LCD itself can not emit light, so it needs backlight to ensure its normal work, so the development of LCD industry will drive the development of backlight industry. Backlight is an important component of LCD module, its cost accounts for 3% ~ 5% of the total cost, and its power consumption accounts for about 75% of the total power consumption. High performance backlight is essential for high performance liquid crystal display. With the development of information technology, LCD technology continues to achieve new breakthroughs, LCD products are gradually to the direction of lightweight and diversified rapid development, at the same time, backlight must also be in accordance with this trend of development.