Large-area metal sinter-joining in power electronics packaging: challenges and perspectives

Abstract

With the rapid development of emerging fields such as new energy vehicles, smart grids, and aerospace, the operating temperature and current density of power devices continue to increase, placing higher demands on the thermal conductivity, reliability, and high-temperature performance of joining materials. Owing to its excellent electrical and thermal conductivity, low-temperature joining capability, and high-temperature service reliability, metal paste sinter-joining technology has emerged as one of the most promising joining approaches for power electronics packaging. At present, this technology has achieved remarkable progress in small-area joining applications. However, when applied to large-area joining, issues such as delamination of the sintered joints and structural warpage readily arise, severely threatening the integrity and long-term stability of the packaging structure. This review provides a systematic summary of recent advances in large-area sinter-joining using metal pastes, clarifies the mechanisms underlying delamination and warpage, and highlights mainstream strategies for mitigating these issues, including solvent-free materials, incorporation of materials with different coefficients of thermal expansion (CTE), patterned printing, low-temperature sintering, and gradient porosity design. These insights offer theoretical support and technical guidance for further improving joint performance and service reliability. Additionally, the review summarizes the reliability evaluation methods for large-area sintered joints and discusses the key challenges and prospects for their practical applications.