KR20060095356A - Liquid crystal display device and method for fabricating the same - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device that simplifies the process of forming a color filter layer by attaching a film type color filter layer on an outer surface of the substrate, and more particularly, to a gate wiring, a data wiring, a thin film transistor, and a pixel formed on an inner surface of a first substrate. Any one of the first and second substrates, and a second substrate opposed to the first substrate with a liquid crystal layer interposed between an electrode, a column spacer formed on the thin film transistor, and the first substrate. It characterized in that it comprises a color filter film attached to the outer surface.

Color Filter Films, Column Spacers

Description

Liquid Crystal Display Device and Method for Manufacturing the Same {Liquid Crystal Display Device And Method For Fabricating The Same}

1 is a cross-sectional view of a liquid crystal display device according to the prior art.

2a to 2e are process cross-sectional views showing a color filter process according to the prior art.

3 is a cross-sectional view of a liquid crystal display device according to a first embodiment of the present invention.

4 is a perspective view of a liquid crystal display device showing the arrangement of column spacers according to the present invention;

5 is a cross-sectional view of a liquid crystal display device according to a second embodiment of the present invention.

6 is a perspective view of a liquid crystal display device showing a process of attaching a color filter film according to the present invention.

* Explanation of symbols on the main parts of the drawings

101: upper substrate 102: lower substrate

103: liquid crystal layer 112: color filter film

113: common electrode 115: column spacer

116 sealant 122 pixel electrode

132: gate wiring 135: data wiring

The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device using a color filter film to simplify the process of the color filter layer, and a manufacturing method thereof.

Recently, with the development of new advanced imaging devices such as high definition TVs, liquid crystal displays (LCDs), electro luminescence displays (ELDs), vacuum fluorescence displays (VFDs), and PDPs are used instead of CRTs. Research on flat panel display devices such as plasma display panels is being actively conducted.

Among them, the liquid crystal display device is a representative technology of a flat panel display, and has characteristics such as thin, low cost, low power consumption, and the like, such as a display of a lap top computer or a pocket computer, a vehicle loading, and a color TV image. Its use is also rapidly expanding.

A liquid crystal display device having such characteristics is a structure in which a color filter array substrate as an upper substrate and a TFT (Thin Film Transistor) substrate as a lower substrate are disposed to face each other, and a liquid crystal having dielectric anisotropy is formed therebetween. By driving a thin film transistor (TFT) added to hundreds of thousands of pixels through the pixel selection address wiring to drive a voltage applied to the pixel.

In order to manufacture the liquid crystal display device as described above, a transistor process, a color filter process, a liquid crystal cell process, etc. should be largely performed.

The transistor process is a process of fabricating a thin film transistor array on an organic substrate by repeating deposition, photolithography, and etching processes.

In the color filter process, a red, green, and blue color filter layer is formed on the organic substrate on which a black matrix is formed to realize colors. It is a process of forming the ITO film for common electrodes. In this case, the color filter layer may be classified into a dyeing method, a dispersion method, a coating method, an electrodeposition method, an inkjet method, etc. according to a manufacturing method, and the most common method currently used in manufacturing a color filter layer of a TFT-LCD is a pigment dispersion method. to be.

In addition, the liquid crystal cell process is a process of forming a liquid crystal layer by bonding a glass substrate on which a thin film transistor is completed and a glass substrate on which a color filter process is completed so that a predetermined gap is maintained between the two substrates, and then injecting a liquid crystal between the gaps.

Hereinafter, a method of manufacturing a liquid crystal display device according to the prior art will be described with reference to the accompanying drawings.

1 is a cross-sectional view of a liquid crystal display device according to the prior art, Figures 2a to 2e is a process cross-sectional view showing a color filter process according to the prior art.

First, a plurality of pixels are defined by forming a gate wiring (not shown) for scanning an active element on the lower substrate 2 and a data wiring 35 for introducing an image signal into each pixel in a lattice form to define a plurality of pixels. A pixel electrode 22 and a thin film transistor TFT for switching the image signal to be inserted into each pixel electrode are formed.

Then, a black matrix 11 is formed on the upper substrate 1 to serve as the division and light blocking between the pixels, and the color filter layer 12 is formed by sequentially applying the color resists of R, G, and B. After that, a common electrode 13 is formed on the color filter layer to face the pixel electrode.

Specifically, referring to the color filter process, first, as shown in FIG. 2A, the first color resist 14a in which red is colored on the entire upper substrate 1 on which the black matrix 11 is formed is illustrated. ) Is applied, the mask 17 is aligned on the top, and partially exposed and developed to form a first color filter layer 12a colored in red (R), as shown in FIG. 2B.

Next, as shown in FIG. 2C, a second color resist 14b colored with green is applied to the entire surface including the first color filter layer 12a, and the mask is shifted and then moved in the same manner. After exposure and development, as shown in FIG. 2D, a second color filter layer 12b colored green (G) is formed.

Subsequently, a third color resist 14c colored with blue is coated on the entire surface including the green second color layer pattern 15b, and exposed and developed in the same manner using the same mask. As shown in FIG. 3, the third color filter layer 12c colored in blue (B) is formed. As a result, the color filter layer 12 including R, G, and B is completed, and the common electrode 13 is formed on the entire surface including the color filter layer 12.

As described above, after performing the transistor process and the color filter process, a plastic ball made of a size of 4 to 5㎛ on the front surface of the upper substrate 1 to maintain the cell gap between the substrates. Or ball spacers 15, such as silica spheres.

Subsequently, in order to form a cell gap and prevent leakage of liquid crystal, a sealant 16 mixed with micro pearl or the like is formed on the edge of the lower substrate 2 by screen printing. At this time, the liquid crystal is not formed in the liquid crystal injection hole to be injected.

Subsequently, the upper substrate 1 on which the ball spacer is formed and the lower substrate 2 on which the sealant is formed are automatically aligned based on the alignment marks, and then faced to each other, and the sealant is cured under high temperature and high pressure to completely seal the two substrates. After the adhesion, the inside of the liquid crystal cell is evacuated, and then liquid crystal is injected between the two substrates by capillary action, and the liquid crystal inlet is sealed to complete the liquid crystal display device.

However, the above-described conventional liquid crystal display device and its manufacturing method have the following problems.

That is, conventionally, in order to change the color coordinate of the color filter layer, the colored color resists were used for each of R, G, and B. The patterning process was also performed a number of times to form each of the R, G, and B patterns. The color filter layer is formed.

Therefore, the process is complicated and takes a long time, and a color filter layer having a non-uniform thickness is formed.

The present invention has been made to solve the above problems, a liquid crystal display device and a method for manufacturing the same by implementing a color by attaching a color filter film to the outer surface of the substrate to simplify the process and form a uniform color filter layer The purpose is to provide.

The liquid crystal display device according to the present invention having the above structure includes a gate wiring, a data wiring, a thin film transistor and a pixel electrode formed on an inner surface of a first substrate, a column spacer formed on the thin film transistor, and the first substrate. And a color filter film attached to an outer surface of any one of the first and second substrates, the second substrate having a liquid crystal layer and opposed to the first substrate.

In addition, a method of manufacturing a liquid crystal display device for achieving another object of the present invention includes preparing a first and a second substrate, defining a pixel by crossing a gate wiring and a data wiring on the first substrate, Forming a thin film transistor and a pixel electrode in the pixel, opposing the first and second substrates to form a liquid crystal layer therebetween, and forming a liquid crystal layer between the first and second substrates, It characterized in that it comprises a step of attaching a color filter film.

That is, by attaching the R, G, B color filter film to the outer surface of one of the upper and lower substrates to form a color filter layer, the process is simplified and prevents misalignment. It is characterized in that the overcoat layer is not formed separately because it is flat.

Hereinafter, a liquid crystal display device and a method of manufacturing the same according to the present invention will be described in detail with reference to the accompanying drawings.

3 is a cross-sectional view of a liquid crystal display device according to a first embodiment of the present invention, and FIG. 4 is a perspective view of a liquid crystal display device showing the arrangement of column spacers according to the present invention.

5 is a cross-sectional view of a liquid crystal display device according to a second embodiment of the present invention, and FIG. 6 is a perspective view of a liquid crystal display device showing a process of attaching a color filter film according to the present invention.

As shown in FIG. 3, the liquid crystal display device according to the first embodiment of the present invention is formed at the edges of the lower substrate 102 except the upper and lower substrates 101 and 102 and the liquid crystal inlet, respectively. A sealing agent 116 for adhering the lower substrate, a column spacer 115 for maintaining a cell gap between the upper and lower substrates 101 and 102 and a cell gap at the liquid crystal inlet, and encapsulation between the upper and lower substrates The liquid crystal layer 103 and the color filter film 112 attached to the outer surface of the lower substrate 102.

In this case, an inner surface of the lower substrate 102 is vertically intersected to form a data line 135 and a gate line 132 of FIG. 4, and are formed at the intersections of the two lines to turn on / off each pixel. A thin film transistor (TFT) for determining (On / Off) and a pixel electrode 122 facing the common electrode and applying a voltage for driving the liquid crystal are formed. The thin film transistor includes a gate electrode 132a branched from the gate wiring, a semiconductor layer 134 formed on the gate electrode insulated from the gate electrode, and a source / drain electrode 135a branched from the data wiring 135. 135b).

In addition, the common electrode 113 for applying a voltage to the liquid crystal together with the pixel electrode is formed on the inner surface of the upper substrate 101 by a transparent conductive material.

As described above, the inner surface of the upper substrate 101 according to the present invention is characterized in that a color filter layer of RGB and a black matrix for preventing the mixing of RGB are not separately formed, thereby greatly reducing the manufacturing cost of the upper substrate and lowering the temperature. Since the process becomes possible, the board | substrate of various materials, such as a plastic substrate, can be used in addition to a glass substrate.

In this case, the conventional color filter layers of R, G, and B are replaced by the color filter film 112 attached to the lower substrate outer surface, and the conventional black matrix is replaced by the gate wiring and the data wiring.

Therefore, since the color filter layer is not formed by applying and patterning colored colored resists, the process for forming the color filter layer is simplified, and since the black matrix does not need to be formed, the aperture ratio is improved and the adhesion margin by the black matrix is considered. You can design patterns without

As described above, since the bonding margin with the black matrix does not have to be taken into consideration, the width of the gate wiring and the data wiring can be increased, and eventually, a large-area device is formed by using a conductive material such as Mo and AlND without using low resistance wiring. Can be supported. However, in order to prevent light leakage between the wiring and the pixel electrode, the pixel electrode may be formed to overlap the edges of the gate wiring and the data wiring.

Subsequently, as shown in FIGS. 3 and 4, the column spacer 115 according to the present invention is disposed above the thin film transistor TFT to prevent external natural light from being incident on the semiconductor layer 134. That is, since the black matrix is not formed, the semiconductor layer of the thin film transistor may be exposed to external natural light. When light is incident on the semiconductor layer, leakage current may occur, thereby reducing the reliability of the thin film transistor. The provided column spacer is formed on the semiconductor layer of the thin film transistor.

Meanwhile, in addition to attaching the color filter film 112 to the outer surface of the lower substrate 102, as shown in FIG. 5, the color filter film 112 may be attached to the outer surface of the upper substrate 101.

At this time, the color filter film 112 is formed by transferring and developing the color of the mask of the R, G, B on the film and developed or by printing a pigment of R, G, B in a desired pattern on a transparent film, the adhesive tape It is completely attached to the outer surface of the substrate using When attached, the boundary lines between the R, G, and B colors correspond to the wires so that R, G, and B mixed colors do not occur in one pixel.

Hereinafter, the liquid crystal display device according to the present invention through the manufacturing method will be described in detail.

First, a gate agent, a data line, a thin film transistor, a lower substrate on which pixel electrodes are formed, and an upper substrate on which a common electrode is formed are prepared, and a sealant that serves as an adhesive on the remaining region except the liquid crystal inlet at the edge of the upper substrate is prepared. 116 is formed seamlessly, and all column spacers 115 are formed on the thin film transistor of each pixel of the lower substrate.

To form the column spacer, a polymer material of an organic insulating material such as benzocyclobutene (BCB) or photo acryl or an inorganic insulating material such as silicon nitride or silicon oxide is formed to a predetermined thickness on a substrate, and then the upper portion of the thin film transistor It is formed by patterning with photolithography so as to remain.

Subsequently, the upper and lower substrates 101 and 102 are automatically aligned based on the alignment marks, and then faced to each other, the sealant is cured under high temperature and high pressure to completely bond the two substrates, and the inside of the liquid crystal cell is vacuumed. After the liquid crystal is injected between the two substrates by using a capillary phenomenon, the liquid crystal inlet is sealed to complete the liquid crystal display device.

On the other hand, it can be formed by the liquid crystal dropping method, not the liquid crystal injection method. That is, a lower substrate on which a gate wiring, a data wiring, a thin film transistor, and a pixel electrode are formed, and an upper substrate on which a common electrode are formed are prepared. A sealant 116 acting as an adhesive is formed on the outer side of the upper substrate or the lower substrate without a liquid crystal injection hole, and a column spacer 115 is formed on the thin film transistor. Thereafter, an appropriate amount of liquid crystal is dropped on the upper substrate 101 or the lower substrate 102, and the upper and lower substrates 101 and 102 are aligned to face each other. Then, the sealant 116 is cured by thermal curing and / or UV curing.

Next, as shown in FIG. 6, the color filter film 112 is attached to the outer surface of the lower substrate 102 by using an adhesive tape to complete the liquid crystal display device according to the present invention. Of course, it can be attached to the outer surface of the upper substrate.

As described above, the color filter film 112 is formed by printing a pigment on the transparent film by an inkjet method or the like, or by arranging a mask on the transparent film and irradiating light from the top to form the same image as the mask. It can be formed by transferring to a transparent film.

On the other hand, the present invention described above is not limited to the above-described embodiment and the accompanying drawings, it is possible that various substitutions, modifications and changes within the scope without departing from the technical spirit of the present invention. It will be apparent to those of ordinary skill in Esau.

That is, the above description is limited to the TN mode in which the lower substrate on which the pixel electrode is formed and the upper substrate on which the common electrode are formed are opposed to each other to drive the liquid crystal layer by a vertical electric field formed between the pixel electrode and the common electrode. However, the present invention is not limited thereto and can be applied to the IPS mode. Unlike the TN mode, the IPS mode forms a pixel electrode and a common electrode on one substrate in parallel and drives the liquid crystal layer in a transverse electric field formed therebetween.

As described above, the liquid crystal display device and the manufacturing method thereof according to the present invention have the following effects.

First, since the upper substrate according to the present invention does not separately form a color filter layer of RGB and a black matrix to prevent RGB mixing, the manufacturing cost of the upper substrate is greatly reduced and the bonding margin is not set when the upper and lower substrates are bonded. do.

Second, unlike the conventional method in which a color filter layer is formed by applying and patterning a colored resist, the color filter process is simpler and easier because the color filter film is attached to the outer surface of the substrate to form a color filter layer. Become.

Third, since the black matrix does not need to be formed, the aperture ratio is improved and the pattern can be designed without considering the bonding margin by the black matrix.

Fourth, the black matrix and the bonding margin do not have to be taken into consideration, so that the width of the gate wiring and data wiring can be increased, and eventually, even if the wiring is formed using a conductive material such as Mo and AlND without using low resistance wiring, It becomes possible to cope with LCD.

Fifth, since the color filter film attaching process is performed at a low temperature, substrates of various materials such as plastic substrates may be used in addition to glass substrates.

Sixth, since the color filter film according to the present invention is flat, color reproducibility can be improved.

Claims (8)

A gate wiring, a data wiring, a thin film transistor and a pixel electrode formed on the inner surface of the first substrate; A column spacer formed on the thin film transistor, A second substrate opposed to and bonded to the first substrate with a liquid crystal layer between the first substrate, And a color filter film attached to an outer surface of one of the first and second substrates. The method of claim 1, And a common electrode on the inner surface of the second substrate. The method of claim 1, And a common electrode parallel to the pixel electrode on an inner surface of the first substrate. The method of claim 1, Liquid crystal display device characterized in that the gate wiring and data wiring serves as a black matrix. The method of claim 1, The color filter film is a manufacturing method of a liquid crystal display device, characterized in that consisting of colors of R, G, B (Red, Green, Blue). The method of claim 1, And an edge of the pixel electrode and an edge of the gate line and the data line overlap each other. Preparing a first and second substrates; Defining pixels by crossing gate lines and data lines on the first substrate, and forming a thin film transistor and a pixel electrode in each pixel; Opposing the first and second substrates to form a liquid crystal layer therebetween; A method of manufacturing a liquid crystal display device, comprising attaching a color filter film to an outer surface of one of the first and second substrates. The method of claim 1, And forming a column spacer on the thin film transistor on the first substrate.

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