Reduction of test effort. Looking for more acceleration for reliable components for automotive applications

Experience shows that chip package interaction is a dominant cause for failures of electronic components. Optimising the technology by applying the standard temperature cycling test to detect these failures is very time consuming and not any more compatible with today’s development cycles.Early failure indicators (preferable electrically measurable) could be the key element to reduce the test effort and to guarantee the performance in an application.From the package point of view there are three main drivers to be taken into consideration: The temperature, i.e. all degradation processes with an activation energy, temperature swings, which cause thermo-mechanical stress due to different CTE (coefficient of thermal expansion) of the variety of different materials used for the assembly, and temperature gradients, especially when active cycles are applied (switching of the device) can lead to metal reconstruction and plastic deformation, reducing lifetime of the component drastically. Knowledge of the weak areas allows choosing the best test in order to make the addressed failure mode observable in the shortest time.This paper provides a decision basis to speed up technology qualification by using TS (thermal shock) instead of TC (thermal cycling). Results will be shown for different die attach materials.