Mechanical behavior analysis of heterogeneous interface in stretchable electronics packaging

Stretchable electronics can be summarized as an emerging electronic technology that manufactures electronic devices on flexible substrates, and has broad application prospects due to its unique ductility. In order to improve product reliability, it has become critical to understand all the failure modes that caused it to fail. Interface delamination is an important factor leading to its failure, especially at the interface between the flexible substrate and the metal conductive layer. In this study, in order to explore the stress distribution of the interface layer between the substrate (PDMS) and the metal conductive layer (Cu) under load, a uniaxial tensile simulation and a three-point bending simulation were first performed, and it was found that stress occurred at the corners Concentration phenomenon. Therefore, a peeling model without prefabricated cracks was used. The finite element model with cohesive elements is used for numerical simulation, and the stripping process is described in detail. Finally, the influence of cohesion parameters on peeling force is analyzed. It is found that with the increase of C1, the maximum peel force also increases, but it has no effect on the stable expansion stage. This research content is of great significance for quantitative analysis of the delamination of stretchable electrons and improving the reliability of stretchable electrons.