PCBA processing wetting bad solution
PCBA processing wetting bad also called not wetting or half wetting, refers to the solder and substrate soldering area in the soldering process, after wetting does not generate mutual reaction layer, and cause leakage or less soldering failure. In the PCBA processing, when the solder surface tension is destroyed, it will cause the surface mount component’s poor welding.
The main causes of poor wetting are:
1, the surface of the soldering area is contaminated, the surface of the soldering area stained with flux, or the surface of the SMD components generated metal compounds. All will cause poor wetting. Such as silver surface sulfide, the surface of tin oxide, etc. will produce poor wetting.
2, when the residual metal in the solder more than 0.005%, the degree of flux activity is reduced, the phenomenon of poor wetting will also occur.
3, wave soldering, the existence of gas on the surface of the substrate, it is also easy to produce poor wetting.
The methods to solve the poor wetting are:
1, strict implementation of the corresponding soldering process.
2, PCB board and component surface should be well cleaned.
3, choose the appropriate solder, and set a reasonable soldering temperature and time.