Wave soldering is a relatively common electronic device, so how much do you know about its working principle?
Wave soldering is to let the soldering surface of the plug-in board directly contact with the high temperature liquid tin to achieve the purpose of welding, the high temperature liquid tin maintains a sloping surface, and by a special device to make the liquid tin form a wave-like phenomenon, so called "wave soldering", its main material is solder bar.
Wave soldering working principle
Wave soldering machine is mainly composed of transportation belt, flux adding area, preheating area, and tin furnace.
The main purpose of the transport belt is to feed the circuit base into the wave soldering machine, along the way through the flux adding area, preheating area, and soldering furnace. The flux adding area is mainly composed of infrared sensors and nozzles. The infrared sensor is used to sense whether there is a circuit board entering, and if there is a sensor, the width of the circuit board will be measured. The role of flux is to form a protective film on the soldering surface of the circuit board.
The preheat zone provides sufficient temperature for good solder joints to form. There is infrared heat generation for even heating of the circuit backplane. In a dual wave system, the turbulent part of the wave prevents leakage, and it ensures proper distribution of solder through the board. The solder penetrates through the slit at a high speed and thus penetrates the narrow gap. The direction of injection is the same as the direction in which the board proceeds. The turbulent wave alone does not properly solder the component; it leaves unevenness and excess solder on the solder joint, so a second wave is required.
The second laminar flow wave or smooth wave eliminates the burrs and solder bridges created by the first turbulent wave. The laminar flow wave is actually the same wave used for conventional through-hole cartridge assemblies. Therefore, when a conventional component is soldered on a single machine, the turbulence wave can be turned off and the conventional component can be soldered with the laminar wave.
The most commonly used dual-peak system on the market today has a turbulent wave of reciprocating motion where solder is ejected from a nozzle rather than from a narrow slit. A moving nozzle is more effective than a slit in preventing solder leakage because it not only generates turbulence, but also has a cleaning effect.
The molten solder in the solder pool is ejected upward to form a projecting waveform. During the soldering process, a PCB (PCBA) with a component inserted is coated with solder, preheated, and then passed through a wave formed by the melted solder, so that the PCB touches the top of the wave and the connection between the component and the PCB pad is soldered.
The internal structure of wave welding consists of five main parts: spray system, preheating system, welding system, cooling system, and transportation system.
