KR20050114139A - Liquid crystal display device and fabrication method thereof - Google Patents

Abstract

The present invention relates to a liquid crystal display device and a method of manufacturing the same for preventing the seal burst, and is formed along the outer periphery of the first and second substrates and the first and second substrates to bond the first and second substrates together. A black matrix formed on the seal pattern, the second substrate and having irregularities in a region corresponding to the seal pattern, an overcoat layer formed on the entire surface of the second substrate including the black matrix; Provided is a liquid crystal display device including a liquid crystal layer formed between the first and second substrates.

Description

Liquid crystal display device and manufacturing method thereof {LIQUID CRYSTAL DISPLAY DEVICE AND FABRICATION METHOD THEREOF}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and in particular, a seal that may occur due to overlap of a seal formed to bond a color filter substrate and a thin film transistor substrate and a black matrix formed on the color filter substrate. The present invention relates to a liquid crystal display device and a method of manufacturing the same that can be prevented.

Recently, with the development of various portable electronic devices such as mobile phones, PDAs, and notebook computers, there is a growing demand for flat panel display devices for light and thin applications. Such flat panel displays are being actively researched, such as LCD (Liquid Crystal Display), PDP (Plasma Display Panel), FED (Field Emission Display), VFD (Vacuum Fluorescent Display), but mass production technology, ease of driving means, Liquid crystal display devices (LCDs) are in the spotlight for reasons of implementation.

1 schematically illustrates a cross section of a general liquid crystal display device. As shown in the figure, the liquid crystal display device 1 is composed of a lower substrate 5 and an upper substrate 3 and a liquid crystal layer 7 formed between the lower substrate 5 and the upper substrate 3. . Although the lower substrate 5 is a driving element array substrate, although not shown in the drawing, a plurality of pixels are formed on the lower substrate 5, and each pixel is driven such as a thin film transistor. An element is formed. The upper substrate 3 is a color filter substrate, and a color filter layer for realizing color is formed. In addition, a pixel electrode and a common electrode are formed on the lower substrate 5 and the upper substrate 3, respectively, and an alignment film for aligning liquid crystal molecules of the liquid crystal layer 7 is coated.

The lower substrate 5 and the upper substrate 3 are bonded by a sealing material 9, and a liquid crystal layer 7 is formed therebetween, and is driven by a driving element formed on the lower substrate 5. Information is displayed by controlling the amount of light passing through the liquid crystal layer by driving the liquid crystal molecules.

The manufacturing process of the liquid crystal display device can be largely divided into a driving element array substrate process of forming a driving element on the lower substrate 5, a color filter substrate process of forming a color filter on the upper substrate 3, and a cell process. However, the process of the liquid crystal display will be described with reference to FIG. 2.

First, a plurality of gate lines and data lines arranged on the lower substrate 5 to define a pixel region are formed by a driving element array process, and the gate line and the data are formed in each of the pixel regions. A thin film transistor which is a driving element connected to the line is formed (S101). In addition, the pixel electrode is connected to the thin film transistor through the driving element array process to drive the liquid crystal layer as a signal is applied through the thin film transistor.

In addition, the upper substrate 3 is provided with a black matrix to prevent light leakage, a color filter layer of R, G, and B and a common electrode by a color filter process (S104). The black matrix may be formed of a metal material such as chromium (Cr), but in a horizontal field type liquid crystal display device having a common electrode and a pixel electrode formed on a lower substrate, a horizontal electric field between the two electrodes (common electrode and pixel electrode) is used. Resin film is mainly used because it affects. In this case, an overcoat layer for planarization of the color filter layer may be further formed.

Subsequently, an alignment layer is applied to the upper substrate 3 and the lower substrate 5, respectively, and then the alignment control force or surface fixing force (ie, the liquid crystal molecules of the liquid crystal layer formed between the upper substrate 3 and the lower substrate 5). In order to provide a pretilt angle and an orientation direction, the alignment layer is rubbed (S102 and S105). Subsequently, a spacer is disposed on the lower substrate 5 to maintain a constant cell gap, and a sealing material is applied to an outer portion of the upper substrate 3. Then, the lower substrate 5 and the upper substrate are dispersed. Pressure is applied to (3), and it adheres (S103, S106, S107).

On the other hand, the lower substrate 5 and the upper substrate 3 is made of a large area glass substrate. In other words, a plurality of panel regions are formed on the glass substrate of a large area, and a TFT and a color filter layer serving as driving elements are formed in each of the panel regions, so that the glass substrates are cut to produce a single liquid crystal panel. Must be processed (S108). Thereafter, the liquid crystal is injected into the liquid crystal panel processed as described above through the liquid crystal inlet, and the liquid crystal inlet is encapsulated to form a liquid crystal layer. Then, the liquid crystal display is manufactured by inspecting each liquid crystal panel (S109 and S110). .

In the conventional liquid crystal display device manufactured through the process as described above, when the size of the panel is small, such as a notebook, the black matrix and the seal pattern formed on the outer side of the upper substrate overlap, the liquid crystal injection when the black matrix and the seal pattern In this overlapping area, a seal failure will occur.

FIG. 3 is an enlarged view of the seal pattern region A of FIG. 1, and in particular, illustrates a region where the black matrix and the seal pattern overlap.

As shown in the drawing, when the size of the liquid crystal panel is small, the black matrix 4 and the overcoat film 6 are formed on the upper substrate 3 corresponding to the seal pattern 9, so that the seal pattern 9 ) And the black matrix 4 overlap. Furthermore, in the case where the black matrix 4 is formed of an opaque resin film, the adhesion between the black matrix 4 and the overcoat film 6 formed thereon is overcoat 6 and the seal pattern 9. Since it is weaker than the adhesiveness, the overcoat film 6 in the region where the seal pattern 9 is formed is separated from the black matrix 4 due to frequent fluctuation of the substrate during liquid crystal injection. As described above, the seal burst occurs due to the lifting between the black matrix 4 and the overcoat layer 6, thereby causing a problem in that the liquid crystal injection is not qualitatively performed.

Accordingly, the present invention has been made to solve the conventional problems as described above, and an object of the present invention is to improve the adhesion between the black matrix and the overcoat layer overlapping the seal pattern, thereby preventing the seal burst. The present invention provides a device and a method of manufacturing the same.

The liquid crystal display device of the present invention for achieving the object of the present invention as described above is formed along the outer periphery of the first and second substrates, the first and second substrates to bond the first and second substrates. A black matrix formed on the seal pattern, the second substrate and having irregularities in a region corresponding to the seal pattern, an overcoat layer formed on the entire surface of the second substrate including the black matrix; And a liquid crystal layer formed between the first and second substrates. In this case, the black matrix is formed of an opaque resin that blocks light, and the unevenness is formed on the contact surface between the black matrix and the overcoat film.

The first substrate may include a gate line and a data line arranged vertically and horizontally to define a pixel, a switching element formed at an intersection of the gate line and the data line, and a pixel electrode disposed in the pixel and generating a horizontal electric field. The liquid crystal display device further comprises an electrode, and the second substrate further comprises a color filter.

In addition, the first substrate may include a gate line and a data line arranged vertically and horizontally to define a pixel, a switching element formed at an intersection of the gate line and the data line, and a pixel electrode formed at the pixel and electrically connected to the switching element. In addition, the second substrate may be a twisted nematic (TN) type liquid crystal display device further comprising a color filter and a common electrode.

On the other hand, the method of manufacturing a liquid crystal display device according to the present invention comprises the steps of preparing the first and second substrates, forming a black matrix on the second substrate, the surface of the black matrix formed in the outer region of the second substrate Forming an unevenness on the black matrix, forming a color filter on the black matrix, forming an overcoat layer in contact with the unevenness of the black matrix on the color filter, and any one of the first and second substrates. Forming a seal pattern along the periphery of the substrate, bonding the first and second substrates to each other by the seal pattern, and forming a liquid crystal layer between the first and second substrates.

Forming a black matrix on the second substrate, and forming the irregularities on the surface of the black matrix formed in the outer region of the second substrate, the step of applying an opaque resin film to block the light on the second substrate; Applying a slit mask provided with a slit-shaped light transmitting part on the resin film, exposing the resin film through the slit mask, and developing the exposed resin film, thereby forming a seal pattern to be formed later; Forming irregularities in the corresponding region.

In addition, forming a black matrix on the second substrate, and forming an unevenness on the surface of the black matrix formed in the outer region of the second substrate, applying an opaque resin film that blocks the light on the second substrate. And applying a half-tone mask having a semi-transmissive region partially transmitting light over the resin film, exposing the resin film through the halftone mask, and exposing the resin. By developing the film, it may be a step of forming irregularities in a region corresponding to a seal pattern to be formed later.

In addition, forming a black matrix on the second substrate, and forming an unevenness on the surface of the black matrix formed in the outer region of the second substrate, applying an opaque resin film that blocks the light on the second substrate. And applying a first mask having a transmission area for transmitting light over the resin film, exposing the resin film through the first mask, and developing the exposed resin film, thereby forming a seal to be formed later. Forming a first groove having a first depth in an area corresponding to the pattern, applying a second mask that partially blocks light to the first groove, and forming a first groove in the first groove area through the second mask; By partially irradiating light, it may consist of forming an unevenness | corrugation.

In this case, the irregularities may be formed in a stripe or dot shape, and the present invention does not limit the shape of the irregularities.

In addition, forming a black matrix on the second substrate, and forming an unevenness on the surface of the black matrix formed in the outer region of the second substrate, applying an opaque resin film that blocks the light on the second substrate. And irradiating plasma to a partial region of the black matrix formed in the outer region of the second substrate, thereby forming irregularities on the surface thereof.

As described above, unlike the case of using a halftone or a slit mask, when the plasma is used, the unevenness of the resin film is irregularly etched by the plasma, and is formed from the roughness of the surface.

Meanwhile, forming a gate line and a data line arranged vertically and horizontally on the first substrate to define a pixel, forming a switching element at an intersection area of the gate line and the data line, and applying a horizontal electric field to the pixel. A horizontal electric field type liquid crystal display device may be manufactured, further comprising forming a common electrode and a pixel electrode.

The method may further include forming a gate line and a data line arranged vertically and horizontally on the first substrate to define a pixel, forming a switching element at an intersection of the gate line and the data line, and forming a pixel electrode on the pixel. A horizontal field type liquid crystal display device further comprising the step of forming a common electrode on the second substrate may be manufactured.

As described above, the present invention prevents the seal burst by forming irregularities on the surface of the black matrix corresponding to the seal pattern to improve the adhesion between the black matrix and the overcoat film. That is, the basic concept of the present invention is to improve the adhesion between the black matrix and the overcoat film in the area corresponding to the seal pattern, thereby preventing the separation phenomenon between the black matrix and the overcoat film generated in this area. In order to improve the adhesiveness between the and the overcoat film, irregularities are formed on the adhesive surface between them. The unevenness is formed in the black matrix, and as the unevenness is formed, the adhesion area between the black matrix and the overcoat film increases. As described above, although the region where the seal pattern is formed is the same, the adhesion area between the black matrix and the overcoat film is increased, so that the adhesive force between the black matrix and the overcoat film is improved.

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

4A and 4B are related to the liquid crystal display device according to the present invention. FIG. 4A is a schematic plan view, and FIG. 4B is a sectional view taken along the line II ′ of FIG. 4A.

As shown in the figure, the liquid crystal display device 100 according to the present invention is bonded by a seal pattern 116 in which the first substrate 101 and the second substrate 102 are formed along its periphery. The liquid crystal layer 113 is formed between the first and second substrates 101 and 102.

The first substrate 201 includes an image display unit 113 in which the liquid crystal cells defined by the gate lines 108 and the data lines 109 arranged vertically and horizontally are arranged in a matrix form, and a gate of the image display unit 113. The gate pad part 114 connected to the line 208 and the data pad part 115 connected to the data lines 109 are included. In this case, the gate pad part 114 and the data pad part 115 are formed in an edge region of the first substrate 101 which does not overlap the second substrate 102, and the gate pad part 114 is formed by a gate driving circuit ( The gate signal supplied from the image display unit 113 is supplied to the gate lines 108 of the image display unit 113, and the data pad unit 115 supplies the data signal supplied from the data driving circuit (not shown) to the image display unit 113. To the data lines 109. Although not shown in the drawings, a thin film transistor is formed as a switching element for switching each liquid crystal cell in an area where the gate line 108 and the data line 109 cross each other. The thin film transistor includes a gate electrode, a semiconductor layer, and a source / drain electrode. The gate electrode and the semiconductor layer are insulated by a gate insulating film 134 interposed therebetween, and the gate insulating film 134 is formed of a thin film transistor. One substrate 101 is formed over the entire surface. In addition, a passivation layer 138 for protecting the thin film transistor is formed over the entire surface of the substrate, and the gate insulating layer 134 is formed on the first substrate 101 outside the image display unit 113, that is, the seal pattern 116. ) And a protective film 138 are laminated.

In the case of a TN (twisted nematic) liquid crystal display device, a pixel electrode is formed on the first substrate 101 and becomes a common electrode on the second substrate 102. On the other hand, in the case of an in plane switching (IPS) type liquid crystal display device, a common electrode and a pixel electrode for generating a flat field are formed together on the first substrate 101.

On the other hand, the second substrate 102 is applied to the color filter 122 separately applied for each cell region, the switching element of the first substrate 101, the gate line 108, the data line 109, and the image display unit 113 A black matrix 103 is formed between the pads 114 and 115 to prevent light leakage. In the drawing, only the black matrix 103 formed on the outside of the image display unit 113 is shown. An overcoat layer 123 is formed on the entire surface of the second substrate 102 including the black matrix 103 and the color filter 122. At this time, since the color filter 122 is formed in the image display unit 113, the color filter is not formed in the outer region of the image display unit 112, that is, the region corresponding to the seal pattern 116. Therefore, the overcoat layer 123 formed in the outer region of the image display unit 113 is in direct contact with the black matrix 103.

In addition, an unevenness 103 'is formed on the contact surface E between the black matrix 103 and the overcoat film 123, and the unevenness 103' is formed on the surface of the black matrix 103 to form an overcoat film ( 123) to improve adhesion. That is, when the unevenness 103 'is formed on the surface of the black matrix 103 as compared with the case where the surface of the black matrix 103 is flat, the adhesion to the overcoat film 123 is improved because the surface area of the black matrix 103 is wide.

In this case, the black matrix 103 is formed of an opaque photosensitive film to block light, and the unevenness formed on the surface of the black matrix 103 may be integrally formed with the black matrix 103. That is, the unevenness 103 ′ may be formed by patterning the surface of the black matrix 103 corresponding to the seal pattern 116 through a photolithography process.

5A to 5C illustrate an example of a method for manufacturing a black matrix according to the present invention. First, as shown in FIG. 5A, a transparent second substrate 202 is prepared, and then an opaque resin film 203 is formed thereon. ) Is applied. As shown in FIG. 5B, the mask 210 is applied to the black matrix 203 and then irradiated with light such as UV (indicated by arrows on the screen). In this case, the mask 210 used is a slit mask, and a slit for transmitting light in a region corresponding to the seal pattern is formed. Therefore, when the black matrix is exposed through the slit mask 210, light is transmitted to the area where the slit is formed and light is blocked in the remaining area.

Subsequently, when the black matrix 203 exposed through the slit mask is applied to the developing solution, as shown in FIG. 5C, the resin film in the exposed area is removed, and the unevenness 203 ′ is formed on the surface thereof. At this time, the extent to which the resin film is removed is determined by the exposure amount, and depending on the characteristics of the resin film, the exposed region may be left in some cases. That is, in the case where the resin film has a positive photosensitive characteristic, as shown in the drawing, the exposed region is removed by development, while in the case where the resin film has a negative photosensitive characteristic, it is exposed. Will remain in the area. In the present invention, both positive and negative photoresist films may be used, and when the negative photoresist film is used, the mask pattern should be changed, that is, the positions of the transmission and non-transmission areas should be designed.

In the present invention, a half-tone mask that partially transmits light may also be used. Unlike the silt mask, the halftone mask is composed of a non-transmissive region that blocks light and a semi-transmissive region that transmits light, but transmits only a portion of the light, and adjusts the amount of light transmitted through the semi-transmissive region.

6A to 6C illustrate a method of forming irregularities through a halftone mask. First, as shown in FIG. 6A, a transparent second substrate 302 is prepared, and then an opaque resin film 303 is formed thereon. Apply. 6B, a mask 310 is applied to the black matrix 303 and then irradiated with light such as UV (indicated by an arrow on the screen). In this case, the mask 310 used is a half-tone mask, and includes a non-transmissive region that completely blocks light and a semi-transmissive region that partially transmits the light. Here, the partial transmission of light does not transmit 100% of the irradiated light, blocks a part of the light, and transmits only a part of the light, and the degree of exposure is determined according to the amount of light transmitted through the transflective area.

Subsequently, when the black matrix 303 exposed through the halftone mask 310 is applied to the developer, the exposed region is removed, as shown in FIG. 6C, to form the unevenness 303 ′ on the surface thereof. do. The degree to which the black matrix is removed is determined by the light transmittance or the exposure time of the semi-transmissive region of the mask.

In addition, the present invention may use a general mask in addition to the slit mask and halftone mask as described above. Here, a general mask means the mask which selectively provides the non-transmissive area | region which blocks 100% of irradiated light, and the transmission area | region which transmits 100% of irradiated light.

7A to 7E illustrate a method of forming irregularities through a general mask. First, as shown in FIG. 7A, a transparent second substrate 402 is prepared, and then an opaque resin film 403 is applied thereon. do. As shown in FIG. 7B, the first mask 410a is applied to the black matrix 403 and then irradiated with light such as UV (indicated by arrows) on the screen. In this case, the first mask 410a to be used is formed with a transmission region for transmitting light in a region corresponding to the seal pattern. Therefore, when the black matrix is exposed through the first mask 410a, light is transmitted through the seal pattern region in which the transmission region is formed and light is blocked in the remaining region. Therefore, when this is applied to the developing solution, as shown in Fig. 7C, the exposed areas are removed to form the grooves 403a.

Subsequently, as shown in FIG. 7D, after applying the second mask 410b having the light transmissive region and the non-transmissive region partially formed in the region corresponding to the groove 403, and then applying the light to the developer, FIG. As shown in 7e, part of the transmissive area is removed to form the unevenness 403 '.

As described above, the present invention can form irregularities on the surface of the black matrix by using various kinds of masks, and the form of the irregularities is not limited in the present invention. That is, the basic concept of the present invention is to increase the contact area between the black matrix and the overcoat film formed on the upper part, thereby improving the contact force between them, and the uneven shape may be varied in a stripe shape or a dot shape. It can be shaped.

In addition, as described above, the present invention may form irregularities through plasma etching without using a photolithography process. In other words, after exposing the black matrix of the region corresponding to the seal pattern, the exposed region is etched through the plasma, thereby increasing the roughness of the black matrix surface. Therefore, the unevenness formed using the plasma is relatively small in size and has a very irregular distribution as compared with the case of using the slit / heart mask.

As described above, the method for improving the adhesion between the black matrix and the overcoat layer through the unevenness may include all processes capable of forming the unevenness on the surface of the black matrix in addition to the photolithography process and the plasma etching. That is, the basic idea of the present invention is to form irregularities on the surface of the black matrix, thereby to increase the adhesion area with the overcoat film and to improve their adhesion. Other examples and modifications of the present invention utilize the basic idea of the present invention. Anyone who is engaged in the technical field to which the present invention belongs will be able to easily invent.

As described above, according to the present invention, the present invention improves the adhesive force between the black matrix and the overcoat film by forming irregularities between the black matrix and the overcoat film of the color filter substrate corresponding to the seal pattern to improve the adhesion area thereof. I can do it. In this way, by improving the adhesive force between the black matrix and the overcoat film, it is possible to prevent the seal failure caused during the liquid crystal injection, thereby improving productivity and image quality.

1 is a schematic cross-sectional view of a general liquid crystal display device.

2 is a process flow diagram showing a manufacturing process of the liquid crystal display device.

3 is an enlarged view of a portion of a seal pattern region and a color filter substrate of FIG. 1; FIG.

4A and 4B show a liquid crystal display device according to the present invention, FIG. 4A is a schematic plan view, and FIG. 4B is a sectional view taken along line II ′ of FIG. 4A.

5A to 5C are process cross-sectional views showing a method of forming irregularities in a black matrix according to an example of the present invention.

6A to 6C are cross-sectional views illustrating a method of forming irregularities in a black matrix according to another embodiment of the present invention.

7A to 7E are cross-sectional views illustrating a method of forming irregularities in a black matrix according to still another embodiment of the present invention.

*** Explanation of symbols for main parts of drawing ***

116: seal pattern 123: overcoat film

103,203,303,403: Black Matrix

103 ', 203', 303 ', 403': irregularities

Claims (17)

First and second substrates; A seal pattern formed along the periphery of the first and second substrates to bond the first and second substrates together; A black matrix formed on the second substrate and having irregularities in a region corresponding to the seal pattern; An over coat layer formed on the entire surface of the second substrate including the black matrix; And And a liquid crystal layer formed between the first and second substrates. The liquid crystal display device according to claim 1, wherein the black matrix is made of a resin. The liquid crystal display device according to claim 1, wherein the unevenness is formed on a contact surface between the black matrix and the overcoat film. The method of claim 1, wherein the first substrate, Gate lines and data lines arranged vertically and horizontally to define pixels; A switching element formed at an intersection of the gate line and the data line; And And a pixel electrode and a common electrode disposed on the pixel to generate a horizontal electric field. The liquid crystal display device of claim 4, wherein the second substrate further comprises a color filter. The method of claim 1, wherein the first substrate, Gate lines and data lines arranged vertically and horizontally to define pixels; A switching element formed at an intersection of the gate line and the data line; And And a pixel electrode formed on the pixel and electrically connected to the switching device. The liquid crystal display device of claim 6, wherein the second substrate further comprises a color filter and a common electrode. Preparing first and second substrates; Forming a black matrix on the second substrate and forming irregularities on a surface of the black matrix formed in an outer region of the second substrate; Forming a color filter on the black matrix; Forming an overcoat layer on the color filter in contact with the unevenness of the black matrix; Forming a seal pattern along an outer edge of one of the first and second substrates; Bonding the first and second substrates to each other by the seal pattern; And A method of manufacturing a liquid crystal display device comprising the step of forming a liquid crystal layer between the first and second substrates. The method of claim 8, wherein the forming of the black matrix on the second substrate and forming the unevenness on the surface of the black matrix formed in the outer region of the second substrate comprises: Applying an opaque resin film to block light on the second substrate; Applying a slit mask provided with a slit-shaped light transmitting part on the resin film; Exposing a resin film through the slit mask; And And developing unevenness in a region corresponding to a seal pattern to be formed later by developing the exposed resin film. The method of claim 8, wherein the forming of the black matrix on the second substrate and forming the unevenness on the surface of the black matrix formed in the outer region of the second substrate comprises: Applying an opaque resin film to block light on the second substrate; Applying a half-tone mask having a semi-transmissive area partially transmitting light over the resin film; Exposing a resin film through the halftone mask; And And developing unevenness in a region corresponding to a seal pattern to be formed later by developing the exposed resin film. The method of claim 8, wherein the forming of the black matrix on the second substrate and forming the unevenness on the surface of the black matrix formed in the outer region of the second substrate comprises: Applying an opaque resin film to block light on the second substrate; Applying a first mask having a transmission region through which light is transmitted on the resin film; Exposing a resin film through the first mask; Developing the exposed resin film to form a first groove having a first depth in a region corresponding to a seal pattern to be formed later; Applying a second mask that partially blocks light to the first groove; And And irradiating light partially to the first groove region through the second mask to form irregularities. The method of claim 8, wherein the irregularities are formed in a stripe shape. The method of claim 8, wherein the unevenness is formed in a dot shape. The method of claim 8, wherein the forming of the black matrix on the second substrate and forming the unevenness on the surface of the black matrix formed in the outer region of the second substrate comprises: Applying an opaque resin film to block light on the second substrate; And And etching the surface thereof by irradiating a plasma to a region corresponding to a seal pattern to be formed later. The method of claim 8, Forming gate lines and data lines arranged vertically and horizontally on the first substrate to define pixels; Forming a switching device at an intersection of the gate line and the data line; And And forming a common electrode and a pixel electrode for generating a horizontal electric field in the pixel. The method of claim 8, Forming gate lines and data lines arranged vertically and horizontally on the first substrate to define pixels; Forming a switching device at an intersection of the gate line and the data line; And And forming a pixel electrode in the pixel. 17. The method of claim 16, further comprising forming a common electrode on the second substrate.