A. The improvement of luminous flux still needs to be further improved at the basic level of high-power LED epitaxial technology and chip technology. The method for producing white LED at home and abroad is to first place the LED chip on a packaged substrate, bond it with gold wire, then apply YAG fluorescent powder around the chip, and then encapsulate it with epoxy resin. Resin not only protects chips but also serves as a condenser. The blue light emitted from the LED chip is reflected and absorbed multiple times into the surrounding fluorescent powder layer, and finally emitted outwards. The peak of the spectral line of LED (blue) is at 465nm, with a half width of 30nm. The partial blue light emitted by the LED excites the yellow YAG phosphor layer, causing it to emit yellow light (with a peak of 555nm). A portion of the blue light is emitted directly or after reflection, and finally reaches the external light, which is blue yellow dichroism, i.e. white light. FlipChip technology can achieve more effective light output than traditional LED chip packaging technology. However, if a reflective layer is not added below the electrode of the chip's luminescent layer to reflect the wasted light energy, it will result in approximately 8% light loss. So it is necessary to add a reflective layer on the bottom plate material. The light on the side of the chip must also be reflected by the mirror surface of the heat sink to increase the output rate of the device. Moreover, a layer of silicone material should be added between the sapphire substrate of the flip chip and the light guide interface of the epoxy resin to improve the refractive index of the chip's output light. Through the improvement of optical packaging technology, the output rate (luminous flux) of high-power LED devices can be significantly increased.

B. Optimize the design of LED lighting fixtures to improve the quality of LED usage. Therefore, it is particularly urgent to study the secondary optical distribution design of high-power LED light sources to meet the needs of large-area projection and floodlighting distribution. By using secondary optical design technology to design additional reflective cups, multiple optical lenses, and aspherical output surfaces, the light extraction efficiency of the device can be improved. The traditional light source illumination direction is 360 °, and the lamp relies on a reflector to reflect most of the light to a specific direction. Only about 40% of the light directly reaches the road surface through the glass cover, while the other light is projected out of the lamp through the reflector. The efficiency of the reflector of the lamp is generally only 50%~60%, so about 60% of the light output is in the lamp, and it is projected onto the road surface after a loss of 30%~40%. A large portion of the light output from the light source is limited to the internal heat consumption of the lamp. The vast majority of the light emitted by LED lamps is front beam, which can achieve a light efficiency of>95%. This is one of the important characteristics that distinguish LEDs from other light sources. If this feature is not well utilized, it will greatly discount the advantages of LEDs. Most high-power LED lights, due to the assembly of multiple LED chips, need to illuminate so many light sources in different directions. We fully utilize the characteristics of the overall packaging of the chip and use lenses to solve the problem. Through optical design, different convex curves are equipped according to different needs, and the lens is used to distribute light in different directions, ensuring that the angle of light output can reach 120 °~160 ° for large ones and 30 ° for small ones, Once the lens is finalized, under the premise of ensuring production technology, the light distribution characteristics of the same type of lamp will also reach consistency. It is completely possible to achieve the bat wing light type required by road lighting standards for LED street lights through multiple trial productions and continuous experience summarization. Tunnel lights, street lights, and general lighting have met the lighting requirements of their respective application areas.