Reasons and countermeasures for whitening of solder joints in automatic soldering machines

In the field of electronic manufacturing, automatic soldering machines have become a powerful assistant for many companies to improve production efficiency and product quality with their high efficiency and precision. However, in the actual production process, the phenomenon of whitening of solder joints in automatic soldering machines occurs from time to time, which not only affects the appearance of the product, but also may bury hidden dangers for the reliability and performance of the product. As an enterprise deeply engaged in the automation equipment industry, Xiaomao Automation Technology Co., Ltd. has in-depth research and rich experience in solving the problem of whitening of solder joints in automatic soldering machines. The following is a detailed analysis of the reasons for whitening of solder joints.

Analysis of core reasons

Flux residue and chemical reaction
Flux plays a vital role in the welding process. It can remove the oxide film on the metal surface, prevent re-oxidation during welding, and ensure a good combination of solder and substrate. However, if the flux fails to completely volatilize or remains too much after welding, it will react chemically with moisture and oxygen in the air. For example, some halogen-containing flux residues are easily combined with water vapor in a humid environment to form corrosive acidic substances, which will form white crystals or corrosion products on the surface of the solder joint,

causing the solder joint to turn white.
Improper control of welding temperature and time
When the welding temperature is too high, the active ingredients in the flux will evaporate quickly and lose their due effect. At the same time, high temperature will accelerate the oxidation process of the solder. After the solder is oxidized, a layer of white tin oxide will form on the surface, making the solder joint appear white. In addition, too long welding time will also aggravate the oxidation reaction, and may cause excessive melting of the solder, change the microstructure of the solder joint, and increase the possibility of whitening. On the contrary, if the temperature is too low or the time is too short, the solder may not be able to fully wet the substrate, the solder joint surface is uneven, and the whitening problem may also occur in subsequent use due to uneven stress distribution.

Poor adaptation of solder material to substrate
The quality and composition of solder material, as well as its compatibility with the substrate to be welded, are key factors affecting the quality of solder joints. If there are impurities in the solder material, or the proportion of its components is unreasonable, it is easy to produce abnormal reactions during the welding process, causing the solder joints to turn white. In addition, when the expansion coefficients of the solder and the substrate do not match, large internal stress will be generated during the cooling process of welding, which may cause cracks or whitening on the surface of the solder joints.

Poor welding environment conditions
Excessive humidity is one of the common environmental factors that cause solder joints to turn white. In a high humidity environment, moisture in the air is easily adsorbed on the surface of the solder joints, reacting with solder or flux to form white hydrates or corrosion products. At the same time, pollutants such as dust and impurities may also adhere to the surface of the solder joints, affecting the wettability and bonding strength of the solder, which in turn causes the solder joints to turn white. In addition, if there are harmful gases in the welding environment, such as hydrogen sulfide, sulfur dioxide, etc., these gases will also react chemically with the solder joints, accelerating the corrosion and whitening of the solder joints.

In response to the problem of whitening solder joints of automatic soldering machines, Xiaomao Automation has provided customers with a series of professional solutions based on years of technical accumulation and industry experience.

In terms of equipment, Xiaomao's soldering machine adopts an advanced temperature control system, which can accurately control the welding temperature, ensure that the temperature is within the appropriate range, and avoid whitening of the solder joints due to excessively high or low temperatures. At the same time, the equipment has an intelligent time setting function, which can accurately adjust the welding time according to different welding requirements to ensure the stability and consistency of the welding process.

In the selection of solder materials and flux, Xiaomao Automation cooperates with high-quality suppliers to provide customers with high-quality and compatible solder materials and flux. These materials have undergone strict quality testing and can effectively reduce oxidation reactions and residual problems, reducing the risk of whitening of solder joints from the source.

In addition, Xiaomao Automation also provides customers with professional technical support and training services. Our technical team will develop personalized welding process plans based on the customer's production environment and product characteristics to help customers optimize welding parameters, improve the welding environment, and ensure that the quality of solder joints reaches the best state.

Although the problem of whitening of solder joints in automatic soldering machines is common, it can be effectively controlled by in-depth analysis of the causes and taking effective solutions. Xiaomao has always been committed to providing customers with high-quality automation equipment and professional solutions to help customers improve production efficiency and product quality and stand out in the fierce market competition. If you encounter any problems during the use of the automatic soldering machine, please feel free to contact us and we will serve you wholeheartedly.