Self-adaptive remote phosphor coating for pc-LEDs packaging by self-exposure slurry method

High efficiency white light-emitting diodes (LEDS) with superior spatial color homogeneity (SCH) have been investigated. In this paper, a new method of packaging of white pc-LEDs that employs a self-exposure technique as well as a remote phosphor configuration is presented. It is suggested that this remote phosphor configuration reduces the backscattering of emission light of LEDs as well as the operating temperature of the phosphor, which improve the efficiency and reliability of white pc-LEDs. The slurry method with self-exposure process was applied to achieve a self-adaptive remote phosphor coating layer surrounding the LED chips which could map the angular intensity distribution of blue light emitted by LED chips and therefore improve the spatial color homogeneity. The experimental results show that the white pc-LEDs with self-adaptive remote phosphor coating has remarkable advantages over conventional dispensing coating and conformal coating in terms of efficiency and color homogeneity.