Two soldering processes are commonly used in PCBA processing, namely wave soldering and reflow soldering. Reflow soldering is suitable for soldering SMT patches, while wave soldering is suitable for soldering DIP inserts. If the PCB board size is too large during PCBA production and processing, wave soldering must be used for soldering.
Wave soldering is a type of PCBA soldering process that requires the use of wave soldering equipment. Unlike the principle of reflow soldering, the principle of wave soldering is to place solder into a machine tin bath, heat the machine to melt the solder, and the solder surface of the PCB board, which has already been inserted with components, comes into contact with the liquid solder under the conveying device and is cooled to form a solder joint. This is the principle of wave soldering, and because under the pumping pressure of an electric pump or electromagnetic pump, the surface of the liquid solder will form specific shaped waves, similar to waves, it is called wave soldering;
Wave soldering can be divided into four parts: flux spraying, PCB preheating, soldering, and final cooling. Among them, flux spraying is the process of uniformly spraying flux on the PCB board. The preheating zone is the process of preparing the PCB board from room temperature to high temperature to adapt to the high temperature of the soldering furnace. The soldering zone is the process of melting and immersing the solder into the PCB board, and after passing through the final cooling zone, it forms soldering. This is the process flow of wave soldering;
As a type of PCBA soldering process, wave soldering used to use lead based technology, with tin lead alloy as the solder material. However, with people’s awareness of the hazards of lead and environmental protection, new lead-free soldering processes are now being used in PCBA processing, with tin silver copper alloy or other tin metal alloys used as the solder material.