Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : October 07, 2017 - October 09, 2017
The strength reliability of fine solder joints must be evaluated by conducting a finite element analysis (FEA) considering the presence of the Cu/Sn intermetallic compounds (IMCs) layer, which consists of Cu3Sn and Cu6Sn5, generated at the interface between solder and copper wiring. To conduct such FEA accurately, the tensile stress-strain curves of the Cu/Sn IMCs are needed. Therefore, we proposed a method to estimate the stress-strain curve of the IMCs by conducting the tensile test using the miniature composite solder specimen with IMCs layer. The stress-strain curve estimated by the proposed method suggested that the both IMCs have material nonlinearity. This finding needs to be verified in some way, because the IMCs have been regarded as elastic materials for a long time. In this study, the shear tests using a copper-solder joint specimen, in which the solder joint has the IMCs layer, were conducted both experimentally and numerically. The numerical tests were conducted as FEAs, and the FEAs employed two different constitutive models of elastic model and elasto-plastic model to describe the deformation behavior of the IMCs. Collate the experimental results and the results of FEAs, we discussed the presence or absence of the material nonlinearity of the Cu/Sn IMCs.
