A heat-dissipating interposer includes an insulating base, a plurality of conductive pillars and a thermal conducting frame. The insulating base includes a first surface and an opposite second surface. The conductive pillars are arranged on the insulating base. The conductive pillars protrude from the second surface. The height of the conductive pillars relative to the second surface is greater than the thickness of the insulating base. The thermal conducting frame is placed on the second surface and receives a heat-generating component. The interposer can be used in a package on package structure.