Design and performance of metal conductors for stretchable electronic circuits

Abstract

Purpose The purpose of this paper is to present an update on the progress of the design and reliability of stretchable interconnections for electronic circuits. Design/methodology/approach Finite element modelling (FEM) is used to analyse the physical behaviour of stretchable interconnects under different loading conditions. The fatigue life of a copper interconnect embedded into a silicone matrix has been evaluated using the Coffin‐Manson relation and FEM. Findings The mechanical properties of the substrate and the design of the metal interconnection play an important role on the fatigue lifetime of circuit. In the case of copper embedded into a PDMS Sylgard 186, more than 2,500 tensile cycles have been observed for a periodic deformation of 10 per cent. Research limitations/implications Reliability results are limited and need further work to create a more accurate empirical model to estimate the lifetime of stretchable interconnections. Originality/value The combined use of FEM and experimental analysis enable a more reliable design of the stretchable metal interconnections. The proposed horseshoe design offers the benefit of reduced permanent damage during elongation.