Shape prediction of the BGA solder joint in hot air reflow soldering based on CFD

Inhalt:
Solder joint failure is one of the main causes of electronic product failure. The shape of BGA solder joint is an important factor affecting the solder joint failure. In previous studies, the solder joint shape is simplified as spherical, cylindrical or hourglass shape, which theoretically deviated from the real shape of the solder joint. In this paper, based on the principles of the CFD (Computational Fluid Dynamic) and heat transfer, the Fluent code is used to establish the shape prediction model of the solder joint of the BGA (Ball Grid Array) devices in hot air reflow soldering process. Based on the prediction model, the dynamic melting and solidification process of the BGA solder joint with multi-field coupling of the flow field, the temperature field and the solid-liquid phase field is simulated and the whole evolution process of BGA solder joint morphology in hot air reflow soldering process is obtained. The predicted result of the BGA solder joint shape is compared with the measured data. The comparison shows that the predicted maximum height and the maximum width of the solder joint shape is basically consistent with the measured value. It is evidenced that the CFD based numerical model of the BGA solder joint shape brought is effective.