Interface regulation of micro-sized sintered Ag-10Al composite based on in-situ surface modification and enhanced microstructure stability in power electronic packaging

• Published in: Materials & design Vol. 240; p. 112863
• Main Authors: Huo, Fupeng, Chen, Chuantong, Zhang, Zheng, Wang, Ye, Suetake, Aiji, Takeshita, Kazutaka, Yamaguchi, Yoshiji, Momose, Yashima, Suganuma, Katsuaki
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.04.2024; Elsevier
• Subjects: In-situ TEM; Interface; Microstructure; Reliability; Sintered Ag-Al composite; Surface modification; Surface modification; Microstructure; Reliability; Sintered Ag-Al composite; Interface; In-situ TEM
• ISSN: 0264-1275; 1873-4197
• DOI: 10.1016/j.matdes.2024.112863

[Display omitted] •Ultrafine Ag nanoparticles ejection phenomenon of micron Ag flake is observed for the first time by in-situ TEM.•In-situ surface modification of Al particles in sintered Ag-Al composite is completed via Ag nanoparticles ejection phenomenon.•A specific Ag/nano Ag2O/Al2O3 amorphous/Al composite interface structure was formed via mutual dissolution at the atomic level.•Shear strength of sintered Ag-10Al joint reached 34.1 MPa after 1000 h aging, meeting the requirements for power semiconductor packaging. The increasing demand for high-power SiC semiconductors necessitate the development of a die attachment material that combines high-temperature resistance, reliability, and cost-effectiveness. In this study, a novel micro-sized composite, Ag-10Al paste, containing 10 wt% Al particles, was designed. A remarkable phenomenon, the ejection of ultrafine Ag nanoparticles from micron-sized Ag flakes, was observed for the first time. The phenomenon was utilized for the in-situ surface modification of Al. Subsequently, the microstructure and mechanical properties of the sintered Ag-10Al/direct bonded copper (DBC) joints were studied. Results indicated that the Ag-10Al composite exhibited superior microstructure stability compared to sintered Ag. The Ag/Al interface was systematically analyzed, revealing a unique Ag/nano Ag2O/Al2O3 amorphous/Al structure. This structure was formed through the Ag nanoparticle jetting effect of Ag flakes, achieving effective bonding between nano Ag2O and Al2O3 amorphous phases through mutual dissolution at the atomic level. Moreover, the sintered Ag-10Al joint demonstrated enhanced mechanical performance stability over the sintered Ag joint. After 1000 h aging at 300 ℃, the shear strength of the sintered Ag-10Al joint reached 34.1 MPa, meeting the requirements for power semiconductor packaging. In conclusion, the Ag-10Al composite paste was thoughtfully designed, excelling in both performance and cost-effectiveness.