Developing a ThetaJC standard for electronic packages

Theta jc data are commonly reported for most electronic packages. However, a JEDEC standard that specifies best practices for performing steady-state Theta jc measurements is not yet available. Presented in this study are recommendations for making consistent Theta jc measurements, including criteria for mounting the case thermocouple, predicting the impact of TIM II material, bond line thickness, effect of heat-sink construction materials and testing variability introduced by different test engineers. At a critical Theta jc value, predictions show that case temperature measurements must be made using a thermocouple embedded into the case of the package.