Remotely-controlled tensile test of copper-cored lead-free solder joint in liquid using permanent magnet

Solder balls are used for electric connections in various electric devices. Since the electric devices have been widely used for automobiles, airplanes, electric home appliances, personal digital assistances besides conventional computers, their reliability under various conditions including humid and corrosive environments has to be evaluated. The authors proposed a non-contact tensile test method using permanent magnet and applied it to the solder joint testings. As the tensile force is remotely given to the solder joint, it becomes possible to isolate solder joint from gripping jig and set the joint in a liquid container. In this paper, tensile tests of copper-cored lead-free solder joint are carried out both in air and in water conditions, and the results on joint strength are discussed.