TECHNICAL FIELD

Embodiments of the disclosure are in the field of electronics packaging and, in particular, to structures that provide improved heat transfer away from embedded inductors or any other heat source in a package substrate.

BACKGROUND

Due to increased CPU currents, power dissipated due to conduction loss in package integrated inductors for integrated voltage regulators (IVRs) is causing local package substrate temperature to exceed reliability limits. Power from these air core inductors (ACIs) is dissipated in all of the traces of the ACIs including the backside package layers. The heat path from the inductor is up through the front-side layers of the package to bumps (e.g., C4 bumps), and ultimately to the die and any thermal solution attached to the die. However, the thermal pathway has a high thermal resistance due to high thermal resistivity of the organic material in the package substrate. As such, the inductor is not able to transfer heat adequately. An ACI operating in a package, therefore, has a finite capacity to carry current at a given maximum substrate temperature. If the temperature of the substrate is lowered, the ACIs can carry more current. This improved current capacity will allow for systems to have improved performance.

