tft lcd manufacturing process factory

Actually, the monitors 20 year ago were CRT (Cathode Ray Tube) displays, which requires a large space to run the inner component. And now the screen here in your presence is the LCD(Liquid Crystal Display) screen.

As mentioned above, LCD is the abbreviation of Liquid Crystal Display. It’s a new display technology making use of the optical-electrical characteristic of liquid crystal.

STN LCD: STN is for Super-twisted Nematic. The liquid crystal in STN LCD rotate more angles than that in TN LCD, and have a different electrical feature, allowing STN LCD to display more information. There are many improved version of STN LCD like DSTN LCD (double layer) and CSTN LCD (color). This LCD is used in many early phones, computers and outdoor devices.

TFT LCD: TFT is for Thin Film Transistor. It’s the latest generation of LCD technology and has been applied in all the displaying scenario including electronic devices, motor cars, industrial machines, etc. When you see the word ‘transistor’, you may realize there’s integrated circuits in TFT LCD. That’s correct and the secret that TFT LCD has the advantage of high resolution and full color display.

In a simple way, we can divide TFT LCD into three parts, from bottom to top they are: light system, circuit system and light and color control system.In manufacturing process, we’ll start from inner light and color control system and then stretch out to whole module.

It’s accustomed to divide TFT LCD manufacturing process into three main part: array, cell and module. The former two steps are about the production of light and color control system, which contains TFT, CF (color filter) and LC (liquid crystal), named a cell. And the last step is the assembly of cell, circuit and light system.

Now let’s turn to the production of TFT and CF. Here is a common method called PR (photoresist) method. The whole process of PR method will be demonstrated in TFT production.

This marks the end of this post. If you find it useful or want to know more about TFT LCD, just leave your comment below or contact us. We’re hearing!

Important technical improvements of LCD, such as LED backlighting and wide viewing Angle, are directly related to LCD. And account for an LCD display 80% of the cost of the LCD panel, enough to show that the LCD panel is the core part of the entire display, the quality of the LCD panel, can be said to directly determine the quality of an LCD display.

The production of civil LCD displays is just an assembly process. The LCD panel, the main control circuit, shell, and other parts of the main assembly, basically will not have too complex technical problems.

Does this mean that LCDS are low-tech products? In fact, it is not. The production and manufacturing process of the LCD panels is very complicated, requiring at least 300 process processes. The whole process needs to be carried out in a dust-free environment and with precise technology.

The general structure of the LCD panel is not very complex, now the structure of the LCD panel is divided into two parts: the LCD panel and the backlight system.

Due to the LCD does not shine, so you need to use another light source to illuminate, the function of the backlight system is to this, but currently used CCFL lamp or LED backlight, don’t have the characteristics of the surface light source, so you need to guide plate, spreadsheet components, such as linear or point sources of light evenly across the surface, in order to make the entire LCD panel on the differences of luminous intensity is the same, but it is very difficult, to achieve the ideal state can be to try to reduce brightness non-uniformity, the backlight system has a lot to the test of design and workmanship.

In addition, there is a driving IC and printed circuit board beside the LCD panel, which is mainly used to control the rotation of LCD molecules in the LCD panel and the transmission of display signals. The LCD plate is thin and translucent without electricity. It is roughly shaped like a sandwich, with an LCD sandwiched between a layer of TFT glass and a layer of colored filters.

LCD with light refraction properties of solid crystals, with fluid flow characteristics at the same time, under the drive of the electrode, can be arranged in a way that, in accordance with the master want to control the strength of the light through, and then on the color filter, through the red, green, blue three colors of each pixel toning, eventually get the full-screen image.

According to the functional division, the LCD panel can be divided into the LCD panel and the backlight system. However, to produce an LCD panel, it needs to go through three complicated processes, namely, the manufacturing process of the front segment Array,the manufacturing process of the middle segment Cell, and the assembly of the rear segment module. Today we will be here, for you in detail to introduce the production of the LCD panel manufacturing process.

The manufacturing process of the LCD panel Array is mainly composed of four parts: film, yellow light, etch and peel film. If we just look at it in this way, many netizens do not understand the specific meaning of these four steps and why they do so.

First of all, the motion and arrangement of LCD molecules need electrons to drive them. Therefore, on the TFT glass, the carrier of LCD, there must be conductive parts to control the motion of LCD. In this case, we use ITO (Indium Tin Oxide) to do this.ITO is transparent and also acts as a thin-film conductive crystal so that it doesn’t block the backlight.

The different arrangement of LCD molecules and the rapid motion change can ensure that each pixel displays the corresponding color accurately and the image changes accurately and quickly, which requires the precision of LCD molecule control.ITO film needs special treatment, just like printing the circuit on the PCB board, drawing the conductive circuit on the whole LCD board.

First, the ITO film layer needs to be deposited on the TFT glass, so that there is a smooth and uniform ITO film on the whole TFT glass. Then, using ionized water, the ITO glass is cleaned and ready for the next step.

Rinse the basic label of glass with an organic solution and remove the photolithographic tape after reaction to keep the glass clean. This completes the first thin-film conductive crystal process, which generally requires at least five identical processes to form a complex and sophisticated pattern of electrodes on the glass.

This completes the previous Array process. It is not difficult to see from the whole process that ITO film is deposited, photoresist coated, exposed, developed, and etched on TFT glass, and finally, ITO electrode pattern designed in the early stage is formed on TFT glass to control the movement of LCD molecules on the glass. The general steps of the whole production process are not complicated, but the technical details and precautions are very complicated, so we will not introduce them here. Interested friends can consult relevant materials by themselves.

The glass that the LCD board uses makes a craft also very exquisite. (The manufacturing process flow of the LCD display screen)At present, the world’s largest LCD panel glass, mainly by the United States Corning, Japan Asahi glass manufacturers, located in the upstream of the production of LCD panel, these manufacturers have mastered the glass production technology patents. A few months ago, the earthquake caused a corning glass furnace shutdown incident, which has caused a certain impact on the LCD panel industry, you can see its position in the industry.

As mentioned earlier, the LCD panel is structured like a sandwich, with an LCD sandwiched between the lower TFT glass and the upper color filter. The terminal Cell process in LCD panel manufacturing involves the TFT glass being glued to the top and bottom of a colored filter, but this is not a simple bonding process that requires a lot of technical detail.

As you can see from the figure above, the glass is divided into 6 pieces of the same size. In other words, the LCD made from this glass is finally cut into 6 pieces, and the size of each piece is the final size. When the glass is cast, the specifications and sizes of each glass have been designed in advance.

Directional friction:Flannelette material is used to rub the surface of the layer in a specific direction so that the LCD molecules can be arranged along the friction direction of the aligned layer in the future to ensure the consistency of the arrangement of LCD molecules. After the alignment friction, there will be some contaminants such as flannelette thread, which need to be washed away through a special cleaning process.

After the TFT glass substrate is cleaned, a sealant coating is applied to allow the TFT glass substrate to be bonded to the color filter and to prevent LCD outflow.

Finally, the conductive adhesive is applied to the frame in the bonding direction of the glass of the color filter to ensure that external electrons can flow into the LCD layer. Then, according to the bonding mark on the TFT glass substrate and the color filter, two pieces of glass are bonded together, and the bonding material is solidified at high temperatures to make the upper and lower glasses fit statically.

Color filters are very important components of LCD panels. Manufacturers of color filters, like glass substrate manufacturers, are upstream of LCD panel manufacturers. Their oversupply or undersupply can directly affect the production schedule of LCD panels and indirectly affect the end market.

As can be seen from the above figure, each LCD panel is left with two edges after cutting. What is it used for? You can find the answer in the later module process

Finally, a polarizer is placed on both sides of each LCD substrate, with the horizontal polarizer facing outwards and the vertical polarizer facing inwards.

When making LCD panel, must up and down each use one, and presents the alternating direction, when has the electric field and does not have the electric field, causes the light to produce the phase difference and to present the light and dark state, uses in the display subtitle or the pattern.

The rear Module manufacturing process is mainly the integration of the drive IC pressing of the LCD substrate and the printed circuit board. This part can transmit the display signal received from the main control circuit to the drive IC to drive the LCD molecules to rotate and display the image. In addition, the backlight part will be integrated with the LCD substrate at this stage, and the complete LCD panel is completed.

Firstly, the heteroconductive adhesive is pressed on the two edges, which allows external electrons to enter the LCD substrate layer and acts as a bridge for electronic transmission

Next is the drive IC press. The main function of the drive IC is to output the required voltage to each pixel and control the degree of torsion of the LCD molecules. The drive IC is divided into two types. The source drive IC located in the X-axis is responsible for the input of data. It is characterized by high frequency and has an image function. The gate drive IC located in the Y-axis is responsible for the degree and speed of torsion of LCD molecules, which directly affects the response time of the LCD display. However, there are already many LCD panels that only have driving IC in the X-axis direction, perhaps because the Y-axis drive IC function has been integrated and simplified.

The press of the flexible circuit board can transmit data signals and act as the bridge between the external printed circuit and LCD. It can be bent and thus becomes a flexible or flexible circuit board

The manufacturing process of the LCD substrate still has a lot of details and matters needing attention, for example, rinse with clean, dry, dry, dry, ultrasonic cleaning, exposure, development and so on and so on, all have very strict technical details and requirements, so as to produce qualified eyes panel, interested friends can consult relevant technical information by a search engine.

LCD (LC) is a kind of LCD, which has the properties of light transmission and refraction of solid Crystal, as well as the flow property of Liquid. It is because of this property that it will be applied to the display field.

However, LCD does not emit light autonomously, so the display equipment using LCD as the display medium needs to be equipped with another backlight system.

First, a backplate is needed as the carrier of the light source. The common light source for LCD display equipment is CCFL cold cathode backlight, but it has started to switch to an LED backlight, but either one needs a backplate as the carrier.

CCFL backlight has been with LCD for a long time. Compared with LED backlight, CCFL backlight has many defects. However, it has gradually evolved to save 50% of the lamp and enhance the transmittance of the LCD panel, so as to achieve the purpose of energy-saving.

With the rapid development of LED in the field of lighting, the cost has been greatly reduced.LCD panels have also started to use LED as the backlight on a large scale. Currently, in order to control costs, an LED backlight is placed on the side rather than on the backplate, which can reduce the number of LED grains.

At the top of the diffusion plate, there will be 3~4 diffuser pieces, constantly uniform light to the whole surface, improve the uniformity of light, which is directly related to the LCD panel display effect. Professional LCD in order to better control the brightness uniformity of the screen, panel procurement, the later backlight control circuit, will make great efforts to ensure the quality of the panel.

Since the LCD substrate and the backlight system are not fixed by bonding, a metal or rubber frame is needed to be added to the outer layer to fix the LCD substrate and the backlight system.

After the period of the Module, the process is completed in LCM (LCDModule) factory, the core of this part of the basic does not involve the use of LCD manufacturing technology, mainly is some assembly work, so some machine panel factories such as chi mei, Korea department such as Samsung panel factory, all set with LCM factories in mainland China, Duan Mo group after the LCD panel assembly, so that we can convenient mainland area each big monitor procurement contract with LCD TV manufacturers, can reduce the human in the whole manufacturing and transportation costs.

However, neither Taiwan nor Korea has any intention to set up factories in mainland China for the LCD panel front and middle manufacturing process involving core technologies. Therefore, there is still a long way to go for China to have its own LCD panel industry.

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).

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.

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.

At present, the mainstream display on the market is TFT-LCD, that is, thin film transistor liquid crystal display (Thin Film Transistor-Liquid Crystal Display).

As we mentioned above, people may not think that filtration is so closely connected to the production of TFT-LCD. Below we will explain the importance of filtration in production for flat panel displays.

TFT-LCD combines microelectronics technology with liquid crystal display technology, and its structure is like a “sandwich”. The TFT array is processed on the glass, and the substrate with color filtering film is used to form a liquid crystal box using LCD technology, and then the polarizer is laminated to form a liquid crystal display.

The TFT-LCD array process is similar to that of semiconductors, except that semiconductors use silicon wafers, while thin-film transistors process glass substrates.

In the manufacture of flat panel displays, the glass substrate is first cleaned, and after the film is formed on the surface, the photoresist is evenly coated on the substrate, and after the processes of exposure, development, etching, and stripping, the graphics on the mask plate are transferred to the substrate to form the exact corresponding graphics.

In the TFT-LCD array process, pollutants mainly come from the manufacturing process and the handling, packaging, transportation, and storage of glass substrates, the main pollutants are dust particles, fiber paper dust, mineral oil and grease, and other greases, inorganic particles such as silicon oxide, and residues of the preparation process, water stains, fingerprints, etc.

These contaminants directly affect the quality and economic efficiency of the final product, so the product goes through a complex cleaning process, and after filtration, these cleaning solutions can be discharged or recycled.

For the different manufacturing stages, Brother Filtration offers accordingly filtration solutions. The followings are filtration solutions in detail.

The film-forming process is mainly divided into two ways, one is sputtering metal film deposition, by charged particles bombarding the surface of the material, so that the atoms get enough energy to enter the gas phase, deposited on the surface of the workpiece, and the use of gas is generally inert gas (such as argon);

In the lithography process of thin film transistors, each step may introduce harmful particle contamination, microbubble void defects, and metal contamination on the surface of the glass substrate, so the washing process is essential.

The etching process removes the film layer that is not masked by the photoresist, thus obtaining the exact same pattern on the film as on the photoresist. Etching methods are divided into wet etching, which uses the chemical reaction of the solution, and dry etching, which uses gas and plasma technology to etch the material.

In wet etching, the glass substrate is etched in a special tank and then cleaned in a wash tank, and finally dried, the process, as well as the flying damp solution, is as follows.

In flat panel display manufacturing, the residual photoresist needs to be peeled off after the film formation-lithography-etching process, thus bringing the process of this layer of film to an end.

With years of filtration experience and advanced manufacturing technology, Brother Filtration is able to provide helpful membrane-pleated filter cartridges and gas filter housing in every TFT-LCD production process.

Brother Filtration not only manufactures all kinds of filter products that can be applied in TFT-LCD production but also offers better filtration solutions for panel display manufacturers. If you need more filtration solutions or a better filter cartridge to help your manufacturing, please feel free to contact us directly.

The cutting-edge G10 production line is a result of cutting-edge technology. To consistently manufacture LCD panels using the G10 glass substrates, each individual manufacturing process incorporates a range of unique know-how. Developed in collaboration with several world-leading production equipment manufacturers, SDP"s large-scale, one-of-a-kind manufacturing equipment delivers state-of-the-art accuracy and performance levels. One example is the photolithography machine, which is about the size of a tennis court. Our master-craftsmen operate and monitor this machine with the utmost care, to manufacture next-generation products.

In this process, the entire G10 glass substrate is covered with various types of film, such as the circuitry that forms the TFT* (thin-film transistor). There are numerous, extremely large pieces of equipment that produce uniform layers across the entire glass substrate—for example, a sputtering machine that deposits a metallic film, and a CVD (chemical vapor deposition) system that deposits an insulation film and a semiconductor film using the plasma-enhanced chemical vapor deposition method.

In the design of the substrate, photolithography is used to form circuits and wiring. First, a coater system is used to apply photosensitive material—called “photoresist”—rapidly and uniformly across the entire glass substrate. Next, using a photolithography machine, the glass substrate is irradiated with ultraviolet light, transferring onto it a high-precision TFT pattern via a mask. A developing system uses developer fluid to dissolve and remove the photoresist previously applied using the photolithography machine, and only the resist that forms the TFT pattern remains.

In the etching process, portions not covered by resist are removed to form the transistor circuits. There are two kinds of etching machines: a dry etching machine that uses corrosive gas to decompose and remove the insulation film and semiconductor film; and a wet etching machine that uses a liquid chemical to dissolve the metal film. After etching, a resist stripping machine is used to remove the photoresist.

In a typical LCD factory, a large number of product types are produced concurrently, 24 hours a day and 365 days a year, and there exist various constraints and re-entrant flows in the manufacturing processes. As a result, efficient planning and scheduling of LCD production is a big challenge. Presented in this paper is a simulation-based DPS (daily planning & scheduling) system that was developed by the authors and is being used in a modern LCD Fab in Korea. Also presented in the paper are a business architecture of LCD production management, internal structure of the DPS system, and Fab scheduling logic. The DPS system was installed at a large-size LCD Fab in 2006, and the system has been successfully used for two years leading to a considerable increase in on-time production of LCD panels and a sharp decrease in turn-around time.

TFT LCD Panel Manufacturing Plant Project Report: Industry Trends, Manufacturing Process, Machinery, Raw Materials, Cost and Revenue provides a techno-commercial roadmap for setting up a TFT LCD panel manufacturing plant. The study, which has been done by one of the world’s leading research and advisory firms, covers all the requisite aspects of the TFT LCD panels market. This ranges from macro overview of the market to micro details of the industry performance, processing and manufacturing requirements, project cost, project funding, project economics including expected returns on investment, profit margins, etc.

This report is a must-read for entrepreneurs, investors, researchers, consultants, business strategists, and all those who have any kind of stake or are planning to foray into the TFT LCD panels industry in any manner.