利用板上芯片封装chip-on-board(COB)技术封装大功率LED，比较分析其在不同散热器上的温度变化规律。研究了不同的热平衡温度对大功率LED光通量、电学参数的影响。在实验过程中，光通量、驱动电压、功率和发光效率都呈现出下降的趋势，并且最终稳定在其热平衡值。研究还发现：对于大功率LED照明系统，光通量、驱动电压、发光效率与散热器温度具有线性关系。在电源接通时，随着散热器温度的升高，LED的反向饱和电流迅速升高。通过线性拟合，得到大功率LED照明系统的光通量温度系数、驱动电压温度系数和光效温度系数。

Using the high power light-emitting diode(LED) made by the method of chip-on-board (COB) packaging, this article compared and analyzed the temperature variation discipline on the different thermal radiators. We investigated the relationship between the different thermal equilibrium temperature and photo-electric parameter, such as luminous flux, electrical parameters, and so on. The results shown that when the LED illumination system is turned on, the temperature of the radiator rises rapidly, and keeps in a certain value after a period of time. In this process, the luminous flux, the forward voltage, power and luminous efficiency presents the downward trend. These parameters fluctuate around the equilibrium value. For high-power white light LED illumination systems, luminous flux, forward voltage and luminous efficiency keeps good linear relationship with radiator temperature, respectively. The results also showed that, with the rising of reverse saturation current, the radiator temperature rapidly rises. By linear fitting, luminous flux temperature coefficient, vol-tage temperature coefficient and luminous efficiency temperature coefficient were calculated.Finally, the relation formula of temperature and luminous flux was proposed. By measuring the radiator temperature, the luminous flux can be calculated. It can be used as a kind of calculation methods of luminous flux. High-power white LED lighting system should be reasonable design to improve its thermal dissipation capacity. Reducing equilibrium temperature of high-power LED-lighting system is an effective method to improve performance of the system.