From theory to industry: Accelerated wrinkle prediction in FPCs via 2D simulation and critical mesh estimation

• Developed a 2D model to predict bending-induced wrinkling in flexible circuits • Proposed mesh size estimation to eliminate iterative refinement for industrial use • Achieved reliable wrinkle detection for rapid cosmetic check, validated experimentally • Provided a cost-effective 2D model approach, reducing reliance on 3D models and physical tests Wrinkling in flexible printed circuits (FPCs) during bending poses product quality challenges for industries manufacturing foldable devices and miniaturized electronics. Conventional 3D simulations and experiments, while accurate, are time- and resource-consuming for rapid design cycles, especially as experiments often require long production-line queues to prepare FPCs and fixtures. This study introduces a streamlined 2D simulation framework integrated with a critical mesh size estimation strategy to enable fast and reliable bending-induced wrinkle prediction aligned with industrial cosmetic check practices. By converting 3D into 2D plane-stress simulations, the approach reduces degrees of freedom and mesh count without compromising predictive capability, to mimic cosmetic check. A simplified mesh estimation method, adapted from plate-wrinkling theory and requiring only the material properties of the two innermost layers, eliminates iterative sensitivity analyses. Benchmarking against experimental observations across eight bending radii confirmed qualitative agreement in wrinkle occurrence and disappearance trends, while two case studies validated applicability across different FPC stackups and loading conditions. Results demonstrate that this method accelerates industrial cosmetic checks, reducing reliance on costly and slow experimental workflows. The proposed framework offers a practical pathway for industries to adopt simulation-driven design, contributing toward narrowing the gap between academic modeling and industrial implementation.