Thermal solutions for package on package (PoP) architectures

Embodiments disclosed herein include electronic packages with improved thermal performance. In an embodiment, the electronic package comprises a first package substrate, a first die stack over the first package substrate, and a heat spreader over the first die stack. In an embodiment, the heat spreader comprises arms that extend out past sidewalls of the first package substrate. In an embodiment, the electronic package further comprises an interposer over and around the heat spreader, where the interposer is electrically coupled to the first package substrate by a plurality of interconnects. In an embodiment, the electronic package further comprises a second package substrate over the interposer, and a second die over the second package substrate.