Tensile test of small lead-free solder joint using permanent magnet

Since solder materials are often used for electric connections in various electric devices, the strength of solders and that of interfaces to the other metallic materials are very important. After the restriction of lead solder usage according to the European Union Waste Electrical and Electronic Equipment (WEEE) and Restriction of Hazardous Substances (RoHS) Directives, various lead-free solders have been developed and their optimized joining condition is being investigated. The mechanical test of solder joints is one of the best ways to check the joining condition and it gives us useful information to secure the safety of electric devices. From the viewpoint of mechanical testing, it is not easy to handle the solder materials because of their very low deformation resistance and small size. In this paper, a new method of tensile test is proposed using permanent magnet, and the results are discussed. By using the permanent magnet, various non-contact tensile tests are going to be possible. The present paper is a basic study to realize the non-contact tensile tests for micro materials.