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Presents the thermo‐mechanical modelling of a new type of area array package: the flip chip on polymer stud grid array (PSGA). The objective is to optimise the material and geometrical design of this PSGA package and the flip chip assembly in order to achieve the highest thermal fatigue reliability for the solder joints in this structure. A parameterised non‐linear finite element model is used to calculate the inelastic strains induced in the solder joints due to thermal cycling. The techniques of design of experiments (DOE) and response surface modelling (RSM) enhance the parameter sensitivity analysis and optimisation of the PSGA design. After the optimisation of the structure, a very high solder joint fatigue reliability of this flip chip to PSGA package has been achieved.

The purpose of this paper is to present an update on the progress of the design and reliability of stretchable interconnections for electronic circuits.

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.

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.

Reliability results are limited and need further work to create a more accurate empirical model to estimate the lifetime of stretchable interconnections.

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.

The purpose of this paper is to demonstrate electromechanical properties of a new stretchable interconnect design for “fine pitch” applications in stretchable electronics.

A patterned metal interconnect with a zigzag shape is adhered on an elastomeric substrate. In situ home‐built electromechanical measurement is carried out by the four‐probe technique. Finite element method is used to analyze the deformation behavior of a zigzag shape interconnect under uniaxial tensile loading.

The electrical resistance remains constant until metal breakdown at elongations beyond 40 percent. There is no significant local necking in either the transverse or the thickness direction at the metal breakdown area as shown by both scanning electron microscopy micrographs and resistance measurements. Micrographs and simulation results show that a debonding occurs due to the local twisting of a metal interconnect, out‐of‐plane peeling, and strain localized at the crest of a zigzag structure.

In this paper, the zigzag shape is, for the first time, proven as a promising design for stretchable interconnects, especially for fine pitch applications.