RELIABILITY EVALUATION OF FATIGUE LIFE FOR SOLDER JOINTS IN CHIP COMPONENTS CONSIDERING DISPERSION OF THE SHAPE AND THE PROPERTIES

Recently, the downsizing of car components becomes a big trend for the development of car electronics, and it is becoming very difficult to achieve the reliability results target without managing controlling the dispersion of the fatigue lives. The authors proposed an isothermal fatigue test method using small size solder joints to get the fatigue properties. The Manson-Coffin's law given by this method could improve the correspondence between the simulation results and experimental results. Based upon the Manson-Coffin's law and Miner's law, the authors proposed a fatigue crack propagation simulation approach. Furthermore, in order to consider the heterogeneity of PCB due to the distribution of fiber network, the authors made heterogeneous model considering the distribution of the fiber. And the authors evaluated the fatigue life of solder joints in chip components with considering dispersion of the material properties by using the heterogeneous model.