Recent Advances in Thermal Metamaterials and Their Future Applications for Electronics Packaging

Abstract
Thermal metamaterials exhibit thermal properties that do not exist in nature but can be rationally designed to offer unique capabilities of controlling heat transfer. Recent advances have demonstrated successful manipulation of conductive heat transfer and led to novel heat guiding structures such as thermal cloaks, concentrators, etc. These advances imply new opportunities to guide heat transfer in complex systems and new packaging approaches as related to thermal management of electronics. Such aspects are important, as trends of electronics packaging toward higher power, higher density, and 2.5D/3D integration are making thermal management even more challenging. While conventional cooling solutions based on large thermal-conductivity materials as well as heat pipes and heat exchangers may dissipate the heat from a source to a sink in a uniform manner, thermal metamaterials could help dissipate the heat in a deterministic manner and avoid thermal crosstalk and local hot spots. This paper reviews recent advances of thermal metamaterials that are potentially relevant to electronics packaging. While providing an overview of the state-of-the-art and critical 2.5D/3D-integrated packaging challenges, this paper also discusses the implications of thermal metamaterials for the future of electronic packaging thermal management. Thermal metamaterials could provide a solution to nontrivial thermal management challenges. Future research will need to take on the new challenges in implementing the thermal metamaterial designs in high-performance heterogeneous packages to continue to advance the state-of-the-art in electronics packaging.