KR101357803B1 - Seal Pattern of Liquid Crystal Display Device - Google Patents

Abstract

The present invention relates to a seal pattern for a liquid crystal display device, and more particularly, to an improvement in lifting failure of a seal pattern generated when the array substrate for a liquid crystal display device and the color filter substrate are opposed to each other.

The seal pattern for a liquid crystal display device according to the present invention includes a substrate divided into a display area and a non-display area; A main seal pattern surrounding the display area on the substrate; First and second dummy seal patterns surrounding an outer portion of the main seal pattern; A plurality of injection hole dams corresponding to the liquid crystal injection hole in which one side of each of the main seal pattern and the first and second dummy seal patterns is opened; First and second auxiliary seal patterns corresponding to a section between the injection hole dam and the alignment key.

Since the above-described configuration can improve the bonding ability by additionally configuring the first and second auxiliary seal patterns configured adjacent to the inlet dam, there is an advantage of preventing the seal lifting failure during the bonding process.

Description

Seal Pattern for Liquid Crystal Display Device

The present invention relates to a seal pattern for a liquid crystal display device, and more particularly, to an improvement in lifting failure of a seal pattern generated when the array substrate for a liquid crystal display device and the color filter substrate are opposed to each other.

Generally, the driving principle of a liquid crystal display utilizes the optical anisotropy and polarization property of a liquid crystal. Since the liquid crystal has a long structure, the liquid crystal has directionality in the arrangement of molecules, and an electric field is artificially applied to the liquid crystal, Can be controlled.

Therefore, when the molecular alignment direction of the liquid crystal is arbitrarily adjusted, the molecular arrangement of the liquid crystal is changed, and light is refracted in the molecular alignment direction of the liquid crystal due to optical anisotropy, so that image information can be expressed.

Currently, active matrix LCDs (AM-LCDs) in which thin film transistors and pixel electrodes connected to the thin film transistors are arranged in a matrix manner are attracting the most attention because of their excellent resolution and video performance.

Hereinafter, a conventional liquid crystal display device will be described with reference to the accompanying drawings.

1 is a cross-sectional view schematically showing a conventional liquid crystal display device.

As illustrated, the upper substrate 5 and the lower substrate 10 respectively divided into the display area AA and the non-display area NAA are opposed to each other, and the upper substrate 5 and the lower substrate 10 are bonded to each other. The liquid crystal layer 15 is interposed with a constant cell gap in a space between the gaps.

Including the upper and lower substrates 5 and 10 and the liquid crystal layer 15, it is called a liquid crystal panel 30, and a backlight unit (not shown) serving as a light source is disposed on the rear surface of the lower substrate 10. .

In this case, the upper and lower substrates 5 and 10 are opposed to each other by a seal pattern 60 made of a thermosetting resin along the outermost edge. The seal pattern 60 serves to maintain a constant cell gap of the upper and lower substrates 5 and 10 and to prevent the injected liquid crystal 35 from leaking to the outside.

The lower surface of the upper substrate 5 has a black matrix 12 for blocking light incident to the non-display area NAA, and a red pattern sequentially patterned for realizing color under the black matrix 12. The color filter layer 16 including the (R), green (G), and blue (B) sub color filters, and a common electrode 18 made of a transparent conductive metal under the color filter layer 16 are sequentially disposed.

Although not shown in the drawings, an overcoat layer (not shown) may be further configured for the purpose of planarization between the color filter layer 16 and the common electrode 18.

On the other hand, the upper surface of the lower substrate 10 includes a gate and data lines (not shown) vertically intersected in a matrix form, and a thin film transistor T serving as a switching point at the intersection of the gate and data lines.

The thin film transistor T may include a gate electrode 25 extending from a gate wiring, a gate insulating layer 45 on the gate electrode 25, a semiconductor layer 42 on the gate insulating layer 45, and the semiconductor layer. Source and drain electrodes 32 and 34 extending from the data line on 42 and spaced apart from each other.

The semiconductor layer 42 includes an active layer 40 made of pure amorphous silicon (a-Si: H) and an ohmic contact layer 41 made of an amorphous silicon layer (n + a-Si: H) containing impurities. Include.

On the thin film transistor T, one selected from the group of inorganic insulating materials including silicon oxide (SiO ₂ ) and silicon nitride (SiNx), or an organic insulating material including photo acryl and benzocyclobutene. The protective film 55 is formed with one selected from the group.

 In addition, the pixel electrode 70 connected to the thin film transistor T is configured to correspond to the pixel area P. FIG. The pixel electrode 70 is in contact with the drain electrode 34 through the drain contact hole CH1 exposing a part of the drain electrode 34.

In the liquid crystal panel 30 having the above-described configuration, the upper substrate 5 on which the color filter element is formed and the lower substrate 10 on which the array element is formed are bonded to each other, and then the cell process step of injecting the liquid crystal 35 is performed. do.

2 is a flowchart illustrating a cell process step, which will be described in detail with reference to this.

As shown, generally, the cell process steps can be classified into seven stages.

ST1 is a step of initially cleaning the surfaces of the upper and lower substrates on which the color filter element and the array element are formed, and removing foreign matter remaining on the upper and lower substrates.

ST2 is a step of performing an alignment film forming and rubbing process on each of the upper and lower substrates having passed through ST1. The above step is to form an alignment film on the upper and lower substrates using a polymer material such as polyimide, respectively. It is a pretreatment process for uniformly aligning the liquid crystal molecules by giving a pretilt angle.

ST3 is a cell gap forming process and is a process for uniformly securing a cell gap between the upper and lower substrates. In this case, since the liquid crystal display device is an electro-optical device for driving the upper and lower substrates by applying a voltage to the injected liquid crystal molecules with a constant cell gap, the light passing through the portion of the upper and lower substrates is not constant. Transmittance is difficult to achieve uniform brightness. Therefore, in the above step, it is important to uniformly secure the cell gaps of the upper and lower substrates by uniformly spraying spacers on the front surface of the lower substrates.

ST4 is a bonding process. The above step is a process of bonding the upper and lower substrates while maintaining a constant cell gap through a seal pattern made of a thermosetting resin or an ultraviolet curable resin.

At this time, the seal pattern serves to maintain a constant cell gap of the upper and lower substrates, and prevents the injected liquid crystal from being exposed to the outside. The seal pattern is bonded to the lower substrate in a state in which a sealant made of a thermosetting resin is applied along the outermost edge of the upper substrate through screen printing.

ST5 is a cell cutting process, and the cutting step is a subsequent process of curing the seal pattern, and a cutting line is formed on the glass surface by using a diamond-hardened pen that cuts the upper and lower substrates in units of cells. It is divided into scribing process and brake process to apply force.

ST6 is a liquid crystal injection process, and the above step is a process of injecting liquid crystal into the upper and lower substrates. In general, the liquid crystal injection is a vacuum injection method using a pressure difference between the inside and outside of the cell. In this case, an end seal process is performed to prevent the liquid crystal from flowing out to the liquid crystal injection hole of the liquid crystal panel where the liquid crystal injection is completed.

Usually, the end seal process refers to a process of finally blocking the liquid crystal injection hole by irradiating ultraviolet rays after applying the ultraviolet curable resin using a dispenser. At this time, the end seal process may be deteriorated by ultraviolet light because the liquid crystal and the organic film should be careful not to be irradiated with ultraviolet light other than the irradiated portion.

ST7 is a polarizing plate attaching process. The above step is a process of attaching polarizing plates to both sides of the cell after inspecting by applying optical and electrical signals to the cells into which the liquid crystal is injected.

In the above, the cell process step is completed through the ST1 to ST7 process steps.

3 is a plan view illustrating a seal pattern for a liquid crystal display according to the related art, which will be described in detail with reference to the drawing.

As shown, a seal pattern 60 is formed along the outermost edge of the upper substrate 5 on which the color filter element is formed. In this case, a plurality of injection hole dams 64 spaced at regular intervals are designed in the liquid crystal injection hole F having one side of the seal pattern 60 opened so that the liquid crystal (35 in FIG. 1) may be injected.

At this time, the liquid crystal panel (30 of FIG. 1) including the upper substrate 5 and the lower substrate (10 in FIG. 1) is a liquid crystal through the liquid crystal injection hole (F) by using a vacuum injection method using a pressure difference between the inside and outside of the cell Will be injected.

In general, nine injection hole dams 64 corresponding to the liquid crystal injection hole F are disposed evenly spaced at first intervals, and the liquid crystal injected into the liquid crystal panel in the process of injecting the liquid crystal is externally disposed. Prevents contact with

In this case, the bonding of the upper and lower substrates includes a process of curing the seal pattern 60, and the liquid crystal injection hole may smoothly escape the internal gas of the liquid crystal panel to the outside during the curing process of the seal pattern 60. The seal pattern 60 is not designed in the part corresponding to (F) except the injection port dam 64.

In addition, in order to maintain a constant cell gap between the upper and lower substrates, a column spacer (not shown) made of organic material may be designed in a one-to-one pattern corresponding to the non-display area (NAA of FIG. 1), or The cell gap is maintained between the upper and lower substrates by spraying ball spacers on the lower substrates.

However, the above-described configuration has an injection hole dam corresponding to a liquid crystal injection hole that is weak in adhesion due to shaking of the upper substrate when friction occurs instantaneously in the process of bonding the upper and lower substrates or when sufficient curing is not performed on the seal pattern, or There is a problem in that the liquid crystal is leaked and not filled due to the seal lifting phenomenon in which the main seal pattern formed at a position adjacent to the inlet dam is split.

FIG. 4 is experimental data for measuring a seal lift failure according to a seal thickness, and FIG. 5 is a plan view showing the inside of the liquid crystal panel when the seal is lifted. The measurement value of FIG. 5 is a seal pattern corresponding to part A of FIG. This is an example of using a cross section as a sample.

As shown in FIG. 4 and FIG. 5, the main seal pattern positioned in a portion adjacent to the liquid crystal injection hole F while the array substrate TFT is positioned above and the color filter substrate CF is located below (see FIG. 3). Fig. 61 shows a cross section of the normal sample I in which the seal lift failure did not occur, and the first to third defective samples II, III, and IV in which the seal lift failure occurred for the above reason.

At this time, the seal thickness of the normal sample (I) is about 4.3μm, the seal thickness of the first to third defective samples (II, III, IV) is a sample designed to about 9.8μm, 14.1μm, 15.9μm respectively.

When a seal lift failure occurs between the array substrate TFT and the color filter substrate CF, it acts as a cause of lifting the space between the array substrate TFT and the color filter substrate CF, thereby acting as a passage through which the liquid crystals come out. This causes a problem that the liquid crystal is not filled.

Referring to FIG. 5, reference numeral 72 of FIG. 5 denotes a portion in which a liquid crystal is present, and reference numeral 74 denotes a portion in which a liquid crystal does not exist. The liquid crystal is smoothly injected at the portion adjacent to (F), but the liquid crystal is not filled at the portion far from the liquid crystal inlet F, resulting in unfilled liquid crystal.

The unfilled problem of the liquid crystal results in light leaking when the liquid crystal panel is driven, and thus acts as a factor of degrading image quality.

The present invention has been made to solve the above-mentioned problem, and an object of the present invention is to improve the production yield through improving the problem of unfilled liquid crystal due to poor seal lifting.

The seal pattern for a liquid crystal display device according to the present invention for achieving the above object is a substrate divided into a display area and a non-display area; A main seal pattern surrounding the display area on the substrate; First and second dummy seal patterns surrounding an outer portion of the main seal pattern; A plurality of injection hole dams corresponding to the liquid crystal injection holes opened in the main seal pattern and the first and second dummy seal patterns; First and second auxiliary seal patterns corresponding to a section between the injection hole dam and the alignment key.

Each of the plurality of injection hole dams corresponding to the liquid crystal injection hole is configured to be spaced apart at equal intervals, and the plurality of first and second auxiliary seal patterns are designed to be the same as the pattern of the injection hole dam.

The third and fourth auxiliary seal patterns are further designed in a section between the first and second auxiliary seal patterns. The alignment key is formed at one end of the substrate in the step of forming the color filter element.

First, the seal lifting failure can be prevented by the dummy seal pattern additionally designed to correspond to the section between the injection hole dam and the alignment key.

Second, the internal gas of the liquid crystal panel may be smoothly discharged to the outside by configuring the additionally designed dummy seal pattern spaced apart from each other to correspond to the inlet dam.

Third, the production yield can be improved by improving the liquid crystal unfilled problem due to the lifting of the seal.

--- Example 1 ---

6 is a plan view illustrating a seal pattern for a liquid crystal display according to a first embodiment of the present invention.

As shown, the seal pattern 160 is formed along the outermost edge on the upper surface of the lower substrate 105 on which the color filter elements divided into the display area AA and the non-display area NAA exemplifying the image are formed. This is made up. The seal pattern 160 may include a main seal pattern 161 surrounding the display area AA, first and second dummy seal patterns 162 and 163 surrounding an outer portion of the main seal pattern 161, and the main seal pattern 161. And a plurality of injection hole dams 164 corresponding to the liquid crystal injection hole F having one side opened so that the liquid crystal can be injected into the seal pattern 161 and the first and second dummy seal patterns 162 and 163, respectively. .

In this case, the liquid crystal panel (not shown) including the upper substrate 105 and the lower substrate (not shown) injects the liquid crystal through the liquid crystal injection hole F using a vacuum injection method using a pressure difference between the inside and outside of the cell. .

In general, nine injection hole dams 164 corresponding to the liquid crystal injection hole F are disposed evenly spaced at first intervals, and the liquid crystal injected into the liquid crystal panel in the process of injecting the liquid is externally provided. Prevents contact with

In the bonding process of the upper and lower substrates, the process of curing the seal pattern 160 using a hot presser is performed. The main seal pattern 161 and the first and second dummy seal patterns 162 and 163 are not designed in an adjacent portion of the injection hole dam 164 corresponding to the liquid crystal injection hole F so as to smoothly exit.

The above-described configuration has an advantage of reducing the seal lifting failure between the upper and lower substrates by the first and second dummy seal patterns 162 and 163 surrounding the outer portion of the main seal pattern 161.

However, in the first embodiment of the present invention, there is a situation in which the seal is lifted in a portion corresponding to the liquid crystal injection hole F which is vulnerable to the seal lift in the process of bonding the upper and lower substrates.

In order to solve the above problems, the second embodiment of the present invention has been devised. Hereinafter, the second embodiment of the present invention will be described in detail with reference to the accompanying drawings.

--- Example 2 ---

The second embodiment of the present invention smoothly discharges the internal gas of the liquid crystal panel to the outside by additionally designing a seal pattern in the section between the alignment hole and the injection dam corresponding to the liquid crystal injection hole in the process of bonding the upper and lower substrates. It is characterized by being capable of preventing the lifting of the seal while inducing to.

Hereinafter, a seal pattern for a liquid crystal display device according to the present invention will be described with reference to the accompanying drawings.

7 is a plan view illustrating a liquid crystal display according to the present invention, FIG. 8 is an enlarged view of a portion B of FIG. 7, and FIG. 9 is a cross-sectional view taken along the line VII-VII of FIG. 8. This will be explained in detail.

7, 8, and 9, the upper surface of the lower substrate 205, on which the color filter element divided into the display area AA and the non-display area NAA excluding the image, is formed. A seal pattern 260 is constructed along the outer edge.

The seal pattern 260 may include a main seal pattern 261 surrounding the display area AA, first and second dummy seal patterns 262 and 263 surrounding an outer portion of the main seal pattern 261, and the main seal pattern 261. A plurality of injection hole dams 264 corresponding to the liquid crystal injection hole F having one side opened so that the liquid crystal can be injected into the seal pattern 261 and the first and second dummy seal patterns 262 and 263, respectively, First and second auxiliary seal patterns 265 and 266 configured in a section between the inlet dam 264 and the alignment key 280 are included.

In this case, the degree of alignment margin of the upper and lower substrates 205 and 210 is determined by a design value given at the time of designing each substrate, and a precision of several micrometers (μm) is generally required. When the alignment margins of the upper and lower substrates 205 and 210 deviate from a given design value, light leaks out, so that desired image quality characteristics cannot be obtained when the liquid crystal panel is driven.

In order to solve this problem, in the second embodiment of the present invention, the upper alignment key 280 is disposed at one end of the non-display area NAA in the step of forming the color filter element on the surface of the upper substrate 205. Form. Although not shown in detail in the drawings, a lower alignment key (not shown) is formed on the lower substrate to correspond to the upper alignment key 280. Therefore, during the bonding process between the upper and lower substrates 205 and 210, the distortion due to the bonding error between the upper and lower substrates 205 and 210 may be minimized by using the upper alignment key 280 and the lower alignment key. There is an advantage.

Until the above-described process, since the alignment layers formed on the upper and lower substrates 205 and 210 are exposed to the outside, process defects may occur due to contamination of the upper and lower substrates 205 and 210 or inflow of particles. It must be maintained.

In addition, the process of bonding the upper and lower substrates 205 and 210 requires a process of curing while maintaining a uniform cell gap. If the cell gap is spatially non-uniform, the injection of liquid crystal does not proceed smoothly. One of the transmission characteristics is to appear on the screen in the form of spots. Therefore, in the process of curing the seal pattern 260 using a thermocompressor, it is important to uniformly secure parallelism, spatial pressure, and temperature between the upper and lower substrates 205 and 210.

In general, nine injection hole dams 264 corresponding to the liquid crystal injection hole F are equally spaced at first intervals, and the liquid crystal injected into the liquid crystal panel in the process of injecting the liquid is externally provided. Prevents contact with

In particular, in the present invention, the inner gas of the liquid crystal panel may smoothly escape to the outside in the bonding process of the upper and lower substrates 205 and 210 and the curing of the seal pattern, and the seal pattern corresponding to the liquid crystal injection hole F may be The first and second auxiliary seal patterns 265 and 266 may be configured in a section between the injection hole dam 264 and the alignment key 280 to prevent the lifting of the 260.

8 and 9, a plurality of injection dams 264 are disposed on the substrate 205 corresponding to the liquid crystal injection hole F, and the substrate 205 spaced apart from the injection dam 264. At one end of the) align key 280 is located. In addition, the upper and lower sides of the liquid crystal main inlet F may include a main seal pattern 261 surrounding the display area AA, and first and second dummy seal patterns 262 surrounding an outer portion of the main seal pattern 261. , 263 are located respectively.

In this case, in the second embodiment of the present invention, a plurality of first and second auxiliary seal patterns 265 and 266 may be configured in a section between the injection hole dam 264 and the alignment key 280. This configuration improves the bonding ability at the liquid crystal inlet F by additionally designing a plurality of first and second auxiliary seal patterns 265 and 266 in the vicinity of the inlet dam 264 vulnerable to the lifting of the seal. Has the advantage.

That is, in the present invention, the internal gas is smoothly discharged to the outside by constituting the nine first auxiliary seal patterns 255 and the nine second auxiliary seal patterns 256 at equal intervals with the nine inlet dams 264. Can be. In addition, the first and second auxiliary seal patterns 265 and 266 may be additionally formed in a vertical direction corresponding to the inlet dam 264, thereby enhancing the bonding ability of the inlet dam 264. .

In a situation where a sufficient space of a section is secured between the injection hole dam 264 and the alignment key 280, not only the first and second auxiliary seal patterns 265 and 266 but also the third and fourth auxiliary seal patterns (not shown) ) May be additionally designed, and the first and second auxiliary seal patterns 265 and 266 may be configured by nine, but this may vary depending on the size of the substrate and the design margin.

Although not shown in detail in the drawing, the first and second dummy seal patterns 262 and 263 are not designed in the liquid crystal injection hole F and the first and second dummy seal patterns 262 and 263 are formed in the opening region G adjacent to the liquid crystal injection hole. ) Can be expected, but this part is not only a portion where the upper alignment key 280 is formed, but also has a problem in that the bonding ability is lowered because it is located at a relatively long distance from the inlet dam 264.

Therefore, as the present invention improves the bonding ability between the upper and lower substrates by additionally designing the first and second auxiliary seal patterns in the section between the inlet dam corresponding to the liquid crystal inlet and the alignment key, it is possible to improve the failure of the seal lifting. There is an advantage that can be prevented.

1 is a cross-sectional view schematically showing a conventional liquid crystal display device.

Figure 2 is a process flow diagram illustrating a cell processing step.

3 is a plan view illustrating a seal pattern for a liquid crystal display according to the related art.

4 is an experimental data of measuring the seal lift failure according to the seal thickness.

5 is a plan view showing the inside of the liquid crystal panel when the seal is lifted.

6 is a plan view illustrating a seal pattern for a liquid crystal display according to a first embodiment of the present invention.

7 is a plan view showing a liquid crystal display device according to the present invention.

FIG. 8 is an enlarged view of a portion A of FIG. 7; FIG.

9 is a cross-sectional view taken along the line VII-VII of FIG. 7.

Description of the Related Art [0002]

205: substrate 260: seal pattern

261: main seal pattern 262, 263: first and second dummy seal pattern

264: inlet dam 265, 266: first and second auxiliary seal pattern

280: alignment key F: liquid crystal injection hole

Claims (5)

A substrate divided into a display area and a non-display area; A main seal pattern surrounding the display area on the substrate; First and second dummy seal patterns surrounding an outer portion of the main seal pattern; A plurality of injection hole dams corresponding to the liquid crystal injection holes opened in the main seal pattern and the first and second dummy seal patterns; First and second auxiliary seal patterns corresponding to a section between the inlet dam and the alignment key Seal pattern for a liquid crystal display device comprising a. The method of claim 1, And a plurality of injection hole dams corresponding to the liquid crystal injection holes are spaced at equal intervals. The method of claim 1, The first and the second auxiliary seal pattern is a plurality of seal patterns for the liquid crystal display device, characterized in that the same design as the pattern of the injection dam. The method of claim 1, And the third and fourth auxiliary seal patterns are additionally designed in a section between the first and second auxiliary seal patterns. The method of claim 1, And the alignment key is formed at one end of the substrate in the step of forming the color filter element.

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