Effect of Low-Temperature Storage on Power Cycling Lifetime of Power Semiconductor Devices

Power semiconductor devices are widely used in renewable energy generation, smart grids and electric vehicles, but often suffer failures under extreme conditions such as low temperatures and high altitudes. Existing research has primarily focused on short-term changes in electrical parameters under low temperature conditions, while the effects of long-term low temperature storage on the lifetime have received less attention. In order to systematically study the reliability evolution after long-term low temperature storage, power semiconductor devices (module with solder layer degradation and discrete with bond wire failure) were stored at low temperatures for 360 hours and 1000 hours, the reliability and power cycling test (PCT) lifetime was evaluated before and after storage, compared with no-stored case. The results show that after 1000 hours of low temperature storage, the lifetime of power modules decreases by 13.4% compared with the un-stored power semiconductor devices, whereas the bond wire lifetime of discrete devices increases by 24.19% owing to reduced thermal expansion coefficient mismatch and higher epoxy resin hardness. Finite element analysis further confirms that the reduced strain growth at the bond wire interface explains the improved lifetime of discrete devices. These results highlight the distinct effects of low temperature storage on power cycling lifetime of power semiconductor devices with different package structures and provide valuable insights for optimizing package design under extreme environmental conditions.