A Comparative Study of the Performance of Compact Model Topologies and Their Implementation in CFD for a Plastic Ball Grid Array Package

Abstract

A detailed model of a die-up 256-pin Plastic Ball Grid Array (PBGA) package was created and validated against experimental data for natural convection and forced convection environments. Next, four compact models were derived; two two-resistor models (one created through a two-point computational cold plate test; the other using the DELPHI optimization approach), a multi-resistor Star network model and a shunt network model. The latter three models were derived using the methodology established by the DELPHI (Development of Libraries of Physical models for an Integrated design environment) project. The four compact models and the detailed model were each placed in natural convection and forced convection (velocities of 1,2, and 4 m/s) environments. Good agreement was obtained for the die-junction temperature rise for both the detailed and the shunt compact models. The star and two-resistor models were seen to be inferior in terms of accuracy. The two-resistor model created using the DELPHI methodology was found to be superior compared to the one created with the computational cold-plate test. The star model showed little gain in performance as compared to the DELPHI two-resistor model.