Chips are the core components of LEDs. At present, there are many led chip manufacturers at home and abroad, but chip classification does not have a unified standard, if by power classification, there are high-power and medium-sized power points; if classified by color, the main red, green, blue three species; if classified by shape, generally divided into square slices, round pieces of two; if classified by voltage, it is divided into low voltage DC chip and high voltage DC chip. Domestic and foreign chip technology contrast, foreign chip technology, domestic chip weight production technology.
The key of substrate material and wafer growth technology
At present, the development of LED chip technology is the key of substrate material and wafer growth technology. In addition to traditional sapphire, silicon (SI), silicon carbide (sic) substrate materials, zinc oxide (ZnO) and gallium nitride (Gan) are also the focus of the current LED chip research. At present, most of the market use sapphire or silicon carbide substrate to epitaxial growth broadband gap semiconductor gallium nitride, both of these materials are very expensive and are monopolized by large foreign enterprises, and the price of silicon substrate is much cheaper than sapphire and silicon carbide substrate, which can make a larger substrate, improve the utilization rate of MOCVD, thereby improving the core yield. Therefore, in order to break through the international patent barrier, Chinese research institutes and led enterprises from silicon substrate materials to proceed.
But the problem is that the high quality of silicon and gallium nitride is the technical difficulty of LED chips, the lattice constants and the great mismatch of thermal expansion coefficient, the high defect density and cracks, etc., have long hindered the development of chip field.
Undoubtedly, from the substrate point of view, the mainstream substrate is still sapphire and silicon carbide, but silicon has become the field of chip development trend in the future. For China that is relatively serious in price wars, silicon substrate has more cost and price advantage: silicon substrate is conductive substrate, not only can reduce the core area, but also can omit the gallium nitride epitaxial layer of dry etching steps, coupled with the hardness of silicon than sapphire and silicon carbide low, in the processing can also save some costs.
Currently, the LED industry is mostly 2 inches or 4 inches of sapphire substrate, if silicon nitride technology can be used, at least 75% of the cost of raw materials can be saved. According to Japan's three-ken Electric Company estimated that the use of silicon substrate to make large-sized blue gallium nitride led manufacturing costs will be 90% lower than the sapphire substrate and silicon carbide substrate.
Differences in chip technology at home and abroad
Abroad, Osram, United States of America, Japan and other first-class enterprises have been in large size silicon nitride substrate led research on the breakthrough, Philips, South Korea Samsung, LG, Toshiba, Japan and other international led Giants also set off a silicon substrate on gallium nitride led research craze. Among them, in 2011, U.S.-based on 8 inch silicon substrate developed a high-light-effect gallium nitride led, obtained with the sapphire and silicon carbide substrate on the top level of LED device performance comparable to the luminous efficiency of 160lm/W; in 2012, Osram succeeded in producing 6-inch silicon nitride-based gallium LEDs.
Reverse view of China, LED chip Enterprise technology breakthrough is mainly to improve production capacity and large size sapphire crystal growth technology, in addition to photovoltaic in 2011 to achieve a successful 2-inch silicon substrate nitride-based high-power LED chips, the volume of production, Chinese chip enterprises in silicon nitride substrate led research on the no big breakthrough, the current mainland LED Chip Enterprise is the main production capacity, sapphire substrate materials and wafer growth technology, three Ann Photoelectric, Tak Hao run Tatsu, The same side shares, such as the mainland chip giants are also most of the capacity to make breakthroughs.
- The Distribution Of PCB Industry An...
- Cause Analysis Of PCB Price Difference
- Schematic Design Step Of PCB Design
- Selection Of Four Main Points For E...
- PCB Circuit Boards How To Distingui...
- Introduction To Common Knowledge Of...
- Process Optimization And Improvemen...
- Relevant Standards For SMT Industry
- LED Industry SMD Machine
- Description Of Different Processing...
- SECC FAIR