Biweekly in the digital age: LED becomes the revolutionary corner of the next generation of light sources




LEDs have high color saturation and specific characteristics such as filial piety and environmental protection. As energy conservation issues are taken seriously, they are gradually developing into indoor lighting and architectural lighting applications. In the first half of the year, Taiwan's LED output value was about 22 billion yuan. It is estimated that the output value in the second half of the year will increase by 14% compared with the same period of last year, showing a steady upward trend.

Since Edison invented the light bulb, it broke the darkness for humans and brought a bright vision. However, as environmental protection and energy conservation issues become more and more important, humans have been seeking new sources of illumination, from tungsten filament bulbs to mercury lighting, the role of light has even expanded from lighting applications to display applications, and the largest light source revolution in recent years. It is an LED (Light Emitting Diode).

An LED is a semiconductor that converts electrical energy into visible light. It uses a semiconductor chip as a material for illuminating, and emits energy in the form of photons through a forward voltage at both ends to generate a light source. LEDs have different illuminating properties than ordinary bulbs. Generally, bulbs use heat to illuminate. LED sources use voltage to illuminate the wavelength of light emitted by semiconductors.

Has long been a mobile phone panel light source

LEDs were developed as early as 1970. Until the red, orange, blue and green LEDs were released in 1991, the application of LED full colorization has been realized.

Because LED does not contain mercury, has a long life, high reaction speed, environmental protection, energy saving, and high color saturation, it has been applied to the source of light source for mobile phone panels since 2003. In recent years, it has gradually moved to the car. Use lighting, indoor lighting, dashboard lighting and even traffic display billboards, architectural lighting equipment, etc.

According to the survey of the Industrial Technology Research Institute, the output value of Taiwan's LED in the first half of 2006 was about 22 billion Taiwan dollars (about 5.5 billion yuan). It is estimated that the output value in the second half of this year will grow by 14% compared with the same period of last year. The market size of 26.7 billion yuan (about 6.67 billion yuan). ITIS (Industrial Technology Knowledge Service Plan of the Ministry of Economic Affairs) also pointed out in the report that the high-density LED industry has shown steady growth and will reach a market scale of US$5 billion (approximately RMB 4 billion) by 2008. .

High-brightness LEDs are used in a wide range of applications, and the most mature applications are mobile communication products. Tsai Yi-shing, an analyst at Tektronix Industrial Research Institute, said, "From 2003 to 2004, mobile phone panels and keyboards use LED as a backlight source. From 2005 to 2006, LED applications began to enter the car. With the light source market often with the EU's environmental protection claims, LED applications will continue to develop towards the backlight of large-size panels.

LCD monitors or LCD TV backlight sources rely mostly on cold cathode tubes (CCFLs) today, but with the future environmental issues and legal restrictions, it is bound to find a new source of backlight, and LED has become the backlight source that replaces CCFL's highest voice.

High prices have become the resistance to popularization

At present, Japanese manufacturers such as Sony, Toshiba, and Fujitus have launched notebook computers with LEDs as backlights, but the prices are several times more expensive than those of Taiwanese manufacturers. Although LEDs have recently had a large price drop, according to the research of the Institute of Industrial Research, the cost of a backlight module with LED as a backlight is still nearly five times higher than that of CCFL. This is one of the reasons why LED backlight applications in notebook computers and LCD TVs are not popular.

LED is used as the backlight of the display, because it is more power-saving, smaller, and can achieve more ultra-thin functions. The LED backlight panel is half the thickness of the CCFL backlight panel. In the power consumption section, the LED backlight panel also saves 20% to 30% of the power compared to the CCFL backlight panel.

In the future, LED will definitely replace the status of CCFL, and the city's Chang Cai, who is attacking large-size displays, analyzes. From the second half of 2006 to 2007, the LED application is mainly the backlight of notebook computers, to 2008. It will be applied to the backlight of LCD TVs after the year.

However, there are still technical problems in the application of LED backlights in display panels. The first is that the brightness of the die has a lot of room for improvement. If the brightness can be improved by optimizing the luminous efficiency, the number of LEDs can be reduced, thereby reducing the cost. In addition, there are heat dissipation problems, which are also problems encountered by the backlights of the 12-inch ED display panel.

Analysts believe that since the panel factory has mastered the development specifications of large-size LCD TVs, LEDs as the development of LCD TV backlights also depend on the panel industry's LED industry layout, including the upstream epitaxy mastery, midstream grain. The manufacturing and downstream die packaging, from the light source factory to the backlight module factory, to the TFT module factory, will be different price wars



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