Measuring thermal resistance of high-power LED junction case based on integral difference method

Thermal resistance is critical to the life cycle and performance of LED devices. The case thermal resistance of LEDs is commonly used to assess heat dissipation capability, therefore, accurate measurement of the case thermal resistance of LED devices is important to assess heat dissipation performance. The methods used to measure the thermal resistance parameters of semiconductor devices include the transient double interface method and the thermocouple method. When the chip bonding layer of the LED to be measured is a high thermal conductivity material, the results of the transient dual interface method are very close to the standard case thermal resistance of the device itself. However, when the bonding layer of the LED chip is made of materials with low thermal conductivity, the thermal impedance curves obtained from two measurements by the transient dual interface method cannot separate the obvious differences, and the separation point is not easy to be recognized, and the measurement results deviate from the real value. In view of the above problems, this chapter analyzes the integral structure function of the transient thermal impedance curve on the basis of the transient dual-interface method, and thus researches a kind of improved crust thermal resistance measurement method based on the integral difference method, and proves that the method improves the measurement accuracy by using the experimental results.