Cu-Sn金属間化合物を考慮したはんだ接続部のインデンテーションクリープ解析

抄録

In solder joints, intermetallic compound layer (IMC layer) is formed between the solder and the conductive part. Considering the IMC layer, there are a few materials which have the different creep characteristics in the solder joints. Therefore, in order to conduct the FEM analysis of the solder joints with high accuracy, it is necessary to evaluate the deformation characteristics considering both creep and plastic deformation in the solder joints. In this study, the authors conducted the numerical experiments simulating the indentation test, which is effective for evaluating the deformation characteristics of micro regions. In the analysis, it is assumed that the specimen is made of the eutectic solder and that Vickers indenter diamond. The eutectic phase (Ag₃Sn/Cu₆Sn₅・β-Sn) is assumed to be the elastic-plastic-creep material, and the primary phase (β-Sn) the elastic-plastic-creep deformable material or the elastic-plastic material. The Cu-Sn intermetallic compound layer is composed of two layers of Cu₃Sn and Cu₆Sn₅, which are assumed to be the elastic-plastic materials. The numerical test showed that, the reasonable simulations are obtained when both the primary phase and the eutectic phase are assumed to be the elastic-plastic-creep material. On the other hand, the reasonable numerical results are not obtained when the primary phase is assumed to be the elastic-plastic material.