When it comes to the principle of minimum single of the stress from shear stress and Von Mises stress, the size of big solder joints 0.5mm × 0.328mm is the most suitable choice. The shape of solder joints don’t influence the reliability of whole structure a lot. We can ignore the shape of solder joints when we analyze the whole structure in some certain circumstances. In the whole structure, the material of solder joints affect the reliability of whole structure. In the study of three materials, the material of Sn3.0Ag0.5Cu has good function. Maybe the lower ingredient of Cu plays a significant role. Theses results of creep strain is consistent with the actual electronic application components’ experimental results.
Keywords: 3D package; Finite element method; Creep strain; Reliability