Wave solder slag is a very difficult problem faced by electronics factories. There are many reasons for wave solder slag. The main reason for wave soldering is that there are too many impurities in wave soldering and improper operation. Tin dross). Guangshengde wave soldering summarizes the reasons and solutions for the large amount of dross in wave soldering.

Reasons for excessive dross caused by excessive impurity content of wave soldering tin:

Wave solder dross

1. The copper content and trace elements of tin in the wave tin furnace exceed the standard. Excessive copper content and iron content are the main reasons for the formation of more slag. The circuit boards are made of copper, and most of the electronic feet are made of iron. There will be more or less copper and iron during the operation. Elements fall into the tin furnace, causing copper and iron elements to exceed the standard over time. When copper is greater than 0.8% and iron is greater than 0.05%, a large amount of tin dross will be generated, which will affect the defective tin on the circuit board;

2. The operating temperature of the wave furnace is too high. Excessive temperature is also the cause of more slag. Too high temperature will make copper and iron elements more likely to exceed the standard;

3. The usual cleaning of the furnace is also very important. If the furnace has not been cleaned for a long time, the content of impurities in the furnace is too high, which is also the cause of excessive tin slag;

4. The artificial relationship is also very important to add tin bars at the right time. When adding tin bars, always keep the distance between the tin surface and the peak short. Don't wait for the difference between the tin level in the wave soldering furnace and the wave soldering furnace. Tin is too big;

6. The design of wave crest furnaces in some factories on the market is not ideal. The wave crest is too high, the peak table is too wide, the double crest furnace is too close, and the rotary pump is used. The wave crest is too high. When the solder falls from the peak, the temperature decrease deviation is relatively large. The solder mixes with air and rushes into the tin furnace to cause oxidation and semi-dissolution, leading to the generation of tin dross. The rotary pump does not take preventive measures, and continuously presses the tin slag into the furnace, and the chain reaction of the loop stimulates the generation of the tin slag.

The solution to more wave solder dross:

Energy-saving and tin-saving wave soldering

1. Regularly test the tin in the wave furnace. When the copper content is greater than 0.8% and the iron is greater than 0.05%, the tin in the wave furnace should be replaced. Usually, the wave soldering furnace tin takes about one month. Choose high-quality tin bars, especially those with anti-oxidation function; add anti-oxidation oil or anti-oxidation powder to prevent oxidation; suppliers who do not use recycled materials for reproduction;

2. The tin furnace is evenly heated. Try to fill up the tin as much as possible to maintain the tin level and reduce the drop. The smaller the peak drop, the better. The peak should be lowered when the work is allowed. Add tin bars to increase the tin level and maintain the height of the liquid level. Do not fish out with a little tin dross. If it does not affect the production, you do not need to fish all the time. If the liquid level is low, it is easier to accelerate the oxidation than the high liquid level. Lower the height of the tin waterfall and reduce the amount of air contact;

3. Control the operating temperature of the wave furnace (about 260-275 degrees Celsius), and regularly check whether the temperature gauge of the wave furnace is accurate. If there is any abnormality, it should be repaired immediately. The flux should be of better quality. If the flux is not good, do it Work at around 260-275 degrees Celsius;

4. Use nitrogen and fill nitrogen locally, but the equipment is very important. Many modified equipment is useless if it is not handled properly;

5. Add ge and phosphorus to the raw material tin rod. In fact, phosphorus (P) element will be added by the basic manufacturers, that is, there are many types, and the anti-oxidation effect is very good. The effect of germanium (GE) is very good in a nitrogen furnace;

6. Use reducing agent, but most equipment manufacturers require not to use it. The reducing agent is more corrosive to the furnace. Please verify carefully before using it. According to feedback, it will reduce the life of the tin furnace. After someone has used the reducing agent, the blades are corroded and the furnace is perforated.

7. Welding materials are spot-checked, and the liquid tin samples in the tin furnace are tested and analyzed, and the composition and impurities are significantly changed. At present, welding material factories are mixed, and many manufacturers use secondary recycled tin dross to save costs. The welding quality is effective. Inferiority is also an important reason for the large amount of tin dross;

8. When the tin slag is floating on the surface, do not directly use a colander to fish it. Use a scraper to grind the tin slag into a powder on the tin furnace wall. Squeeze the tin dross with a colander, which can also avoid some waste;

9. Guangshengde developed an energy-saving wave soldering solution for the reason of the large amount of wave soldering slag in the market, which has solved the problem of excessive wave soldering slag. Open the possibility to click on the energy-saving wave soldering to find out.