Analysis of Crack Parameters and Electrical Property in Flexible Devices Under Bending State

Abstract

Repeated or sustained bending in flexible displays induces mechanical stress on all components, particularly affecting narrow and thin electronic circuits. There is a lack of research that maintains the bending state during observation of cracks and analyzes electrical properties based on crack parameters. This study aims to observe crack parameters under the bending state and analyze the relationship between crack parameters and electrical properties. The results showed that a smaller bending radius induced greater tensile stress on the specimen surface, which in turn increased both crack density and crack width. Measurement of resistance under bending state also revealed that smaller bending radius resulted in larger crack width and corresponding increases in resistance. We also demonstrated that analyzing cracks in the flat state (after bending state) significantly underestimated the effects of crack width in electrical properties because crack width was almost recovered indicating reversible deformation while crack density remained unchanged, representing irreversible damage after bending state. Therefore, crack analysis under actual bending state is essential for accurately evaluating the mechanical and electrical reliability of flexible electronic components.