A package on packaging structure comprising a first package and a second package provides for improved thermal conduction and mechanical strength by the introduction of a thermally conductive substrate attached to the second package. The first package has a first substrate and a first integrated circuit. The second package has a second substrate containing through vias that has a first coefficient of thermal expansion. The second package also has a second integrated circuit having a second coefficient of thermal expansion located on the second substrate. The second coefficient of thermal expansion deviates from the first coefficient of thermal expansion by less than about 10 or less than about 5 parts-per-million per degree Celsius. A first set of conductive elements couples the first substrate and the second substrate. A second set of conductive elements couples the second substrate and the second integrated circuit.