lcd panel layers manufacturer

Flat-panel displays are thin panels of glass or plastic used for electronically displaying text, images, or video. Liquid crystal displays (LCD), OLED (organic light emitting diode) and microLED displays are not quite the same; since LCD uses a liquid crystal that reacts to an electric current blocking light or allowing it to pass through the panel, whereas OLED/microLED displays consist of electroluminescent organic/inorganic materials that generate light when a current is passed through the material. LCD, OLED and microLED displays are driven using LTPS, IGZO, LTPO, and A-Si TFT transistor technologies as their backplane using ITO to supply current to the transistors and in turn to the liquid crystal or electroluminescent material. Segment and passive OLED and LCD displays do not use a backplane but use indium tin oxide (ITO), a transparent conductive material, to pass current to the electroluminescent material or liquid crystal. In LCDs, there is an even layer of liquid crystal throughout the panel whereas an OLED display has the electroluminescent material only where it is meant to light up. OLEDs, LCDs and microLEDs can be made flexible and transparent, but LCDs require a backlight because they cannot emit light on their own like OLEDs and microLEDs.

Liquid-crystal display (or LCD) is a thin, flat panel used for electronically displaying information such as text, images, and moving pictures. They are usually made of glass but they can also be made out of plastic. Some manufacturers make transparent LCD panels and special sequential color segment LCDs that have higher than usual refresh rates and an RGB backlight. The backlight is synchronized with the display so that the colors will show up as needed. The list of LCD manufacturers:

Organic light emitting diode (or OLED displays) is a thin, flat panel made of glass or plastic used for electronically displaying information such as text, images, and moving pictures. OLED panels can also take the shape of a light panel, where red, green and blue light emitting materials are stacked to create a white light panel. OLED displays can also be made transparent and/or flexible and these transparent panels are available on the market and are widely used in smartphones with under-display optical fingerprint sensors. LCD and OLED displays are available in different shapes, the most prominent of which is a circular display, which is used in smartwatches. The list of OLED display manufacturers:

MicroLED displays is an emerging flat-panel display technology consisting of arrays of microscopic LEDs forming the individual pixel elements. Like OLED, microLED offers infinite contrast ratio, but unlike OLED, microLED is immune to screen burn-in, and consumes less power while having higher light output, as it uses LEDs instead of organic electroluminescent materials, The list of MicroLED display manufacturers:

LCDs are made in a glass substrate. For OLED, the substrate can also be plastic. The size of the substrates are specified in generations, with each generation using a larger substrate. For example, a 4th generation substrate is larger in size than a 3rd generation substrate. A larger substrate allows for more panels to be cut from a single substrate, or for larger panels to be made, akin to increasing wafer sizes in the semiconductor industry.

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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.

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.

TFT is an LCD Technology which adds a thin-film transistor at each pixel to supply common voltages to all elements. This voltage improves video content frame rates. Displays are predominantly utilizing color filter layers and white LED backlighting.

In both LCD and OLED displays, producing these cells – which are highly complex – is by far the most difficult element of the production process. Indeed, the complexity of these cells, combined with the levels of investment needed to achieve expertise in their production, explains why there are less than 30 companies in the whole world that can produce them. China, for instance, has invested more than 300 billion yuan (approximately $45 billion USD) in just one of these companies – BOE – over the past 14 years.

Panox Display has been involved in the display industry for many years and has built strong and long-term partner relationships with many of the biggest OLED and LCD panel manufacturers. As a result, we are able to offer our clients guaranteed access to display products from the biggest manufacturers.

LG Display was, until 2021, the No. 1 display panel manufacturer in the world. Owned by LG Group and headquartered in Seoul, South Korea, it has R&D, production, and trade institutions in China, Japan, South Korea, the United States, and Europe.

Founded in 2001, AUO – or AU Optronics – is the world’s leading TFT-LCD panel manufacturer (with a 16% market share) that designs, develops, and manufactures the world’s top three liquid crystal displays. With panels ranging from as small as 1.5 inches to 46 inches, it boasts one of the world"s few large-, medium -and small-sized product lines.

AUO offers advanced display integration solutions with innovative technologies, including 4K2K ultra-high resolution, 3D, ultra-thin, narrow bezel, transparent display, LTPS, OLED, and touch solutions. AOU has the most complete generation production line, ranging from 3.5G to 8.5G, offering panel products for a variety of LCD applications in a range of sizes, from as small as 1.2 inches to 71 inches.

Now Sharp is still top 10 TV brands all over the world. Just like BOE, Sharp produce LCDs in all kinds of size. Including small LCD (3.5 inch~9.1 inch), medium LCD (10.1 ~27 inch), large LCD (31.5~110 inch). Sharp LCD has been used on Iphone series for a long time.

Beside those current LCDs, the industrial LCD of Sharp is also excellent and widely used in public facilities, factories, and vehicles. The Sharp industrial LCD, just means solid, high brightness, super long working time, highest stability.

Since its establishment, Truly Semiconductors has focused on researching, developing, and manufacturing liquid crystal flat panel displays. Now, after twenty years of development, it is the biggest small- and medium-sized flat panel display manufacturer in China.

Truly’s factory in Shanwei City is enormous, covering an area of 1 million square meters, with a net housing area of more than 100,000 square meters. It includes five LCD production lines, one OLED production line, three touch screen production lines, and several COG, LCM, MDS, CCM, TAB, and SMT production lines.

Its world-class production lines produce LCD displays, liquid crystal display modules (LCMs), OLED displays, resistive and capacitive touch screens (touch panels), micro camera modules (CCMs), and GPS receiving modules, with such products widely used in the smartphone, automobile, and medical industries. The LCD products it offers include TFT, TN, Color TN with Black Mark (TN type LCD display for onboard machines), STN, FSTN, 65K color, and 262K color or above CSTN, COG, COF, and TAB modules.

In its early days, Innolux attached great importance to researching and developing new products. Mobile phones, portable and mounted DVD players, digital cameras, games consoles, PDA LCDs, and other star products were put into mass production and quickly captured the market, winning the company considerable market share.

Looking forward to the future, the group of photoelectric will continue to deep LCD display field, is committed to the development of plane display core technology, make good use of global operations mechanism and depth of division of labor, promise customers high-quality products and services, become the world"s top display system suppliers, in 2006 in the global mobile phone color display market leader, become "Foxconn technology" future sustained rapid growth of the engine.

Founded in June 1998, Hannstar specializes in producing thin-film transistor liquid crystal display panels, mainly for use in monitors, notebook displays and televisions. It was the first company in Taiwan to adopt the world’s top ultra-wide perspective technology (AS-IPS).

The company has three LCD factories and one LCM factory. It has acquired state-of-the-art TFT-LCD manufacturing technology, which enables it to achieve the highest efficiency in the mass production of thin-film transistor liquid crystal display production technology. Its customers include many of the biggest and most well-known electronics companies and computer manufacturers in Taiwan and overseas.

TCL CSOT – short for TCL China Star Optoelectronics Technology (TCL CSOT) – was founded in 2009 and is an innovative technology enterprise that focuses on the production of semiconductor displays. As one of the global leaders in semiconductor display market, it has bases in Shenzhen, Wuhan, Huizhou, Suzhou, Guangzhou, and India, with nine panel production lines and five large modules bases.

TCL CSOT actively produces Mini LED, Micro LED, flexible OLED, printing OLED, and other new display technologies. Its product range is vast – including large, medium, and small panels and touch modules, electronic whiteboards, splicing walls, automotive displays, gaming monitors, and other high-end display application fields – which has enabled it to become a leading player in the global panel industry.

In the first quarter of 2022, TCL CSOT’s TV panels ranked second in the market, 55 inches, 65 " and 75 inches second, 8K, 120Hz first, the first, interactive whiteboard and digital sign plate; LTPS flat panel, the second, LTPS and flexible OLED fourth.

EDO (also known as EverDisplay Optonics) was founded in October 2012 and focuses on the production of small- and medium-sized high-resolution AMOLED semiconductor display panels.

Tianma Microelectronics was founded in 1983 and listed on the Shenzhen Stock Exchange in 1995. It is a high-tech enterprise specializing in the production of liquid crystal displays (LCD) and liquid crystal display modules (LCM).

After more than 30 years of development, it has grown into a large publicly listed company integrating LCD research and development, design, production, sales, and servicing. Over the years, it has expanded by investing in the construction of STN-LCD, CSTN-LCD, TFT-LCD and CF production lines and module factories across China (with locations in Shenzhen, Shanghai, Chengdu, Wuhan and Xiamen), as well R&D centers and offices in Europe, Japan, South Korea and the United States.

The company"s marketing network is all over the world, and its products are widely used in mobile phones, MP3/MP4 players, vehicle displays, instrumentation, household appliances, and other fields. In terms of technical level, product quality, product grade, and market share, it ranks at the forefront of the domestic industry and has become a leading enterprise in the field of small- and medium-sized displays.

JDI (Japan Display Inc.) was established on November 15, 2011, as a joint venture between the Industrial Innovation Corporation, Sony, Hitachi, and Toshiba. It is dedicated to the production and development of small-sized displays. It mainly produces small- and medium-sized LCD display panels for use in the automotive, medical, and industrial fields, as well as personal devices including smartphones, tablets, and wearables.

Although Sony’s TVs use display panels from TCL CSOT (VA panel), Samsung. Sony still produces the world’s best micro-OLED display panels. Sony has many micro OLED model such as 0.23 inch, 0.39 inch, 0.5 inch, 0.64 inch, 0.68 inch, 0.71 inch. Panox Display used to test and sell many of them, compare to other micro OLED manufacuturers, Sony`s micro OLEDs are with the best image quality and highest brightness (3000 nits max).

2. To coat the glass substrate with a metal film, the metal material needs to be placed in a vacuum chamber, and after the special gas on the metal generates plasma, the atoms on the metal will be knocked against the glass, and then a layer of layers will be formed Metal film too.

6. To form usable thin film transistors, it is necessary to repeat the process of cleaning, coating, photoresist, exposure, development, etching, and photoresist removal. Generally speaking, to manufacture TFT-LCD, it is necessary to repeat 5 to 7 times.

1. After completing the thin-film transistor glass substrate, we will proceed to the combination of the liquid crystal module. The liquid crystal panel is composed of the transistor glass substrate and the color filter. First, we must clean the glass first, and then proceed The next step. The entire manufacturing process of TFT-LCD must be in a clean room, so that there will be no impurities in the display.

4. Before combining the two glass plates, we must first evenly cover the spherical-like gaps at a fixed interval to prevent the two glass plates from bending inward after the liquid crystal display is combined. Usually, when the liquid crystal panel is assembled, one or two gaps are left to facilitate the subsequent filling of the liquid crystal, and then the edge of the two pieces of glass is sealed with frame glue and conductive glue, thus completing the glass assembly.

5. After sealing the frame, place the LCD panel in the vacuum chamber, and drain the air from the LCD panel through the gap just reserved, and then pour the liquid crystal with the help of atmospheric pressure, and then close the gap. The liquid crystal is a kind of The compound substance between solid and liquid has the characteristic of regular molecular arrangement.

2. Then connect the input end of the DRIVE IC to the circuit board by soldering. In this way, the signal can be sent out smoothly, and then the image on the control panel is ready.

3. The light of the LCD module is emitted from the backlight. Before assembling the backlight, we will first check whether the assembled LCD panel is perfect, and then assemble the backlight. The backlight is the source of light behind the LCD panel.

Our company specializes in developing solutions that arerenowned across the globe and meet expectations of the most demanding customers. Orient Display can boast incredibly fast order processing - usually it takes us only 4-5 weeks to produce LCD panels and we do our best to deliver your custom display modules, touch screens or TFT and IPS LCD displays within 5-8 weeks. Thanks to being in the business for such a noteworthy period of time, experts working at our display store have gained valuable experience in the automotive, appliances, industrial, marine, medical and consumer electronics industries. We’ve been able to create top-notch, specialized factories that allow us to manufacture quality custom display solutions at attractive prices. Our products comply with standards such as ISO 9001, ISO 14001, QC 080000, ISO/TS 16949 and PPM Process Control. All of this makes us the finest display manufacturer in the market.

Ever wondered how devices display graphics and text on their screen? It’s the work of a graphic LCD module. An electronic visual display technology, a graphic LCD implements tiny crystals made from a liquid-crystal solution. The tiny crystals are manipulated to create images on a two-dimensional screen by producing accurate electronic signals.

That is how a graphic LCD works, but there’s more to it than that, and it’s important to understand how this technology works for you to utilize it properly in the manufacture of devices.

A graphic LCD has five basic layers that are parallel to each other. The first and second layers are responsible for transforming and changing light signals’ polarization to create images. Once the signals are polarized and hit the third layer, the technology is able to determine the required color and shape of the image that will be displayed. This third layer will then bring the constructed shape to the fourth layer, which utilizes a liquid crystal solution to make the image more distinct. It’s in the fifth layer where the image is completely polarized and shown through its glass or plastic screen.

Ordinary users may not know it, but graphic LCDs are almost everywhere–most commonly, in cell phone and laptop screens. They’re also used in calculators, electronic watches, and digital readers. Flat-screen televisions also utilize it, as well as medical gadgets and appliances. Thanks to continuing advancements, graphic LCDs are starting to receive enhanced design and operational assembly allowing them to process inputs by users such as text, sound, or artwork and produce the corresponding output.

Many manufacturers use a graphic LCD because of its advantages over traditional CRT-based visual display units. One key advantage lies in its thin, compact dimensions and lighter weight, allowing it to be used in portable electronic devices. It shows a detailed display of three-dimensional images as well. It also consumes less power, making it more energy efficient.

When it comes to creating and displaying images and text on an LCD display module, you can turn to a graphic LCD. Understanding how this technology functions is essential to your production. If you’re still not sure how to utilize it properly for your business, you can always obtain expert advice from a supplier of graphic LCDs. They can help you make the best choice.

When you stop and think about what goes into displaying one of these amazing images, you might recognize most are protected by a glass cover. You might even be familiar with display types like LCD or OLED. Yet for many, the recognition stops there. You may see the image on the surface, but rarely think about what creates that image, how it achieves life-like, vibrant color, and the journey it makes to reach our eyes.

If we look deeper, beyond the surface and the cover glass of our devices, we would find one or more layers of ultra-thin, technical glass make such images possible. Each layer with a different purpose, all working together to deliver the beautiful, thin displays we use each and every day. Combined, these layers form what we at Corning call the “glass stack.”

It’s worth looking at the individual layers of the glass stack, since each layer is the result of breakthroughs in glass science, optical physics, and state of the art manufacturing. At the top of the stack, we have the protective cover glass of a mobile device that most consumers have heard of – Corning Gorilla Glass. This cover glass protects and maintains the appearance of the display, and also supports the use of front-facing cameras and various sensors. Often, the rear side of such devices is covered with a similar protective glass, which also allows for wireless charging.

Though each layer of the glass stack is formed with the same fusion manufacturing process, the compositions of the glass are different – allowing for different properties and benefits. LCD and OLED displays, whether on mobile devices with glass cover and back or otherwise, utilize different super-thin layers of glass specific to their applications:

A liquid crystal display (LCD) has liquid crystal material sandwiched between two sheets of glass. Without any voltage applied between transparent electrodes, liquid crystal molecules are aligned in parallel with the glass surface. When voltage is applied, they change their direction and they turn vertical to the glass surface. They vary in optical characteristics, depending on their orientation. Therefore, the quantity of light transmission can be controlled by combining the motion of liquid crystal molecules and the direction of polarization of two polarizing plates attached to the both outer sides of the glass sheets. LCDs utilize these characteristics to display images.

An LCD consists of many pixels. A pixel consists of three sub-pixels (Red/Green/Blue, RGB). In the case of Full-HD resolution, which is widely used for smartphones, there are more than six million (1,080 x 1,920 x 3 = 6,220,800) sub-pixels. To activate these millions of sub-pixels a TFT is required in each sub-pixel. TFT is an abbreviation for "Thin Film Transistor". A TFT is a kind of semiconductor device. It serves as a control valve to provide an appropriate voltage onto liquid crystals for individual sub-pixels. A TFT LCD has a liquid crystal layer between a glass substrate formed with TFTs and transparent pixel electrodes and another glass substrate with a color filter (RGB) and transparent counter electrodes. In addition, polarizers are placed on the outer side of each glass substrate and a backlight source on the back side. A change in voltage applied to liquid crystals changes the transmittance of the panel including the two polarizing plates, and thus changes the quantity of light that passes from the backlight to the front surface of the display. This principle allows the TFT LCD to produce full-color images.

Liquid crystal displays are commonly known as LCD, consist of liquid crystals that are activated by electric current, and they are used to display lines of alpha-numeric information (one or more lines) in a variety of devices, for example, fax machines, answering machines call counters, laptop computer screens, scientific instruments, portablecompact disc players,clocks, and so forth. The basis of LCD technology is the liquid crystal, a substance made of complicated molecules.

LCD uses a liquid crystal to produce a visible image. Liquid crystal displays are super-thin technology display screens that are generally used in laptop computer screens, TVs, cell phones, and portable video games.Liquid crystal displays (LCDs) have become the dominant technology in televisions and monitors in our homes and offices.

In an LCD, an electric current is used to switch segments of liquid crystals from a transparent phase to a cloudy phase, each segment forming part of a number or letter. The segments can also be in the shape of tiny dots or pixels, and they can be arranged in rows and columns. They are turned on and off individually to either block or allow polarized light to pass through. When the light is blocked, a dark spot is created on the reflecting screen.

Liquid crystal display (LCD) screens are manufactured by assembling a sandwich of two thin sheets of glass.  On one of the sheets are transistor “cells” formed by first depositing a layer of indium tin oxide (ITO), an unusual metal alloy that you can actually see through.  That’s how you can get electrical signals to the middle of a screen.  Then you deposit a layer of silicon, followed by a process that builds millions of precisely shaped transistor parts.  This patterning step is repeated to build up tiny little cells, one for each dot (known as a pixel) on the screen.  Each step has to be precisely aligned to the previous one within a few microns. Remember, the average human hair is 40 microns in diameter.

On the other sheet of glass, you make an array of millions of red, green, and blue dots in a black matrix called a color filter array (CFA). This is how you produce the colors when you shine light through them.  Then you drop tiny amounts of liquid crystal material into the cells on the first sheet and glue the two sheets together.  You have to align the two sheets so the colored dots sit right on top of the cells, and you can’t be off by more than a few microns in each direction anywhere on the sheet.  The sandwich is next covered with special sheets of the polarizing film, and the sheets are cut into individual “panels” – a term that is used to describe the subassembly that actually goes into a TV.

Generally, a brush is used toscrubat the same time to enhance the stripping effect. Then use DI water to clean and dry the glue crumbs. Generally, the above processes are calledlithography processes, which play a key role in LCD manufacturing.

Generally, the orientation materials for the production of low- and medium-grade LCDs are made of PA, that is, polyimide acid, which is made by the polymerization reaction of dianhydride and diamine at low temperature. It is dehydrated and cured at high temperature (the upper chemical layer is a kind of ring Chemical reaction), it becomes polyimide (PI). Polyimide has good chemical stability, excellent mechanical properties, high insulation, high-temperature resistance, high dielectric constant, radiation resistance, and non-flammability.

Screen printing is used for seal printing and thick layer printing. Flexo-Printing is used for polyimide layer printing and printing of thin layers with high precision.

Flexo printing is offered in order to form polyimide layers in glass plates for LCD manufacturing. We can integrate these machines in an in-line production street or in a polyimide cluster, consisting of a polyimide printing machine, a coupled hot plate curing system and related automation incl. loading and unloading devices.

Punctuation silkscreen is used to connect the circuits of the LCD because there are 2 glasses of the LCD. up one and down. Only the pin side glass has an electricity connection, that dots are for supplying electricity for the glass which doesn’t have electricity. that dots are for supplying electricity for the glass which doesn’t have electricity.

As described above already, the seal has to be finally cured after the cell assembly process. This has to be done under pressure in order to make sure that the seal thickness is properly related to the spacer diameter and the calculated liquid crystal thickness can be reached with low tolerances. Hotpress ovens are available as a batch process tool and as a single panel press oven. The batch oven requires a previous collection of panels and preparation of a larger pile of panels that are pressed together. The pressed pile of wafers is then cured in a clean convection oven. The single panel hot press oven is easier to integrate with automatic lines and works continuously.

Usually, a pair of ITO glasses can make multiple liquid crystal cells. In order to expose the LCD filling port, the glass must be appropriately cut into strips or granules.

This stage includes filling the liquid crystal into the prepared empty cell and sealing the filling hole so that the liquid crystal cell is basically made. Generally, a special liquid crystal filling machine is used to form a vacuum in the liquid crystal cell, and then the liquid crystal is filled into the LCD cell by the pressure difference and the capillary action of the liquid crystal cell.

Detection Visuallyinspects the appearance and background color of semi-finished LCD products under the polarized light table and picks out the unqualified products.

The electrical testis to check the display graphics, electrical and functional defects, and other appearance defects of the LCD screen under the power-on state.

This is the most important point in LCD manufacturing, where silkscreens are used for printing. High-resolution silkscreens have more than 130 meshes per cm, enabling them to print lines with a width down to 50µm. The layer thickness is in the range of 10µm normally, which is regarded as a “thick” layer in LCD manufacturing.

Display device technology and performance is advancing at a remarkable pace. The design and manufacture of Liquid Crystal and Light Emitting Diode Displays that include touch screen layers is very demanding. These display components and assemblies can be characterized with Bristol Instruments non-contact thickness gauges to sub-micron accuracy.

In general, there are two types of displays in the market today: active matrix liquid crystal display (AMLCD) and AMOLED. In its simplicity, the fundamental components required to make up the display are the same for AMLCD and AMOLED. There are four layers of a display device (FIGURE 1): a light source, switches that are the thin-film-transistor and where the gases are mainly used, a shutter to control the color selection, and the RGB (red, green, blue) color filter.

Technology trends TFT-LCD (thin-film-transistor liquid-crystal display) is the baseline technology. MO / White OLED (organic light emitting diode) is used for larger screens. LTPS / AMOLED is used for small / medium screens. The challenges for OLED are the effect of < 1 micron particles on yield, much higher cost compared to a-Si due to increased mask steps, and moisture impact to yield for the OLED step.

Although AMLCD displays are still dominant in the market today, AMOLED displays are growing quickly. Currently about 25% of smartphones are made with AMOLED displays and this is expected to grow to ~40% by 2021. OLED televisions are also growing rapidly, enjoying double digit growth rate year over year. Based on IHS data, the revenue for display panels with AMOLED technol- ogies is expected to have a CAGR of 18.9% in the next five years while the AMLCD display revenue will have a -2.8% CAGR for the same period with the total display panel revenue CAGR of 2.5%. With the rapid growth of AMOLED display panels, the panel makers have accel- erated their investment in the equipment to produce AMOLED panels.

There are three types of thin-film-transistor devices for display: amorphous silicon (a-Si), low temperature polysilicon (LTPS), and metal oxide (MO), also known as transparent amorphous oxide semiconductor (TAOS). AMLCD panels typically use a-Si for lower-resolution displays and TVs while high-resolution displays use LTPS transistors, but this use is mainly limited to small and medium displays due to its higher costs and scalability limitations. AMOLED panels use LTPS and MO transistors where MO devices are typically used for TV and large displays (FIGURE 3).

This shift in technology also requires a change in the gases used in production of AMOLED panels as compared with the AMLCD panels. As shown in FIGURE 4, display manufacturing today uses a wide variety of gases.

A method for manufacturing a liquid crystal display panel includes preparing first and second substrates having an active region, forming a sealant along a periphery of the active region on at least one of the first and second substrates, dispersing a liquid crystal material on the at least one substrate, the liquid crystal material having a photo-reactant material, attaching the first and second substrates, and irradiating ultraviolet light on an entire surface of the at least one substrate.

The present invention relates to a liquid crystal display (LCD), and more particularly, to a liquid crystal display panel and method for manufacturing a liquid crystal display panel. [0003]

Historically, the cathode ray tube (CRT) has been widely used as a display device in applications such as televisions and computer monitors, for example, because CRT screens can display multiple colors with high brightness. However, the CRT cannot adequately satisfy present demands for display applications requiring reduced volume and weight, portability, and low power consumption while having a large screen size and high resolution. Accordingly, a greater emphasis has been placed on developing flat panel displays to replace the CRT. To date, flat panel displays have found wide application in monitors for computers, spacecraft, and aircraft. Examples of flat panel display types currently in use include liquid crystal displays (LCDs), electroluminescent displays (ELDs), field emission displays (FEDs), and plasma display panels (PDPs). Flat panel displays are advantageous because of their light weight, high luminance, high efficiency, high resolution, high speed response time, low driving voltage, low power consumption, low cost, and natural color. [0005]

Currently, LCD devices are widely used as monitors for portable computers. These LCDs typically include two opposing glass substrates with a liquid crystal layer sealed therebetween. A plurality of pixel patterns is formed on one of the glass substrates, and a color filter layer is provided on the other substrate. The two glass substrates are attached to each other using a sealant that serves to attach and fix the two glass substrates to each other. Since liquid crystal materials have low specific resistance and easily absorb ambient moisture, they are susceptible to contamination by impurities. Accordingly, the sealant used to attach the two glass substrates must also resist permeation of external moisture that can adversely affect the liquid crystal material. Commonly used sealants include inorganic and organic materials. Inorganic sealant materials have been conventional for sealing LCDs. However, with development of new liquid crystal materials, inorganic sealant materials are generally no longer used. Instead, organic epoxy-based resins such as phenol-based or acryl-based resins, for example, are presently used as LCD sealant materials. The organic epoxy-based resins can be divided into either a two-liquid state type that requires mixing a main material with a hardener, or a one-liquid state type that includes hardener already incorporated into the main material. [0006]

Depending on the type of hardener, an organic resin sealant is generally hardened by either a thermal process or exposure to ultra-violet (UV) rays. In either case, high adhesion strength, high crystallization ratio, and exceptional printing performance are required to obtain a seal with high reliability. Uniform distribution of the organic sealant also is necessary to accurately control a liquid crystal cell gap while pressurizing, heating, and hardening the glass substrates. Thermo-hardening resins have high mechanical strength, high adhesion strength, and high cross-linkage at high temperature. Epoxy and phenol resins are mainly used as a thermohardening resin. However, UV hardening resins are most often used for sealing large size display panels because, as compared to thermohardening resin, they harden at low temperature, have reduced hardening time and improved adhesion. Moreover, when a thermo-hardening resin is applied to large sized substrates, thermal expansion of the resin often occurs. [0007]

FIG. 1 is a plane view of a related art LCD panel, and FIGS. 2A to [0009] 2E are sectional views illustrating manufacturing processes of the related art LCD panel. In FIG. 1, the related art LCD panel comprises a thin film transistor (TFT) substrate 13 where an active region A is defined, a color filter substrate 15, and a sealant 17 for attaching the TFT substrate 13 to the color filter substrate 15. A plurality of TFTs and pixel electrodes are patterned on the TFT substrate 13 corresponding to the active region. In addition, a plurality of color filter patterns, light-shielding layers, and common electrodes are patterned on the color filter substrate 15.

However, the related art method for manufacturing an LCD panel has several problems. With the development of large-sized LCD panels, UV hardening sealants are conventionally used to attach lower and upper substrates to each other. In this case, UV light must be radiated on the UV hardening sealant and not on the active region that is filled with liquid crystals. Accordingly, if UV light is irradiated on the entire LCD panel without a mask, characteristics of the liquid crystals are changed by the UV light, thereby deteriorating picture quality. Therefore, it is necessary to use a mask to prevent the UV light from irradiating the active region. Implementing a mask will increase costs. [0015] SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a liquid crystal display panel and a method of manufacturing a liquid crystal display panel that substantially obviates one or more problems due to limitations and disadvantages of the related art. [0016]

An object of the present invention is to provide a method for manufacturing a liquid crystal display panel, in which a UV hardening sealant is hardened without using a separate mask. [0017]

To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a method for manufacturing a liquid crystal display panel includes preparing first and second substrates having an active region, forming a sealant along a periphery of the active region on at least one of the first and second substrates, dispersing a liquid crystal material on the at least one substrate, the liquid crystal material having a photo-reactant material, attaching the first and second substrates, and irradiating ultraviolet light on an entire surface of the at least one substrate. [0020]

In another aspect, a method for manufacturing a liquid crystal display panel includes forming at least one sealant along a periphery of an active region between first and second substrates, dispersing a liquid crystal material in the active region, the liquid crystal material having a photo-reactant material, and irradiating ultraviolet light on an entire surface of the first and second substrates. [0022]

FIGS. 4A to [0028] 4D are cross-sectional views illustrating exemplary fabricating processing steps for manufacturing an LCD according to the present invention;

FIGS. 6A and 6B illustrate an alignment state of liquid crystals depending on whether a voltage is applied between two electrodes, in an IPS mode LCD device according to the present invention.[0030] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 3 is a plane view of an LCD panel according to the present invention, and FIGS. 4A to [0032] 4D are sectional views illustrating exemplary fabricating process steps of manufacturing an LCD panel according to the present invention.

In FIG. 3, an exemplary LCD panel according to the present invention may include a double sealant [0033] 37, and liquid crystals containing a photo-reactant are formed in an active region A inside the double sealant 37 between a first substrate 33 and a second substrate 35. The first substrate 33 includes thin film transistors (TFTs) and pixel electrodes, and the second substrate includes a color filter pattern. The photo-reactant may include a photo-reactive polymer or a photo-reactive oligomer, for example.

In FIG. 4A, a first substrate [0034] 33 and a second substrate 35 are prepared. On the first substrate, a plurality of TFTs (not shown) and pixel electrodes (not shown) are formed in an active region A. On the second substrate 35, a plurality of color filter patterns (not shown) are formed. Then, alignment layers 36 and 36 aare respectively formed on the first and second substrates 33 and 35. Alternatively, alignment layers may be formed on only a single one of the first and second substrates 33 and 35.

In FIG. 4D, the first and second substrates [0039] 33 and 35 may be attached in a chamber, for example. Accordingly, the liquid crystals 41 (of FIG. 4C) may be dispersed by a uniformly dispensing method in the panel, thereby forming a liquid crystal layer 41 a. Then, if UV light is irradiated over the entire LCD panel, the UV hardening double sealant 37 is hardened by the UV light, and the liquid crystal layer is aligned as shown in FIG. 5B since the photo-reactant is contained in the liquid crystal layer.

For example, an IPS mode determines an alignment direction of liquid crystal molecules by application of an electric field in a horizontal direction between two electrodes. The IPS mode can obtain high speed response time by using the liquid crystal containing the photo-reactant according to the present invention. That is, a photo-reactant, monomer is mixed with the liquid crystal and then injected into a cell. Subsequently, a polymer is formed by a photo polymerization, thus obtaining a Polymer Stabilized (PS)-IPS cell. Herein, constituents of the polymer affect operational characteristic of the IPS mode and corresponding drive voltages. Generally, an IPS mode LCD panel has an improved off-time characteristics as compared with on-time characteristic. The PS-IPS considerably improves the off-time characteristics through a polymer network. [0043]

As described above, an exemplary method for manufacturing an LCD panel of the present invention has the following advantages. First, a UV hardening sealant or a sealant that can be hardened by UV light and heat is formed to attach upper and lower substrates to each other, and a liquid crystal layer containing a photo-reactant is formed in a cell. Accordingly, a separate mask is not required to mask the inside of the cell when UV light is irradiated to harden the sealant, thereby reducing production costs. In addition, a total number of processing steps can be minimized since the sealant is hardened and alignment of the liquid crystal is performed by a single irradiation process, thereby reducing processing time. [0046]