Flexure and Twist Test Reliability Assurance of Flexible Electronics

Abstract

Additively printed flexible electronics in wearable application may be subjected to twisting or flexing depending on the form factor and the intended use. There is a dearth of standards for testing and reliability assurance of flexible electronics and reliability data for various use conditions. In this paper, a test protocol has been developed for twisting and flexing on aerosol-jet additively printed flexible circuits. Test patterns with commonly used traces geometries have been developed, aerosol-jet printed, and thermally sintered at various conditions. Effect of sintering temperature on fatigue robustness in cyclic-flexing and cyclic-twisting has been studied for straight, horse-shoe, and zig-zag trace geometries. Reliability data have been acquired under both twist and flex using continuous resistance monitoring until 100,000 cycles. Failure mechanisms have been studied for both cyclic-flexure and cyclic-twist using scanning electron microscopy (SEM) and optical imaging.