Mentor Graphics

This paper covers the cooling analysis from conceptual design through detailed component analysis of predicting junction temperatures of critical components. Industrial grade components are housed in a card cage and have a temperature rating of 85°C. The software simulations indicate the local air in the cardcage has a temperature of 66 Deg C. Presented in this paper are the following: 1) The system level analysis of the card cage. 2) The use of a Computational Fluid Dynamics tool (Flotherm) which was used to simulate the heat transfer of the critical components using theta j-a (junction-to-ambient thermal resistance) and theta j-c (junction-to-case thermal resistance). 3) The effect that component density and the effect of a double-sided PCB will have on the temperature rating of a component.