The rapid development of the high power led lighting business is expected to increase the market demand of the white LED phosphor, in all walks of life continue to invest under the R & D energy of the phosphor, has developed three major white LED phosphor, can be expected in response to different applications to meet the requirements for the performance of diversity and demanding degree.
Light-emitting diode (LED) has a low heat, low power consumption, long life, fast response, small size, etc., the world's white LED lighting industry continues to flourish, especially in the application of the mobile phone panel backlight, lighting and automotive industries more infinite potential. In recent years, a number of panel manufacturers at home and abroad LED 200W into Notebook LCD backlight, replace the use of mercury in traditional cold cathode fluorescent tubes. From the viewpoint of environmental protection and energy issues in terms of incandescent bulbs has always been the presence of low energy efficiency and heat; mercury-containing fluorescent lamps, there are shortcomings of mercury pollution, this LED strip lights lighting will undoubtedly become the global lighting manufacturers all targets. Although the white LED used in the lighting of the people's livelihood are still many problems to be solved, However, for the foreseeable future, decreased manufacturing costs, and lighting applications are being developed under the next 10 years, the white LED is expected to become the great potential of lighting products.
Nichia Chemical of Japan in 1993 successfully developed the world's first commercial material indium gallium nitride (InGaN) blue, violet LEDs, but also accelerated the arrival of white LED lighting for generations. Nichia in 1996, published InGaN/Y3Al5O12: Ce3 + (referred to as YAG: Ce) phosphor single-die white LED, since the global warm expand the white LED technology research and development to compete.
White LED Blue 150W production technology on the market is divided into two main lines, the first to take advantage of the phosphor blue LED or ultraviolet UV-LEDs produce Blu-ray or ultraviolet light are converted to dual-wavelength (Dichromatic) or wavelength (Trichromatic ) white light, this technology is called phosphor converted white LED (of Phosphor Converted LED); second class compared to multi-chip type white LED, through a combination of two (or more) different shade of LED combination to form white light, the current The white light LED products on the market with a yellow phosphor to blue LED chip is most common, is mainly used in automotive lighting, mobile phone panels, etc., phosphor converted white LED white LED products market analysis, can be described as mainstream.
Figure 1 briefly summarizes and a variety of white LED packaging principles and the strengths and weaknesses, (a) The packaging, the best color rendering, but the most expensive, have not been able to popularize; Packaging (b) with technical the most mature and the cost advantage, but the color cast and poor color rendering, to be the appropriate red, yellow phosphors to improve, the most severe cases is difficult to avoid the Nichia patent restrictions; and packaging method (c) and (d) both produced white LED 400W color rendering is superb, the color is too small, low cost and patent limitations are less severe, and therefore of great potential for development in the future.