Nanoengineered materials have emerged as efficient thermal interface materials in a variety of thermal management applications. For example, integrated circuits (IC) are subject to tight thermal budgets to maintain acceptable reliability standards. This letter presents thermal contact resistance measurement results and analyses for copper gap-filled carbon nanofiber−copper composite arrays. Experimental results demonstrate the efficient interfacial thermal conduction of these structures. Using copper as a gap-fill material for improving lateral heat spreading and mechanical stability is discussed.