Algorithm for Prediction of the Thermal Resistance of Finned LSI Packages Mounted on a Circuit Board.

A study on the thermal resistance of finned LSI packages mounted on a circuit board is performed on a semi-empirical base. Based on the result of flow visualization, a physical model which is suitable for finned LSI packages mounted on a circuit board is developed. The recommended correlations obtained by modifying those for finned LSI packages in the free stream predict the thermal resistance of the LSI package very accurately. The estimation error is found to be within ±10% compared with experimental data. The thermal resistance of finned LSI packages in the downstream can be predicted with reasonable accuracy by considering the effect of thermal wake from the packages in the upstream on those in the downstream.