Main function of reflow soldering
Reflow soldering is mainly used in SMT process。The main function of reflow soldering is to put PCB plates with components into the orbit of the reflow soldering machine ，The solder paste is changed from paste to liquid at high temperature through heating, heat preservation, welding and cooling，and to achieved the SMT electronic component and PCB plate welding .
Reflux welding machine, also known as reflux welding machine, reflux welding, are the same equipment. The function of reflow welding is to weld PCB board and components, which has high production efficiency, less welding defects and stable performance. It is an important welding equipment in PCBA processing plant.
Reflow welding mainly consists of four temperature zones: heating zone, constant temperature zone, welding zone and cooling zone. This reflects the change process of the solder paste on the circuit board of the assembled components in the reflow soldering machine. The following is a brief explanation of the four temperature zone of reflow welding machine
1. Role of reflow solder heating zone:
The heating zone is in the first stage of backflow welding, preheating and heating of PCB board, activation of solder paste, evaporation of part of solvent, evaporation of moisture of PCB board and components, and elimination of stress in PCB board
2. Reflow soldering insulation
PCB boards enter the thermal insulation area and reach a certain temperature to prevent sudden entry into the high temperature area and damage the PCB boards and components, The effect of this temperature zone is also to keep the temperature of components stable, keep the temperature of components of different sizes on the PCB board at all times, reduce the temperature difference of the entire PCB board, volatilize the solder flux in the solder paste, and remove the oxide of the pad and pin of components.
3. Function of reflow soldering zone
PCB board enters the welding area, and the temperature reaches the highest. At this time, the solder paste has changed from paste to liquid, fully infiltrating the solder pad and component pin. The duration of this link is relatively short, preventing damage to PCB board and components at high temperature
4.Reflow solder cooling zone:
Solder paste into a liquid can then be cooling, cooling speed faster the better, generally cooled to 75 ℃ is solidified, then realize to the PCB welding
The main function of reflow oven is the temperature changes in the oven, Solidify the solder paste so that the SMT components are welded together with the circuit board, Another function is to solidify the SMT component through the red glue and the PCB to solidify and paste together, so as to facilitate the wave soldering machine.
