Design and Analysis of Flexible Interconnects on an Extremely Thin Silicon Substate for Flexible Wearable Devices

In this paper, we designed, fabricated and analyzed the microstrip line structure flexible interconnects on an extremely thin silicon substrate for future flexible wearable devices. The electrical characteristics of a flexible silicon chip and a PCB are analyzed when mechanical structural changes. The fabricated flexible chip is attached on the flexible PCB using elastic polymer bumps. By using the fabricated flexible chip and PCB, S-parameter of the interconnects were measured with the bending radius until the flexible chip is disconnected from the PCB. As the results, the designed flexible chip on the flexible PCB showed the resonance peaks when the bending radius is less than 10 mm. Moreover, the interconnection between the chip and PCB is fully disconnected when r is less than 7.5 mm.