Novel strain relief design for multilayer thin film stretchable interconnects

Most electronic systems are rigid and inflexible. Many applications, however, require or benefit from conformable designs. To create efficient conformable systems, multilayer stretchable interconnects are necessary. A novel strain relief structure for multilayer stretchable interconnects is proposed. The numerical analysis shows that the proposed structure will function indefinitely when stretched as much as 20% of its initial length. Electromechanical measurements demonstrate that the onset of microcrack formation in the interconnects occurs, on average, after 89% elongation. These measurements also show that the structures are able to withstand elongations of up to 285%. Additionally, precise failure mechanisms, including interconnect straightening and microcrack formation are documented.