Influence of SAC0307-TiO2 Composite Solder Joint on Thermal Parameters of MOSFETs

The effect of composite solder joint fabrication on the thermal properties of MOSFETs was investigated. On the basis of the reference alloy (SAC0307), reinforced composite solder joints with the addition of titanium oxide nanopowder (TiO 2 nanoparticles) were prepared. Reinforced joints differed in the weight percentage of TiO 2 , ranging from 0.125 to 1.0 wt%. MOSFET transistors in the TO-263 package were soldered to metal core substrates (MCPCB). The transient thermal impedance Z thj-a (t) was measured using an indirect electrical method. Based on the measured values, thermal resistances R thj-a were determined. It was proven that the thermal resistance R thj-a depends on TiO 2 concentration in the composite solder joint, having a minimum at the level of 0.25 wt%. The research highlights the importance of the soldering technology used in the case of the assembly of MOSFETs devices.