Microstructure and properties of Cu matrix composites reinforced with surface-modified Kovar particles
(1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Key Laboratory of Electronic Packaging and Advanced Functional Materials, Central South University, Changsha 410083, China)
2. Key Laboratory of Electronic Packaging and Advanced Functional Materials, Central South University, Changsha 410083, China)
Abstract: The thermal conductivity of Cu/Kovar composites was improved by suppressing element diffusion at the interfaces through the formation of FeWO4 coating on the Kovar particles via vacuum deposition. Cu matrix composites reinforced with unmodified (Cu/Kovar) and modified Kovar (Cu/Kovar@) particles were prepared by hot pressing. The results demonstrate that the interfaces of Cu/FeWO4 and FeWO4/Kovar in the Cu/Kovar@ composites exhibit strong bonding, and no secondary phase is generated. The presence of FeWO4 impedes interfacial diffusion within the composite, resulting in an increase in grain size and a decrease in dislocation density. After surface modification of the Kovar particle, the thermal conductivity of Cu/Kovar@ composite is increased by 110% from 40.6 to 85.6 W·m-1·K-1. Moreover, the thermal expansion coefficient of the Cu/Kovar@ composite is 9.8×10-6 K-1, meeting the electronic packaging requirements.
Key words: electronic packaging material; Cu/Kovar composite; surface modification; thermal conductivity