Sintered metal alloy and composite as bonding materials for electronics applications

Sintered silver (Ag) offers excellent thermal and mechanical properties for high-temperature electronic packaging but faces adoption barriers due to high cost and electrochemical migration. Sintered copper (Cu), a cheaper alternative, is limited by its oxidation susceptibility. To overcome these issues, recent research explores the combination of Ag- and Cu-based sintering to leverage the benefits of both metals. The technology can be further enhanced with functional additives, sometimes combined with intermetallic-based transient liquid phase sintering strategies. This review critically examines their synthesis methods, mechanical performance, and processing challenges, with a particular focus on key properties such as shear strength, thermal conductivity, and electrical resistivity. The benefits of Ag–Cu based sintered joints, especially their superior thermal performance and mechanical robustness, are highlighted. Additionally, combining Ag and Cu in sinter pastes enhances oxidation resistance through the thermal stability of Ag and improves structural reliability by leveraging mechanical strength and cost-effectiveness of Cu. Ultimately, this review provides insights into the potential of sintered Ag–Cu metal interconnect as high-performance and lead-free bonding materials.