Embodiments may relate to a microelectronic package that includes a die coupled with a package substrate. A plurality of solder thermal interface material (STIM) thermal interconnects may be coupled with the die and an integrated heat spreader (IHS) may be coupled with the plurality of STIM thermal interconnects. A thermal underfill material may be positioned between the IHS and the die such that the thermal underfill material at least partially surrounds the plurality of STIM thermal interconnects. Other embodiments may be described or claimed.