How to control the quality of reflow welding?

We are no stranger to the technology of reflow welding in the field of electronic manufacturing, and the components on all kinds of boards of our electronic products must be welded to the circuit board through the technology of reflow welding. The advantage of this process is that the temperature is easier to control, the welding process can also avoid oxidation, and the cost of manufacturing products is easier to control. There is an electric circuit inside the device that heats up nitrogen to a sufficiently high temperature and then blows to the circuit board that has been attached to the element, allowing the solder on both sides of the element to melt and bond to the motherboard.


How to control the quality of reflow welding, the production process is mainly optimized from these aspects.


1. Setting up a scientific reflow welding temperature curve and regularly doing real-time testing of the temperature curve.


2. Welding should be carried out according to the welding direction of PCB design.


3. The vibration of the conveyor belt should be prevented in the welding process.


4. The welding effect of the first printed circuit board must be checked.


5. Whether the welding is sufficient, whether the surface of the solder joint is smooth, whether the shape of the solder joint is semilunar, the case of tin ball and residue, the case of continuous welding and virtual welding, we should check the PCB surface color change and so on. The temperature curve is adjusted according to the inspection results. The welding quality should be checked regularly in the whole batch production process.


6. Regularly maintaining of reflow soldering, due to long-term work of the machine, attached and solidified rosin and other organic or inorganic pollutants, in order to prevent the secondary pollution of PCB and ensure the smooth implementation of the process, so it is necessary to carry out regular maintenance and cleaning.