Tailoring the thermal conductivity of boron nitride-based materials through microstructural and architectural design for thermal management applications

The escalating power density of modern electronics has intensified the demand for thermal interface materials (TIMs) that simultaneously deliver high thermal conductivity and reliable electrical insulation. Hexagonal boron nitride (h-BN) has emerged as a leading filler candidate; however, its practical performance remains constrained by interfacial phonon scattering and insufficiently interconnected conduction pathways. This review adopts a multi-scale structure–heat-transport perspective, systematically correlating BN microstructure, mesoscale orientation control via force, magnetic, and electric fields as well as freeze-casting, and three-dimensional thermal network construction with macroscopic thermal and mechanical performance. The discussion critically examines the extent to which interfacial bonding can be quantitatively correlated with interfacial thermal resistance (ITR), how vertical alignment can be reconciled with increasing filler loading, and whether oriented architectures can be scaled up without compromising structural integrity. This long-standing yet unresolved issues are shown to underlie the persistent gap between laboratory-scale thermal conductivity and device-level heat dissipation. Applications in the cooling of state-of-the-art electronic devices are highlighted, positioning BN-based materials as indispensable for next-generation thermal management.