Thermal Design Guidelines for FC-BGA Package With Hot Spot Problem

With the evolving function integration and power consumption of high-end IC applications, thermal management has become one of the most important concerns of semiconductor designers. In particular, hot spot problem, in recent years, has turned into a popular topic in IC chip thermal management that it comes from the uneven power consumptions in various logical blocks and results in local high temperature that would increase IC chip failure risks. In this paper, thermal evaluations for hot spot impacts on Flip-Chip Ball Grid Array (FC-BGA) packages were presented using CFD modeling technique. The evaluation topics covered hot spot power density effects on substrate designs and heat sink module characterizations including passive heat sink and fan heat sink performance under various hot spot conditions. Finally, thermal suggestions were concluded for package designers to improve the substrate design in substrate via arrangements to effectively dissipate hot spot source. Also heat sink module performance was derived for different ratings of hot spots and external heat sink performance is obtained for the hot spot impact elimination.