As we all know, in the SMT processing industry, we need not only solder paste, but also welding wire. Before we buy tin wire and put it into storage, the first thing is to identify the quality of tin wire? The quality of tin wire directly affects the quality of welding!
The first is to touch; Good solder wire is white and shiny. It is not easy to apply it to your hands when wiping by hand, while the tin wire with high lead content is black. It is easy to get black hands when wiping by hand! The hardness of tin wire is not high! Good ductility, so the softer it is, the better its purity is! Some experienced teachers can tell by touching with their hands that the difference in the general quality of current welding wires is not big, and it may not be so big from the naked eye, so they still need to make a certain judgment through the accumulation of experience.
The second is to see; Through visual inspection, the good tin wire shall be smooth, shiny, free of oxidation and blackening!
The quality of solder wire is generally thinner, and the color is brighter. Too thick solder wire has higher lead content and is relatively less easy to melt. These are the simplest basic judgments that can be drawn from direct observation.
The third is welding; Before welding, the temperature of the soldering iron should be adjusted correctly. If the temperature is too high or too low, tin can not be lined normally. The melting point is also different due to the difference of its yield and composition. Only by adjusting the appropriate temperature can it be detected accurately!
In the welding process, it can be judged according to the size of solder smoke. Less smoke means high purity! After welding, it can be identified according to the gloss of the solder joint.
