There are many reasons for the generation of tin dross, involving product quality, operation methods and maintenance methods of machinery and equipment, welding materials, etc. It is often encountered that many factories do not care about the height of the tin surface. Some tin bar
factories with the same specifications and series use only about 5KG/8 hours of tin dross, while others use more than 10 kg/8 hours of tin dross. Professional tin factories have corresponding expertise in tin bar manufacturing. We believe that there is less dross than a factory with standard process technology and better mechanical equipment maintenance, so process technology and mechanical equipment are very important. In addition, solder curing is also necessary.
Too much slag, how to deal with it?
When dealing with excessive dross in wave soldering, it should be clear whether the dross is normal. Usually, black powder dross is normal, but tofu-like dross is not normal. In this case, the generation of tin dross has the following points:
1. The main reason is the condition of the wave furnace equipment: at this stage, some wave furnaces on the market are not well designed, the wave peak is too high, the peak platform is too wide, the double wave furnace is too close, and a rotary pump is used. The crest is too high and the temperature difference is very large when the solder falls off the top of the crest. Solder mixed with air and rushed into the tin pot, causing oxidation and semi-dissolving. For the generation of tin dross, the rotary pump does not take preventive measures to continuously press the slag into the furnace, and the chain reaction of the circuit stimulates the formation of tin dross.
2. The temperature of wave soldering is usually controlled very low, usually 280℃±5℃, which is the most basic temperature to be reached. If the temperature is too low, the effective dissolution of tin cannot be achieved indirectly. This can lead to excessive dross.
3. For human reasons, it is also very important to add tin bars in time. The most suitable process for adding tin strips is to keep the distance between the tin surface and the peak as short as possible.
4. Whether the dross is cleaned frequently so that the solder falling from the peak can quickly enter the furnace instead of staying on the dross. Unbalanced heating can also lead to excessive dross.
5. Daily cleaning of the furnace is also very important. If the furnace is not cleaned for a long time, the sediment content in the furnace is relatively high, which is one of the reasons for the excessive tin dross.