A 
heat sink in a 
heat transfer relationship with a substrate such as an integrated 
chip, 
chip carrier, or other electronic 
package. The 
heat sink is connected to a frame which is connected to a 
printed circuit board or other suitable support on which the substrate is positioned. The 
heat sink, which extends through an aperture in the frame is coupled to a surface of the substrate. The heat sink is mechanically decoupled from the substrate. Large heat sinks may be thermally connected to surface 
mount substrates mounted using technologies such as 
ceramic ball or column grid arrays, plastic ball or column grid arrays, or solder balls or columns. The heat sink is attached coaxially through the aperture to the substrate. After 
assembly and lead / 
tin or other metallic surface 
mount interconnects are relaxed such that the substrate and is completely supported by the frame and the heat sink imparts zero or nearly zero downward force. Because the heat sink moves freely within the aperture during 
assembly, the heat sink 
package is useful for a variety of different substrates. Preferably, the frame is a plate and a plurality of studs. The plate material are selected to match the 
thermal expansion of the underlying support, and the stud material matched the 
thermal expansion of the substrate. Thus, the frame construction allows matching expansion and contraction of the 
assembly to the underlying substrate and support.