Thermal management of packages with 3D die stacking

The objective of thermal design requirement for 3D stacked die package is to maintain the junction temperatures of active devices in the package at or below specified limits. In this paper, die-to-die thermal resistance is identified as the key bottleneck in 3D thermal management, and two solution paths are proposed: fully-populated thermal bump array and thermally conductive underfill materials. The sensitivity of the thermal bump array design and the effective thermal conductivity of underfill materials will be discussed.