As the volume of electronic products is getting smaller and smaller, the precision of PCBA assembly is getting higher and higher. As a result, the volume of electronic components can no longer be described as small, but as tiny components.In addition, due to the influence of technology, solder materials, PCB board quality, equipment and other factors on the welding quality, there are many invisible defects in the wave soldering process, which are generally not easy to be detected in the appearance inspection.Often after the delivery to the customer, in the process of use, due to power, vibration, environmental temperature changes and other factors, resulting in solder joint failure ahead of time.In view of this situation jingbang electronic xiaobian to make up some suggestions.
Finally, some suggestions on wave soldering process are put forward:
1. Many defects of wave soldering bell are related to PCB design, so DFM must be considered
2. Many defects are related to the quality of PCB and SMT processing components, in order to avoid the impact of fake and inferior components on quality.Should select qualified suppliers, controlled logistics, storage conditions.
3. Many defects are caused by inadequate flux activity.A good flux can withstand high temperatures, prevent bridging, and improve tin penetration through holes.
4. The wave soldering temperature should be set as low as possible to prevent component overheating and material damage, especially to control the secondary tin melting in the mixed assembly process.
5, low solder temperature can reduce solder oxidation, reduce tin slag, reduce the molten solder on the solder tank and impeller erosion.Limit the formation of FeSn2 crystals.
6. Excellent process control can reduce defect level.The process parameters should be adjusted comprehensively and the temperature curve must be controlled.
7, pay attention to solder maintenance in the tin furnace, strengthen the daily maintenance of equipment.