Bumpless build-up layer package including an integrated heat spreader

A system, comprising:

• a microelectronic die having an upper die surface, a lower die surface parallel to the upper die surface, and a die side, the microelectronic die including an active region and an inactive region;
• a heat spreader having an upper heat spreader surface, a lower heat spreader surface parallel to the upper heat spreader surface, and at least one heat spreader side, the heat spreader disposed on the lower surface of the microelectronic die in thermal communication with the inactive region of the die and electrically insulated from the active region;
• an encapsulation material encapsulating the die side and the heat spreader side and upper heat spreader surface, the encapsulation material including an upper surface substantially parallel to the upper die surface and a lower surface substantially parallel to the lower die surface, wherein the encapsulation material defines a lower encapsulation material opening in the lower surface with the lower die surface exposed through the lower encapsulation material opening, wherein the heat spreader defines a heat spreader opening in the lower surface with the lower die surface exposed through the lower encapsulation material opening, wherein at least one electrical interconnect extends through the heat spreader opening and is coupled to through vias of the microelectronic die along the lower die surface, the electrical interconnects coupling a second die to the microelectronic die;
• a plurality of build-up layers disposed on the upper surface of the encapsulation material;
• and
• a plurality of conductive traces disposed on the build-up layers and in electrical communication with the active region;
• and
• dynamic random-access memory coupled to the microelectronic die.