Construction of novel plate-shaped 4H–SiC network skeleton for enhancing 3D-interpenetrated network structure SiC/Al composites

In this study, a robust 3D-SiC network skeleton composed of strongly bonded plate-shaped 4H–SiC through mutual interactions was constructed by inducing phase transformation from 6H–SiC into plate-shaped 4H–SiC via doping B4C at 2250 °C. Further, 3D-interpenetrated network structured SiC/Al (SiC3D/Al) composites for electronic packaging were manufactured by vacuum-pressure infiltration of Al alloy into 3D-SiC network skeleton. Effects of different contents of plate-shaped 4H–SiC as 3D network skeleton on thermal conductivity (TC), coefficient of thermal expansion (CTE), and flexural strength of the SiC3D/Al composites were systematically studied. Results showed that composites with optimal properties were characterized by excellent flexural strength of 306.25 MPa, low CTE of 4.95 × 10−6/K, and high TC of 235.14 W m−1 K−1. Moreover, the composite displayed low thermal deformation parameter (TDP) of 0.021 comparable to that of semiconductor material Si, highlighting its excellent thermal stability. This unique property allowed the composite to achieve well-compatible effect of high TC and low CTE and thus occupied isolated position in the Ashby plot. Integration of multiple thermal functions and mechanical properties was mainly achieved through the synergistic effect of clean well-bonded interface and complete 3D network skeleton. This technique offers a new approach to the design and synthesis of SiC/Al composites for electronic packaging with scalable and tunable properties.