Many skilled friends know that in the PCBA welding process, if there are defects such as false soldering and false soldering, they are generally caused by various reasons, mainly due to the insufficient infiltration of solder into the solder pads and meta equipment pins, and the inability to achieve sufficient soldering between meta equipment and circuit board pads. How can PCBA processing avoid the defects of false soldering and false soldering during the production process?

The editor will explain the methods and methods of prevention to everyone through the following methods.

1. Moisture-proof storage of meta equipment

If the meta equipment is placed in the air for too long, it will cause the meta equipment to absorb moisture, oxidize the meta equipment, and cause the meta equipment to be unable to fully remove oxides during the welding process, resulting in the drawbacks of false soldering and false soldering. Therefore, during the welding process, it is necessary to bake the components with moisture and replace the oxidized components. Generally, PCBA processing plants are equipped with ovens to bake raw materials with moisture.

2. Choose well-known brand solder paste

The defects of false soldering and false soldering during the PCBA welding process are closely related to the quality of solder paste. The complex metal composition and flux equipment in the solder paste composition are unreasonable, which easily leads to the weak activation ability of flux in the welding process, the solder paste can not fully soak the pad, and then leads to the defects of faulty soldering and false soldering. Therefore, it is possible to choose solder pastes from well-known brands such as Qianzhu, Alpha, and Vitol.

3. Adjusting printing parameters

The problem of false soldering and false soldering is mostly due to a lack of tin. During the printing process, it is necessary to adjust the pressure of the scraper and choose a suitable steel mesh. The steel mesh opening should not be too small to avoid the situation of low tin content.

4. Adjust the reflow soldering temperature curve

During the reflow welding process, it is necessary to control the welding time. The time in the preheating area is not good, and the flux cannot be fully activated. The surface oxide at the welding point can be removed. If the time in the welding area is too long or too short, it will cause faulty welding and false welding.

5. Try to use reflow welding and reduce craft welding

In general, when using electric soldering iron for craft welding, the skill requirements for the welding personnel are relatively high. The temperature of the soldering iron head is too high or too low, or the welding equipment is loose during welding, which is easy to cause false welding and false welding. The use of reflow welding can reduce the external factors of human behavior and improve the quality of welding.

6. Avoid high or low temperature of electric soldering iron

During the post welding processing and maintenance of PCBA welding, it is necessary to use an electric soldering iron for manual welding. When using an electric soldering iron, improper operation can lead to excessive or low temperature of the soldering iron tip, which can easily lead to false soldering and false soldering. Therefore, during welding, it is necessary to keep the soldering iron head clean and select different power types of soldering irons based on the size of different components and welding points, as well as the shape of equipment. The welding temperature should be controlled between 300 ℃ and 360 ℃.

The false welding and false welding caused by PCBA welding process are formed by many factors. The above only lists some common reasons. By taking these preventive measures and combining them with the actual situation, the shortcomings of false welding and false welding can be effectively reduced.