Development of a pure bending equipment for measuring the bending behavior of thin films

Abstract

With the development of thin film manufacturing technology, it is changing from rigid substrate products to flexible products that can transform the shape of products. Examples of products using this flexible thin film can be used in various fields such as organic photocells, substrate printing, and display technology, and play an important role in the development and research of materials with new properties. However, thin films used in industry are rarely designed to withstand external stress and are vulnerable to external stress due to their thin structure. In order to solve the problem of mechanical reliability of products using thin films, it is essential to understand the mechanical properties of thin films to predict and prevent mechanical damage to products. Thin film structures do not exist alone in the actual environment, but in the actual process of laminating other materials, such as substrates, residual stress occurs due to the interaction between the thin film and the substrate, resulting in bending behavior. In addition, since the main behavior of flexible devices manufactured using a thin film is the bending behavior, it is necessary to measure the bending behavior of the thin film. In this thesis, we propose a pure bending device for measuring the bending behavior of a thin film. The moment-curvature diagram generated by the bending of the thin film was shown through the developed experimental equipment, and the flexural rigidity, which is a mechanical property related to the bending behavior of the thin film, was measured through the diagram. In addition, two experimental verifications were conducted to secure the reliability of the designed experimental equipment, and as a result, the reliability of the designed experimental equipment was secured.