High Power LED Phosphors Colloidal Packaging Technology Research

With the world’s energy shortage, energy-saving products are rapiddeveloping. Compared with conventional light sources, LED solid-state lightemitting devices have many advantages such as low operating voltage, highluminous efficiency, long life, good color, solid-state, free of harmful substances.And it has been recognized as the next-generation light source of general lighting.How to increase the external quantum efficiency and the heat dissipation is importantfor LED development. Improving LED packaging technology is an important way toimprove the external quantum efficiency and heat dissipation. In this paper, do thefollowing research on the phosphor glue packaging technology.Based on the principle of the ultraviolet curing and the optical requirements ofLED packaging glue, choose the right composition of curing glue and the properultraviolet curing conditions. Adjust proportions of each component to get differentUV glue, to find the effect of each ingredient on colloid’s transmittance andrefractive index. Through the experiment, we can find that the refractive index isdecided by Oligomer and diluent, while the colloidal transmittance is decided bythose three components. When the Photosensitizer is less than0.1%, lighttransmittance falls with the decrease of cationic photosensitizer.. As diluent deceasesfrom1%to0.5%, the transmittance rises, while from0.5%to0, the transmittancefalls.According to the results of former experiments, use the UV glue with thehighest transmittance to make comparison with silicon by experiments. Mixphosphor with UV glue and Silicon respectively, in the same proportion, put thesetwo kinds of blending intest tubes to observe settlement phenomenon, it can be foundthat phosphor in UV glue settles more slowly. Package high power LEDs with thesetwo kinds of adhesive, then measure LED optical performance. It can be found thatthere is no difference between these two adhesives in luminous flux, correlated colortemperature, color rendering index. Analyze the influence of nano particals on colloid’s transmittance. Dope TiO2nano particals with water and AB adhesive respectively, measure their refractiveindex to verify the correctness of theoretical analysis. Measure transmittance ofcolloids with different TiO2proportions, it is found that when the mass ratio of TiO2and colloid more than10%, the transmittance is nearly zero. Make ageingexperiments with colloids of different doping density，find that when doping densityis0.05%, colloid s ability to UV-resistant can be promoted.Mix phosphor with colloids of different TiO2doping density, and observesettlement phenomenon. It is found that when the mass ratio of TiO2and colloid lessthan0.1%, there is no obvious impact on phosphor settlement. As the doping densityincreases, it can speed up phosphor settlement. Package LEDs with different dopingdensity, then measure optical performance, it can be found that as the TiO2dopingdensity increases, the blue light reduces and luminous flux reduces, correlated colortemperature and color rendering index drops.