Abstract
As three-dimensional (3D) nanopackaging continues to drive miniaturization and functional integration in high-performance microelectronics, severe thermal management challenges arise from localized high heat fluxes and transient thermal surges. Traditional thermal interface materials and composite phase change materials (PCMs) often suffer from limited thermal conductivity due to randomly dispersed conductive fillers. Here, we report an advanced dual-functional thermal dissipation composite based on vertically oriented hexagonal boron nitride nanosheet (BNNS) aerogels impregnated with a paraffin-based phase change material. Utilizing a directional freeze-casting technique followed by vacuum-assisted infiltration, a continuous 3D thermally conductive BNNS framework with minimal interfacial thermal resistance was constructed. The resulting oriented BNNS/PCM composite exhibits an extraordinary out-of-plane thermal conductivity of 5.12 W/m·K at a low BNNS loading of 8.5 vol%, representing a 2100% enhancement compared to pure paraffin. Furthermore, the composite demonstrates a robust latent heat storage capacity of 142.6 J/g and outstanding shape stability over 200 thermal cycles. Transient thermal response testing under simulated 3D nanopackaging conditions reveals that the oriented BNNS/PCM composite effectively dampens thermal spikes, lowering peak operating temperatures by up to 18.4 °C during high-power load surges. This work offers a promising strategy for engineering smart, high-efficiency thermal management solutions tailored for next-generation 3D microelectronic packaging.
