KR20060011585A - Liquid crystal display device and the fabrication method thereof - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device and a method of manufacturing the same, which implement light weight and thinness.

A liquid crystal display device according to the present invention comprises: a first substrate on which an array element and a color filter are formed; A second substrate made of a plastic material facing the substrate; And a liquid crystal layer formed between the first substrate and the second substrate.

As described above, the present invention forms an array element and a color filter layer on a first substrate in a liquid crystal display device, and the second substrate facing the first substrate is made of a plastic substrate, thereby reducing the weight and impact resistance of the liquid crystal display device. Low cost is realized.

COT, TOC, Plastic Board, Lightweight, Thin

Description

Liquid crystal display device and method for manufacturing same

1 is a schematic view of a general liquid crystal display device;

FIG. 2 is a cross-sectional view taken along line AA ′ of FIG. 1. FIG.

3 is a plan view showing a liquid crystal display device having a COT structure according to an embodiment of the present invention.

4 is a cross-sectional view taken along the line B-B 'in FIG.

5a to 5h are cross-sectional views of the process sequence shown in the present invention.

<Description of the symbols for the main parts of the drawings>

200: first substrate 202: gate wiring

204: gate electrode 205: second substrate

206: data pad 208: gate insulating film

 210: active layer 212: ohmic contact layer

214: source electrode 216: drain electrode

218: data wiring 220: data pad

222: island-like metal layer 224: second insulating film

228 black matrix 230 third insulating film                 

234a, 234b, 234c: color filter 238, 240: pixel electrode

242: gate pad contact hole 244: data pad contact hole

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device and a method of manufacturing the same, which implement light weight and thinness.

Recently, with the development of the electronics industry, display devices, which have been limitedly used for TV CRTs, have been widely used in personal computers, notebooks, wireless terminals, automobile dashboards, electronic displays, etc. As a result, the importance of the next generation display device that can process and implement this is increasing.

Such next-generation display devices should be able to realize light and small size, high brightness, large screen, low power consumption and low price. And various flat panel display devices such as a vacuum fluorescent display (VFD) have been studied, and one of them has recently attracted attention.

The liquid crystal display device is superior in resolution to other flat panel display devices, and exhibits characteristics such that the response speed is faster than that of a CRT when a moving image is realized.                         

In addition, the liquid crystal display device has excellent characteristics such as high brightness, high contrast, low power consumption, and so is used in a wide range of fields such as a desktop computer monitor, a notebook computer monitor, a TV receiver, a vehicle-mounted TV receiver, and navigation.

In general, a liquid crystal display device is formed by arranging two substrates having electrodes formed on one side thereof so that the surfaces on which the two electrodes are formed face each other, injecting a liquid crystal material between the two substrates, and then applying voltage to the two electrodes. By moving the liquid crystal molecules by the electric field is a device that represents the image by the transmittance of light that varies accordingly.

More specifically, the liquid crystal display may be largely divided into a liquid crystal panel displaying an image and a driving unit for applying a driving signal to the liquid crystal panel, wherein the liquid crystal panel has a predetermined space and is bonded to the first and second substrates. And a liquid crystal layer injected between the two substrates.

The first substrate may include a plurality of gate lines arranged in one direction at a predetermined interval, a plurality of data lines arranged at regular intervals in a direction perpendicular to the gate lines, and each of the gate lines and the data lines. A plurality of pixel electrodes formed in a matrix form in the cross-defined pixel regions and a plurality of thin film transistors that are switched by signals of the gate lines and transfer the signals of the data lines to the pixel electrodes are formed.

The second substrate is provided with a black matrix layer for blocking light in portions other than the pixel region, a color filter layer for expressing R, G, and B color colors, and a common electrode for implementing an image.

As such, the gate electrode and the source / drain electrode constituting the gate line, the data line, and the thin film transistor formed on the first glass substrate of the liquid crystal panel are formed of metal to improve a signal transfer speed.

FIG. 1 is a schematic view illustrating a general liquid crystal display, and FIG. 2 is a cross-sectional view taken along line AA ′ of FIG. 1.

As shown in FIGS. 1 and 2, a general liquid crystal display 111 includes a color filter 107 including a sub color filter 108 and a black matrix 106 configured between each sub color filter 108. The second substrate 105 having the common electrode 118 deposited on the color filter 107 and the pixel region P are defined, and the pixel electrode 117 and the switching element T are configured in the pixel region. The liquid crystal 114 is filled between the first substrate 122 having the array wiring formed around the pixel region P, and the second substrate 105 and the first substrate 122.

The first substrate 122 is also referred to as an array substrate, and the thin film transistor T, which is a switching element, is positioned in a matrix type, and has a gate wiring crossing the plurality of thin film transistors TFT. 113 and data wiring 115 are formed.

In this case, the pixel area P is an area defined by the gate wiring 113 and the data wiring 115 intersecting. A transparent pixel electrode 117 is formed on the pixel area P as described above.

The pixel electrode 117 uses a transparent conductive metal having relatively high light transmittance, such as indium-tin-oxide (ITO).

A storage capacitor C connected in parallel with the pixel electrode 117 is formed on the gate wiring 113, and a part of the gate wiring 113 is used as the first electrode of the storage capacitor C, and a second is formed. As an electrode, an island-shaped source / drain metal layer 130 formed of the same material as the source and drain electrodes is used.

In this case, the source / drain metal layer 130 may be in contact with the pixel electrode 117 to receive a signal from the pixel electrode 117.

As shown in FIG. 2, the first substrate 122 and the second substrate 105 are spaced apart from each other, and the liquid crystal layer 114 is positioned between the first and second substrates 122 and 105.

A thin film transistor T including a gate electrode 132, an active layer 134, a source electrode 136, and a drain electrode 138 on the first substrate 122, and an upper portion of the thin film transistor T. The protective film 140 is configured to protect it.

In the pixel region P, a transparent pixel electrode 117 is formed in contact with the drain electrode 138 of the thin film transistor T, and a storage capacitor C connected in parallel with the pixel electrode 117 includes a gate wiring 113. It is configured on the top.

The second substrate 105 includes a black matrix 106 corresponding to the gate wiring 113, the data wiring 115, and the thin film transistor T. The pixel region P of the first substrate 122 is formed. Correspondingly, sub color filters 107a, 107b, and 107c are configured.

At this time, the configuration of the first substrate 122, which is a general array substrate, is configured such that the data line 115 and the pixel electrode 117 are spaced apart from each other by a predetermined interval A to prevent vertical cross talk. The gate wiring 113 and the pixel electrode 117 are also configured to be spaced apart from each other by a predetermined interval (B).

Since the spaces A and B spaced apart between the data line 115 and the gate line 113 and the pixel electrode 117 are regions where light leakage occurs, the black matrix formed on the upper color filter substrate 105 ( black matrix 106 is used to mask this part.

In addition, the black matrix 106 configured at the upper portion of the thin film transistor T serves to block the light so that the light radiated from the outside does not affect the active layer 134 through the passivation layer 140. .

When the liquid crystal panel is manufactured by bonding the second substrate 105 and the first substrate 122 configured as described above, the light leakage due to the bonding error between the second substrate 15 and the first substrate 122. There is a very high probability of failure.

In addition, since the color filter substrate and the array substrate have to be formed respectively, the time required for the process becomes long and there is a problem in that the manufacturing yield is lowered.

Meanwhile, liquid crystal displays using thin film transistors are applied to various fields, and their required performances are also diversified.

In particular, weight reduction, impact resistance improvement, cost reduction, and the like have been chiefly used as performance required for liquid crystal display devices.

However, the liquid crystal display device in which a thin film transistor is formed on a conventional glass substrate or a quartz substrate has a limitation in reducing the thickness of the substrate itself.                         

Moreover, when the thickness of a glass substrate or a quartz substrate is made thin in order to reduce a liquid crystal display device, a board | substrate will be easy to be broken and will be weak to an impact. Further, due to the cost required for the glass substrate and the quartz substrate, there is a limit to the cost reduction of the liquid crystal display device.

According to the present invention, an array element and a color filter layer are formed on a first substrate in a liquid crystal display, and the second substrate facing the first substrate is made of a plastic substrate to reduce the weight, improve impact resistance, and reduce cost of the liquid crystal display. It is an object of the present invention to provide a liquid crystal display device and a method for manufacturing the same.

In order to achieve the above object, a liquid crystal display according to the present invention comprises: a first substrate on which an array element and a color filter are formed; A second substrate made of a plastic material facing the substrate; And a liquid crystal layer formed between the first substrate and the second substrate.

Gate wiring and data wiring intersecting each other on the first substrate to define a pixel region; A thin film transistor formed in an area where the gate line and the data line cross each other; A black matrix formed on the thin film transistor, gate wiring and data wiring; A color filter formed in the pixel region; And a pixel electrode formed on the color filter.

A color filter formed on the first substrate; A thin film transistor including a gate electrode, an active layer, and a source / drain electrode in a pixel region formed by crossing gate lines and data lines on the color filter; A black matrix formed on the thin film transistor, the gate wiring and the data wiring; And a pixel electrode formed on the pixel region.

A black matrix formed on the first substrate; A color filter formed on the black matrix; A thin film transistor comprising a gate electrode, an active layer, and a source / drain electrode in a pixel region formed by crossing gate lines and data lines on the color filter; And a pixel electrode formed on the pixel region.

In addition, in order to achieve the above object, a method of manufacturing a liquid crystal display device according to the present invention includes the steps of forming a color filter and an array element on the first substrate; Preparing a second substrate made of a plastic material facing the first substrate; Forming a liquid crystal layer between the first and second substrates.

Forming a color filter and an array element on said first substrate, said method comprising the steps of: forming a gate wiring and a data wiring on the first substrate to define a pixel area crossing each other; Forming a thin film transistor including a gate electrode, an active layer, and a source / drain electrode in a region where the gate line and the data line cross each other; Forming a black matrix formed on the thin film transistor, the gate wiring and the data wiring; Forming red, blue, and green color filters in the pixel region; And forming a pixel electrode on the color filter.                     

Forming a color filter and an array element on the first substrate, comprising: forming a color filter on the first substrate; Forming a thin film transistor including a gate electrode, an active layer, and a source / drain electrode in a pixel region formed by crossing gate lines and data lines on the color filter; Forming a black matrix on the thin film transistor, the gate wiring, and the data wiring; And forming a pixel electrode on the pixel area.

Forming a color filter and an array element on said first substrate, comprising: forming a black matrix on said first substrate; Forming a color filter on the black matrix; Forming a thin film transistor including a gate electrode, an active layer, and a source / drain electrode in a pixel region formed by crossing gate lines and data lines on the color filter; And forming a pixel electrode on the pixel area.

Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings.

3 is a plan view illustrating a liquid crystal display device having a COT structure according to an embodiment of the present invention, and FIG. 4 is a cross-sectional view taken along line BB ′ of FIG. 3.

Here, although an embodiment according to the present invention has been described using a color filter on TFT (COT) structure, the present invention is not limited thereto and may be applied to a TFT on color filter (TOC) structure in which a thin film transistor is positioned on a color filter. .

As shown in FIG. 3 and FIG. 4, in the liquid crystal display according to the present invention, the first and second substrates 200 and 205 are positioned to face each other, and the liquid crystal is between the first and second substrates 200 and 205. Form layer 290.

In addition, the gate wirings 202 extending in one direction on the first substrate 200 and including the gate pads 206 at one end thereof are configured to be parallel to each other, and perpendicularly cross the gate wirings 202. A plurality of pixel areas P are defined and data lines 218 including data pads 220 are formed at one end thereof.

The thin film transistor T including the gate electrode 204, the active layer 210, and the source and drain electrodes 214 and 216 is formed at the point where the gate line 202 and the data line 218 cross each other.

In the region P defined by the intersection of the two wires 202 and 218, the color electrodes 234a and 240 interposed between the transparent electrodes 238 and 240 formed of a double layer contacting the drain electrode 216 and the transparent electrodes 238 and 240 of the double layer are formed. 234b and 234c.

The pixel electrodes 238 and 240 are connected in parallel with the storage capacitor C _st formed on the gate wiring 202.

The storage capacitor C _st has an island-shaped metal layer 222 positioned above a portion of the gate line 202 and in contact with the pixel electrodes 238 and 240 as a first electrode, and a lower gate line 202. ) Is used as the second electrode.

As described above, the COT structure has a black matrix 228 and red, green, and blue color filters 234a, 234b, and 234c formed on the thin film transistor (T) array unit.

Here, the black matrix 228 covers the light leakage region and is configured to correspond to the gate wiring 202, the data wiring 218, and the thin film transistor T.

The black matrix 228 is formed by applying an opaque organic material, and serves as a protective film for protecting the thin film transistor T together with blocking light.

In the above-described configuration, the gate pad 206 and the data pad 220 are completed in a shape exposed through the gate and the data contact holes 242 and 244.

The second substrate 205 may be bonded to face the first substrate 200 including the thin film transistor and the color filter to form a liquid crystal layer therebetween.

In this case, the second substrate 205 uses a transparent substrate made of plastic, and is thinner and lighter than the glass substrate of the first substrate 200, so that a thin liquid crystal display device can be manufactured.

Hereinafter, a method of manufacturing an array substrate for a liquid crystal display device according to an exemplary embodiment of the present invention will be described with reference to FIGS. 5A to 5G.

5A to 5H are cross-sectional views illustrating a liquid crystal display according to the present invention in the order of process.

As shown in FIG. 5A, a conductive metal is deposited and patterned on the first substrate 200 to extend from the gate wiring 202 and the gate wiring 202 including the gate pad 206 at one end thereof. The gate electrode 204 is formed.                     

One selected from the group of inorganic insulating materials including silicon nitride (SiN _X ) and silicon oxide (SiO ₂ ) on the entire surface of the substrate 200 on which the gate wiring 202, the gate electrode 202, and the gate pad 206 are formed. Is deposited to form a gate insulating film 208 which is a first insulating layer.

Pure amorphous silicon (a-Si: H) and amorphous silicon (n + a-Si: H) containing impurities are deposited on the gate insulating film 208 and patterned to form a gate insulating film on the gate electrode 204. The active layer 210 and the ohmic contact layer 212 are formed on the 208.

Next, as shown in FIG. 5B, chromium (Cr), molybdenum (Mo), tungsten (W), and titanium are formed on the entire surface of the first substrate 200 on which the active layer 210 and the ohmic contact layer 212 are formed. A source electrode 214 and a drain electrode 216 contacting the ohmic contact layer 212 by depositing and patterning a selected one of a conductive metal group including (Ti) and copper (Cu), and the source electrode A data line 218 connected to 212 and including a data pad 220 at one end thereof, and an island-shaped metal layer 222 is formed on the gate line 202.

Inorganic insulation including silicon nitride (SiN ₂ ) and silicon oxide (SiO ₂ ) on an entire surface of the first substrate 200 on which the data line 218 including the source and drain electrodes 214 and 216 and the data pad 220 are formed. The second insulating layer 224 is formed by thickening a selected one of the material groups.

In this case, the function of the second insulating layer 224 serves to prevent a poor contact that may occur between the organic layer (not shown) and the active layer 210 formed later.                     

The second insulating layer 224 may not be formed unless contact failure occurs between the organic layer (black matrix) and the active layer 210 formed in a later step.

The process of forming the thin film transistor array unit through the above-described process is completed.

Next, as illustrated in FIG. 5C, an opaque organic material having a low dielectric constant is coated on the second insulating layer 224 to form and pattern the black organic layer 226, thereby forming the black and white organic layers 226. The black matrix 228 is formed on a part of the upper portion, a part of the island-shaped metal layer 222, and an upper portion of the data line 218 and the gate line 202 passing through the display area.

Next, as illustrated in 5d, an insulating material is deposited on the entire surface of the first substrate 200 on which the black matrix 228 is formed to form the third insulating layer 230.

The third insulating layer 230 is formed by depositing one selected from the group of inorganic insulating materials including silicon nitride (SiN _X ) and silicon oxide (SiO ₂ ).

As illustrated in FIG. 5E, the third insulating film 230, the second insulating film 224, and the gate insulating film 208 are etched to form one side of the drain electrode 216, the pixel region P, and the island. One side of the source drain metal layer 222 is exposed.

In this case, the gate pad 206 and the data pad 220 are not exposed.

As shown in FIG. 5F, indium tin oxide (ITO) and indium zinc oxide (IZO) as described above are included on the entire surface of the substrate 100 on which the patterned third insulating layer 230 is formed. The transparent conductive metal is deposited to form the first transparent electrode layer 232.

Subsequently, color resins are coated on the entire surface of the first substrate 200 on which the first transparent electrode layer 232 is formed, and the red, green, and blue color filters 234a, 234b, and 234c are applied to the plurality of pixel regions P. FIG. ) Respectively.

As shown in FIG. 5G, the transparent electrode described above is deposited on the entire surface of the first substrate 200 on which the plurality of color filter patterns 234a and 234b are formed to form a second transparent electrode layer 236. The second transparent electrode layer 236 and the first transparent electrode layer 232 thereunder are simultaneously patterned to form the double layer pixel electrodes 238 and 240 corresponding to the pixel region P. FIG.

The first pixel electrode 238 is in direct contact with one side of the exposed drain electrode 216 and the island-shaped metal layer 222, and the second pixel electrode 240 is disposed with the color filter interposed therebetween. The first pixel electrode 238 is in contact with the shape.

Accordingly, the first pixel electrode 238 receives a signal from the drain electrode 216 through the second pixel electrode 240.

In addition, a storage capacitor having an island-shaped metal layer 222 in contact with the pixel electrodes 238 and 240 as a first electrode on the gate wiring 202, and a gate electrode 202 below as a first electrode. (C _st ) is formed.

With the above configuration, the process of forming the color filters 234a and 234b and 234c of FIG. 3 and the pixel electrodes 238 and 240 is completed.

As shown in FIG. 5H, the second substrate 205 is prepared to face the first substrate 200 configured as described above.

The second substrate 205 uses a glass substrate and a heterogeneous substrate, for example, a plastic substrate.

The plastic substrate may be lighter and thinner than the glass substrate, and the manufacturing cost is low.

In addition, the plastic substrate has good impact resistance and light weight, thereby ensuring stability of the product during movement.

Therefore, the second substrate 205 made of plastic material is opposed to the first substrate 200, and then bonded to form a thin liquid crystal display device.

As described above, the present invention has been described in detail through specific embodiments, which are intended to specifically describe the present invention, and the liquid crystal display and the manufacturing method according to the present invention are not limited thereto. It is apparent that modifications and improvements are possible by those skilled in the art.

The present invention provides a liquid crystal display device having a light weight by forming an array element including a thin film transistor and a color filter together on a first substrate in a liquid crystal display device, and forming a second substrate facing and bonded to the first substrate using a plastic substrate. Since it can be manufactured in a thin form, there is an effect that can satisfy the needs of consumers.                     

In addition, since the impact resistance is enhanced by using the plastic substrate in the liquid crystal display device, defects do not occur even when various impacts occur during movement, and thus the durability of the product is good, and the weight is light, thereby making it easy to move the product.

Claims (8)

A first substrate on which an array element and a color filter are formed; A second substrate made of a plastic material facing the substrate; And a liquid crystal layer formed between the first substrate and the second substrate. The method of claim 1, Gate wiring and data wiring intersecting each other on the first substrate to define a pixel region; A thin film transistor formed in an area where the gate line and the data line cross each other; A black matrix formed on the thin film transistor, gate wiring and data wiring; A color filter formed in the pixel region; And a pixel electrode formed on the color filter. The method of claim 1, A color filter formed on the first substrate; A thin film transistor including a gate electrode, an active layer, and a source / drain electrode in a pixel region formed by crossing gate lines and data lines on the color filter; A black matrix formed on the thin film transistor, the gate wiring and the data wiring; And a pixel electrode formed on the pixel region. The method of claim 1, A black matrix formed on the first substrate; A color filter formed on the black matrix; A thin film transistor comprising a gate electrode, an active layer, and a source / drain electrode in a pixel region formed by crossing gate lines and data lines on the color filter; And a pixel electrode formed on the pixel region. Forming a color filter and an array element on the first substrate; Preparing a second substrate made of a plastic material facing the first substrate; Forming a liquid crystal layer between the first and second substrates. The method of claim 5, Forming a color filter and an array element on the first substrate; Forming a gate line and a data line on the first substrate to cross each other to define a pixel area; Forming a thin film transistor including a gate electrode, an active layer, and a source / drain electrode in a region where the gate line and the data line cross each other; Forming a black matrix formed on the thin film transistor, the gate wiring and the data wiring; Forming red, blue, and green color filters in the pixel region; And forming a pixel electrode on the color filter. The method of claim 5, Forming a color filter and an array element on the first substrate; Forming a color filter on the first substrate; Forming a thin film transistor including a gate electrode, an active layer, and a source / drain electrode in a pixel region formed by crossing gate lines and data lines on the color filter; Forming a black matrix on the thin film transistor, the gate wiring, and the data wiring; And forming a pixel electrode on the pixel area. The method of claim 5, Forming a color filter and an array element on the first substrate; Forming a black matrix on the first substrate; Forming a color filter on the black matrix; Forming a thin film transistor including a gate electrode, an active layer, and a source / drain electrode in a pixel region formed by crossing gate lines and data lines on the color filter; And forming a pixel electrode on the pixel area.

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