Performance Enhancement of White LEDs Through Phosphor/Silicone Composite Particles

Settling of the heavy phosphor particles in the silicone encapsulation is a root-cause for variation of the correlated color temperature causing yield reduction in the fabrication of white light-emitting diodes (LEDs). When prefabricated particles consisting of the phosphor and the silicone are used, settling can be significantly reduced and a dramatic enhancement of the consistency of LED performance can be achieved. A reduction of the change in correlated color temperature after 60 min of settling on the chip from >900 K for traditional phosphor particles to only 8 K for particles with a weight ratio of phosphor and silicone of 1:1 in an otherwise identical coating procedure is demonstrated.