The technology of LED chip industry and the difference analysis at home and abroad
Chip, is the core of the LED components. At present, there are many led chip manufacturers at home and abroad, there is no unified standard chip classification, if by power classification, there are high power and medium and small power of the cent; if by color classification, the main is red, green, blue three kinds; if according to the shape classification, generally divides into the square piece, the round piece two kinds; if according to the voltage classification, then divides into the low-voltage DC chip and the High-voltage DC chip. Domestic and foreign chip technology contrast, foreign chip technology new, domestic chip heavy production technology.
substrate material and wafer growth technology is the key, at present, the development of LED chip technology is the key to substrate materials and wafer growth technology. In addition to traditional sapphire, silicon (SI), sic (sic) substrate materials, zinc oxide (ZnO) and gallium nitride (Gan) are also the focus of current LED chip research. At present, most of the market using sapphire or silicon carbide substrate epitaxial growth broadband gap semiconductor gallium nitride, these two materials are very expensive, and are monopolized by foreign large enterprises, while silicon substrate price is much cheaper than sapphire and silicon carbide substrates, can make a larger size substrate, improve the utilization rate of MOCVD, thereby improving the core yield. Therefore, in order to break through the international patent barriers, Chinese research institutions and led enterprises from silicon substrate materials to start research.
The problem is that the high quality combination of silicon and gallium nitride is the technical difficulty of the LED chip, and the high defect density and crack caused by the lattice constants and the large mismatch of the thermal expansion coefficients have hindered the development of the chip field for a long time.
No doubt, from the substrate point of view, the mainstream substrate is still sapphire and silicon carbide, but silicon has become the chip field of future development trends. For China, where price wars are relatively serious, silicon substrate is more cost and price advantage: silicon substrate is conductive substrate, not only can reduce the core area, but also to eliminate the gallium nitride epitaxial layer of dry etching steps, coupled with silicon hardness than sapphire and silicon carbide lower, in processing can also save some costs.
The current LED industry is mostly 2-inch or 4-inch sapphire substrate, such as the use of silicon-based gallium nitride technology, at least can save 75% of raw material costs.