Microelectronic package including thermally conductive sealant between heat spreader and substrate

A microelectronic package. The package includes a substrate; a die mounted onto the substrate; an integrated heat spreader mounted onto the substrate, and thermally coupled to a backside of the die; and a sealant material bonding the integrated heat spreader to the substrate, the sealant material having a bulk thermal conductivity above about 1 W/m/° C. and a modulus of elasticity lower than a modulus of elasticity of solder.