What are the characteristics of TFT LCD?
TFT LCD display is characterized by good brightness, high contrast, strong sense of layering, and bright colors, but it also has the disadvantages of relatively high power consumption and high cost. TFT LCD technology has accelerated the development of mobile phone color screens. Many of the new-generation color screen mobile phones support 65536-color displays, and some even support 160,000-color displays. At this time, the advantages of TFT high contrast and rich colors are very important.
Technical characteristics
TFT technology was developed in the 1990s. It adopts new materials and new processes for large-scale semiconductor full integrated circuit manufacturing technology. It is a liquid crystal (LC), inorganic and organic thin film electroluminescence (EL and OEL) flat panel display. basis. TFTs are formed on glass or plastic substrates and other non-single wafers (of course, they can also be on wafers) by sputtering and chemical deposition processes to form various films necessary for manufacturing circuits, and large-scale semiconductor integrated circuits (LSIC) are produced by processing the films . The use of non-single-crystal substrates can greatly reduce costs, which is the extension of traditional large-scale integrated circuits to large areas, multi-functions, and low costs. Manufacturing TFTs that control the switching performance of pixels (LC or OLED) on large-area glass or plastic substrates is more difficult than manufacturing large-scale ICs on silicon wafers. The requirements for the production environment (purification degree is 100), the requirements for the purity of raw materials (the purity of electronic special gas is 99.999985%), the requirements for production equipment and production technology exceed the large-scale integration of semiconductors, and are the top of modern large-scale production technology. Its main features are:
(1) Large area: The first generation of large-area glass substrate (300mm×400mm) TFT-LCD production line was put into operation in the early 1990s. By the first half of 2000, the area of the glass substrate had been expanded to 680mm×880mm), and 950mm×1200mm The glass substrate will also be put into operation. In principle, there is no area limit.
(2) High integration: The resolution of the 1.3-inch TFT chip used for liquid crystal projection is XGA containing millions of pixels. The 16.1-inch TFT array amorphous silicon with a resolution of SXGA (1280×1024) has a film thickness of only 50 nm, and TABONGLASS and SYSTEMONGLASS technologies. The IC integration, the requirements for equipment and supply technology, and the technical difficulty are more than traditional LSI.
(3) Powerful function: TFT was the first matrix addressing circuit to improve the light valve characteristics of liquid crystal. For high-resolution displays, through the voltage adjustment in the range of 0-6V (its typical value is 0.2 to 4V), the precise control of the object element is realized, thereby making it possible for the LCD to achieve high-quality high-resolution display. TFT-LCD is the first flat panel display in human history that exceeds CRT in display quality. And people began to integrate the driver IC on the glass substrate, the function of the entire TFT will be more powerful, which is unmatched by traditional large-scale semiconductor integrated circuits.
(4) Low cost: Glass substrates and plastic substrates have fundamentally solved the cost problem of large-scale semiconductor integrated circuits, and opened up a broad application space for the application of large-scale semiconductor integrated circuits.
(5) Flexible process: In addition to sputtering, CVD (Chemical Vapor Deposition), MCVD (Molecular Chemical Vapor Deposition) and other traditional processes for film formation, laser annealing technology has also begun to be applied. It can produce both amorphous and polycrystalline films. A single crystal film can be manufactured. Not only can silicon films be made, but other II-VI and III-V semiconductor thin films can also be made.
(6) Wide application fields, LCD flat panel displays based on TFT technology are the pillar industries of the information society, and the technology can also be applied to the rapidly growing thin film transistor organic electroluminescence (TFT-OLED) flat panel displays. Growing up.
Other main features
With the maturity of TFT technology in the early 1990s, color liquid crystal flat panel displays have developed rapidly. In less than 10 years, TFT-LCD has rapidly grown into a mainstream display, which is inseparable from its advantages. The main features are:
(1) Good use characteristics: low-voltage application, low driving voltage, solidified use safety and reliability improvement; flat, light and thin, saving a lot of raw materials and use space; low power consumption, its power consumption is about CRT display One tenth, reflective TFT-LCD is only about 1% of CRT, which saves a lot of energy; TFT-LCD products also have specifications, sizes, series, variety, convenient and flexible use, maintenance, update , Easy upgrade, long service life and many other features. The display range covers the application range of all displays ranging from 1 inch to 40 inches and the large plane of projection. It is a full-size display terminal; the display quality ranges from the simplest monochrome character graphics to high resolution, high color fidelity, High-brightness, high-contrast and high-response video monitors of various specifications and models; display methods include direct-view type, projection type, perspective type, and reflective type.
(2) Good environmental protection characteristics: no radiation, no flicker, no damage to the user's health. In particular, the emergence of TFT-LCD electronic books and periodicals will bring human beings into the era of paperless office and paperless printing, triggering a revolution in the way humans learn, spread, and document civilization.
(3) Wide application range, can be used normally within the temperature range from -20℃ to +50℃, and the low-temperature working temperature of the TFT-LCD after temperature strengthening treatment can reach minus 80℃. It can be used as a mobile terminal display, desktop terminal display, and can also be used as a large-screen projection TV. It is a full-size video display terminal with excellent performance.
(4) The degree of automation of manufacturing technology is high, and the characteristics of large-scale industrial production are good. The technology of the TFT-LCD industry is mature, and the yield rate of large-scale production reaches more than 90%.
(5) TFT-LCD is easy to integrate and update, it is the perfect combination of large-scale semiconductor integrated circuit technology and light source technology, and there is great potential for continued development. There are currently amorphous, polycrystalline, and monocrystalline silicon TFT-LCDs, and in the future there will be TFTs of other materials, both glass substrates and plastic substrates.
If you want to know more, our website has product specifications for TFT LCD, you can go to ALLICDATA ELECTRONICS LIMITED to get more information