Static and thermal FE analysis of a Flexible Electronic BOard (FEBO) prototype and the characterization of its innovative materials

An FE model of an experimental flexible electronic board was built to determine its performance in terms of mechanical and thermal distortions, heat and transient thermal flow, thereby detecting critical issues and identifying opportunities for improvement. Commercial sensors were connected to the flexible board (100x40x2mm), which was based on a commercial thermoplastic polyurethane (TPU), with a PEDOT-based conductive resin trapped in a PEGDA network, a biocompatible polymer. Three thermal loads (ΔT=175°C, ΔT=100°C, ΔT=50°C) were applied which revealed critical stresses for high ΔTs but at ΔT=50°C only the connectors had a critical σvm, while for ΔT=50°C + 1mm displacement a critical strain value occurred in one area of the substrate. Heat transient analysis and overheating simulations were performed to determine the heat flow behavior for the photodiode and accelerometer. FE analyses allow more studies to be undertaken to improve material properties and suggest redesign activities for similar concept demonstrators. The funds of the European Union and the Piedmont Region, and agreements with the most important players in SBE (Simulation Based Engineering) software sales and services, allowed the authors (ITACAe srl, Proplast, and Politecnico di Torino) to conduct industrial research and experimental development together with manufacturers and users of innovative technologies to identify, study and optimize the design parameters of the board while simultaneously contributing to its technological development.