Wave soldering is the role of the molten liquid brazing pump, which forms a certain shape of solder wave in the liquid surface of the brazing groove. Insert (Mount) the components of the PCB placed on the conveyor chain, through a specific angle and a certain depth of immersion through the solder peak to achieve solder welding process, lead-free wave soldering compared to lead-free reflow soldering process is much more difficult, The corresponding requirements for wave soldering equipment are more stringent. Wave soldering process including flux spraying, preheating, welding, cooling four stages, each phase of welding quality is critical.
The temperature curve of wave soldering process has the following requirements:
1. The maximum warming slope is 3 degrees/s, the maximum cooling slope is 6 degrees/s;
2. preheating zone and tin furnace cooling between 5 degrees. (Meet T1 less than 120 degrees);
3. The temperature drop between the two peaks is less than 50 degrees T2 (to prevent excessive volatilization of flux);
4. before and after the crest of the peak immersion tin time is generally not more than 5S.