Fabrication and Analysis of Biaxial Surface Wrinkling of Thin Metal Film on Compliant Substrate Based on Low Adhesion-Assisted Transfer Technique and Direct 3D Numerical Simulation

This paper presents direct 3D numerical simulation of undulated thin metal film wrinkling on a compliant substrate. Compared with the previous cylindrical thin film wrinkling pattern, an undulated wrinkling pattern has been implemented by increasing the width of the thin metal film and creating biaxial straining in the thin film. The selected compliant substrate is a commercial scotch tape on which a gold metal thin film has been transferred by using low adhesion between thin metal film and polyimide substrate. Direct numerical simulation depends on imperfection defined in compliant substrate. FEM model for 3D direct numerical simulation has been built to understand the wrinkling behavior of the thin film on the scotch tape by using only one imperfection defined at the top of the compliant substrate for the 3D direct simulation. Through the simulation, it is confirmed that biaxial straining of the thin metal film on the compliant substrate has created the undulated thin film wrinkling which has good agreement with the theoretical solution. The modeling and simulation results are useful to understand wrinkling behaviors frequently encountered in mechanical mismatched thin film material and polymer substrate and to estimate material properties from the wrinkling parameters.