What are the differences between reflow soldering machines and wave soldering machines?

Wave soldering machine and reflow soldering machine are two different soldering methods commonly used in the production of SMT electronic products. The difference between them is:

Reflow soldering machine is a kind of equipment commonly used for soldering SMD components. It heats air or nitrogen to raise the temperature to a certain level, and then blows the hot air to the circuit board with the components attached. In this way, the solder will melt and bond with the motherboard, and finally complete the soldering process after cooling.

Wave soldering is a method used for soldering plug-in components. It achieves soldering by directly contacting the soldering surface of the plug-in board with high-temperature liquid tin. During the wave soldering process, the high-temperature liquid tin exists in the form of an inclined surface and forms a wave-like phenomenon through a special device. The pins of the plug-in are soldered through these waves. Wave soldering is mainly used for soldering plug-in components, which usually need to be placed manually.

What are the differences between reflow soldering machines and wave soldering machines:

　The reflow process is to achieve mechanical and electrical connection between the solder joints or pins of external assembled components and the printed circuit board pads by reheating the paste solder pre-dispensed on the printed circuit board pads. This process uses soft soldering technology to complete the welding process.

As people's awareness of environmental protection increases, new soldering processes have also emerged in wave soldering. In the past, wave soldering usually used lead-containing tin-lead alloys, but lead is a heavy metal that is harmful to the human body. Therefore, lead-free processes have now emerged. Lead-free processes use tin-silver-copper alloys and special fluxes, and the requirements for soldering temperatures are higher. In addition, after the PCB board passes the soldering area, a cooling area workstation needs to be set up to avoid thermal shock. In addition, if there is ICT (testing), it may affect the detection.

　　Wave soldering can be simply understood as being used to solder larger or relatively smaller components. Unlike reflow soldering, wave soldering does not heat the entire board and components, but rather liquefies the solder paste pre-applied on the pads to achieve the connection between the components and the board. In other words, reflow soldering achieves soldering by heating the board and components, while wave soldering achieves soldering by liquefying the solder paste.

1. In terms of process, wave soldering requires spraying flux first, and then going through the steps of preheating, soldering and cooling zone.

2. Reflow soldering goes through the process of preheating zone, reflow zone and cooling zone. Wave soldering is suitable for hand-inserted boards and dispensing boards. For components, they are required to be heat-resistant, and components that have been previously used with SMT solder paste cannot be used for wave soldering. For boards that use SMT solder paste, soldering can only be performed through reflow soldering, not wave soldering.

3. Wave soldering is to dissolve the tin bar into liquid and use a motor to stir it into a wave shape to solder the PCB and components together. It is usually used for hand plug-in soldering and SMT glue board. Reflow soldering is mainly used in the SMT industry. It melts the solder paste printed on the PCB and solders it to the components through hot air or other heat radiation conduction.

Wave soldering process features:

Four new technologies of tin furnace system:

1. Adopt new impeller and flow channel design to improve wave peak stability

2. Use the nozzle to spray the flux vertically to the PCB to improve the uniformity and penetration of the spraying

3. Use new flow channels, new nozzles and other devices to reduce oxidation, effectively reducing customers' operating costs

4. The cast iron surface is plated with ceramic furnace, which can prolong the life of the furnace.