Laser-weldable Sip-SiCp/Al hybrid composites with bilayer structure for electronic packaging
(College of Aerospace Science and Engineering, National University of Defense Technology, Changsha 410073, China)
Abstract: Laser-weldable Sip-SiCp/Al hybrid composites with high volume fraction (60%-65%) of SiC reinforcement were fabricated by compression moulding and vacuum gas pressure infiltration technology. Microscopic observation displayed that the Sip-SiCp/Al hybrid composites with bilayer structure were compact without gas pores and the intergradation between Sip/Al layer and SiCp/Al layer was homogeneous and continuous. Further investigation revealed that the Sip-SiCp/Al hybrid composites possessed low density (2.96 g/cm3), high gas tightness (1.0 mPa×cm3)/s), excellent thermal management function as a result of high thermal conductivity (194 W/(m×K) and low coefficient of thermal expansion (7.0×10-6 K-1). Additionally, Sip-SiCp/Al hybrid composites had outstanding laser welding adaptability, which is significantly important for electronic packaging applications. The gas tightness of components after laser welding (48 mPa×cm3)/s) can well match the requirement of advanced electronic packaging. Several kinds of these precision components passed tests and were put into production.
Key words: Sip-SiCp/Al hybrid composites; laser welding; thermo-physical properties; electronic packaging