How to prevent the defects of virtual welding and false welding in PCBA welding process?
2022-11-25
PCBA welding processing mainly refers to the production process of soldering PCB circuit board and components. In the process of welding, it is easy to have poor welding, such as false welding and false welding, which will seriously affect the reliability of the product and greatly improve the maintenance cost of the product.
The defects of virtual welding and false welding in PCBA welding process are caused by many reasons. The main reason is that the solder cannot fully infiltrate the pad and the pin of the component, and the pad of the component and the circuit board cannot be fully welded. In the production process, it can be prevented in the following ways.
1. Moisture-proof storage of components
If the components are placed in the air for a long time, the components will absorb moisture and oxidize, resulting in insufficient removal of oxides in the welding process, resulting in defects of virtual welding and fake welding. Therefore, in the welding process, it is necessary to bake the moisture components and replace the oxidized components. Generally, the PCBA processing plant will be equipped with an oven to bake the components with water vapor.
2, choose well-known brand solder paste
The defects of solder paste and solder paste in PCBA welding are closely related to the quality of solder paste. The combination metal composition and flux configuration in the solder paste composition are not reasonable, which is easy to lead to the weak activation ability of flux in the welding process, and the solder paste can not fully infiltrate the solder plate, resulting in virtual welding and false welding defects. Therefore, you can choose famous brands such as Qianzhu, Alpha, Witcouple and so on.
3. Adjust printing parameters
The problem of virtual welding and false welding is largely due to the lack of tin. In the printing process, the pressure of scraper should be adjusted, the appropriate steel mesh should be selected, and the steel network port should not be too small to avoid the situation of too little tin.
4. Adjust the reflow temperature curve
In the reflow welding process, it is necessary to control the welding time. If the time is not enough in the preheating zone, the flux cannot be fully activated and the surface oxide of the welding can be cleared. If the time is too long or too short in the welding zone, it will cause virtual welding and false welding.
5, try to use reflux welding, reduce manual welding
Generally, when the electric iron is used for manual welding, the technical requirements for welding personnel are relatively high. If the temperature of the iron head is too high or too low, or the welding components are loose during welding, it is easy to cause virtual welding and fake welding. The use of reflux welding can reduce the artificial external factors and improve the quality of welding.
6, avoid the electric iron temperature is too high or low
In the post-welding process and maintenance of PCBA welding, it is necessary to use electric soldering iron for manual welding. In the use of electric iron, non-standard operation, resulting in the temperature of the iron head is too high or too low, it is easy to cause virtual welding and false welding. Therefore, when welding, to keep the iron head clean, according to the different parts and solder joint size, device shape to choose different power types of electric iron, the welding temperature is controlled between 300℃ - 360℃.
Virtual welding and false welding caused in the welding process of PCBA are caused by many factors, and the above is just to list some common reasons. Through the above preventive measures, combined with the actual situation, it can effectively reduce the welding defects of virtual welding and false welding.
The defects of virtual welding and false welding in PCBA welding process are caused by many reasons. The main reason is that the solder cannot fully infiltrate the pad and the pin of the component, and the pad of the component and the circuit board cannot be fully welded. In the production process, it can be prevented in the following ways.
1. Moisture-proof storage of components
If the components are placed in the air for a long time, the components will absorb moisture and oxidize, resulting in insufficient removal of oxides in the welding process, resulting in defects of virtual welding and fake welding. Therefore, in the welding process, it is necessary to bake the moisture components and replace the oxidized components. Generally, the PCBA processing plant will be equipped with an oven to bake the components with water vapor.
2, choose well-known brand solder paste
The defects of solder paste and solder paste in PCBA welding are closely related to the quality of solder paste. The combination metal composition and flux configuration in the solder paste composition are not reasonable, which is easy to lead to the weak activation ability of flux in the welding process, and the solder paste can not fully infiltrate the solder plate, resulting in virtual welding and false welding defects. Therefore, you can choose famous brands such as Qianzhu, Alpha, Witcouple and so on.
3. Adjust printing parameters
The problem of virtual welding and false welding is largely due to the lack of tin. In the printing process, the pressure of scraper should be adjusted, the appropriate steel mesh should be selected, and the steel network port should not be too small to avoid the situation of too little tin.
4. Adjust the reflow temperature curve
In the reflow welding process, it is necessary to control the welding time. If the time is not enough in the preheating zone, the flux cannot be fully activated and the surface oxide of the welding can be cleared. If the time is too long or too short in the welding zone, it will cause virtual welding and false welding.
5, try to use reflux welding, reduce manual welding
Generally, when the electric iron is used for manual welding, the technical requirements for welding personnel are relatively high. If the temperature of the iron head is too high or too low, or the welding components are loose during welding, it is easy to cause virtual welding and fake welding. The use of reflux welding can reduce the artificial external factors and improve the quality of welding.
6, avoid the electric iron temperature is too high or low
In the post-welding process and maintenance of PCBA welding, it is necessary to use electric soldering iron for manual welding. In the use of electric iron, non-standard operation, resulting in the temperature of the iron head is too high or too low, it is easy to cause virtual welding and false welding. Therefore, when welding, to keep the iron head clean, according to the different parts and solder joint size, device shape to choose different power types of electric iron, the welding temperature is controlled between 300℃ - 360℃.
Virtual welding and false welding caused in the welding process of PCBA are caused by many factors, and the above is just to list some common reasons. Through the above preventive measures, combined with the actual situation, it can effectively reduce the welding defects of virtual welding and false welding.
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