Exploring the process-microstructure-thermal properties relationship of resin-reinforced Ag sintering material for high-power applications via 3D FIB-SEM nanotomography

• Published in: Materials & design Vol. 244; p. 113185
• Main Authors: Hu, Xiao, Martin, Henry Antony, Poelma, René, Huang, Jianlin, van Rijckevorsel, Hans, Scholten, Huib, Smits, Edsger, van Driel, Willem D., Zhang, Guoqi
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.08.2024; Elsevier
• Subjects: 3D FIB-SEM nanotomography; Effective thermal conductivity; Geometric tortuosity; High-power application; Thermal percolation phenomenon; Transient thermal impedance; Geometric tortuosity; High-power application; Effective thermal conductivity; Thermal percolation phenomenon; 3D FIB-SEM nanotomography; Transient thermal impedance
• ISSN: 0264-1275
• DOI: 10.1016/j.matdes.2024.113185

Resin-reinforced Ag sintering materials represent a promising solution for die-attach applications in high-power devices requiring enhanced reliability and heat dissipation. However, the presence of resin and intricate microstructure poses challenges to its thermal performance, and improvement strategies remain unclear. This work utilizes 3D FIB-SEM nanotomography to reconstruct the microstructure of this material under various process conditions. The analysis reveals that, even with an Ag volume fraction as low as 47.3%, Ag particles form a robust 3D network. Geometric tortuosity quantifies the effect of different sintering conditions on the Ag particle network in all spatial directions. Effective thermal conductivity is simulated based on realistic microstructure models. Results show a significant negative correlation between tortuosity and effective thermal conductivity. Increasing sintering temperature in Model B notably reduces tortuosity and enhances effective thermal conductivity. Sensitivity analysis underscores the dominant role of Ag volume fraction in regulating effective thermal conductivity. Finally, transient thermal impedance measurement of this material as a thin die-attach layer in actual high-power devices demonstrated its application potential. This article strives to explore the relationship between process, microstructure, and thermal properties of this material to provide a reference for further development. •3D FIB-SEM nanotomography meticulously reconstructed and distinguished the microstructure under different process conditions.•Effective thermal conductivity is simulated from a realistic microstructure model using a high-performance cluster.•Tortuosities intuitively reflects the influence of process conditions on the microstructure and thermal properties.•Sensitivity analysis shows the dominant role of Ag volume fraction on the effective thermal conductivity.