Thermal expansion-enhanced heat sink for an electronic assembly
A heat sink and method of fabrication are provided for removing heat from an electronic component(s). The heat sink includes a heat sink base and frame. The base has a first coefficient of thermal expansion (CTE), and includes a base surface configured to couple to the electronic component to facilitate removal of heat. The frame has a second CTE, and is configured to constrain the base surface in opposing relation to the electronic component, wherein the first CTE is greater than the second CTE. At least one of the heat sink base or frame is configured so that heating of the heat sink base results in a compressive force at the base surface of the heat sink base towards the electronic component that facilitates heat transfer from the electronic component. A thermal interface material is disposed between the base surface and the electronic component.
1. A method of fabricating a thermal expansion-enhanced heat sink comprising:
providing a heat sink base comprising a base surface configured to couple to a surface of a heat-generating electronic component to facilitate removal of heat from the heat-generating electronic component, the heat sink base having a first coefficient of thermal expansion;
providing a frame configured to couple to the heat-generating electronic component and constrain the base surface of the heat sink base in opposing relation to the surface of the heat-generating electronic component, the frame having a second coefficient of thermal expansion, wherein the first coefficient of thermal expansion of the heat sink is greater than the second coefficient of thermal expansion of the frame, and wherein at least one of the heat sink base or the frame is configured so that heating of the heat sink base expands the heat sink base relative to the frame and results in a force component at the base surface of the heat sink base towards the surface of the heat-generating electronic component that facilitates heat transfer from the surface of the heat-generating electronic component to the heat sink base; and
wherein providing the heat sink base comprises providing the heat sink base with an angled side surface sloping inward from the base surface of the heat sink base, and wherein providing the frame comprises providing the frame with an angled inner surface in opposing relation to the angled side surface of the heat sink base, and wherein heating of the heat sink base expands the heat sink base, forcing the angled side surface of the heat sink base against the angled inner surface of the frame, and thereby producing the force component at the has surface of the heat sink base towards the surface of the heat-generating electronic component that facilitates heat transfer from the surface of the heat-generating electronic component to the heat sink base.
2. The method of claim 1 , further comprising coupling the thermal expansion-enhanced heat sink to the heat-generating electronic component and providing a thermal interface material disposed between the base surface of the heat sink base and the surface of the heat-generating electronic component, wherein heating of the heat sink base increases compressive loading on the thermal interface material disposed between the base surface of the heat sink base and the surface of the heat-generating electronic component, which facilitates heat transfer from the surface of the heat-generating electronic component to the heat sink base across the thermal interface material.
3. The method of claim 1 , wherein the heat-generating electronic component further comprises a module cap, and the frame is configured to affix to the module cap of the heat-generating electronic component, and wherein the frame encircles the heat sink base.
4. The method of claim 1 , further comprising providing a plurality of air-cooled fins extending from the heat sink base for removing heat from the heat sink base.
5. The method of claim 1 , further comprising providing a liquid-cooled cold plate coupled to the heat sink base for removing heat from the heat sink base.
6. The method of claim 1 , wherein the heat sink base comprises copper, and the frame comprises at least one of steel, molybdenum or aluminum-silicon carbide.