Interposer package-on-package (PoP) with solder array thermal contacts

A computing system, comprising:

• a printed circuit board (PCB);
• and an electronics package assembly attached to the PCB, wherein the electronics package assembly comprises:
• a die embedded in a mold layer, wherein a surface of the die is coplanar with a surface of the mold layer;
• a thermal interface pad on a surface of the die and on a surface of the mold layer;
• solder balls over the thermal interface pad;
• and an underfill material laterally surrounding the thermal interface pad and the plurality of solder balls;
• and an interposer over the mold layer, wherein the solder balls are in contact with the interposer, wherein the interposer comprises a plurality of thermal pathways, wherein each thermal pathway contacts one of the solder balls, and wherein the thermal pathways comprise heat dissipation traces or a heat dissipation pad formed over a surface of the interposer facing away from the die.

A method of forming an electronics package assembly, comprising:

• mounting a die to a package;
• disposing a mold layer over the die;
• recessing the mold layer to expose a surface of the die;
• disposing a thermal pad on the exposed surface of the die and on a surface of the mold layer;
• disposing solder balls over the thermal pad;
• forming an underfill material laterally surrounding the thermal interface pad and the plurality of solder balls;
• and
• attaching an interposer to the mold layer, wherein the solder balls contact the interposer, and wherein the solder balls are electrically isolated from circuitry of the electronics package;
• and
• attaching a second package to the interposer.