Inhibition of phosphor sedimentation for white light-emitting diodes with a facilely realizable and economical method

In LED packaging, phosphor particles are usually mixed with silicone resin and then dispensed onto the top surface of LED chips. The phenomenon of phosphor sedimentation during dispensing and curing process is a serious problem in the LED packaging industry. In this paper, a facilely realizable and economical method was proposed to restrain phosphor sedimentation in high-power white LED packaging. The method has no influence on the property of phosphor, and makes phosphor settle much slower than that in the conventional packaging. The reason of gravity effect for this phenomenon was figured out by forces analysis. From the results it can seen that the new method is facilely realizable, cost saving and environmental friendly. With subsequent improvement, it may be widely applied in the LED packaging industry.