Junction temperature measurement and luminous properties research of the integrated packaged LED

The high-power white LED was prepared based on the integrated packaging.The junction temperature of LEDs was measured based on the integrated packaging substrate with low thermal resistance.The photoelectric parameters under different junction temperatures were measured by spectrometer and the mechanism was researched.The applied current is 0.34 A and the temperature range is from 10.8 ℃ to 114.9 ℃.The results show that the junction temperature has a good linear relationship with forward voltage,luminous flux,luminous efficiency and color temperature.The change of junction temperature has little effect on the dominant wavelength and color coordinate.The rise of junction temperature will lead to decreasing intensity and red shift for blue light spectrum.Meanwhile,the intensity of yellow light is increased,the spectrum is widened,and the peak wavelength shifs from 450 nm to 550 nm.