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.

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