The fundamental difference between selective wave soldering and ordinary wave soldering. Wave soldering is to contact the entire circuit board with the tin-sprayed surface and rely on the surface tension of the solder to climb naturally to complete the soldering. For large heat capacity and multi-layer circuit boards, wave soldering is difficult to meet the requirements of tin penetration. The choice of wave soldering is different. The dynamic tin wave is punched out of the soldering nozzle, and its dynamic strength will directly affect the vertical tin penetration in the through hole; especially for lead-free soldering, because of its poor wettability, more Dynamic and powerful tin waves are required. In addition, the strong flow of the wave peak is not easy to remain oxide, which will also help improve the quality of the solder.
The welding efficiency of selective wave soldering is indeed not as high as that of ordinary wave soldering, because selective soldering is mainly aimed at high-precision PCB boards, which cannot be welded by ordinary wave soldering. When traditional wave soldering cannot complete through-hole group soldering (defined in some special products, such as automotive electronics, aerospace, etc.), at this time, selective soldering that can accurately control each solder joint by programming is used, which is better than manual soldering. , The soldering robot is stable, the temperature, process, welding parameters, etc. are controllable, and the control is repeatable; it is suitable for the current through-hole welding that is becoming more and more miniaturized and welding parts dense products. The production efficiency of selective wave soldering is lower than that of ordinary wave soldering (even 24 hours), and the cost of production and maintenance is high. The key to the yield of solder joints depends on the NOZZLE status.
Post time: Oct-25-2022