1. Standard
solder bar: the standard is Sn63/Pb37, deformation seam, steel grid plate Sn60/Pb40 solder bar. Usually it is mainly used for wave soldering and hot dip soldering, and the working temperature is 220°C-260°C. It has the following advantages:
1. Excellent wettability, reducing the occurrence of bad solder joints;
2. There are very few harmful impurities, which can improve the diffusion force and enhance the fluidity;
3. The solder joints are brighter;
4. The liquid surface is bright and there is less tin slag;
2. High-temperature anti-oxidation solder bar: The temperature of the soldering furnace is 400°C-500°C. The tin bar is refined with a special formula based on the standard tin bar, which can effectively enhance the high-temperature anti-oxidation performance. It is mainly supplied to electronic components containing enameled wires. Component building formwork, coolers (such as transformers, inductors, coils, relays, degaussing coils, etc.) are used for tinning. It has the following advantages:
1. When the solder furnace is working at high temperature, the liquid surface is bright, and there is no need to scrape off the tin slag on the soldering surface every time it is operated. It has good workability and high production efficiency;
2. The components are easy to be tinned and the bottom plate is almost free of tin slag;
3. After tinning, the surface of the pin is bright, smooth and has a good appearance;
Ordinary solder bar: When ordinary tin bar works at a temperature above 400°C, yellow or brown oxides will be produced on the liquid surface of the tin furnace. Therefore, the operator needs to scrape the tin slag on the tin surface every time before tinning. Attached to the bottom plate, in addition, manual brushing is required, which not only affects the operation rate but also wastes solder resources. It has the following advantages:
1. Avoid welding problems such as bridging, sharpening, and poor wettability caused by harmful impurities.
2. The fluidity of the solder bar is good, the tin is even and fast, and the temperature of the tin furnace is lower. Slow down the speed of solder leaching, effectively inhibit the dissolution speed of copper on the circuit board, and prolong the use time of solder in the furnace. the
3. The solder joints of the solder bar are bright and have very little tin slag, which can reduce product costs and improve production efficiency;
The quality of solder bars is guaranteed. Although our company has guaranteed the high purity of electrolytic raw materials and electric heaters, it is impossible to achieve 100% purity due to the newly built concrete chimney, and there are trace impurities in it. The impurities contained in the raw materials are also relatively different due to different origins, and the qualitative changes between each other will cause quality instability. However, our company uses raw materials from a single origin, which reduces the possibility of the above problems.
Currently, the world's annual output of tin, the main component of solder bars, is 210,000 tons, of which 130,000 tons are solder bars that are reapplied from residues. It can be seen that the proportion is large. However, lead-free solder bars are not made of lead-containing re-used solder bars, so they must be made of raw material tin. Although the density of lead-free solder bars is 10% to 20% lighter than that of the original eutectic solder bars, taking into account the weight reduction factor, 200,000 tons of raw materials are still needed to produce lead-free solder bars every year.
