Dynamic Energy-Dissipating Interface Design Reconciles Thermal Performance with Interfacial Reliability

Abstract

Highly filled thermal interface materials (TIMs) are essential for reliable heat dissipation in high-power electronics, yet restricted polymer chain mobility and reduced interfacial conformability make it difficult to achieve high thermal conductivity, strong adhesion, and crack-growth resistance simultaneously. We propose a dynamic energy-dissipating interface (DEDI) strategy that coordinates favorable interfacial affinity, stable chemical anchoring, and dynamic bulk energy dissipation to improve interfacial stability and crack resistance in highly filled TIMs. γ-Methacryloxypropyl trimethoxysilane (γ-MPS) provides stable chemical anchoring at the substrate interface, while urethane-associated polar interactions contribute to favorable interfacial affinity. Reversible disulfide and hydrogen-bond interactions within the bulk network promote deformation accommodation and mechanical energy dissipation. Surface-modified Al2O3/ZnO hybrid fillers form a multiscale network that provides efficient heat-transfer pathways. The resulting PSM-60-1.2 exhibits a thermal conductivity of 3.88 W·m−1·K−1, an adhesion strength of 4.25 MPa, and an adhesion energy of 3080.04 J·m−2. Combined experimental and finite-element analyses support coordinated interfacial stabilization, bulk energy dissipation, and enhanced thermomechanical deformation accommodation. After 100 thermal shock cycles between −40 and 150 °C, PSM-60-1.2 shows a 6.0 °C increase in maximum steady-state temperature, compared with 16.2 °C for the commercial thermally conductive adhesive, with less interfacial cracking and low-viscosity liquid infiltration. The DEDI design offers a molecular strategy for combining high thermal conductivity, high adhesion energy, and long-term thermomechanical reliability in highly filled TIMs.