Design for reliability of multi-layer stretchable interconnects

In this investigation, the electrical performance and reliability of multi-layer stretchable metal interconnects are evaluated using numerical simulations and experimental analysis. The numerical results show that the bi-layer design of stretchable interconnects have similar mechanics when compared to single layer interconnect structures. In contrast, interconnects configured in an in-plane stacked arrangement exhibit increased equivalent plastic strain during elongation, and consequently support less stretching. Our experimental results support these numerical findings. Maximum stretchability approaches ~150% elongation for single layer and bi-layer interconnects. In addition, fatigue experiments at 60% elongation show that the bi-layer design of stretchable interconnects have life cycles three orders of magnitude higher than the in-plane stacked arrangement of stretchable interconnects.