Evaluation of Thermal Characteristics of Board-level High Performance Flip-chip Package Equipped with Vapor Chamber as Heat Spreader

Thermal analysis was performed in this work to compare the thermal performance of a board-level high performance flip-chip ball grid array package equipped with solid Cu or vapor chamber (VC) as the heat spreader and Al-filler gel or In solder as the thermal interface material (TIM). The effect of different heat source sizes was also examined. Numerical results indicate that for the particular test vehicle under a power dissipation of 160 W, the thermal performance is remarkably enhanced by switching TIM from Al-filler gel to In solder while the enhancement by using VC instead of solid Cu heat spreader is only observable when In solder is incorporated. Moreover, the performance of VC gradually enhances then retards as the heat source size decreases. The retardation can be attributed to the more dominant role of die in heat dissipation when the heat source size gradually shrinks.