With the continuous development of LED lighting technology and the increasing attention of the society to the energy crisis today, LED lighting industry ushered in a comprehensive outbreak period, attracting a large number of capital and enterprises into the lighting market competition is increasingly fierce.
From the perspective of the development of LED lighting technology, it can be seen from three aspects: the chip level, the packaging level and the application level. At the chip level, the manufacturing technology of LED is mainly concerned. The packaging level is mainly about how to convert LED chips into beads or light sources that can be used for lighting. The development of LED application technology is relatively complex, including the development of electronic control technology, the development and use of new materials, and the development and improvement of environmental lighting quality evaluation technology.
The chip level
The development of LED chip technology is driven by the pursuit of high luminous efficiency. Flip chip technology is one of the main technologies for obtaining high-efficiency and high-power LED chips. Sapphire and its matching vertical structure laser substrate stripping technology (LLO) and new bonding technology will still dominate in the substrate materials for a long time.
However, in the near future, the metal semiconductor structure will be adopted to improve ohmic contact, improve crystal quality, improve electron mobility and electric injection efficiency. Meanwhile, the extraction efficiency will be improved by roughening the surface of the LED chip, photonic crystal, high reflectivity mirror and transparent electrode, and then the total efficiency of white LED will reach 52%.
With the improvement of LED light efficiency, on the one hand, chips are getting smaller and more and more chips can be cut on epitaxial chips of a certain size, so as to reduce the cost of a single chip. On the other hand, the power of a single chip is getting larger and larger, such as 3W now, and it will be developed to 5W and 10W in the future. This can reduce the number of chips used and the cost of the application system for lighting applications with power requirements.
In short, flip – chip, high voltage, silicon – based gallium nitride will continue to be the direction of semiconductor lighting chip development.
Chip level package, LED filament package, high color index and wide color gamut will be the development trend of packaging technology in the future. Using transparent conductive film, surface roughening technology and DBR reflector technology to improve the light efficiency of LED beads formal package is still the mainstream technology; At the same time, flip COB/COF technology is also the focus of packaging manufacturers, integrated packaging optical engine will become the focus of next quarter’s research and development.
De-energization solution (high-voltage LED), the popularity of COB/COF application: driven by cost factor, de-energization solution has gradually become an acceptable product, and high-voltage LED fully caters to the de-energization solution, but what it needs to solve is chip reliability. COB will be widely used in the future due to its advantages such as low thermal resistance, good light shape, no welding and low cost.
In addition, medium power will become the mainstream packaging. At present, most products on the market are high-power LED products or low-power LED products. Although they have their own advantages, they also have insurmountable defects.
And the application of new materials in packaging. Materials with higher environmental tolerance such as high-temperature resistance, uv resistance and low water absorption, such as thermosetting materials EMC, thermoplastic PCT, modified PPA and ceramic like plastics, will be widely used.
As for the demand of light quality, for indoor lighting, LED color rendering index CRI takes 80 as the standard and 90+ as the target to make the light and color of lighting products as close as possible to the Planck curve, so as to improve the light quality of LED. In the future, indoor lighting will pay more attention to the quality of light.
By optimizing LED packaging technology, the light efficiency has been further improved to over 135lm/W, which is far higher than other traditional light sources. LED bead heat dissipation performance will be further improved, the reliability will be further improved, lamp bead life will be further extended, so that the quality of light and color will be further improved, finally the comfort level of human eyes to achieve further improvement.
LED application research and development level
At present, the application manufacturers mainly adopt new heat dissipation materials, advanced optical design and application of new optical materials to optimize the cost of LED lighting products and ensure product performance. But in the future, LED lighting applications will focus on these points:
- Interchangeable LED light engine technology based on application scenarios;
- LED intelligent lighting system architecture technology based on Internet of things platform;
- Development of LED lighting based on reliability design and high-performance LED lighting with consistent color/brightness in the service cycle;
- Luminaire development based on large-area and high-efficiency diffuser diffusion plate technology;
- Lighting system solution technology and service system for online light environment experience;
6.LED light source is rich in color, which makes scene lighting the core competitiveness of LED flood lighting.