Numerical and experimental investigation of a tape ball grid array package

The study aims to investigate the numerical (CFD) modeling of a 35 mm square body size 352-pin Tape Ball Grid Array (TBGA) Package, and the experimental validation of the same. The impact on the numerical model of various parameters is considered, including the spreader plate shape, the die-to-package interconnect, tape/trace layer, and the solder balls. It is shown that the TAB ILB (inner lead bond) and trace layer do have an impact on the accuracy of the model due to the high thermal resistance of the die attach material used. The conclusions from the sensitivity study are used to define the final numerical model for the 352 TBGA. This model is then simulated for three environmental conditions (natural convection and forced convection at 1 and 2 m/s) on a 4-layer test board. Finally, a 2-resistor compact model of the 352 TBGA is created based on the computational equivalent of the JEDEC standard approach. The performance of the 2-Resistor model is compared to the detailed model.