Researchers from Eindhoven University of Technology identified inaccuracies of thermal transient measurements interpretation associated with the secondary heat sources
The market of solid-state lighting has witnessed rapid growth in the recent past. According to Electric Lamp and Component Manufacturers Association, the market for LEDs in India reached around US$ 1 Billion in 2016. High use of LEDs requires their accurate thermal modeling to ensure highly reliable end products. Compact thermal modeling allows for rapid and dependable thermal simulations of the devices of interest and does not disclose confidential information from LED suppliers. Compact thermal models (CTMs) find application in modern production and optimization processes.
Now, a team of researchers from Eindhoven University of Technology identified inaccuracies of thermal transient measurements interpretation associated with the secondary heat sources. The team described transient analysis method, and the thermal structure function (SF) concept and defined the LED’s finite element analysis (FEA) thermal model. The team also experimentally demonstrate the significance of the secondary thermal sources consideration for the thermal transient analysis of LEDs.
The team demonstrated that the accuracy of the thermal transient analysis results is significantly impacted by that secondary heat sources. The distortion of the SF’s die and the die attach layer (DAL) regions associated with the presence of secondary heat sources was numerically modeled and experimentally confirmed. The related error of the die and the DAL thermal resistance evaluation can be as high as 35% and reach up to 50% for LEDs with phosphor light conversion. The error is proportional to the fraction of the secondary heat sources in the total power dissipation. The method to separate main and the secondary heat sources can significantly increase the accuracy of calibration procedures for 3D FEA thermal models. The research was published in the journal MDPI Energies on May 15, 2019.