Abstract
This paper explores and discusses heat transfer paths of microprocessors in electronic equipment such as PCs (Personal Computers) and tablet devices utilizing a one-dimensional thermal network. Three-dimensional steady state heat conduction simulations are also conducted with different cooling solutions, motherboard sizes, and heat flux distributions at the microprocessors’ silicon die bottoms. After that, thermal resistance values defined in the one-dimensional thermal network with average temperature nodes are calculated and the variation of each thermal resistance with the given conditions is discussed. This paper also discusses the prediction accuracy of the two-resistor model and tries to explain the reasons for its prediction errors. It is found that thermal local resistance and thermal spreading resistances vary with condition differences and the variations result in differences in the microprocessor’s hot spot temperature.