Factors influence the LED light failure

　　The advent of blue light is one of the industry's most mature white packaging methods of using a combination of phosphor and blue LED, which can easily get the white LED.

　　1 the influence of chip on the light failure of white light

　　From the results of the present experiment , the effects of the chip light fades into two categories: the first is the chip lead to different attenuation of different materials , the most commonly used substrate material for blue -chip silicon carbide and sapphire , silicon carbide general structural design single electrode , its thermal effect is better , sapphire generally designed for dual electrode, difficult to export heat, poor thermal effects ; second is the size of the wafer , the wafer material is the same, different attenuation gap size is different.

　　2 the impact of crystalline solid primer on the light failure of white LED

　　In the white LED packaging industry, it typically uses epoxy die attach adhesive insulating plastic, silicone rubber insulation, silver plastic. Three have advantages and disadvantages, to be taken into account in the selection. Epoxy glue thermal insulation is poor, but the high brightness ; silicone rubber thermal insulation effect is slightly better than epoxy , high brightness, but because certain proportion of silicon components , while the chip next to the residual solid silicone rubber in the ring with fluorescence will produce oxygen barrier resin combined with the phenomenon , after thermal shock will cause peeling dead lights ; thermal conductivity than the previous two silver plastic are good, you can prolong the life of the LED chip , but the absorption of silver plastic light large, resulting in low brightness. For blue -chip dual-electrode in solid crystal with silver plastic, the amount of plastic is also very strict control, or prone to short-circuit a direct impact on product yield .

　　3. Impact of phosphor on the light failure of white LED

　　There are a variety of ways to achieve white LED, currently the most widely used one is the most mature one through a layer of yellow phosphor coated on the blue chips, so blue and yellow mixed into white , so white LED phosphor material attenuation great influence . Most mainstream market YAG phosphor is yttrium aluminum garnet phosphor, silicate phosphor, nitride phosphor, and blue phosphor LED chips as compared with the effect of accelerated aging white LED , fluorescent light and different vendors failure is not the same degree of influence , which is closely related to raw ingredients phosphor. Lehman photoelectric finest white phosphor materials that make the white LED has been greatly improved compared to peers in the attenuation control.