With the development of technology, in the SMT patch process, soldering is an inevitable operation, and its requirements are constantly improving. Even the degree of brightness of the solder joints is clearly defined. If the inspection finds that the gloss of the solder joint is not enough, it can be defined as unqualified, so what causes this phenomenon?
Let’s analyze it below:
- Solder paste: for example, there is oxidation in the tin powder, or the flux itself has an additive that forms a matting effect, thereby reducing the gloss of the solder joint.
- There is a residue of solder joints after rosin or resin residue in the welding. Especially when the rosin-type solder paste is used in the SMT patch processing factory, although the rosin-type flux and the clean-free solder will slightly brighten the solder joint, the residue is The existence of this often affects this role.
- Temperature: the preheating temperature during welding is relatively low, and the expected setting value is not reached, so that it is not easy to have the appearance of the solder joints in the evaporation material, so that the appearance does not look so bright.