Comparison of dynamic and static mechanical stress applied on soldered joints

This article deals with the mechanical stress of lead free soldered joints. During usage of electrical equipment are found structural changes of soldered joints, which can lead to cracks or failure of the solder joints. Therefore solder joints have influence on a total quality of electronic assembly. Mechanical tests are mainly used for resistance evaluation of components, devices and whole products against stress. This stress takes effect during function, transport and storage of the devices. Mechanical stress can change electrical properties of the soldered joints, e.g. electrical resistance. Even a small change of the electrical resistance could cause the malfunction of the electrical equipment. In this article, the changes of the electrical resistance of dynamic and static stressed soldered joints (lead Sn62Pb36Ag2 and lead free Sn95,5Ag4Cu0,5) are compared.