Automated BIST Technique for Interconnect Characterization and Reliability Enhancement in Flexible Electronic Circuits

Electronic circuits used in Flexible Electronics are often prone to reliability issues due to mechanical stresses exerted on the substrate material during operation. Such flexible electronic circuits often include meandered interconnect wirings routed on flexible and stretchable substrate materials such as elastomers, polymers, etc. Mechanical stresses exerted on the substrate material can cause the interconnect wires to deform, thereby significantly affecting the electrical properties of the interconnect routes such as resistance, parasitic capacitance, inductance, etc. Extreme levels of mechanical stresses in the system can lead to open circuit faults in the interconnect routes. Hence, it becomes imperative to monitor the health of interconnects in such flexible electronic circuits, so that appropriate automated repair actions can be taken, whenever there are any reliability issues in the circuits. In this work, we propose an automated Built-in Self Test (BIST) technique to monitor the variations in resistances of interconnects. The BIST technique also involves automated steps to take appropriate measures to active a redundant subcircuit present in the system, whenever faults are diagnosed in the interconnects, such that the circuits are kept functional.