There is an ongoing rapid growth in the market for electric and hybrid vehicles. As this technology develops, the operating voltage and current draw of these systems increase to meet end-user requirements. Both of these factors (the higher voltage and higher current) can lead to a range of failure mechanisms. It is important that the reliability of these systems is well understood and can be appropriately tested/investigated. In the near future this technology will move onto electric aircraft where reliability plays is a key consideration in the design.
At NPL we have recently run a project investigation the electrical and thermal degradation of power modules, evaluating their performance from a materials aspect. We have developed our power cycling capability enabling us to heat power module systems at device level leading to local heating. Using active cooling, we are able to rapidly cycle the device temperature and accelerate lifetime testing to evaluate the performance of the electrical interconnects and the thermal interfaces in the device stack