Keywords: CNS, Carbon nanostructure, nanotube
Summary:We present a suite of heat dissipating solutions based on a platform of polymer encapsulated vertically aligned carbon nanotube (VACNT) arrays, with the nanotubes covalently anchored to metal foils. The resultant technology is a thermal pad with tunable properties that leverage the unique mechanical, electrical and thermal properties of the underlying VACNT arrays. When used as a thermal interfacing solution, the array of nanotubes provide billions of high thermal conductivity contact points, enhanced by specially chosen polymers that reduce contact resistance at the tube to surface intersection. The mechanics of the array provide for a material that provides elastic compression on the macroscale while the individual nanotubes can freely move along the asperities of the surface, effectively “wetting” the surface like a liquid. While the thermal solution can flow like a liquid at the free tips, the covalent bond between the CNTs and the metal foil substrate, combined with the polymer encapsulant provide a robust anchoring of the array that ensure that the solution never pumps out, collapses or otherwise degrades in operation, even when exposed to stress like thermal cycling, or mechanical shock and vibration. In application, the combination of these unique properties provide numerous advantages. The material can accommodate contact pressures across the potential operating pressure ranges seen in electronics systems (as well as many other applications); ranging from >1,000 psi (for example, seen close to bolts in gasketed joints) to < 2 psi (seen in systems with low allowable clamping pressures like bare die assemblies). Furthermore, excellent elastic recovery after compression of the composite delivers a product that can be easily reworked with no loss in performance between rework operations. All together, the combination of features delivers a solution that delivers not only world class thermal performance, but also significantly improved user experience, reliability, and flexibility compared to other materials in its class.