Figure 1 TFT-LCD architecture and module full project

Generally, LCDs are filled with a liquid crystal layer with a thickness of about 3~4um between the upper and lower transparent electrodes, and the electric field of the liquid crystal interlayer is controlled by the method of filling the pixel electrode voltage, and then the intensity of the transmitted light is adjusted to produce a full brightness. Gray level between and full darkness. At present, LCD is mainly composed of three parts: color filter (CF), TFT array (TFT Array) substrate and backlight module (Backlight) as shown in Figure 1 (a). Each Pixel of TFT-LCD has a set of TFTs to control its voltage value, and to make the light generated by the backlight module and transmitted through the LC have different colors, red, blue, and green (R/B/G) are needed. Three colors of color resist are formed on the CF glass, and the gray scales are used to produce a full-color effect; after the TFT array and the CF substrate are respectively completed, then the CF upper plate and the TFT lower plate are filled with LC and bonded together. Finally, attach the polarizer. This process is called the "LCD process"; and the final "LCM process" is the connection between the driver IC and the control circuit board (PCBA) and the glass substrate (JI Process). Assemble with the backlight module (MA Process), and finally the lighting detection of the module... and so on as shown in Figure 1 (b).

Figure 2 G8.5 glass substrate size

AU Optronics (hereinafter referred to as AU Optronics) has developed a process above the 8.5 generation factory to produce large-size LCD TV panels (see Figure 2). In December 2008, AUO successfully lighted the first 46-inch LCD TV panel produced in the G8.5 plant in China. The process technology once again led the whole Taiwan, marking a new page in the milestone of the new generation of TFT-LCD plant. Also established a new model of TFT-LCD green plant. The size of the G8.5 glass substrate is equivalent to the size of a pool table, but the thickness of the glass is less than 1mm. Therefore, the new-generation plant requires higher process technology; as the technology of large-size panels gradually matures, AUO will still Continue to focus on the development of new-generation plants, and continue to advance with the goal of increasing production capacity, improving process quality, and targeting customer service.

Vigorously implement green production technology

The development direction of next-generation process technology is nothing more than simplifying the process and selecting optimized raw materials and components to increase process yield and productivity, and reduce production costs. The capital investment of the front-end TFT Array and CF process equipment accounts for more than 60% of the total TFT-LCD expenditure. Therefore, the front-end process research and development first focuses on simplifying the process and improving the utilization of raw materials: for example, the four-pass mask technology that simplifies the mask process ( See Figure 3 (a)) and the pattern forming method without exposure and etching. In addition, the use of thinned glass substrates not only reduces the consumption of glass raw materials, but also has the advantages of lighter weight and thinner products; at the same time, it can achieve the goals of energy saving and waste reduction such as reducing packaging materials and improving transportation efficiency. As for LCM, with the rapid development of gate drive circuit substrate technology (Gate on Array, GOA) and HSD (Half source driving) technology in Figure 3 (b), it has not only simplified the material dependence of traditional panels on a large number of driver ICs. , Also contributes to the increase of LCM production capacity. In terms of module backlights, replacing traditional cold cathode tubes with light-emitting diodes (Light Emitting Diode, LED) not only avoids the harm of mercury (Hg) vapor in the tubes to the environment; the better luminous efficiency of LEDs also makes the products more efficient Energy saving.

What is TFT-LCD? Introduction to LCD manufacturing process