The study of spatial radiation variation for Dome-type LED package achieved by dispensing

摘要

the polymer dispensing technology used for a lens type LED package had been revealed in [1]. The ring type micro structure is adopted to confine the dispensed silicone encapsulant so as to form the packaged lens. To use the dispensing technology, the deviations in lens geometry are larger as comparing to that as using the silicone lens molding process. In this study herein, the dome-type UV LED and White LED packages are selected to verify the variations in the spatial radiation induced by the collimation between lens and LED chip, the height of lens and the phosphor application. Comparing to the collimating ones, as the collimation between lens and LED chip increases to 100 μm, the shape of radiation pattern changes from a mountain type to a slope type at the spatial range of -75° to 75°. Furthermore, the view angle also increases 4°～7°. The diffusive character from phosphor significantly reduces the variation in radiation pattern causing by the collimation. The view angle could reach 150° in white LED package. The view angles are 149° and 141° for the packages with the lens height of 1.3 mm and 1.5 mm, respectively. However, the radiation patterns are similar to each other in these two conditions of lens height.