Copper Particle Sintering for Low‐Temperature Electronic Joining: A Review of Materials Design and Processing Strategies

Low‐temperature copper (Cu) sinter‐bonding has emerged as a promising alternative for conductive layers in electronic parts and die‐attachment in power electronics packaging, particularly for packaging wide‐bandgap (WBG) semiconductors such as silicon carbide (SiC) and gallium nitride (GaN). WBG devices operate at higher temperatures and require bonding materials with superior thermal and mechanical properties. Compared to conventional soldering techniques, Cu sinter‐bonding offers enhanced electrical and thermal conductivity, better resistance to electrochemical migration, and lower material costs. However, challenges such as the oxidation of Cu particles, achieving optimal densification, and controlling processing conditions must be addressed for its widespread application. In this review, the mechanisms of Cu sinter‐bonding, key sintering parameters, and recent advances in Cu paste formulations, including surface modification, hybrid particle systems, and alloying with additional metals, are summarized. Optimization strategies for pressure, temperature, solvent, atmosphere, and substrate metallization to improve the performance of Cu joints are discussed in detail. The potential of Cu sinter‐bonding in next‐generation electronic packaging is analyzed, along with challenges and future research directions.