Effect of Sintering Temperature on the Fatigue Life of Additively Printed Electronics During Cyclic Bending

Flexible devices are been emerging as a new way to the electronics industry. One of the biggest challenges of Aerosol Jet Printing (AJP)is to reduce the resistance of the printed line and get close to comparison with existing Cu trace resistivity. According to the study, with an increase in sintering temperature at constant sintering time, the resistance and shear strength decreases. There is a need to investigate the effect of varying sintering temperature at a constant time on number of cycles to failure (i.e. fatigue life)during cyclic bending. The current challenge in AJP technology is reducing the resistance of the printed lines. In this paper, the failure of the interconnects is been considered according to the end application. Bending (V-bend)motion is considered as the end application considered to be used the wearable technologies. The sintering temperature is been varied in order to optimize resistance and shear strength. In the previous study, the sintering temperature is not been considered, as a parameter to the end application. In this paper, the Aerosol jet printing method is used to print the lines using silver nanoparticle ink. The printing is done on a polyimide substrate. The printed sample is then sintered at different temperature and connectivity is checked. The substrate is then checked for its number of cycles to failure in the v-bend in cyclic loading condition. In this study, the failure criterion is a 20% increase from its initial change in resistance. The reliability of the traces is studied using the ANOVA analysis. The comparison is been done of the varying sintered temperature with respect to its application of bending and find out the point where it can be printed with lower resistance and higher shear load to failure. The failure of the traces is determined as per the IPC standards.