抄録
In the previous work, the authors proposed a method to estimate the tensile characteristics of the Cu/Sn intermetallic compounds (IMCs) of Cu_6Sn_5 and Cu_3Sn. The method provided two new findings. One is that the breaking elongation of the Cu/Sn IMCs is approximately 1%. The other is that the stress-strain relation of the Cu/Sn IMCs shows non-linearity. Since the Cu/Sn IMCs have been regarded as elastic materials for a long time, the latter finding needs to be verified in some way. Then, in this study, we conducted finite element analyses (FEAs) which simulated the shear tests using the copper-solder joint specimen whose solder joint includes the Cu/Sn IMCs layer. The FEA for a loading condition was conducted in two different ways. Namely, two different constitutive models of elastic model and elasto-plastic model were employed to describe the deformation behavior of the IMCs for a loading condition. The real shear tests were also conducted in the same loading conditions as the FEAs. Comparing the results of FEAs with those of the real tests, we discuss the presence or absence of the material nonlinearity of the Cu/Sn IMCs. The discussion result suggests that the Cu/Sn IMCs have non-linear stress-strain curves.
