作者：Blade

LED road lighting products should be more intelligent and environmental-friendly

Recently, Zhuhai (Guangdong Province) announced a large energy-saving project: replacing more than 90,000 traditional streetlights with LED road lighting products before the end of 2013.

 

LED road lighting products should be more intelligent and environmental-friendly

 

LED lighting technology has a lot advantages: high technical content, low power consumption, environmental friendly, etc.. The application field has expanded from residential lighting to road lighting. Outsides Zhuhai, many other cities, like Suzhou, Changde, Chongqing announced LED road lighting related projects in the past two years. The huge energy-saving potential became the biggest motivation behind. During the United Nations Conference on Sustainable Development held in this in Rio, the Climate Group released a copy of independent global research report. According to this report, LED road lighting products are estimated to save more than 85% energy. It is also showed that city activities consumed approximately 70% energy in the world, in which 15% from the street lighting area.

 

In addition to their energy-efficient feature, realizing intelligent control will further improve the energy-saving performance of LED road lamps. In this respect, it is Philips that be the pace maker and has already owned many innovative researches and patents. Their Starsense & City Touch light control platform could connect every light source to the central control platform through wireless, and realize intelligent remote control to these lamps. This lighting system can self-adjust each single  LED Panel Light source in accordance with the actual situation: the flow of people/vehicle, the traffic condition and weather. “These intelligent lighting system can help us to detect pedestrians and vehicles on the road. They can automatically be dimmed and turned off if no vehicles or people have been “seen” by sensors. Intelligent designs made the entire LED lighting system more environmental-friendly.” Explained by Dr. He Dana, senior vice president of Philips Group Research Institute, Asia chief technology officer.

 

According to statistics, in 2011, the domestic LED road lighting industry (including LED streetlights and LED tunnel lights) will realize a total output value of 35 billion yuan and total production output of 910,000, 2.9 billion yuan coming from street lighting area (totally 680,000 pieces). It is predicted that by the end of 2012, the production value LED road lighting products will account for 50% of the entire road lighting market. The urbanization will further stimulate the demand for LED street lamps.

LED energy saving lamp – the future of investment potential of the led industry

2009 was destined a China ” LED “, in April, Ministry of national science and Technology launched the ” Ten City ” plan “. In July 24th, the national development and Reform Commission and the United Nations Development Programme ( UNDP ), the global environment facility ( GEF ) cooperation ” Chinese phasing out the incandescent lamp, energy saving lamps promotion ” project signing ceremony was held in Beijing. United Nations Secretary-General Ban Ki-moon, national hair changes appoint vice director Jie Zhenhua, Chinese Ambassador Zhang Yesui, Li Yong of undersecretary of Ministry of finance, the United Nations Development Programme ( UNDP ) chief representative of China Ma Heli attended the signing ceremony. This marks China’s green lighting  usher into a new level to the international cooperation.

the future of investment potential of the led industry

In fact, the State Ministry of Finance in 2008, begin to execute ” the promotion of efficient lighting products financial subsidies to fund management Interim Measures ” have LED semiconductor lighting products included in the scope of subsidies, then the corresponding supporting tax policies have been introduced. This is a industry unprecedented support. By 2008 Beijing Olympic LED application continues to have a fever, and the 2010 World Exposition in Shanghai, Guangzhou Asian Games and the 2011 Shenzhen World University Games coming soon, driven by the large LED billboard, architectural landscape lighting application opportunities, also it was 2009 LED industry focus.

The support of the government, the national energy-saving emission reduction policies led will be the driving force for sustainable development of LED road lighting and led tunnel light market, in addition to international exhibition, event promotion, governments large purchases and LED street demonstration program implementation, and LED street lamp in LED industry where the specification is made in succession, expects 2009 global LED street lamp market penetration will break through 1%, and began to enter rapid growth period.

On how to carry out the “Ten City ” ” LED pilot demonstrative city, Gao Xinsi of Ministry of science and technology to business offices original proposed scheme the initial idea is: through LED in municipal lighting demonstration project as the carrier, to choose 10 city to promote the application of LED lighting (including lamps, tunnel lights, Metro and led tunnel light rail, gas station, underground parking and other functional lighting) 10000 sets or above. According to LED product technical efficiency, energy conservation effect and the economic and social benefits, taken after subsidies, subsidies, but right now it still has not issued a document.

Policy make the environmental lights in enterprise survival and different

In 2009, the promotion activities at present in state financial subsidies for energy-saving lamps are like a raging fire throughout the country. This year the country plans to extend the 120000000 highly efficient environmental lights products, the central finance will be paid 600000000 yuan special funds for subsidies for residents to purchase energy-saving lamps. In addition to the central government funds, local governments also have specialized finance for local area energy saving lamps promotion allowance. In short, this year’s 120000000 highly efficient lighting products, the broad masses of residents spend only half or 1/3 of the price to buy.

environmental lights

Today the state financial subsidies purchase for energy-saving lamp will adopted by bidding to the whole society, through bidding, the last a total of 23 home lighting companies short-listed government financial subsidies list, these enterprises are the lighting industry in China which is relatively well-known brand, whether the enterprise scale and product quality and product R & D, walk in front of the similar enterprises. This includes opple lighting, OSRAM, Zhejiang sunshine, FSL Philips Lighting appliances, domestic well-known lighting brands.

State financial subsidies for energy-saving lamps take tender procurement, the strength of a strong, in the energy-saving lighting products that has great attainments in bidding enterprises is undoubtedly a great advantage. But once the government’s energy saving lamps procurement, these enterprises will gain enormous economic benefits at the same time, the brand will also get a great promotional opportunities. Many lighting enterprises of national subsidies for energy-saving lamps bidding interest also illustrates the potential business opportunities in the inside.

At present, the biggest factor for restricting energy-saving lamp popularization is price. Even though incandescent lamp save more energy, yet the price compared with energy saving lamp and environmental lights, a little more than ten times, for ordinary people, whether to choose cheap one but energy-consuming incandescent lamp, or expensive but energy efficient lighting products, it may also have to consider. This research results, probably is the choice of incandescent lamp, an incandescent led tunnel light in his life took charge of electricity is not better than energy-saving lamp high price.

The country take the way of financial subsidies to promote energy-saving lamps to the general public. To lead people to have very low price to buy high-quality energy-saving lamp, it is important to promote energy-saving emission reduction. But this policy, in addition to, have social sense, for lighting enterprises influence can not be ignored.

Current status and development of lighting industry in China

The advent of lighting products have a long history dating back now, but it is not a long time to develop as an industry. The lighting industry has been in the direction of the scale, brand development. The more well-known brands in the worldwide Philips, Os-ram, GE, Panasonic and others. In recent years, the share of sales of these enterprises accounted for 40-60% of the global lighting market.

Current status and development of lighting industry in China

The lighting scale in China’s lighting industry

The rapid economic development and the formation of the global processing and manufacturing center provide the opportunities in the lighting industry and at the same time, accompanied by increasingly fierce competition. To the end of February 2009, the lighting industry had more than 2963 companies, small businesses accounted for nearly 90% of the proportion, and large enterprises is only 15. Although there are a number of firms, yet a smaller proportion lighting limited to reach large-scale production led tunnel light. So the scale production of lamp enterprise are even more smaller, and unable to generate economies of scale. The lighting industry, large and dispersed, low industrial concentration, the whole industry is not more than 1% of a company’s market share. In lighting technology is highly developed, the format is quite mature in developed countries such as Germany, the United States and Japan, the entire lighting industry after several strong corporate integrated industry, 2 – 3 controls more than 95% of the country’s market share, industry concentration is very high.

Lighting companies in China

Competition in the domestic market are becoming more international, Philips, GE, Os-ram, represented by the internationally renowned brand known for its high-end technology accumulated over the years and the brand advantage, after several years of running, as well as the understanding of the Chinese market, has entered a stable development period, and occupy a great proportion of high-end products in the domestic market. Domestic enterprises with its price and service advantages are mostly positioning in the low-end market. With the lighting industry competition stage of evolution, whether it is to occupy the high-end market–Philips, GE, OSRAM and other international giants, still in the low-end market–FSL, Zhejiang sunshine and other domestic brands, no one can occupy more market share.

The future development of the LED lighting market forecast and analysis

LED lighting, as a new generation of lighting products, has its own strong advantages: energy saving, high brightness, high efficiency, long service life, environmental protection, because the LED lighting with these merits, so it decided that he would revolutionize the lighting market! From quantitative change to qualitative change. If 1 – 2 years after, LED lighting market enter into the family, so the needs will be not million units, but in one billion, 10 billion for the unit, so it is visible that the market has huge potential business opportunities, and rich. Shanghai long core semiconductor, as a domestic enterprise, has its own characteristics in the power management and LED driver contributing to the development of LED lighting!

The future development of the LED lighting market forecast and analysis

If you want to accelerate LED lighting of the family, it is the important factor to restrict the performance and cost. LED lamp itself can be divided into two main parts : one is the LED drivers, two is LED semiconductor itself. So far, I think LED driving part determines the LED lighting performance, only a stable and efficient drive system can reflect all the advantages of LED lighting, if there is no a good drive system, not only a lot of advantages of LED lighting display, but also plays the side-effect. Domestic LED driver design standards, although many companies involved in and made ​​a lot of products, but still in the Warring States Period, there is not a mainstream program, and there is not a company’s products who is the LED lighting market Leader ! Perhaps there was no good LED driver programs in the past. Most of led tunnel light domestic lighting manufacturer have wrong theory, they just do some big projects in order to meet the market, mainly to do some big orders, just do a lot of LED lights projects, and big orders. They just make a little simple process for LED lighting, because they think it is just can be enlightening. Resulting in inefficiency and waste of resources; drive current instability, uninterruptedly power supply, pulse power, greatly shorten life of the LED lights, which can be said that being contrary to the concept and design of LED lights.

Avoid over-reliance on the government to promote led lighting industry

With the increasingly high demands of energy saving and environmental protection, as well as the start of semiconductor lighting engineering Ten thousand ten cities projects, China has basically identified as the main direction of LED outdoor lighting. Among them, LED street gains a lot of attention by the government as an important entry point for promoting lighting applications market. LED chip and packaging technology continues to progress, we can easily find many elevators, buses, aircraft cabin, restaurant entrance, even including the 2009 National Day military parade, in many star concert, taking the led lighting industry as a role to protagonist Guangyao Quartet. The application of these iconic milestone event, gives more prominence to the significant increase in the trend of white LED applications in China. Coupled with the issues of environmental protection and energy conservation under global attention, including North America, Australia, Japan and Taiwan are the development of energy-saving and carbon reduction regulations and lighting standards will contribute to the development of LED lighting applications market. This also means that the LED lights will immediately become innovative technology to dominate the field of road lighting, therefore, the people regard 2009 as the development of China’s LED Street Light golden year.

Avoid over-reliance on the government to promote led lighting industry

Avoid over-reliance on the Government to promote

The street light is a public works in led lighting industry, government investment is the key elements driving market development. If there is no value added to a product or social benefits, just with any government investment to form a sound market alone, it is very difficult, that is that say the government in overnight can let the market surge. And it is also likely to disappear with overnight, especially in China, where there is a high country of such a policy execution, greater market uncertainties.

China’s relevant government tender and plan put forward in succession. They make the majority of manufacturers more optimistic in the domestic LED street lamp and led tunnel light market size estimation. But in fact, a lot of construction bid or government, implementation of the scale and scale are obvious drop, plus local interest disputes, the manufacturers, whether can obtain the expected market interest or not remains to be seen. We should not be overly optimistic, and also over-reliance.

LED enterprises should be on the alert: EU intends to raise the standard

EU intends to raise the corresponding standard for directional energy-efficient lamps and directional LED lights: EU can only accept directional LED lights and directional fluorescent lamps with energy efficiency coefficient larger than or equal to 0.2 (2.5 times higher than previous energy efficiency standard). The U.S. government launched even more strict standards for directional lighting devices, more strict market supervision and inspection procedures.

 

LED enterprises should be on the alert: EU intends to raise the standard

 

At present, there are more than 3000 LED enterprises in Guangdong, most of which are exporters to Europe and North America. The announcement of new standards from EU and the U.S. government exerted huge influences on our LED industry and export products. According to the estimation of WTO/TBT Notification and Enquiry Center of Guangdong Province, LED enterprises in Guangdong Province will therefore increase the production cost of around 40 billion yuan.

 

In recent years, regions and countries in Europe and the United State continued to limit the export of Chinese products via their technological advantages and patent monopoly, in order to protect the domestic industry. These technical barriers usually caused great loss to our manufacturers, and meanwhile reflected the defects of them: lacking of core technologies and patents, being subject to foreign technologies and enterprises in some areas.

 

In fact, this problem has been existed for a long time. Not only the LED industry, many other industries hindered by such problem, which also blocked the development of relevant industries in China. But now this problem is particularly acute in the led tunnel light industry, waiting for effective solutions urgently.

 

The current state of the domestic LED industry is: low LED technical content and products with different qualities, having no obvious advantages no matter in the international market or in the domestic market. Cutting price is the last and the most upset solutions for them, leading to price war and vicious competitions. In order to survive under such circumstances, many LED manufactures tried to reduce production costs instead of improving their technologies. This is sign of vicious circle and final destruction. Indeed, companies could get short-term profits by doing so, but it is impossible for them to have a long-term sustainable development. And the promotion of LED and other green light sources will take a heavy toll.

How to improve the lifetime of LED chips?

In order to extend the lifetime of LED chips, the most commonly applied method is to change sealing materials, mixing fluorescent materials within them. Siliceous sealing material is more effective in slowing down the material deterioration and lighting attenuation than traditional epoxy resin sealing materials used on blu-ray/ultraviolet LED chips.

 

In order to extend the lifetime of LED chips, the most commonly applied method is to change sealing materials, mixing fluorescent materials within them.

 

The epoxy resin sealing material can absorb around 45% rays with wavelength of 400-450nm, while siliceous sealing materials absorb less than 1% rays within this range. According to estimation, the lifetime of LED chips using epoxy resin packaging materials (light attenuation reach 50%) is less than 10,000 hours, while siliceous package could extend this period to more than 40,000 hours. This is almost equivalent to the service life of the entire lighting device. In another word, the corresponding LED lamp is in no need to replace the LED chips during its operation lifetime. However, siliceous resin is a kind of high elasticity soft materials. Special production technologies must be used during the production process. In addition, dust could be easily attached to siliceous resin materials. Thus developing improved surface characteristic technologies are necessary in the future.

 

Although siliceous sealing materials can ensure a 40,000-hour service life of LED chips, but the lighting application industry have a different view. The main debate is on the service life of traditional incandescent lamps and fluorescent lamps, which has been defined as “brightness dropped to less than 70%”. As we mentioned before, the approximate time of 50% light attenuation of LED lights is 40,000 hours. If calculated as the specification of 70%, then the lifetime of LED chips will recued to 20,000 hours. There are two major countermeasures for this condition:

  1. Limit the heat generation of white-ray LEDs;
  2. Stop using the resin encapsulation;

 

It is generally believed that, the LEDs’ service life could be extended to 40,000 hours (30% light attenuation) by using above two methods. Cooling PCBs is a mostly used method to limit the temperature rising of white-ray LED chips. Basically, the encapsulation resin material will rapidly deteriorate in the high temperature state and under highlight. Stop using resin package can completely eliminate the deterioration, since led tunnel light rays are reflected in the encapsulating resin. Using special resin reflecting plates which are able to change the traveling direction of light from chip side surfaces, the entire light extraction will be sharply dropped. This is the main reason that all LED manufacturers choose to use ceramic and metal based package.

Using heat sinks to solve the heat dissipation problem of white-ray LEDs

In order to reduce the thermal impedance, many foreign LED manufacturers set LED chips on heat sinks made of copper and ceramic materials. Then welding connect them with printed circuit boards. According to the test result of German OSRAM Opto Semiconductors Gmb, the gap thermal impedance between LED chips and welding points mentioned above could reduced to 9K/W, about 1/6 of the conventional LEDs. For example, if the input power is 2W, the bonding temperature of LED chips will be 18K higher than welding points. In normal conditions, the bonding temperature of LED chips will be impacted by PCBs. Thus reducing LED chip working temperature is necessary, namely reducing the thermal impedance between LED chips and welding points. This can effectively reduce the cooling operation burden of LED chips. Conversely, even if white-ray LEDs have special structure to limit the thermal impedance, if heat cannot be successfully conducted from packaging structure to PCBs, the luminous efficiency will reduce dramatically as a result of LED temperature rising. Thus Matsushita Electric developed a new PCB-package integration technology, which can package the 1mm square blue-ray LEDs to ceramic substrates in the form of flipchip. Then attach ceramic substrates to the surface of copper PCBs.

 

Using heat sinks to solve the heat dissipation problem of white-ray LEDs

 

The tightness between heat sinks and PCBs directly affects the heat conducting effect. Therefore the design of PCBs became rather complex. As a result of these, many LED packaging manufacturers (like United States LumiLEDs, Japan CITIZEN) have developed high-power led tunnel light with simple cooling technologies. CITIZEN began to provide white-ray LEDs (new package samples) to their customers. The new heat dissipation technology could directly remove the heat on heat sinks (2-3mm) without any help from special bonding technique. According to CITIZEN, although the thermal impedance between LED chips and welding points is approximately 30K/W, much higher than 9K/W of OSRAM, this white-ray LED model still can maintain a normal working condition even no cooling ventilators are used.

 

LumiLEDs started to promote high-power white-ray LEDs from 2005, the maximum LED chip bonding temperature can reach up to +1850C, 600C higher than similar products from other companies. If using traditional RF4 PCB package, within the ambient temperature range of 0-400C, the equivalent power can be 1.5W (approximately 400mA).

White high-brightness LED packaging structure can extend the lifetime of LED chips

White LEDs can be much brighter than general LEDs and also have similar power consuming characteristics than fluorescent lamps, but on the basis of overcoming the following four shortcomings: a. temperature rising; b. unstable service life; c. need-to-be-improved luminous efficiency; d. the equalization of luminous characteristics; If we can start with the white high-brightness LED packaging structure, everything seems much easier.

 

White high-brightness LED packaging structure can extend the lifetime of LED chips

 

The basic solution for the temperature rising problem is reducing the thermal resistance of the package; improving the chip shape, using small chips can sustain the lifetime of LEDs; there are also some specific methods for equalizing the luminous characteristics of LEDs. Generally, LEDs generated after 2005 can improve their performances though above methods.

 

There are many other methods to increase the lifetime of LEDs, for example, using siliceous sealing materials and ceramic packaging materials can increase LEDs’ lifetime by 10%, especially useful for white LEDs (which spectrum contains wavelength below 450nm). Short-wavelength rays can easily cause damages to traditional epoxy resin sealing materials. White high-brightness LED packaging structure will speed up this process. According to industrial tests, after approximate 10,000-hour continuous lighting, the brightness of high-power white LED applications usually reduced by more than 50%, which can hardly meet the basic requirements for long-term lighting.

 

Improving chip packaging structure can improve the luminous efficiency of high-power white LED products, achieving the same level of low-power LED products. Basically, when the current density is increased by more than 2 times, the extraction of light from high-power LED chips will become more difficult, leading to the dilemma that the luminous efficiency of high-power white led tunnel light is much lower than that of low-power white LEDs. In theory, improving the electrode structure of chips can solve the extraction problem mentioned above.

 

About the equalization of light-emitting characteristics, it is generally believed that improving the uniformity of material (phosphor) density and production technologies of phosphor can overcome this distress. We need also reduced the thermal impedance of white high-brightness LED packaging structure to improve the heat dissipation process, as well as increase the input voltage: a. reduce chip-to-package thermal impedance; b. suppressing the thermal impedance from package to PCBs; c. smooth chips’ cooling performances.