Fatigue behaviour of small-sized in-situ packaging materials based on a single-point nanoindentation with cyclic penetrations

Nanoindentation technology is proposed in this study to evaluate the fatigue behaviour of small-sized in-situ packaging materials. As the most appealing advantage, the proposed method only requires a single nanoindentation with cyclic penetrations, which means the nanoindentation experiments can be performed at minor effort. Combined with nanoindentation technology, the finite element method is employed to simulate the mechanical behavior of packaging materials subjected to cyclic loading due to the single-point nanoindentation with loading and unloading. During the nanoindentation process, the damage evolution and the effect on residual indentation morphology also are numerical simulated and theoretically investigated. The correlation between the mechanical behavior of cyclic penetrations and the maximum applied load on the indenter can shed light on the fatigue properties of in-situ packaging materials in electronic devices. Based on the forward algorithm of nanoindentation for packaging solder materials, the single-point nanoindentation of electronic packaging materials is numerically carried out at the same position, in this study, three groups of tests were carried out at 1000nm, 1200nm and 1500nm. Each group was loaded 5 times with single point cyclic loading, and each time penetration into the same depth. Based on the finite element analysis, the damage evolution of packaging materials under single point cyclic penetration was studied.