KR20120018978A - Method for fabricating liquid crystal panel - Google Patents

Abstract

PURPOSE: A liquid crystal panel manufacturing method is provided to form the seal pattern of a narrow seal by reducing the line width of the seal pattern. CONSTITUTION: A first substrate(101) includes a display area and a non-display area. A second substrate(102) includes a shielding mask at the end of the non-display area. Gel type sealant is spread to an area between the second substrate and the shielding mask in order to overlap the second substrate with the shielding mask. A liquid crystal layer(150) is installed between the first substrate and the second substrate. A seal pattern is formed by emitting ultra violet ray to the gel type sealant.

Description

Manufacturing method of liquid crystal panel {Method for fabricating liquid crystal panel}

The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device having a narrow bezel that can reduce a non-display area where an image of a liquid crystal panel is not displayed.

Recently, liquid crystal displays have been spotlighted as advanced display devices with low power consumption, good portability, technology-intensive, and high added value.

The liquid crystal display device is formed by arranging two substrates having electrodes formed on one side thereof so that the electrodes face each other, injecting liquid crystal between the electrodes of the two substrates, and applying voltage to the electrodes formed on the substrates. By moving the liquid crystal molecules by the electric field, the image is expressed by the transmittance of light that varies depending on the position change of the liquid crystal.

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

As illustrated, the array substrate 11 having the thin film transistor T and the color filter substrate 12 having the color filter (not shown) face and face each other with the liquid crystal layer (not shown) therebetween. The array substrate 11 and the color filter substrate 12 are spaced apart from each other, and the edge portions thereof are encapsulated and sealed through a fail pattern 20.

Here, the display area AA and the non-display area NA, which display an image, are defined. Here, under the premise of an active matrix method, a plurality of surfaces are provided on the inner surface of the display area AA of the array substrate 11, which is commonly called a lower substrate. A pixel pixel P is defined by the intersection of the gate line GL and the data line DL, and a thin film transistor T is provided at each crossing point to form a transparent pixel electrode formed in each pixel P. FIG. One-to-one correspondence with (not shown).

In this case, the non-display area NA on one side of the array substrate 11 where the gate and data lines GL and DL are disposed may include a pad part having gate and data pads connected to the gate and data lines GL and DL, respectively. DPA and GPA are formed so that the gate and the data lines GL and DL are connected to an external driving circuit board (not shown).

In addition, an inner surface of the color filter substrate 12 called an upper substrate may correspond to each pixel P. For example, color filters of red (R), green (G), and blue (B) colors may be used. Black matrices (not shown) are disposed at positions corresponding to the non-display areas NA such as the gate line GL, the data line DL, and the thin film transistor T.

That is, the black matrix (not shown) is formed to separate the pixel areas P in the display area AA, and the display area AA is formed at the edge of the display area AA, which is the non-display area NA. It consists of capturing forms.

The color filter substrate 12 is provided with a transparent common electrode (not shown) covering them.

Here, the bonding between the array substrate 11 and the color filter substrate 12 compresses the substrates 11 and 12 with UV curable sealants applied to the edges of any one of the substrates 11 and 12. In addition, the sealant is cured by irradiating UV light having an appropriate wavelength for an appropriate time to form a failure turn 20.

The failure turn 20 is formed with a line width of 1.2 mm to 2.0 mm in the non-display area NA that surrounds the edge of the display area AA, and serves as an encapsulant.

At this time, the failure turn 20 is formed to have a larger line width after bonding than the initial line width, for example, when the initial line width is designed to 0.4mm, after the bonding of the array substrate 11 and the color filter substrate 12 The line width of the failed turn 20, which is substantially formed, is formed with a line width of 1.2 to 2.0 mm, which is about 3 to 4 times wider than 0.4 mm.

Here, the 0.4mm design line width of the failed turn 20 is the smallest line width that can be formed in the present process.

Recently, display devices have been actively applied not only to TVs or monitors but also to personal portable electronic devices such as mobile phones and PDAs. In the case of such small display devices, the display area is wide and the bezel is a non-display area other than the display area. It is desired to form the region as small as possible.

Therefore, as researches on liquid crystal displays having narrow bezels are reduced by reducing the area of the non-display area NA in which the fail turns 20 are formed, the line width of the fail turns 20 must also be reduced. In addition, it is very difficult to form a failure seal 20 of a narrow seal by reducing the line width of the failure turn 20 that is wider than the design line width.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and a first object of the present invention is to reduce the line width of the failing turn of the liquid crystal display and form a failing turn of the narrow seal.

Accordingly, a second object of the present invention is to provide a liquid crystal display having a narrow bezel.

In order to achieve the above object, the present invention provides a method of manufacturing a display device comprising: providing a first substrate having a display area and a non-display area defined therein, and a second substrate having a shielding mask formed at the outermost edge of the non-display area; Applying a sealant in a gel state to the non-display area of one of the first and second substrates so as to partially overlap the shielding mask; Bonding the first and second substrates to each other and interposing a liquid crystal layer between the first and second substrates; Irradiating UV light on the gel sealant to cure the sealant in a region other than the region overlapping the shielding mask to form a failure turn; Cutting the region in which the shielding mask is formed on the second substrate, and removing the sealant in an uncured gel state with the shielding mask together with the shielding mask. do.

In this case, the first substrate is an array substrate having a gate and a data line and a thin film transistor positioned at an intersection of the gate and the data line, and the second substrate is a color filter substrate having a color filter and a black matrix formed in the display area. The shielding mask is formed of the black matrix and is spaced apart from the black matrix formed in the display area at a predetermined interval.

The line width of the failure turn is adjusted through an overlapping area of the shielding mask and the sealant, and the overlapping area of the shielding mask and the sealant is compared to an area other than the overlapping area of the sealant and the shielding mask. Wider

In addition, after removing the sealant in an uncured gel state overlapping with the shielding mask together with the shielding mask, the non-display area of the first substrate is cleaned, and the cleaning is performed by isopropyl alcohol (IPA) or DI. (Deionized) cleaning liquid is sprayed onto the non-display area of the first substrate, or a brush is used.

The first and second substrates are each formed of a plurality of unit cells that form the liquid crystal panel including the failure turn.

As described above, after curing the sealant formed of a wider line width than the design line width by bonding the array substrate and the color filter substrate according to the present invention, only the uncured sealant is removed in a subsequent cutting process of the substrate. Thus, through this, the failure turn substantially present on the liquid crystal panel can be formed in a narrow line width compared to the line width of the conventional sealant, there is an effect that can form a failure turn of a narrow seal (narrow seal). .

Through this, the liquid crystal display of the present invention has the effect of implementing a narrow bezel.

1 is a schematic cross-sectional view of a general liquid crystal display device.
2 is a flowchart illustrating a manufacturing process of a liquid crystal display according to an exemplary embodiment of the present invention step by step.
3A to 3E are schematic cross-sectional views of a part of the liquid crystal cell shown in accordance with the process flow from the fifth step to the seventh step of the TFT-LCD cell process of FIG.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings.

2 is a flowchart illustrating a manufacturing process of a liquid crystal display according to an exemplary embodiment of the present invention step by step.

The liquid crystal display first performs a TFT-LCD cell process St10, and forms a liquid crystal cell through the cell process St10.

In more detail, the TFT-LCD cell process (St10) is largely divided into the color filter substrate and the array substrate formation (St11), the alignment layer formation (St12), the sealant coating and the spacer formation (St13), the liquid crystal dropping (St14), and the bonding ( St15), sealant curing (St16), cutting (St17), and inspection step (St18).

Accordingly, in the first step St11 of the TFT-LCD cell process St10, after forming the upper substrate as the color filter substrate and the lower substrate as the array substrate, the foreign substances which may be present on the substrate are applied before the alignment layer is applied. This is the initial cleaning step to remove.

In this case, a plurality of gate wirings and data wirings intersect each other to define pixels on the inner surface of the display area of the array substrate, and thin film transistors are provided at each crossing point to connect one-to-one with the transparent pixel electrodes formed in each pixel. .

As an example corresponding to each pixel on the inner surface of the color filter substrate, a color filter of red (R), green (G), and blue (B) colors and each of them is disposed, and the gate wiring, the data wiring, and the thin film transistor are disposed. A first black matrix covering non-display elements, such as a light source, is provided, and a transparent common electrode covering them is provided.

In particular, the present invention is characterized by further comprising a second black matrix along the outermost edge of the color filter substrate. The second black matrix is used as a shielding mask that shields light of a specific area in the process of curing the sealant.

The second step St12 is a step of forming an alignment layer on the color filter substrate and the array substrate. In the third step St13, the sealant is coated so that the liquid crystal to be interposed between the color filter substrate and the array substrate is not leaked. In order to maintain a precise and uniform gap between the color filter substrate and the array substrate, a spacer of a certain size is scattered.

At this time, the sealant is applied to the edge of any one of the color filter substrate and the array substrate by a screen printing method and a dispenser printing method.

The fourth step St14 of the TFT-LCD cell process St10 is a step of dropping liquid crystal onto one of the selected substrates, and the fifth step St15 is a bonding step of the color filter substrate and the array substrate. Thereafter, a sixth step St16 of curing the sealant is performed.

Here, the sealant is characterized in that only a partial region is cured by the second black matrix.

The cured sealant is formed in the non-display area surrounding the edge of the display area, and serves as an encapsulant.

Thus, the original liquid crystal cell is completed.

Therefore, compared to the conventional, the line width of the failure turn is formed as a failure turn of a narrow seal (narrow seal) having a line width of 0.6 ~ 1.0mm narrow about 50%. Through this, the liquid crystal display of the present invention has a narrow bezel. We will discuss this in more detail later.

The uncured sealant is then removed in a later substrate cutting process.

That is, after the sealant curing process St16 of the TFT-LCD cell process St10, a seventh step St17 of cutting the original liquid crystal cell into cell units is performed. In this case, the uncured sealant and the second black matrix are processed. In the process of cutting the color filter substrate is cut together and removed.

Finally, the eighth step St18 of the TFT-LCD cell process St10 is an inspection process of the unit liquid crystal cell. Through the inspection process, high-quality unit liquid crystal cells are selected.

As a result, the TFT-LCD cell process St10 is completed, thereby completing the unit liquid crystal cell.

Next, a polarizing plate attaching process (St20) for attaching a polarizing plate to each of the array substrate and the color filter substrate of the completed unit liquid crystal cell is performed. The polarizing plate converts light sources into linear light on both sides of the unit liquid crystal cell. Play a role.

Next, the process of attaching the driving circuit (St30) is performed, and the driving circuit is a TAB method in which a driving circuit for connecting an electrical signal with an array substrate of a unit liquid crystal cell is directly mounted on a tape carrier package (TCP). To the unit liquid crystal cell.

This completes the actual driveable liquid crystal panel.

Such a driving circuit is divided into a gate driving circuit which scans and transmits an on / off signal of a thin film transistor to a gate wiring of a liquid crystal panel, and a data driving circuit which transmits image signals by frame to a data wiring. It can be located with two edges adjacent to each other.

In the liquid crystal panel having the above-described structure, when the thin film transistor selected for each gate wiring is turned on by the on / off signal of the gate driving circuit which is scanned and transmitted, the signal voltage of the data driving circuit is transferred through the data wiring. The arrangement direction of the liquid crystal molecules is changed by the electric field between the pixel electrode and the common electrode, which is transmitted to the pixel electrode, thereby indicating a difference in transmittance.

Next is a cell test process (St40), the cell test process is a complete liquid crystal panel attached to the driving circuit is completed to check whether it can be displayed by driving.

Through this inspection process, high-quality liquid crystal panels are selected.

Next, the backlight unit assembly and case assembly process (St50) is performed. The backlight unit assembly process includes a light source on the lower surface of the liquid crystal panel, a light source guide for guiding the light source, a light guide plate for moving light incident from the light source toward the liquid crystal panel, and a plurality of light guide plates. It includes an optical sheet of.

Alternatively, although the edge type method using the light guide plate has been described in the above description, a direct type in which a plurality of light sources are arranged side by side under the liquid crystal panel with the light guide plate omitted may be used.

In this case, a fluorescent lamp such as a cold cathode fluorescent lamp or an external electrode fluorescent lamp may be used as the light source. Alternatively, a light emitting diode lamp may be used as a light source in addition to the fluorescent lamp.

Assemble the case after the backlight unit assembly process. The case assembly is modularized through the top cover, the support main and the cover bottom. The top cover is a rectangular frame having a cross section bent in a shape to cover the top and side edges of the liquid crystal panel. It is configured to display an image implemented in the panel.

In addition, the cover bottom, which is the basis for assembling the entire structure of the liquid crystal display device module by mounting the liquid crystal panel and the backlight unit, is configured by vertically bending four edges thereof in a rectangular plate shape.

In addition, a support main mounted on the cover bottom and covering the edges of the liquid crystal panel and the backlight unit is assembled with the top cover and the cover bottom to complete the liquid crystal display module.

Meanwhile, in the liquid crystal display of the present invention, in the sealant curing process St16 of the TFT-LCD cell process St10, only a part of the sealant is cured, and the uncured sealant is subsequently removed in the substrate cutting process St17. Thereby, the failure turn of a narrow seal can be formed.

Through this, the liquid crystal display of the present invention has a narrow bezel.

3A to 3E are cross-sectional views schematically illustrating a part of the liquid crystal cell shown in accordance with the process flow from the fifth step to the seventh step of the TFT-LCD cell process of FIG. 2.

3A is a part of the original liquid crystal cell after the fifth step of FIG. 2 proceeds, and as illustrated, the array substrate 101 and the color filter substrate 102 are bonded to each other with the liquid crystal layer 150 interposed therebetween. .

The liquid crystal cell is divided into a display area AA in which an image is displayed and a non-display area NA which surrounds the edge of the display area AA.

 In more detail, each of the pixels P is defined by crossing gate lines (not shown) and data lines (not shown) on the inner surface of the display area AA of the array substrate 101. The pixel electrode 123 is formed at (P).

In addition, the gate electrode 111, the gate insulating film 113, the semiconductor layer 115, the source and drain electrodes 117 and 119, and the protective layer may be disposed at the intersections of the gate wirings (not shown) and the data wirings (not shown). A thin film transistor Tr, which is a switching element consisting of 121, is provided.

In this case, the semiconductor layer 115 is composed of an active layer 115a of pure amorphous silicon and an ohmic contact layer 115b of amorphous silicon including an impurity. In this case, the thin film transistor Tr is amorphous of pure and impurity in the drawing. A bottom gate type consisting of the silicon silicon 115a and 115b is shown as an example, and may be formed as a top gate type including a polysilicon semiconductor layer as a modification thereof.

In this case, the non-display area NA of the array substrate 101 includes gates and data pads (not shown) connected to gates and data wirings (not shown).

The inner surface of the color filter substrate 102 facing the array substrate 101 includes a thin film transistor Tr, a gate wiring (not shown), a data wiring (not shown), and a liquid crystal such as an edge of the pixel electrode 123. A grid-shaped first black matrix 131a is formed around the pixel area P to cover only the non-display area unrelated to driving and expose only the pixel electrode 123.

In addition, a second black matrix 131b is formed along the outermost edge of the color filter substrate 102. Here, the first black matrix 131a and the second black matrix 131b are spaced apart by a predetermined interval.

For example, R (red), G (green), and B (blue) color filters 133 are sequentially arranged in a lattice of the first black matrix 131a to correspond to each pixel area P. The common electrode 135 is disposed to cover the black matrix 131a and the color filter 133 and face the pixel electrode 123 with the liquid crystal layer 150 therebetween.

In this case, the liquid crystal layer 150, the pixel electrode 123, and the common electrode 135 are interposed with first and second alignment layers (not shown), each of which has a surface rubbing toward the liquid crystal in a predetermined direction, respectively. Evenly align the initial alignment of the molecules with the orientation.

The sealant 200 is applied to the edges of the array substrate 101 and the color filter substrate 102 to prevent leakage of the liquid crystal layer 150. The sealant 200 is a mixture of an epoxy resin and a curing accelerator. As the polymer mixture, it is cured by heating or UV light irradiation to achieve a failure turn of the adhesive role to maintain the bonding state of the two substrates (101, 102).

The failure turn also serves as a gap agent that uniformly controls the cell gap between the substrates 101 and 102 defined by the thickness of the liquid crystal layer 150.

That is, the sealant 200 is formed in the non-display area NA that surrounds the edge of the display area AA, and serves as an encapsulant of the liquid crystal cell.

The sealant 200 maintains a gel state having a certain viscosity before the curing process.

At this time, the sealant in the gel state has a line width d2 that is about 3 to 4 times wider than the design line width d1 by the bonding process of the array substrate 101 and the color filter substrate 102.

Here, the gel sealant 200 is applied in correspondence to a spaced interval between the first black matrix 131a and the second black matrix 131b. That is, the sealant 200 is positioned between the first black matrix 131a and the second black matrix 131b.

At this time, in the direction from the top of the color filter substrate 102 toward the sealant 200, a part of the sealant 200 in a gel state is applied by overlapping with the second black matrix 131b, thereby applying the second black matrix. The rest of the sealant 200 in a gel state not overlapping with 131b is exposed between the first black matrix 131a and the second black matrix 131b.

For convenience of description, a part of the sealant 200 in a gel state exposed between the first black matrix 131a and the second black matrix 131b is defined as a first sealant 200a, and the second sealant 200a is defined as a second sealant 200a. A part of the sealant 200 in a gel state overlapping with the black matrix 131b will be defined as the second sealant 200b.

Next, FIG. 3B is a part of the original liquid crystal cell in which the sixth step of FIG. 2 proceeds, and as shown in FIG. 3B, a lower wavelength toward the gel sealant 200 in the gel state from the top of the color filter substrate 102. UV light having a temperature is irradiated for a predetermined time.

Here, the gel sealant 200 is cured by irradiating UV light for a predetermined time, and a UV high pressure mercury lamp (not shown) may be used to cure the sealant 200 in a gel state. .

That is, the sealant 200 in a gel state is cured using UV emitted from a mercury lamp (not shown).

At this time, the first sealant 200a in a gel state exposed between the first black matrix 131a and the second black matrix 131b is exposed by UV light and exposed to UV light as shown in FIG. 3C. The reaction proceeds to cure, and the UV seal is shielded by the second black matrix 131b of the second sealant 200b overlapping the second black matrix 131b, and thus no reaction occurs.

That is, the second sealant 200b is not cured, and maintains a gel state having an initial property of being applied on the substrate 102, that is, some viscosity.

Here, the reason why the UV light has a low wavelength band is to prevent the sealant 200 from being instantly cured in a short time.

That is, since the sealant 200 of the present invention is cured by being divided into a hardened region and an uncured region, when the UV band has a high wavelength, the sealant 200 may be instantaneously cured to an uncured region in the process of curing the cured region. .

Next, a process of cutting the substrates 101 and 102 of the seventh step of FIG. 2 in cell units is performed. In order to improve the yield in manufacturing a unit liquid crystal cell, a plurality of unit liquid crystal cells are formed on a large substrate. Forming at the same time is generally applied. Accordingly, a process of separating and processing a unit liquid crystal cell from a large area mother substrate by cutting and processing a mother substrate on which a plurality of liquid crystal cells are made is required.

In addition, the array substrate 101 includes gate and data pads connected to the gate and data wirings (not shown), respectively, in a non-display area NA on one side of the array substrate 101 where the gates and data wirings (not shown) are arranged. Since the formed pad portion (not shown) is formed to have a larger area than the color filter substrate 102, the cutting process is performed by cutting each of the color filter substrate 102 and the array substrate 101 using a cutting wheel, The original liquid crystal cell is separated into a unit liquid crystal cell.

3D, in the process of cutting the color filter substrate 102, the cutting wheel 160 has a cured first sealant 200a and a second sealant 200b in an uncured gel state. The color filter substrate 102 is cut in correspondence with the boundary of the "

Thus, as shown in FIG. 3E, the edge of the color filter substrate 102 on which the second black matrix 131b is formed is removed away from the color filter substrate 102 defining the display area AA. The second sealant 200b in a gel state is also attached to the edge of the color filter substrate 102 that is removed and is removed together.

In this case, the color filter substrate 102 and the array substrate 101 maintain a bonding state through the cured first sealant 200a and the liquid crystal layer interposed between the color filter substrate 102 and the array substrate 101. 150) to prevent leakage.

The cell gap between the substrates 101 and 102 defined by the thickness of the liquid crystal layer 150 is uniformly controlled.

That is, both the substrates 101 and 102 defined by the thickness of the liquid crystal layer 150 together with the role of the adhesive to maintain the bonding state of the color filter substrate 102 and the array substrate 101 with the cured first sealant 200a. It serves as a gap agent to uniformly control the cell gap between.

At this time, the line width of the failed turn is formed to have the same line width as the design line width d1.

That is, in the liquid crystal display of the present invention, in the sealant curing process St16 of the TFT-LCD cell process St10, only a part of the sealant is cured, and the uncured sealant is subsequently removed in the substrate cutting process St17. Thereby, the failure turn of a narrow seal can be formed.

Therefore, in the present invention, even when the sealant has a line width d2 of about 3 to 4 times larger than the design line width d1 by the bonding process of the array substrate 101 and the color filter substrate 102, the final failure turn is achieved. Can be formed in the same manner as the design line width d1.

Through this, a failure turn can be formed even with a line width smaller than the smallest design line width d1 that can be formed in the current process. Here, the line width of the failure turn may be adjusted through an overlapping area between the second black matrix 130b and the sealant.

On the other hand, in the process of removing the second sealant 200b away from the array substrate 101, since the residue of the second sealant 200b may exist on the array substrate 101, IPA (Isopropyl Alcohol) or DI (Deionized) A cleaning liquid is preferably sprayed onto the array substrate 101 or cleaned using a brush.

As described above, according to the present invention, after the sealant formed to have a wider line width than the design line width d1 by hardening the array substrate 101 and the color filter substrate 102, only the partial region is hardened. By removing it later in the cutting process of the substrate, it is possible to form a failure turn of a narrow seal.

Through this, the liquid crystal display of the present invention has a narrow bezel.

The present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention.

101: array substrate, 102: color filter substrate
111: gate electrode, 113: gate insulating film
115: semiconductor layer 115a: active layer, 115b: ohmic contact layer
117: source electrode, 119: drain electrode, 121: protective film, 123: pixel electrode
131a: first black matrix, 131b: second black matrix,
133: color filter, 135: common electrode, 150: liquid crystal layer, 160: cutting wheel
200: sealant (200a: first sealant, 200b: second sealant)

Claims (8)

Providing a first substrate defining a display area and a non-display area, and a second substrate having a shielding mask formed at an outermost edge of the non-display area;
Applying a sealant in a gel state to the non-display area of one of the first and second substrates so as to partially overlap the shielding mask;
Bonding the first and second substrates to each other and interposing a liquid crystal layer between the first and second substrates;
Irradiating UV light on the gel sealant to cure the sealant in a region other than the region overlapping the shielding mask to form a failure turn;
Cutting the area in which the shielding mask is formed on the second substrate to remove the sealant in an uncured gel state with the shielding mask together with the shielding mask;
Method of manufacturing a liquid crystal panel comprising a.
The method of claim 1,
The first substrate is an array substrate having a gate and a data line and a thin film transistor positioned at an intersection of the gate and the data line, and the second substrate is a color filter substrate having a color filter and a black matrix formed in the display area. Method of manufacturing the panel.
The method of claim 2,
Wherein the shielding mask is formed of the black matrix and is spaced apart from the black matrix formed in the display area at a predetermined interval.
The method of claim 1,
And a line width of the failing turn is controlled through an overlapping area of the shielding mask and the sealant.
The method of claim 4, wherein
The overlapping region of the shielding mask and the sealant is wider than a region other than the overlapping region of the sealant and the shielding mask.
The method of claim 1,
And removing the sealant in an uncured gel state overlapping with the shielding mask together with the shielding mask, and then cleaning the non-display area of the first substrate.
The method according to claim 6,
The cleaning may be performed by spraying an IPA (Isopropyl Alcohol) or DI (Deionized) cleaning solution on the non-display area of the first substrate, or using a brush.
The method of claim 1,
And the first and second substrates are each formed of a plurality of unit cells including the fail turn to form a liquid crystal panel.

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