High temperature ageing of microelectronics assemblies with SAC solder joints

In some applications, electronic systems are expected to operate at high ambient temperature (e.g. 150 °C). In this paper, we investigate the failure mechanism and microstructure evolution of solder-free (SAC) solder joints at a maximum temperature of 175 °C. It is found that no new failure mechanisms are triggered, and that ageing tests for solder can be accelerated at 175 °C. In particular, the growth rate of the interfacial intermetallic compound (IMC) is found to be consistent with that observed at lower temperatures.