Interface-Driven Thermodynamic Behavior in Cu/Mo/Cu Laminated Composites via Interface Design

Cu-Mo laminated composites possess low thermal expansion and high thermal conductivity, making them ideal materials for electronic packaging heat sinks. The Cu/Mo interface plays a critical role in governing the stress-strain distribution and thermophysical properties of the composites. In this study, a finite element model incorporating an interface transition layer was developed to investigate interface effects on stress-strain behavior and thermal performance through combined simulation and experimental validation. The results show that introducing an interface layer improves prediction accuracy, highlighting the key role of interface effects in regulating stress distribution and thermal expansion. When the Mo layer volume fraction is 30%, the thermal expansion coefficient of the composite with an interface layer is reduced by 0.0177 × 10⁻⁶/°C compared to that without an interface layer. Further analysis of structural parameters indicates that the layer thickness ratio exerts the most pronounced influence on thermal performance. Compared with the copper matrix, a Cu/Mo/Cu composite with a total thickness of 0.6 mm, three layers, and a thickness ratio of 1:4:1 exhibits an approximately 49.5% reduction in thermal expansion coefficient. The model accuracy was verified by experimental results, providing insights into the design of laminated composites with interface transitions.