System short board hinder China's LED to general lighting

In the "national semiconductor lighting project", China's LED industry has initially formed a LED epitaxial wafer production, LED chip preparation, LED chip package and LED application products, a relatively complete industrial chain. Shenzhen, Nanjing and other major cities have also invested heavily in the formation of LED Industrial Park and industrial base, and promulgated the relevant LED industry development plan. At present, China's LED industry has formed 4 large areas, the base of the industrial structure of the 7.

Driven by the huge domestic demand, LED industry has a bright future, according to estimates, China mainland in "ten city lights" policy driven by the market demand will be 1 million 400 thousand LED street lamp this year, next year is expected to grow by 79%, up to 2 million 500 thousand LED street lamp, the total global demand exceeds 5. In addition, large-scale LED lighting and outdoor billboards will also be at a faster rate of growth. According to a research report by investment advisers show that in 2010 the output value of China's entire LED industry will be more than 150 billion yuan.

However, in a good situation, many industry experts began to remind, LED lighting technology is still difficult, to really move towards universal lighting, the system must solve the short board.

Light effect is not enough

In general, the general lighting requirements to achieve 130 lumens of light efficiency. The director of the national solid state lighting planning office Wu Ling said in an interview with the author, the light efficiency can only LED chip production in China reached 80 to 90 lumens, although some laboratory products can do 1000 lumens, but not mass production, the indexes of LED Limited on the promotion of general lighting.

According to experts, the so-called light effect, refers to the light source in a range of brightness. Although the LED chip in our country has made great progress in the past 5 years, it still can not meet the requirements of general lighting. I have learned that in 2005, the use of imported chip packaging, China's best white LED in the current 350mA light efficiency reached 30-35lm/W, while the use of domestic chip packaging is only 20-25lm/W. And now, the domestic LED chip package has reached a 350mA current efficiency of 80-90lm/W.

Although China's LED industry is getting stronger and stronger, but the performance of high brightness products is still lagging behind the world's leading level. Compared with overseas manufacturers, Chinese companies are small, there is a huge gap in product quality. Wu Ling said that the majority of domestic LED chip applications in the low-end products, while 85% of the high-power chips have to rely on imports.

In order to develop a high power LED chip, China's five year plan to promote the current has been designated by the cost of future research and research in the future of 33%. At the same time, the national solid state lighting project is also funded to support enterprises and research institutions to develop new technologies to improve the effectiveness of LED. The goal is to develop a 2010 to support the general lighting 130lm/W chip, and achieve large-scale production of 100lm/W chips. According to Wu Ling introduction. System instability "in theory, the life of the LED chip can reach 100 thousand hours. "Shenzhen semiconductor industry association secretary general Jin Peng pointed out, but life is not the chip is equivalent to the whole life of the lighting system, LED lighting components including chip, driver, radiator and a series of components, and the most advanced driver, its service life can reach 8000 hours, that is to say, the driver will precede the chip to reach the limit so, the whole lighting system will be installed.

Another troubling problem is the development of LED lighting light. Industry experts pointed out that many factors lead to failure, the chip as an example, from the experimental results, the influence of the wafer light is divided into two categories: the first is the chip of different materials resulted in attenuation of different, commonly used blue chip substrate material for silicon carbide and silicon carbide Blaupunkt stone, general structure design for single electrode. The thermal effect is good, the sapphire for the design of double electrode, heat is difficult to export, thermal effect is poor; second is the size of the wafer, the wafer material is the same, different sizes have different attenuation gap.

Experts said, LED lighting is a high-tech products, not only for the higher requirements of components, but also the quality of raw materials is also very important. In order to achieve a stable use effect, LED still has a long way to go.