A study of thermal processes in high-power InGaN/GaN flip-chip LEDs by IR thermal imaging microscopy

Experimental and theoretical study of electrical, thermal, and optical characteristics of InGaN/GaN high‐power flip‐chip LEDs

“…The calibrated relationships between the IR radiation intensity and temperature was then used to determine the absolute temperature of every element of the LED chip under actual operation conditions. Using the above approach, we were able to measure the temperature with the accuracy better than ∼2 K 11.…”

Mathematical simulation of heat transfer processes at the maximum possible electrical loads in typical light-emitting diodes

“…In most cases reliability analysis comes down to thermal mode studying of LED operation [1,[4][5][6][7]9], and the LED efficiency is defined by crystal p-n junction temperature [9] being depended on the current in semiconductor [15]. The analysis of thermal and physical characteristic variation influence allows identifying model's temperature dependences and avoiding the wasted efforts during the LED production and will reduce the organization expense.…”

“…The balanced models and software applications based on them (the LED's thermal resistance calculation models [2], taking into account the infrared radiation effects [6], p-n junction temperature change [4], as well as CFD-simulation [7]) are the mostly widely used. However, many experiments [3,5,6,8,9] with different LEDs showed that the balanced models application domain is very limited. Particularly, the balanced models provide the approximate, quite significantly different from the real, processes at an intensive heat release or an energy absorption due to the chemical reactions and phase transformations (melting, crystallization).…”

Determination of the critical conditions of heat transfer in a LED

“…At first sight, this semiconductor seems to be simple, but the involved thermal processes demand additional attention and understanding of specialists. Many research works are related to the processes of LEDs [1][2][3][4], but it is still difficult to identify a complete evaluative model of heat transfer. Normally, the determination of critical conditions of the heat exchange is achieved experimentally.…”

“…Normally, the calculation of a thermal model is connected with the calculation of the thermal resistance and patterns of change of the volt-ampere characteristics depending on the time and temperature [2,3].…”