Exploring Heatpipe Configurations for Package On Package (PoP) Cooling

摘要

Package on package (PoP) is commonly used in handheld devices to save board area. This configuration has the memory package sitting on top of the System on Chip (SOC) package. However, this package configuration poses challenge for thermal cooling of the SOC, as the memory package considerably increases the thermal resistance from the top of the SOC to the thermal solution over the package. In mobile systems, heat pipes are commonly used as thermal solution to transfer heat away from the SOC to remote heat spreaders or heat sinks. Heat pipes are known for their high effective thermal conductivity. Heat pipes are normally attached to the top of a package. Since there is additional thermal resistance on top of the SOC in a PoP configuration, we tried a novel idea to attach a heat pipe behind the PCB, below the package, and check the comparative heat transfer benefits. A single-sided PCB configuration is required for this thermal solution.