With the continuous development of LED lighting technology and the increasing attention paid by society to the energy crisis, the LED lighting industry has ushered in a period of full-scale explosion, attracting a large number of funds and enterprises to enter, and the competition in the lighting market has become increasingly fierce.
If we look at the development of LED lighting technology, we can talk about it from three aspects: chip level, packaging level, and application level. The chip level mainly focuses on the manufacturing technology of LED; the packaging level is mainly about 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, the development and use of new materials, and the development and improvement of environmental lighting quality evaluation technology.
Chip level
The pursuit of high luminous efficiency has always 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. Sapphire and its supporting vertical structure laser substrate lift-off technology (LLO) and new bonding technology in substrate materials will still dominate for a long time.
But in the near future, metal semiconductor structure will be used to improve ohmic contact, crystal quality, electron mobility and electrical injection efficiency. At the same time, the extraction efficiency of light will be improved by roughening the surface of LED chip shape and photonic crystal, high reflectivity mirror and transparent electrode. At that time, the total efficiency of white light LED can reach 52%.
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 of 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. Ví dụ, it is 3W now, and 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 application systems.
In short, flip chip method, high voltage, and silicon-based gallium nitride will still be the development direction of semiconductor lighting chips.
Packaging level
Chip-level 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 for positive packaging; at the same time, the COB/COF technology with flip-chip structure is also the focus of packaging manufacturers, and the integrated packaged light engine will become the research and development focus of the next season.
The popularization of power-free solutions (high-voltage LEDs) and COB/COF applications: Driven by cost factors, power-free solutions have gradually become acceptable products, and high-voltage LEDs fully cater to power-free solutions, but what needs to be solved is chip reliability. With the advantages of low thermal resistance, good light type, no welding, and low cost, COB applications will be widely popularized in the future.
Ngoài ra, medium power will become the mainstream packaging method. 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 defects. Medium-power LED products that combine the advantages of both have emerged.
There is also 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.
For the demand for light quality, for indoor lighting, the LED color rendering index CRI is 80 as the standard and 90+ as the goal, and the light color of lighting products is as close to the Planck curve as possible, so as to improve the light quality of LED. In the future, indoor lighting will also pay more attention to the quality of light.
By optimizing LED packaging technology, the light efficiency is further improved, and it has exceeded 200lm/W, which is much higher than other traditional light sources used in large quantities. The heat dissipation performance of LED lamp beads will be further improved, the reliability will be further improved, and the life of lamp beads will be further extended, so that the light color quality will be further improved, and finally the comfort of human eyes will be further improved.
LED application research and development level
Currently, application manufacturers mainly use new heat dissipation materials, advanced optical design and new optical materials to achieve cost optimization 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. Development of LED lighting fixtures based on reliability design, and development of high-performance LED lighting fixtures that maintain color/brightness consistency during the use 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, which makes 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.
The characteristics of LED lighting fixtures are:
The shape of the lamp is free and the appearance is creative;
The size of the lamp is free and the size is flexible;
The light quantity of the lamp is free and the lighting is on demand;
The spectrum of the lamp is free and the light color is smart;
The position of the lamp is free and the installation is arbitrary.
In the future, the shape of LED lamps will no longer be limited to the shape of traditional lamps, but will tend to be free and hidden. The free shape can meet individual needs on the one hand, and can be used as a decoration on the other hand; the hidden nature of LED will make the lighting fixtures hidden in an embedded form but ubiquitous.
At the same time, LED lighting products can realize the arbitrary control of light lumens, no longer limited to a fixed wattage in a certain area and a certain scene, which will be a great technological advancement.
Intelligent lighting: future development trend
Intelligent lighting refers to the use of intelligent clients to collect, process and control information, and achieve safety, energy saving, health and comfort through functions such as brightness adjustment, light switch distribution control, spectrum adjustment control, scene setting, vân vân.
The characteristics of intelligent lighting technology include distribution, remote control and telemetry, openness, compatibility, interactivity, vân vân.
To achieve intelligent lighting, it is necessary to have client intelligent operation technology and data collection technology, Internet data transmission technology, cloud big data management and analysis technology, and customer online experience situational lighting technology. Only based on these technologies can intelligent lighting be truly realized.
The requirements for intelligent lighting in the future are personalized display, simple control, and emotional sensing.
Because home lighting has simple lighting needs and is easier to control, intelligent LED lighting will start from here. Tuy nhiên, with the development of technology, a good lighting system will be needed even in public places in the future. Ví dụ, the demand for intelligent outdoor landscape lighting is very high, but technology is difficult to meet the demand.
How to break through the technical bottlenecks and price barriers of intelligent lighting in public places such as outdoor lighting and commercial lighting has also become an urgent problem to be solved.
Intelligence is an inevitable trend in future life. The intelligence of LED lamps is only a small part of the intelligence of various home appliances. Enterprises must make lamps intelligent and diverse through technological research and development to meet the personalized needs of customers. Tuy nhiên, due to the high cost and poor product matching of intelligent lighting technology, LED intelligent lighting products cannot be popularized.
With the improvement of technology, the stabilization of product performance and the reduction of costs, intelligent LED lamps will definitely be widely circulated in the market. Whether LED companies have mastered intelligent lighting technology and designed products and intelligent control systems that meet market demand largely determines whether the company can develop in the long run.
From the perspective of usage scenarios, different scenarios have different lighting needs. As a torrent of LED lighting, the development of LED indoor lighting has gone through three main stages:
1. Improve product performance.
In this stage, LED companies focus on improving product efficiency and ensuring the lighting quality of LED products, such as improving the efficiency of LED light sources, MR16 lamp cups and LED modules;
Second, optimize costs.
In this stage, companies should try to shorten the product recycling cycle, increase their own product capacity, and produce cost-effective products accepted by customers by improving product research and development technology;
Third, lead the digitalization of light.
There are three important indicators for measuring the quality of indoor lighting: physical indicators, physiological indicators and psychological indicators. Different lighting environments will affect consumers’ physiological indicators such as heart rate and blood pressure, thereby affecting consumers’ psychological comfort. In lighting applications, physiological indicators and psychological indicators are more important.
In the future, indoor lighting will not pay too much attention to light efficiency, but will pay more attention to the quality of light, pay more attention to the emotional experience of customers, create a pleasant environment through the perception of light, and the color difference of lamps in different observation directions. The color difference, color drift and stroboscopic of LED products themselves will affect the indoor lighting effect.