Reliability tests of the surface-mounted power MOSFETs soldered using SAC0307-TiO2 composite solder paste

The reliability of the surface-mounted power transistors soldered by SAC0307-TiO2 composite solder paste was investigated. For the measurements, the power cycling method was used. Correlation between transient thermal impedance and switching frequency in the power cycling test was searched. For the measurements, MOSFETs in the TO-263 package were soldered by SAC0307-TiO2 composite solder paste containing 0, 0.25, and 0.5 wt% TiO
2
nano-particles. It was shown that junction-ambient thermal resistance correlates with device time to failure only in the case of the reference SAC0307 solder joints case. It might highlight the importance of the differing microstructural parameters of the composite solder joints compared to the simple SAC0307.