LED 형광체 층의 열적 거동

Abstract

Light Emitting Diode (LED) packages including phosphors are attracting attention as next-generation light sources based on advantages such as high energy efficiency, longer lifetime, and environment friendliness, but they are not thermally robust. In addition, when intensive light of the LED chip passes through the phosphor layer, heat generation occurs due to the optical characteristic of the phosphor.

The increase in the temperature of the phosphor layer due to such heat generation causes the deterioration of the performance of the high power LED package, shortening of the life span, and unintended color conversion.

In this paper, we have established a 1-D heat generation model that considers absorption, scattering, and color conversion due to light propagation through the LED package phosphor layer. Based on the heat generation model, an improved heat generation equation is derived

In addition, the heat generation model was validated by the measurement for various phosphor thicknesses and LED powers

Furthermore, the parametric study was conducted by using the FEA thermal model of the LED package for various distances between the chip and the phosphor layer and the phosphor layer thicknesses.