Highly Stretchable Interconnects for Flexible Electronics Applications

Interconnects that can deform under monotonous and/or repeated loading are increasingly important to a new class of electronic devices used for wearable applications. Such interconnects integrate different material sets such as polymers and metallic conductors and are subjected to large strain levels. A typical method to overcome the material incompatibility involves the conductor in the form of a serpentine or an out-of-the plane buckled geometry. In this paper, we demonstrate a novel combination of interconnect materials that enables significant improvement in the interconnect stretchability using Indium over the state-of-the-art without affecting the system performance. This was achieved without the necessity of the serpentine interconnects geometry that significantly improves the routing density. The manufacturing method used for this approach is also described. Finally, we discuss the cost competitiveness of the materials and the manufacturing method to assess the commercial viability of this approach. (5nm)