A multi-layer thermal interface structure for placement between a microelectronic component package and a heat sink so that the structure has a total thermal resistance of no greater than about 0.03 C.-in²/W. The structure comprises a plurality of superimposed metallic layers including a core layer of a solid metal or metal alloy of high thermal conductivity preferably composed of aluminum or copper, a second layer having phase change properties and a third layer of nickel separating the solid metal layer from the layer having phase change properties.