The chip is the core component of the LED. At present, there are many LED chip manufacturers at home and abroad, but there is no uniform standard for chip classification. According to power classification, there are high power and medium and low power; if classified by color, it is mainly red, green and blue; According to the shape classification, it is generally divided into two kinds of wafers and wafers; if classified by voltage, it is divided into low voltage DC chip and high voltage DC chip. Compared with domestic and foreign chip technology, foreign chip technology is new and domestic chip weight production is not heavy technology.
Substrate material and wafer growth technology key
At present, the key to the development of LED chip technology is substrate materials and wafer growth technology. In addition to traditional sapphire, silicon (Si), and silicon carbide (SiC) substrate materials, zinc oxide (ZnO) and gallium nitride (GaN) are also the focus of current LED chip research. Currently, sapphire or silicon carbide substrates are widely used in the market to epitaxially grow wide bandgap semiconductor gallium nitride. Both of these materials are very expensive and are monopolized by large foreign companies. The price of silicon substrates is higher than that of sapphire and carbonization. The silicon substrate is much cheaper and can produce larger substrates, improve the utilization of MOCVD, and increase the yield of the die. Therefore, in order to break through the international patent barriers, Chinese research institutes and LED companies started researching silicon substrate materials. However, the problem is that the high-quality combination of silicon and gallium nitride is a technical difficulty for LED chips. The technical problems such as high defect density and cracks caused by the large mismatch between the lattice constant and thermal expansion coefficient of the two have long hindered the field of chips. development of.
Undoubtedly, from the perspective of the substrate, the mainstream substrates are still sapphire and silicon carbide, but silicon has become the development trend of the chip field in the future. For China, where the price war is relatively serious, silicon substrates have more cost and price advantages: the silicon substrate is a conductive substrate, which not only reduces the die area, but also eliminates the need for dry etching of the GaN epitaxial layer. In addition, the hardness of silicon is lower than that of sapphire and silicon carbide, and some costs can be saved in processing.
Currently, the LED industry mostly uses 2-inch or 4-inch sapphire substrates. If silicon-based GaN technology is used, at least 75% of raw material cost can be saved. According to estimates by Sanken Electric Co., Japan, the cost of manufacturing a large-size blue GaN LED using a silicon substrate will be 90% lower than that of a sapphire substrate and a silicon carbide substrate.
Differences in chip technology at home and abroad
In foreign countries, first-class companies such as Osram, U.S. Puri, and Sanhe of Japan have made breakthroughs in the research of large-size silicon-based gallium nitride-based LEDs, and international LED giants such as Philips, South Korea’s Samsung, LG, and Toshiba’s Japan have also launched a surge. An upsurge of research on gallium nitride based LEDs on silicon substrates. Among them, in 2011, Puri developed high-efficiency GaN-based LEDs on 8-inch silicon substrates, achieving a luminous efficiency of 160 lm/W that is comparable to that of top-level LED devices on sapphire and silicon carbide substrates. In 2012, Osram succeeded in producing 6-inch silicon-base GaN-based LEDs.
In contrast, in mainland China, the breakthrough point of LED chip technology is mainly to increase production capacity and large-size sapphire crystal growth technology, in addition to the successful mass production of 2-inch silicon substrate GaN-based high-power LED chips by Jingneng Optoelectronics in 2011. China's chip companies have no major breakthrough in the research of silicon-based gallium nitride-based LEDs. At present, LED chip companies in mainland China are still focusing on production capacity, sapphire substrate materials, and wafer growth technologies. Sanan Optoelectronics, BDO Runda, Tongfang shares Most mainland chip giants also made breakthroughs in their production capacity.
Doors & Windows Profile Extrusion Dies
As the eyes and soul of a building, doors and windows are directly related to the quality of the building and the quality of living life. It is not only a tool to protect from wind and rain, but also has the function of separating the inside of the home from the outside society. It also plays an important decorative role. What are the advantages of aluminum alloy door and window profiles?
1. Strong plasticity
Aluminum alloy profiles are metal materials. Aluminum is added with various metal elements to make various alloys. It has the unparalleled advantages of other alloy profiles: light weight and high strength, and can be extruded into various complex cross-section profiles to meet the design of doors and windows. The various new cross-section requirements of the division.
2. Good sealing performance
Aluminum alloy profiles have strong air tightness, water tightness, heat insulation and sound insulation. These properties are suitable for various specific applications in the door and window industry.
3. Long service life
Aluminum alloy profiles have the advantages of light weight, high strength, corrosion resistance, small deformation, strong fire resistance and long service life (more than 50 years).
4. Environmental protection and energy saving
The broken bridge aluminum alloy profile uses a new type of thermal insulation material nylon 66 to form a hot and cold bridge between the inner and outer profiles, thereby minimizing the heat conduction of the aluminum alloy and achieving excellent heat and sound insulation effects.
5. Excellent weather resistance
Aluminum alloy profiles have been treated with various processes, and the surface is resistant to acid and alkali erosion and is not affected by air pollution, acid rain, and ozone. UV resistant, retains inherent color and luster for a long time.
6. Elegant decorative effect
The surface of aluminum alloy profiles can be subjected to various surface treatments, such as powder spraying, anodizing, electrophoretic coating, wood grain transfer and other surface treatment technologies. There are a variety of colors and wood grains. There is a wide range of choices to meet various needs. It meets the needs of architectural decoration and puts beautiful clothes on the building.
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Foshan Jieliwei Metal Products Co., Ltd. , https://www.foshanjlw.com