Rapid formation of Cu–Cu joints with high shear strength using multiple-flocculated Ag nanoparticle paste
- 34 Downloads
A new type of Ag nanoparticle (NP) paste for rapid sintering was prepared by controlling the thickness of the NP capping agent. The Ag NP paste was combined with a rapid thermo-compression (RTC) method to form a reliable Cu–Cu joint. The shear strengths of the Cu/Ag NP/Cu joints were 46.8 MPa and 90.7 MPa after sintering at 300 °C for only 5 s and 20 s, respectively. The sintering sequence phenomenon was observed, and the differences in microstructure between the pressure-assisted and pressureless joints were investigated. Robust bonding at the lattice level between the Ag NPs and Cu substrate was observed by high-resolution transmission electron microscopy, and this bonding contributed to the high shear strength obtained under rapid sintering conditions. A commercially acceptable alternative solution to achieving reliable Cu–Cu joint formation was obtained, especially for thermo-sensitive devices.
The authors would like to gratefully acknowledge the financial support from the Shenzhen Special Funds for Strategic Emerging Industries Grant (JCYJ 20150529152949390 and 20160318095308401) and the Innovation Foundation of Shanghai Aerospace Science and Technology under Grant No. SAST2016050.
- 3.Y.C. Liu, J.W.R. Teo, S.K. Tung, K.H. Lam, High-temperature creep and hardness of eutectic 80Au/20Sn solder. J. Alloys Compd. 44, 8340–343 (2008)Google Scholar
- 15.S.Y. Zhao, X. Li, Y.H. Mei, G.Q. Lu, Novel interface material used in high power electronic die-attaching on bare Cu substrates. J. Mater. Sci. Mater. Electron. 27, 1–10 (2016)Google Scholar