Micro-mechanical and fracture characteristics of Cu6Sn5 and Cu3Sn intermetallic compounds under micro-cantilever bending
journal contributionposted on 24.06.2016, 13:33 by Li Liu, Zhiwen Chen, Changqing Liu, Yiping Wu, Bing An
This study focuses on the fracture characteristics of Cu6Sn5 and Cu3Sn micro beams under micro-cantilever bending tests. These micro beams were fabricated by focused ion beam (FIB) from the Sn-rich solder joints aged at 175 °C for 1132.5 h, and then tested using a nanoindenter with a flat tip. Experimental results show that both Cu6Sn5 and Cu3Sn micro beams underwent elastic deformation before their failure. From fractographic analysis, both cleavage fracture and intergranular fracture can be identified from the tested Cu6Sn5 micro beams, while only intergranular fracture was found in Cu3Sn micro beams. Furthermore, based on the experimental results, finite element analysis was carried out to evaluate the tensile fracture strength and strain of Cu6Sn5 and Cu3Sn micro beams. For Cu6Sn, the tensile fracture strength was estimated to be 1.13 ± 0.04 Pa and the average tensile strain was 0.01. The tensile fracture strength and strain of Cu3Sn were evaluated to be 2.15 ± 0.19 GPa and 0.016, respectively.
This research was supported by a Marie Curie International Research Staff Exchange Scheme Project within the 7th European Community Framework Programme, No. PIRSES-GA-2010-269113, entitled “Micro-Multi-Material Manufacture to Enable Multifunctional Miniaturised Devices (M6)”, as well as a National Natural Science Foundation of China (Number: 60976076).
- Mechanical, Electrical and Manufacturing Engineering