Cu-based composites prepared by powder metallurgy for thermal management of electronic devices

Thermal aspects are becoming increasingly important for the reliability of the electronic components due to the continuous progress of the electronic industries such as the higher output power and the higher level of integration of ICs. To achieve long life and reliable performance of these components, it is necessary to keep the operating temperature of the electronic device within specified limits. Therefore, the effective thermal management is a key issue for packaging of high performance semiconductors. The ideal thermal management material working as heat sink and heat spreader should have a CTE (coefficient of thermal expansion) of 4 ppm/K to 8 ppm/K and a high thermal conductivity. The aim of this work is the development of copper matrix composites reinforced with diamond or SiC in order to obtain a composite material having a thermal conductivity higher than 400 W/mK in case of copper/diamond or higher than 300 W/mK in case of Cu/SiC. The Cu-based composites reinforced with diamond or SiC particles were fabricated by a powder metallurgical method (powder mixing with subsequent pressure assisted consolidation). In order to design the interfacial behaviour between copper and the reinforcement different alloying elements were added to the copper matrix or coated powders were used in case of SiC. The thermophysical properties will be displayed and discussed as a function of the reinforcements as well as the alloying element used for composite preparation. The differences between coated and uncoated powders will be discussed