Thermal characterization of vias using compact models

Thermal vias & balls are key elements in Plastic Ball Grid Array (PBGA) pac kage thermal design as they enhance the performance of the package. Simulat ion is a versatile design optimization tool in characterizing the thermal v ias & balls. However, the finer geometric details of the vias require exces sive memory and modeling & simulation time. Different modeling concepts are being attempted in the industry to include finer geometries in the package . This paper shows the methodology of developing compact thermal via models and validating the same with detailed models. The accuracy of compact ther mal via models with respect to the detailed models has been determined usin g PBGA 352 as the test vehicle. It is found that the accuracy is within 3%. The simulation models of PBGA 352 have been validated by measurements and found that the accuracy of model is within 10%. Two and four layer PBGA352 with different via configurations have been characterized with compact ther mal via models and design guidelines for PBGA352 package have been obtained .