The real-time temperature profile can be measured when conditions are met, and the warm-up time is controlled by the conveyor speed. If the preheating temperature is too low or the preheating time is too short, the solvent in the flux is not sufficiently volatilized, and gas generated during welding causes welding defects such as pores and solder balls; if the preheating temperature is too high or the preheating time is too long, the flux is Decomposition in advance, the flux is inactivated, and it also causes welding defects such as burrs and bridges. Therefore, the preheating temperature and time should be properly controlled. The optimum preheating temperature is the viscosity of the flux applied to the bottom surface of the PCB before wave soldering.

The welding process is a complex process of welding metal surfaces, molten solder and air, etc. The welding temperature and time must be controlled, such as low welding temperatures. The viscosity of liquid solder is too large to wet and spread on the metal surface, and it is easy to produce defects such as tipping and bridging, and rough surface of the solder joint; if the soldering temperature is too high, the components are easily damaged, and solder joint oxidation occurs. Speed up, solder joints, and solder joints are not full.

The wave soldering temperature is determined according to the size and thickness of the printed board, the size and the number of components mounted on the printed board, and the peak temperature is generally 250 ± 5 °C. Since heat is a function of temperature and time, the heat of solder joints and components is increased with time at a certain temperature. The soldering time of wave soldering is controlled by adjusting the speed of the conveyor belt. The speed of the conveyor belt is based on different types of wave soldering machines. The length and the width of the peak are adjusted, and the welding time is expressed by the time when each solder joint contacts the peak. The general welding time is 3-4 s.