The interface in molybdenum-copper-composites used for thermal management applications

Molybdenum-copper-composites are interesting materials in the field of thermal management of gallium nitride based electronic devices. Depending on the application and packaging requirements, the coefficient of thermal expansion and thermal conductivity can be tailored for these composites by varying structure and composition. In this work, the interface between molybdenum and copper is studied. Transmission electron microscopy shows a sharp interface between the molybdenum and copper layers without interdiffusion zone. The low thermal contact resistance between the layers also suggests that there is sharp interface between molybdenum and copper. The electrical resistivity was measured and compared to estimations based on the Wiedemann-Franz law.