In surface mount processing and welding technology, many customers usually have a requirement for the brightness of solder joints.

In the process of surface mount processing and welding, it cannot be guaranteed that the brightness level of each welding point can meet the requirements. What is the reason for insufficient gloss of solder joints?

The tin powder in the solder paste has oxidation phenomenon.

Solder paste has additives in the flux itself to form extinction.

In solder joint processing, the preheating temperature of reflow soldering is low, and the appearance of the solder joint is not prone to residual evaporation.

Solder joints with residual rosin or resin after welding, especially when using rosin solder paste, although rosin agents and non clean fluxes can make the solder joints brighter, often occur in practical operations. However, the presence of residue often affects this effect, especially on larger solder joints or IC pins. If cleaning can be done after welding, the glossiness of the solder joints should be improved.

Due to the non-standard brightness of solder joints, there will definitely be a certain distance between products welded with silver free solder paste and those welded with silver containing solder paste. This requires customers to clarify their solder requirements when choosing a solder paste supplier.