Evaluation of tensile strength of copper-cored lead-free solder joints in air, distilled water, and NaCl solution using testing device with permanent magnets

Solder joints have been used for electric connections in many electric devices. Since the electric devices are subjected to various loadings such as static, cyclic, and thermal stresses, the evaluation of solder joint strength under these conditions is necessary to guarantee the safety of electric devices. In addition, the electric devices are extending their application field and are used in corrosive conditions such as high humid and saline environments. The strength of solder joints under these conditions is also important. In this paper, tensile tests of copper-cored lead-free solder ball and nickel rod joints were carried out in air, distilled water, and salt water environments using a unique tensile testing device with permanent magnet. The joint strength and fracture behavior were discussed.