TFT technology

- Mar 18, 2020-

In terms of a-Si, the three production bases(Taiwan, China, Korea & Japan) have their own advantages. Japanese manufacturers have developed LCD products with a resolution of up to 2560 × 2048. Therefore, some people believe that a-Si TFT technology can fully meet the needs of high-resolution products, but due to the immaturity of the technology, it cannot meet the needs of high-speed video images or animations. LTPS TFT can save costs relatively, which is of great significance for the promotion of TFT LCD. At present, Japanese manufacturers have mass-produced 12.1-inch LTPS

 

TFT LCD capabilities. And Taiwan, China has developed LTPS module manufacturing technology and LTPS SXGA panel technology. South Korea lacks specialized designers and R & D experts in this regard, but major companies such as Samsung have launched LTPS products, showing the strength of Korean manufacturers. However, the current LTPS technology is still immature, the products are concentrated on small screens, and the yield is low, and the cost advantage has not yet been discussed.

 

Compared with LTPS, a-Si is undoubtedly the current mainstream of TFT LCD. Almost all of the Japanese companies' a-Si TFT investment strategies are based on third-generation LCD products. Through improvements in manufacturing technology and yield, they can increase production and reduce costs. Japan has always followed the high-end line, and its technology is undoubtedly the most advanced. Due to limited research and development power, Taiwan's a-Si TFT technology is mainly transferred from Japanese manufacturers, but because Taiwanese companies are generally labor-intensive and have low technology content, they mainly produce low-end products. South Korea has strong R & D capabilities in a-Si. For example, Samsung produced the world's first 24-inch a-Si TFT LCD-240T in mass production. Its response time is less than 25ms, which can meet general application needs. It reached 160 degrees, making LCD not lose to CRT on traditional weaknesses. Samsung 240T marks the maturity of large-screen TFT LCD technology, and it also shows the world that the strength of Korean manufacturers is unquestionable.

 

In addition to the competition between the above two TFT technologies, SED will become a powerful enemy of TFT LCD. However, SED is still a conceptual product and it is difficult to enter the mainstream market in a short time.

 

Although the LCD has been significantly reduced in price, it is still relatively expensive compared to the CRT. Therefore, the issue of cost is the focus of everyone's attention. In fact, the production cost of TFT is comparable to that of CRT, but the extremely low yield rate has caused the cost of TFT panel to remain high. The TFT panel is cut from a larger substrate. And LCD products also need a large number of transistor arrays to control the three primary colors. Current manufacturing technology is difficult to ensure that tens of millions or even hundreds of millions of transistors on a large substrate will not cause a problem. If there is a problem with a transistor, the corresponding color of the point corresponding to that transistor will be a problem (only a certain fixed color can be displayed), then this point is commonly called a "bad point". The probability of a dead point appearing is not fixed, so a substrate is likely to be wasted a lot. At present, LCDs generally require less than 5 dead pixels, and some large manufacturers have reduced this standard to 3 or even 0, which will reduce the yield rate. However, some small manufacturers have expanded the number of bad points. As a result, costs have naturally dropped significantly, and product quality has fallen accordingly. This is one of the reasons why some manufacturers can significantly reduce the price of LCDs.

 

Although there are many manufacturers capable of producing liquid crystal displays, there are only a handful of manufacturers that truly have the ability to make TFT panels. As a well-known company in the IT industry, ACER has considerable strength. Although it does not have the ability to produce TFT panels by itself,

 

However, it has close relations with Taiwan's Dage and has certain advantages in technical cooperation. However, due to the technical strength of Taiwanese enterprises, ACER LCD products are mainly concentrated in the low-end. As a world-renowned display equipment manufacturer, PHILIPS has consistently ranked among the best in sales of displays in China, and has reached an alliance with LG of South Korea to jointly develop and manufacture TFT panels. Also due to technical reasons and market positioning issues, PHILIPS 'current products are mainly concentrated in the mid-range, and PHILIPS action in the retail market has not been obvious. As another strong display device R & D and manufacturer, Samsung has invested a lot of effort in LCD and is committed to continuously enriching its product line. At present, Samsung products cover the high-end, low-end market.

 

LCD technology is still in the stage of continuous development and improvement. The three major production areas have different development directions. There is competition and cooperation between them. It is these factors that have driven LCD forward.