proper activation of the flux and removal of surface oxides on the soldering area. If the time in the soldering zone is either too long or too short, it can lead to defects such as cold solder joints and poor soldering quality.
5. Minimize manual soldering by using reflow soldering
Manual soldering with an electric soldering iron typically requires high skill levels from the operator. Variations in the soldering iron tip temperature, either too high or too low, or issues like loose components during soldering, can easily lead to soldering defects. Using reflow soldering can reduce human error and improve soldering quality.
If you encounter issues with the soldering iron temperature being too high or low, take preventive measures before beginning operation. For post-welding processing and maintenance of PCBA soldering, ensure the soldering iron tip is clean, select soldering irons with appropriate power ratings based on component sizes and shapes, and maintain a soldering temperature between 300°C and 360°C. Many factors can cause soldering defects during PCBA welding, and the above guidelines address some common issues. By implementing these preventive measures and adapting them to your specific situation, you can effectively reduce soldering defects.
The causes of cold soldering and dry soldering defects in PCBA welding are varied, but they mainly arise when solder fails to adequately wet the pads and component pins, leading to incomplete solder joints. To address these issues during production, specific preventive measures can be taken as follows:
1. **Moisture-proof storage of components**
Components exposed to air for extended periods can absorb moisture and become oxidized. This oxidation can prevent proper soldering during the welding process, leading to defects such as cold soldering and dry soldering. To mitigate this, components with moisture should be baked before soldering, and oxidized components should be replaced. Typically, PCBA processing plants are equipped with ovens for baking moisture-laden components.
2. **Choose solder paste from reputable brands**
The quality of the solder paste plays a crucial role in preventing defects like cold soldering and dry soldering. An improperly configured alloy composition or flux in the solder paste can result in inadequate flux activation and poor infiltration of the solder paste into the pads. This leads to soldering defects. Therefore, opting for solder paste from well-known brands such as Senju, Alpha, and Victory is recommended.
3. Adjust printing parameters
The issues of insufficient and incorrect soldering are primarily due to inadequate tin application. During the printing process, adjust the squeegee pressure and select the appropriate steel mesh. Ensure the mesh opening is not too small to avoid insufficient tin application.
PCBA processing
4. Adjust the reflow soldering temperature curve
During the reflow soldering process, it’s essential to control the soldering time precisely. Insufficient time in the preheating zone may prevent proper activation of the flux and removal of surface oxides on the soldering area. If the time in the soldering zone is either too long or too short, it can lead to defects such as cold solder joints and poor soldering quality.
5. Minimize manual soldering by using reflow soldering
Manual soldering with an electric soldering iron typically requires high skill levels from the operator. Variations in the soldering iron tip temperature, either too high or too low, or issues like loose components during soldering, can easily lead to soldering defects. Using reflow soldering can reduce human error and improve soldering quality.
If you encounter issues with the soldering iron temperature being too high or low, take preventive measures before beginning operation. For post-welding processing and maintenance of PCBA soldering, ensure the soldering iron tip is clean, select soldering irons with appropriate power ratings based on component sizes and shapes, and maintain a soldering temperature between 300°C and 360°C. Many factors can cause soldering defects during PCBA welding, and the above guidelines address some common issues. By implementing these preventive measures and adapting them to your specific situation, you can effectively reduce soldering defects.
