13th International Conference on Fracture June 16–21, 2013, Beijing, China -8- Fig.10 The fatigue data with different dwelling time 4. Conclusions Firstly, the shear tests of nano-silver sintered lap-shear joints at elevated temperatures were conducted to study the effect of temperature on shear behavior. Secondly, a series of fatigue tests under fully reversed loading indicated how temperature affected the Basquin equation. Finally, the effect of creep on fatigue was studied at high temperature of 325 ℃. The following conclusions are obtained. (1) Shear behaviors are temperature dependent. The shear strength decreases with the increased of temperature. The shear strength at room temperature is as high as 28MPa, which halve at the temperature of 325℃. (2) Basquin’s equation is presented to predict the fatigue life of the nano-sintered lap-shear joints at different temperatures, where the fatigue strength exponent b is a constant and the fatigue strength coefficient ߪ , ௧ is a value dependent on temperature, which decreases with the elevated temperature (3) With the increasing of the dwell time, the effect of creep becomes more and more significant. It can be concluded from the dwell-fatigue tests at the temperature of 325℃ that creep is the main factor that lead to the final failure of the specimen. Acknowledgements The project was supported by NSFC (No. 10802056 and No.11072171). References [1] L. Nie, M. Osterman, FB. Song, J. Lo, SWR. Lee, M. Pecht, Solder ball attachment assessment of reballed plastic ball grid array packages. IEEE translations on components and packaging, 32 (2009) 901–908. [2] T. Wang, X. Chen, G.Q. Lu, G. Lei., Low-temperature sintering with Nano-silver paste in Die- Attached interconnection. Journal of electronic materials, 36 (2007) 1333–1340
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