Current load capacity of electrical conductor tracks evaluated by simulation and thermographic imaging

Abstract

Today's LEDs operate with high current, causing a significant increase in the device's temperature despite the LEDs being highly energy efficient. Important for having a long LED lifetime is accurate temperature management which requires sensing the device temperature and knowing the temperature distribution. The underlying aim of the project is to simulate the temperature distribution in LED devices mounted on printed circuit boards and to compare the data with simulation results. The focus of this paper is the modelling and simulation of PCB tracks of different widths that are typically used in board designs and device interconnections. Based on the finite element method, the surface temperature of electrical tracks is simulated using the tool COMSOL. For comparison with real world measurements, the simulated structures have been fabricated and analysed via contact-free infrared thermography. The main challenge is the mechanical modelling of the track structure and the setup of the material parameters to have a good match between simulation results and measurements. In a future step, the simulation results will be used to allow for integrated temperature management of LED devices which include power supply structures to avoid overheating at the p-n junctions and at the light conversion material on top of the LED.