In the production process of electronic products, there are two common welding methods of electronic products, which are called reflow soldering and wave soldering;
The difference between the two welding methods is that the wave peak welding is mainly used to weld the plug-in circuit board, while the reflow welding is mainly used for SMT chip board welding.
Reflow welding process is to realize the soldering of mechanical and electrical connection between the welding end of surface assembly components or pins and the solder pad of printed board by remelting the paste solder which is pre distributed to the pad of printed board.
Reflow welding can control the amount of solder applied in the leading process, effectively reduce the incomplete defects of solder, such as false welding and bridge welding, so as to make the welding quality stronger, the weld joint consistency better and the reliability is very high.
During the process of electronic processing, the reflow welding does not directly dip the component into the molten solder, so the component is subject to small thermal impact (because the heating mode of reflow welding is different, in some cases, the temperature applied to the components will be higher, and the thermal stress of the corresponding components will be relatively large).
The solder for reflow welding is a commercial solder paste. It can ensure the normal composition when ordering, and it will not mix impurities in general, and it is easier to ensure the quality of welding.
If the position of solder applied on PCB is correct in the leading process and the position of the sticking component deviates from that of the component, during the reflow welding process, when all the welding ends, pins and corresponding pads of the components are wet at the same time, the effect of the surface tension of the molten solder will produce self setting effect, which can automatically correct the deviation and pull the components back to the approximate accurate position.
Local heating heat source can be used, so different welding methods can be used on the same substrate.
The process is relatively simple, and the workload of repairing electronic components is very small when the defective products appear.
