Power semiconductors empirical diagrams expressing life as a function of temperature excursion

Life expectancy for power semiconductor devices under cyclical power is discussed in practical terms as it has evolved over several decades. Predictions of failure, although not absolute, are supported by sound theoretical concepts based on the generalized behavior of materials under elastic-stress conditions. With that, the known property of silicon to fracture when subjected to a single quenching from 350 degrees C to 0 degrees C is combined with results of long-term and accelerated life testing to establish the life expectancy curves. These would apply for specific models and defined current cycling duty including the time gradient of temperature rise.< >