V. H. Adams
D. L. Blackburn
Computational fluid dynamics (CFD) simulations are
performed for a Plastic Quad Flat Package (PQFP) in the JEDEC recommended
enclosure for thermal measurements in a natural convection environment to
assess the impact of compact thermal modeling strategies on solution run
time. The effect of package die and pad size, relative to the package
dimensions are also examined to determine their effect on the adequacy of
the predicted thermal behavior from these compact thermal models.
Simulation results using a simple block on lead model and a thermal
resistance model are compared to those from a detailed model of the
package. The results show that die size has a predominate effect on
temperature predictions form compact models. For large die size, where
heat transfer is more one-dimensional in nature, these compact models
adequately predict the thermal behavior of the electronic package.