Interpretation of the three levels of LED lighting technology: chip, packaging, and application
With the continuous development of LED lighting technology and the society's increasing attention to the energy crisis, the LED lighting industry has ushered in a period of full-scale outbreak, attracting a large number of funds and enterprises to influx, and thus the competition in the lighting market has become increasingly fierce.
From the perspective of the development of LED lighting technology, it can be said from three aspects, one is the chip level, the other is the packaging level, and the other is the application level. The chip level mainly focuses on the manufacturing technology of LEDs; the packaging level mainly focuses on how to convert LED chips into lamp beads or light sources that can be used for lighting; the technology development at the LED application level is relatively complex, mainly including the development of electronic control technology and the development of new materials. Development and use, development and improvement of environmental lighting quality evaluation technology.
Chip level
The pursuit of high luminous efficiency has been the driving force for the development of LED chip technology. Flip-chip technology is currently one of the main technologies for obtaining high-efficiency and high-power LED chips. The sapphire substrate material and the vertical structure laser substrate lift-off (LLO) technology (LLO) and new bonding technology will still be in a relatively long period of time. Dominate.
However, in the near future, the use of metal semiconductor structures to improve ohmic contact, improve crystal quality, improve electron mobility and electrical injection efficiency, and improve the extraction of light through the roughening of the surface of the LED chip and photonic crystals, high reflectivity mirrors, and transparent electrodes. Efficiency, the total efficiency of white LEDs can reach 52% at that time.
With the improvement of LED light efficiency, on the one hand, the chips are getting smaller and smaller, and the number of chips that can be cut on a certain size epitaxial wafer is increasing, thereby reducing the cost of a single chip. On the other hand, the power of a single chip is getting bigger and bigger. , If it is 3W now, it will develop to 5W and 10W in the future. This can reduce the number of chips used for lighting applications with power requirements and reduce the cost of the application system.
In short, flip chip, high voltage, silicon-based gallium nitride will still be the development direction of semiconductor lighting chips.
Package level
Chip-scale packaging, LED filament packaging, high color rendering index and wide color gamut will be the development trend of packaging technology in the future. The use of transparent conductive film, surface roughening technology, and DBR reflector technology to improve the light efficiency of LED lamp beads is still the mainstream technology; at the same time, the COB/COF technology of flip-chip structure is also the focus of packaging manufacturers, integrating packaged light engines Will become the focus of research and development in the next quarter.
Power-removal solutions (high-voltage LEDs), the popularity of COB/COF applications: Driven by cost factors, power-removal solutions have gradually become acceptable products, and high-voltage LEDs fully cater to the power-removal solutions, but what they need to solve is chip reliability . With the advantages of low thermal resistance, good light profile, no soldering, and low cost, COB applications will be widely popularized in the future.
In addition, medium power will become the mainstream packaging method. At present, most of the products on the market are high-power LED products or low-power LED products. Although they have their own advantages, they also have insurmountable shortcomings. The medium power that combines the advantages of both LED products came into being.
There is also the application of new materials in packaging. Materials with higher environmental resistance 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.
For the light quality requirements, for indoor lighting, the LED color rendering index CRI is 80 as the standard and 90+ as the target. Try to make the light color of lighting products close to the Planck curve, so as to improve the light quality of LEDs. In the future, indoor lighting Lighting will also pay more attention to the quality of light.
By optimizing the LED packaging technology, the light efficiency has been further improved, and it has now exceeded 200lm/W, which is much higher than other traditional light sources that are used in large quantities. The heat dissipation performance of the LED lamp beads will be further improved, the reliability will be further improved, and the life of the lamp beads will be further extended, so that the light color quality will be further improved, and finally the human eye comfort will be further improved.
LED application research and development level
At present, application manufacturers mainly use new heat dissipation materials, advanced optical design and new optical material applications to optimize the cost of LED lighting products while ensuring product performance.
But in the future, LED lighting application manufacturers will focus on these points:
1. Interchangeable LED light engine technology based on application scenario requirements;
2. LED intelligent lighting system architecture technology based on the Internet of Things platform;
3. The development of LED lighting fixtures based on reliability design, and the development of high-performance LED lighting fixtures that maintain color/brightness consistency during the life cycle;
4. Development of lamps based on large-area high-efficiency diffuser technology;
5. Lighting system solution technology and service system for online light environment experience;
6. The rich color characteristics of LED light sources make scene lighting also the core competitiveness of LED lighting.
Traditional lighting fixtures are designed around the shape and size of the light source, and the size is fixed.
