We often encounter many problems in welding. Let's talk about the following reasons why the solder joints do not shine after the lead-free environmental protection
tin bars are welded:
1. The tin content of the lead-free environmental protection tin bar determines the brightness of the tin point. The surface of the tin and lead-tin metal elements, which are part of the tin bar, has a bluish white luster, while the surface of the lead metal element is gray. The higher the tin, the brighter the tin point. On the contrary, the higher the lead content of the solder bar, the duller the tin point.
2 Whether the lead-free environmentally friendly tin bar is produced from raw materials and whether the impurities exceed the standard can also affect the brightness of the tin bar.
3. When the melting temperature of the solder bar does not reach the melting temperature requirement, the surface of the tin will easily produce tin dross. When the solder bar is welded, the tin dross will affect the effect of tin spot welding, and the dross of the tin spot will affect the soldering. point of light.
4. It is possible that the lead-free tin used in the furnace has been used for too long, and the new tin has not been replaced or the furnace has been cleaned. After a long time, the tin and copper of the furnace exceeds the standard, and the solder joints will not be very bright.
5. When the solder bar is welded, the flux occupies a crucial position and plays a decisive role in the brightness of the tin point. If the acidity of the flux is too strong, the surface of the tin point will corrode on the surface of the flux and the solder bar after welding. Air mixing will corrode the surface of the tin point and cause chemical reaction of the tin point to change the surface.
6. Too many impurities in the solder bar will easily cause the surface of the tin point to be rough and granular, frosting and porous, and blistering after welding. The surface of the tin spot will lose its natural luster
7. The humidity in the workshop of the factory will also affect the brightness of the tin spot. The surface of the tin spot will be bright when the tin spot is just welded, but it will become dim after a while because the air contains a lot of moisture. The humidity of the workshop is too high. When the storage place is humid, there will be a layer of oxide on the surface of the tin point, which will also make the brightness of the tin point fade.