The Application of Low-temperature Copper Sintering in Power Devices of New Energy Vehicles

Abstract

With the growing demand for high-reliability, lead-free interconnection materials in power devices for new energy vehicles and related fields, copper particle sintering has emerged as a viable solution. This study presents a systematic analysis of copper sintering technologies at the micro, nano, and bimodal scales. Micro-copper particles provide economic advantages and mechanical stability but require high-temperature processing and specific atmospheric conditions, which limit their energy efficiency. Nano-copper particles, by contrast, offer superior low-temperature sintering due to their high surface energy and uniform morphology. However, they face challenges such as oxidation, high synthesis costs, and limited industrial validation. Bimodal copper systems, combining micro- and nano-sized particles, strike a functional balance by reducing sintering temperature and enhancing bonding strength while maintaining reasonable cost and structural integrity. Despite their potential, issues related to mixing uniformity and oxidation control remain unresolved. The paper concludes that although each copper system presents distinct benefits, no single approach fully meets all practical demands. Future development should prioritize the integration of particle design, atmosphere-independent sintering, and performance optimization to support scalable, cost-effective applications in power electronic packaging.