Market structure and future development trend of high brightness LED chip

High brightness LED is mainly divided into infrared GaAs system and AlGaAs system, red, orange, yellow, green AlGaInP system, green and blue InGaN system, as well as UV GaN and AlGaN system. At present, the blue light effect of the InGaN system has been high, combined with four yuan of red and yellow light, has been widely used in Yu Zhaoming, backlight, display, traffic lights and other fields. UV LED has a broad market prospect, semiconductor UV light source in lighting, sterilization, medical, printing, biochemical testing, high-density information storage and secure communications and other areas of great application value. Infrared LED includes infrared LED peak wavelength from 850nm to 940nm, widely used in remote control, drive, computer mouse, sensor, safety equipment and display backlight field, infrared LED demand growth is mainly driven by household appliances, security systems and wireless communications products etc..

The application of white light is an important market and the most important development direction of the blue chip LED, which uses blue chip and YAG yellow phosphor to form white light source. At present, the international giant LED has obvious advantages in high power blue chip, while LED chip is currently the main domestic enterprises have great development in small and medium power blue chips, but due to excessive investment in previous years due to overcapacity, leading to small and medium power light blue chip market appeared more serious price "war". For Blu ray LED chips, the main direction of development for the silicon based LED chip, high voltage LED chip, flip chip LED, etc.. For small and medium power LED chip market, the current trend of the mainstream market for the 0.2-0.5W market, including 2835, packaging and packaging, such as COB. For other segments, such as the vertical structure of the chip, the package can be applied to directional lighting applications, such as flashlights, miner's lamp, flash, spotlights and other lamps and lanterns products.

Silicon substrate LED chips gradually attention

The blue chip market mainstream are generally grown on sapphire substrate, in which Japan Nichia Corporation as the representative; in addition there is a blue chip is grown on a silicon carbide substrate, with CREE as the representative.

In recent years, more and more attention has been paid to the blue LED chips grown on silicon substrates. The silicon substrate due to the automatic production line can be used for IC factory, relatively easy to adopt mature technology of IC factory 6 inch and 8 inch line at present, coupled with the large size silicon substrate is relatively low cost, and thus the future silicon substrate LED chip costs are expected to decline, but also can promote the rapid penetration of semiconductor lighting. Silicon based LED chip has the following characteristics:

Vertical structure, the use of silver mirror, can make the current distribution more uniform, so as to achieve high current drive;

The silicon substrate has good heat dissipation, which is favorable for the heat dissipation of the chip;

It is characterized by Lambert luminescence, uniform light, easy to carry out the two optical;

Suitable for ceramic substrate packaging;

Suitable for LED flash and directional lighting applications, can be used in indoor, outdoor and portable lighting market.

In the development of silicon based LED chip, crystal energy in 2009, the introduction of low-power silicon based LED chip, is widely used in the field of digital display. Photo released a new generation of high power silicon LED chip products in Guangzhou in June 2012 to crystal, attracted the attention of domestic and international LED industry, launched four silicon high power LED chip including 28mil, 35mil, 45mil and 55mil, including 45mil chip to 120lm/w light effect, and achieve the 130 lm/w at the end of the year, and the reliability is good. Silicon based LED chip ceramic packaging, with the internationally renowned products, has a good price performance, resulting in domestic and foreign packaging plants and LED Lamps Factory Great interest. It is reported that SHARP and Puri also announced at the end of 2012 to achieve a production of silicon substrate white chip, introduced two white chip; in addition, the research including Samsung, OSRAM, giant crystal electric is also actively engaged in silicon chip LED.

LED market is at a stage of rapid development, the further decline in the cost of LED chips will promote semiconductor lighting into the whole family. The silicon substrate has the characteristics of low cost, IC factory mature manufacturing process, with the continuous development of 6-12 inch large size silicon LED technology, LED technology based on silicon will have great advantages in reducing cost and improving production efficiency, the LED industry will have a significant impact.

High brightness chip facing the development bottleneck

At present, the further development of the semiconductor lighting market requires the Blu ray LED chip to improve the efficiency of light, the cost should continue to decline. At present, CREE silicon carbide based LED chip has achieved the production of 200lm/w light efficiency products, R & D level of light efficiency can reach 276lm/w. In the LED chip cost decline and enhance the efficiency of light in this race, the following are facing the development bottleneck.

The first is the blue chip Droop effect. In the condition of high current density, the external quantum efficiency of light emitting diode will decline, there results show that the Droop effect is caused by a variety of reasons, including the Auger effect, the effect of limiting the blue chip under high current density, thus impeding the lumen cost down.

Second is the green energy gap (Green gap) and the red energy gap (Red gap). The quantum efficiency of LED decreases when the wavelength is from the blue light to the green band, such as the green quantum efficiency of 530nm decreases rapidly. For the red light, the internal quantum efficiency can be obtained in the deep red spectrum