Performance of Structural and Hybrid Adhesives in Thermoformed and Over‐Molded In‐Mold Electronics

ABSTRACT Structural adhesives play a critical role in the reliability of In‐Mold Electronics (IME) devices by ensuring secure attachment of surface‐mounted components under mechanical and thermal stress. In this study, the performance of three commercially available adhesives: Loctite AA 3525, Elan‐glue EP 5350, and the hybrid conductive/structural Saral SilverGlue Alpha 600, was evaluated for maintaining component integrity during sequential thermoforming and over‐molding processes. Hybridized polycarbonate films containing 0603 and 1206 capacitors were fabricated and characterized after each process step. Results show that Loctite AA 3525 consistently provides the highest structural support, maintaining functionality across all deformation levels, while Elan‐glue EP 5350 exhibits moderate performance limited by bubble formation during dispensing. Saral SilverGlue Alpha 600 performs well under low‐deformation conditions but shows reduced retention in regions of higher stress. These findings highlight the critical role of structural adhesives in IME devices and provide practical guidance for adhesive selection based on local deformation levels to maximize device yield, precision, and reliability.