LED chip technology and variance analysis at home and abroad
The chip is the core component of the LED. There are a lot of the LED chip manufacturers at home and abroad, but no unified standard chip classification, classification in terms of power, there are points of high power and small power; If according to the classification of color,
Mainly for red, green, blue three; If according to the shape classification, generally divided into two kinds of square piece, wafer; If according to the classification of voltage, it is divided into low voltage dc and high voltage direct current chip. Chip technology at home and abroad
Than in terms of foreign new chip technology, heavy production not heavy domestic chip technology.
Substrate materials and wafer into key growth technology, at present, the LED chip technology substrate materials and wafer growth is the key of the development of technology. In addition to the traditional sapphire, silicon (Si), silicon carbide (SiC) substrate materials,
Zinc oxide (ZnO) and gallium nitride (GaN) is also the focus of current research LED chip. On market at present, most of sapphire and silicon carbide substrate is used to broadband gap semiconductor gallium nitride epitaxial growth, these two kinds of material price
Are very expensive, and monopoly by foreign companies, while prices of silicon substrate sapphire and silicon carbide substrate much cheaper, can produce larger substrate, improve the utilization rate of MOCVD, thus improve the tube core
Production rate. So, to break through the barriers to the international patent, research institutions and LED Chinese companies from working on silicon substrate material.
But the problem is that the high quality of silicon and gallium nitride is combined with the technical difficulties of the LED chip of lattice constant and the thermal expansion coefficient of the two huge mismatch caused by the high density of defects and cracks and other technical problem for a long time
The development in the field of chip.
There is no doubt that from the perspective of the substrate mainstream substrate is still a sapphire and silicon carbide, but silicon has become a development trend of the chip area in the future. For China's price is relatively serious, silicon substrate is more cost and price
Advantage: silicon substrate is electrically conductive substrate, not only can reduce the tube core area, you can also save on gallium nitride epitaxial layer of dry etching step, in addition, the hardness of silicon less than sapphire and silicon carbide, also in the processing
Can save some cost.
At present most of the LED industry to 2 inches or 4 inches of the sapphire substrate is given priority to, such as can use silicon technology of gallium nitride, at least 75% of the raw material cost can be saved. Sanken electric company estimated, using silicon substrate production
Size blu-ray gallium nitride LED manufacturing costs will be 90% lower than the sapphire substrate and the silicon carbide substrate.
The large difference of chip technology at home and abroad
Abroad, osram, American pury, sanken, first-class enterprise in large size silicon substrate on gallium nitride based LED research breakthrough, philips, samsung, LG, Toshiba and other international LED titans
An upsurge of gallium nitride based on silicon substrate LED the study. Among them, in 2011, the United States pury in 8 inches on silicon substrate to develop high photosynthetic efficiency gallium nitride leds, made with sapphire and silicon carbide substrate
Sharp LED device performance comparable to the level of the luminous efficiency of 160 lm/W; In 2012, osram successfully produce 6 inches silicon substrate gallium nitride-based leds.
In mainland China, the LED chip to enterprise technology breakthrough largely increase its production capacity and large size sapphire crystal growth technology, in addition to the lattice lighting in 2011 successfully 2 inches silicon substrate gallium nitride based power
Volume production of LED chip, chip Chinese companies in the silicon substrate gallium nitride LED research on no major breakthrough, the Chinese mainland LED chip companies or main production capacity, the sapphire substrate materials and wafer growth technology,