Measuring and modelling the thermal behavior of LEDs in structural electronics

Structural electronics consists of printed electronics and silicon-based rigid electronics and load-bearing supporting parts of a device (plastic, glass etc.). One interesting example of structural electronics is large area elements in which light emitting diodes (LEDs) are embedded into the glass laminate. LEDs are used as light sources to create i.e. smart surfaces for the architectural and automotive industry. Once the LEDs are embedded into the structure, they undergo the high temperature conditions and stresses, which are known to have an impact on their lifetime. Many of these aspects are not known for structural electronics. In this study, a thermal simulation model for surface mounted LED on polymer substrate was designed in Comsol Multiphysics –simulation software and the validity of it was evaluated with T3ster measurements. According to measurements, the simulation model is accurate and temperature variations between the simulation and the measurement results was less than 1.0 %. Developed model could be used as a basis for designing the structural LED elements and evaluating their performance characteristics in different user cases.