| With the LEDs power rising, the heat produced in PN node is greatly enhanced, The heat will directly affect the LED working temperature, luminous efficiency and reliability of life.Our research focused on the packaging technology of white LED , the study of a single power source 1W white LED and made by the method of chip on board(COB) the 3W white LED bulbs packages of light color characteristics of electrical parameters .The results showed that with the increase in the current drive forward, WLED correlated color temperature (CCT) increases, the luminous efficiency decreases. Under the constant current drive, the voltage gradually decreases (within 5min). Through analyze, we consider the P-N junction temperature, the concentration of phosphor, the thickness of the coating as the main reason for these electric-light-color parameters changes. The photoelectric parameter of copper and aluminum plate substrate high-power white LED bulbs and its discipline of the temperature change were studied in the same test conditions. Analysis showed that under the different condition of substrate materials, sizes of radiator, the flux LED bulbs attenuate different affect extent. But the color coordinates and CCT of commercial white light LEDs aren't change with temperature. |
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