Thermal characterization of cavity-down TBGA package with Flotherm simulation

This paper presents the use of the finite volume analysis method in predicting thermal performance of a TBGA (Tape Ball Grid Array) package in a package level and in a board level, respectively. The effect of heat spreader thickness is also analyzed and the results show that the larger the thickness, the lower the junction temperature. However, it is also shown that more than 75% of heat dissipation is conducted away through solder balls rather than the heat spreader. The thermal performance of a TBGA package mounted on a real graphic card is next analyzed in the board level and the results are compared with two PBGA packages. With other heat sources around the package on the graphic card, the corresponding junction temperatures increase dramatically. The thermal performance of the TBGA is superior to that of both PBGAs. The results also show that a heat sink module attached on the top of the package can further improve the thermal performance of the TBGA package