Optical and thermal properties of flip-chip LED bulbs using chip-scale package

A kind of LED bulb which is made by the school and enterprise is introduced in this paper. Fluorescent film is used for chip-scale packaging on flip-chip LED. The film is made by spin coating method, bonded to the surface of the chip and cut off by laser and then finished by a simple process. The optical properties and thermal properties of the LED bulbs were measured by various methods. The experimental results showed that with the increasing of the voltage, color temperature and the color rendering index changing 0.522% and 0.200% respectively which can be seen as a relatively stable data. The highest surface temperature of the flip-chip LEDs using chip-scale package we estimated which can be kept between 133.8°C and 135 °C can also be accepted. These results have a certain guiding significance for the industrialization of the LED bulbs.