With high-power devices moving towards high voltages, currents, and miniaturization in high-power devices, thermal demands become increasingly stringent. Ceramic substrates are extensively utilized in packaging high-power devices due to their superior thermal conductivity and mechanical robustness. This paper comprehensively reviews the preparation methods, performance characteristics, and research advancements of high thermal conductivity ceramics such as Al₂O₃, SiC, AlN, and Si₃N₄, exploring their compositional influences on thermal conductivity. Subsequently, the article provides detailed insights into metallization technologies including direct copper deposition, copper bonding, reactive metal welding, laser reactive metallization, and thick copper printing, highlighting current challenges and limitations. Finally, the paper offers prospects on the future development of diverse ceramic substrates and their metallization processes.

A number of CaHfO₃ modified BiFeO₃-0.33BaTiO₃ (BF-0.33BT-xCH) lead-free piezoceramics were fabricated through the solid-state sintering method and comprehensively investigated in this work. Under the optimal sintering temperature, all compositions display a typical perovskite structure in a pseudo-cubic phase with slightly larger lattice parameters as the CH content increases. The electrical resistivity is highly enhanced due to the addition of CH. Microstructures, including the grain morphology, core-shell structure, and chemistry inhomogeneities, are demonstrated upon different BF-0.33BT-xCH compositions. In particular, the core-shell structures with non-uniform element distributions in the compositions can be eliminated by adding sufficient CH content (x > 0.05). The highest saturation polarization (40.1 μC/cm²), remnant polarization (26.8 μC/cm²), and converse piezoelectric coefficient (290 pm/V) are achieved in the BF-0.33BT-0.01CH piezoceramic, which are significantly enhanced in comparison with the undoped BF-0.33BT piezoceramic. With further increasing the CH content, the piezoelectric properties of BF-0.33BT-xCH ceramics decline rapidly, and they start to exhibit characteristics of relaxor ferroelectrics.