| Title |
Thermal Characteristics of LED Package depending on Phosphor Layer Position |
| Authors |
Wan-Ho Kim ; Dai-Hyoung Koo ; Ki-Tae Lim ; In-Seon Yeo |
| DOI |
http://dx.doi.org/10.5207/JIEIE.2016.30.11.007 |
| Keywords |
Phosphor layer ; LED package ; Thermal ; Precipitation ; Dispersion ; Reverse precipitation |
| Abstract |
In this paper, we studied for the thermal property LED package depending on the amount of phosphor and position of phosphor layer. The white light was released by energy conversion of phosphor from the blue to yellow range light. However, the heat was also generated according to the quantum efficiency of phosphor leading to the increment of internal temperature of LED package. When the thermal property of LED package was investigated by varying the phosphor concentration, the temperatures of packages with 50 and 100wt% of phosphor were increased by 17 and 19.2℃, respectively compared to the package without phosphor. Also, the heat characteristic was evaluated by changing the phosphor positions such as precipitation, dispersion, and reverse precipitation. In the LED package fabricated with a precipitation layer, the temperatures of upper and lower part were 70.1 and 64.0℃ and their temperature difference was 5.9℃. In the case of LED package with dispersion layer, the temperatures of upper and lower part were 77.2 and 63.0℃ and the temperature difference was 14.2℃. The package with reverse precipitation layer showed the highest (91.4℃) and lowest (62.1℃) temperatures because the heat was not effectively transferred from phosphor layer to LED chip due to long distance between them. |