Electronic package thermal design using boundary elements

The use of the boundary-element method (BEM) for thermal evaluation of electronic packaging systems is discussed. Over the last twenty years, computer-aided engineering analysts have relied heavily on the finite-element method (FEM) for solving a variety of problems. This includes 2-D and 3-D linear or nonlinear heat transfer models on IC packages. However, the BEM, which discretizes only the problem boundary, provides a potentially faster method of modeling a problem. For 3-D models, in particular, parametric variations on a particular design can be evaluated more rapidly. This decreasing turnaround time will become a priority in future analyses of more sophisticated VLSI (very large scale integration) or PGA (pin grid array) packages which require design optimization on size and space arrangement for higher power capacity. BEM thermal models of 2-D and 3-D PGA packages were studied using the computer code BEASY. BEM results were compared to those of FEM models. A 3-D benchmark problem with documented experimental data was modeled to verify the BEM results