KR20150002116A - Alignment layer patterning method and method of fabricating liquid crystal display device using the same - Google Patents

Abstract

Provided is a method for forming an alignment layer which comprises the steps of: printing a liquid alignment layer on each active region of a substrate in which the active regions having a display region and a non-display region around the display region are defined through an alignment layer printing device; curing the alignment layer printed on the substrate; and irradiating a part thicker than other parts or an unnecessarily formed part of the cured alignment layer of each active region with a laser beam through a laser irradiation device and removing incinerated materials and evaporation residues generated by the irradiation of the laser beam around the part of the substrate to which the laser beam is irradiated by sucking the incinerated materials and the evaporation residues through a suction device. According to the method, the width of the alignment layer to which the laser beam is irradiated gets thinner or removed.

Description

[0001] The present invention relates to a method of forming an alignment layer and a liquid crystal display device using the same,

The present invention relates to a method of manufacturing a liquid crystal display device, and more particularly, to a method of forming an alignment film capable of suppressing defects due to occurrence of a thickness difference due to a marginal phenomenon and a method of manufacturing a liquid crystal display device using the same.

Recently, liquid crystal display devices have been attracting attention as next generation advanced display devices with low power consumption, good portability, and high value-added.

Of these liquid crystal display devices, an active matrix type liquid crystal display device having a thin film transistor, which is a switching device capable of controlling voltage on and off for each pixel, .

Generally, a liquid crystal display device forms an array substrate and a color filter substrate through an array substrate manufacturing process for forming thin film transistors and pixel electrodes, and a color filter substrate manufacturing process for forming color filters and common electrodes, And a liquid crystal cell interposed therebetween.

A manufacturing process of such a liquid crystal display device will be briefly described.

First, the array substrate may be patterned by depositing or applying a material layer to be patterned, applying a photoresist, photo-lithography using an exposure mask, development of an exposed photoresist, A mask process including a plurality of unit processes such as etching and a strip of a photoresist is performed to form a thin film transistor which is a switching device in each pixel region, Gate lines and data lines to be defined are formed so as to be connected to the thin film transistors, and pixel electrodes which are in contact with one electrode of the thin film transistors are formed in the respective pixel regions.

In addition, the color filter substrate can be completed by forming a color filter layer on the surface facing the array substrate and a common electrode covering the color filter layer.

After the array substrate and the color filter substrate manufactured as described above are opposed to each other, a liquid crystal layer is interposed between the two substrates, and the two substrates are bonded together to form a panel, Complete the device.

The liquid crystal display device manufactured by this method uses the electro-optic effect of the liquid crystal, and the electro-optical effect is determined by the anisotropy of the liquid crystal itself and the molecular arrangement state of the liquid crystal, The image display quality in the apparatus is greatly influenced.

Accordingly, in order to uniformize the initial alignment of the liquid crystal molecules, an alignment process for forming an alignment film is performed in a cell process step of attaching the array substrate and the color filter substrate.

In the alignment process, an alignment film having a uniform thickness is applied to the array substrate and the color filter substrate by a process such as rubbing to align the polymer chains in one direction, thereby forming an alignment film, And aligning the polymer chains in the alignment film in a predetermined direction by advancing the rubbing process so as to have the orientation in the predetermined direction.

With the progress of the alignment process, the liquid crystal molecules in the liquid crystal layer have a constant initial arrangement. That is, it is the role of the alignment film to give an order of the initial state to the liquid crystal and allow each liquid crystal molecule to make a regular response.

 A method of forming such an alignment film will be described in more detail with reference to the drawings.

1 is a view showing a step of printing an alignment film by a roll coating method using a conventional alignment film printing apparatus on a substrate.

The formation of the alignment layer 50 on the substrate 40 is carried out mainly by an alignment film printing apparatus 10 composed of a plurality of rolls 12 and 14 and a printing stage 20, A roll coating method using a transfer plate 30 having a predetermined pattern shape to be mounted on a substrate 16 is mainly used.

The alignment film printing apparatus 10 includes a printing stage 20 reciprocating in one direction, a driving motor 16 rotating in conjunction with the printing stage 20, and a transfer plate 16 mounted on the surface of the driving motor 16 An anilox roll (14) for transferring the alignment liquid to the transfer plate (30), a doctor roll (12) for evenly lapping the alignment liquid on the anilox roll (14) And a dispenser 18 for supplying the alignment liquid between the doctor roll 12 and the doctor roll 12.

When the substrate 40 is placed on the printing stage 20 and the printing stage 20 moves at a uniform speed in one direction, the printing head 20, which is in engagement with the printing stage 20, The transfer plate 30 mounted on the platen 16 is brought into contact with the substrate 40 placed on the printing stage 20 and the alignment liquid evenly spread on the transfer plate 30 is transferred to the substrate 40 And an alignment layer 50 is formed on the substrate 40 by transferring.

Thereafter, the rubbing process is performed on the thus formed alignment layer 50, thereby aligning the polymer chains in the alignment layer 50 in one direction, thereby completing the alignment process.

However, when the alignment film 50 is formed on the substrate 40 by the roll coating method using the alignment film printing apparatus 10 as described above, the alignment film 50 is formed on the substrate through the alignment film printing apparatus The alignment film 50 formed on the substrate 40 is transferred to the substrate 40 by applying pressure to the transfer plate 30 and transferring the alignment liquid applied to the transfer plate 30 to the substrate 40, 50, the difference in thickness between the center portion and the edge portion of the alignment layer 50 is severely increased by about 2 to 3 times due to the marginal phenomenon.

That is, the center portion of the alignment layer 50 formed on the substrate 40 through the alignment film printing apparatus 10 has a first thickness t1 which is a proper thickness, while the edge portion of the alignment layer 50 has the first thickness t1, And a second thickness t2 that is two to three times the thickness t1.

The difference in the thickness of the alignment layer 50 causes a gap defect in which the thickness of the liquid crystal layer becomes uneven when the adhesion process is performed between the array substrate on which the alignment layer 50 is formed and the color filter substrate via the liquid crystal layer , Which causes unevenness due to the difference in thickness of the alignment layer 50 on the screen when a voltage is applied to the liquid crystal display device, which causes the display quality of the liquid crystal display device to deteriorate.

Further, by the large thickness of the edge portion of the alignment layer 50, the rubbing cloth is damaged during the subsequent rubbing process, so that when the polymer chains in the alignment layer 50 are aligned in one direction by the damaged rubbing cloth, In implementation, defects, which are indicated by stains, are occurring.

In addition, the alignment layer formed through the alignment film printing apparatus may be formed on an area other than the area where the alignment film should be formed on the substrate. In this case, if the alignment film is formed in the area where the sealant is to be provided, The liquid crystal layer leaks, or the array substrate and the color filter substrate are separated from each other after the lapse of a predetermined time.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the problems described above, and it is an object of the present invention to provide an alignment film forming method for forming an alignment film on an array substrate and a color filter substrate to have a uniform thickness, And a manufacturing method of the apparatus.

It is another object of the present invention to improve the bonding force between the array substrate and the color filter substrate by preventing the alignment film from being formed in a region where the sealant is provided.

A method of forming an alignment film according to an embodiment of the present invention includes the steps of: printing a liquid crystal alignment film through an alignment film printing apparatus for each active region on a substrate having a plurality of active regions having a display region and a non-display region around the display region; Curing the printed alignment film on the substrate; A laser beam is irradiated to a portion of the cured alignment layer formed in each active region that is thicker or unnecessarily formed relative to the other region, and a laser beam is irradiated through the laser irradiating device. At the same time, And a step of sucking and removing the incineration substances and the vaporization residues generated by the beam irradiation, wherein the thickness of the alignment layer irradiated with the laser beam is reduced or eliminated.

In this case, the laser irradiating apparatus uses KrF as a reactive gas so that the laser beam has a wavelength of 248 nm and the laser beam has a pulse-wave form. The energy density of the laser beam is 200 to 200 nm, 600 mJ / cm < 2 >.

The substrate may be an array substrate including a gate and a data line crossing each other in the active regions, a thin film transistor connected to the gate and the data line, and a pixel electrode connected to the thin film transistor, A color filter substrate including a black matrix, a color filter layer and a common electrode, or a color filter substrate including a black matrix, a color filter layer and an overcoat layer in each active region.

At this time, the portion irradiated with the laser beam through the laser irradiation device is removed together with the alignment film, the overcoat layer alone or the overcoat layer and the black matrix located below the overcoat layer and the overcoat layer, The energy density of the laser beam is 1000 to 6000 mJ / cm 2, and when the black matrix is removed together with the alignment layer and the overcoat layer, the energy density of the laser beam is 2000 to 10000 mJ / cm 2 desirable.

The overcoat layer alone or the overcoat layer and the black matrix, which are located below the overcoat layer and the black matrix, are irradiated with the laser beam through the laser irradiating device, And the laser beam is irradiated at least once.

The sucking device may include only suction means, or may further include a gas discharging means in addition to the suction means, so that the incineration substances and the vaporization residues generated by the laser beam irradiation on the substrate through the gas discharging means And then sucking and removing the incineration substances and the vaporization residues separated from the substrate through the suction means after separating from the substrate.

A method of manufacturing a liquid crystal display device according to an embodiment of the present invention includes a step of forming a plurality of active regions having a display region and a non-display region therearound, each of which includes a thin film transistor and a pixel electrode, Forming a color filter substrate having a color filter layer in an area; Printing an alignment film of a liquid phase through the alignment film printing apparatus for each of the active regions on the array substrate and the color filter substrate; Curing an alignment film printed on each of the array substrate and the color filter substrate; A laser beam is irradiated to a portion of the cured alignment film formed on each of the array substrate and the color filter substrate for each of the active regions to form a thick or unnecessarily thick portion of the alignment film on the array substrate and the color filter substrate, Sucking and removing the incineration substances and the vaporization residues generated by the laser beam irradiation through the suction device in the vicinity of the irradiation of the laser beam; The array substrate and the color filter substrate are positioned so as to face each other with the alignment film facing each other, the sealant is applied to the outside of each display region for each active region, and the array substrate and the color filter substrate are bonded together with the liquid crystal layer interposed therebetween, ; And cutting the panel by each active area.

At this time, the laser irradiating apparatus uses KrF as a reactive gas, the wavelength of the laser beam is 248 nm, and the laser beam is in the form of a pulse wave.

The color filter substrate is provided with a first black matrix having a lattice shape inside the display area below the color filter layer and a second black matrix surrounding the display area, and covers the color filter layer and the second black matrix An overcoat layer is provided and the overcoat layer alone or the overcoat layer and the second black matrix, which are positioned below the alignment film, are removed together with the alignment film, through which the laser beam is irradiated through the laser irradiation device .

The energy density of the laser beam is 200 to 600 mJ / cm < 2 > when only the alignment layer is removed or the thickness thereof is reduced by the laser beam irradiation, and the alignment layer and the overcoat layer The energy density of the laser beam is 1000 to 6000 mJ / cm 2, and when the second black matrix is removed together with the alignment layer and the overcoat layer by the laser beam irradiation, the energy density of the laser beam is 2000 To 10000 mJ / cm < 2 >.

When the overcoat layer alone or the overcoat layer and the second black matrix are removed together with the alignment film, the sealant is formed in the area from which the overcoat layer is removed.

Further, the sealant is a black sealant comprising a black-based resin material.

The sucking device may be provided only with suction means, or may further include gas discharging means in addition to the suction means, so that the incineration substances and the vaporization residues generated by the laser beam irradiation on the substrate through the gas discharging means And separating the substrate from the substrate, and then sucking and removing the incineration substance and the vaporization residue separated from the substrate through the suction means.

The present invention relates to an alignment film formed on an unnecessary portion of a substrate by irradiating a laser beam through a laser beam irradiating device and a marginal portion of the alignment film formed largely in consideration of a transfer error of the transfer plate, The portion having a thicker thickness than the other region is removed, so that the alignment layer has a uniform thickness in each active region, thereby suppressing the display quality deterioration due to unevenness in alignment layer thickness.

Further, the present invention can suppress the damage of the rubbing cloth by the thickly formed alignment film, and thus has an effect of suppressing the rubbing failure.

In addition, the present invention has the effect of providing a liquid crystal display device capable of realizing a narrow bezel because a width of a non-display area within each active area can be reduced by removing a margin part considering an error caused by a transfer plate.

According to the method of forming an alignment film according to an embodiment of the present invention, since the alignment film formed at the portion where the sealant is formed is removed through the laser irradiation device, the adhesion of the sealant can be improved. The liquid crystal layer is prevented from leaking out or the substrates are separated from each other, thereby maintaining the cohesive state smoothly.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view showing an alignment film printing process by a roll coating method using an alignment film printing apparatus. Fig.
2 is a cross-sectional view showing an alignment film formed on a substrate through an alignment film printing apparatus
3 is a schematic cross-sectional view of a liquid crystal display device;
4 is a cross-sectional view of one pixel region of a transverse electric field mode liquid crystal display device.
5 is a cross-sectional view of one pixel region of a fringe field mode liquid crystal display.
6A to 6C are cross-sectional views illustrating the steps of forming an alignment film according to an embodiment of the present invention.
7 is a plan view of a mother substrate used for manufacturing an array substrate or a color filter substrate of a liquid crystal display device according to an embodiment of the present invention.
8A and 8B are plan views showing a form in which an alignment film is formed by an alignment film formation method according to an embodiment of the present invention.
9 is a schematic cross-sectional view of a suction device used in a method of forming an alignment film according to an embodiment of the present invention.
10 is a cross-sectional view illustrating a method of forming an alignment film according to an embodiment of the present invention, in which both an alignment film, an overcoat layer, and a black matrix are removed from a color filter substrate having a black matrix, an overcoat layer, and an alignment film.
11 is a cross-sectional view of a liquid crystal display device including a color filter substrate in which an alignment film, an overcoat layer, and a black matrix are all removed by applying an alignment film forming method according to an embodiment of the present invention.

Hereinafter, a method of manufacturing a liquid crystal display device including a method of forming an alignment film according to an embodiment of the present invention will be described with reference to the drawings.

First, the configuration of the liquid crystal display device will be briefly described.

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

As shown in the figure, the liquid crystal display device 101 has a configuration in which the array substrate 110 and the color filter substrate 160 are adhered to each other with the liquid crystal layer 180 therebetween, and the liquid crystal display device displays an image And a non-display area outside the display area.

In the liquid crystal display device having such a configuration, the lower array substrate 110 is formed on the upper surface of the transparent first substrate 112, which is the base, with a gate insulating film 118 interposed therebetween, A plurality of gate wirings (not shown) and data wirings 130 defining the gate electrode P are provided.

The array substrate 110 is provided with thin film transistors Tr which are connected to the gate and data lines (not shown) in the respective pixel regions P and are switching elements. Further, the pixel regions P The pixel electrode 150 is formed in contact with the drain electrode 136 of the thin film transistor Tr.

The upper portion of the color filter substrate 120 facing the array substrate 110 has a gate wiring (not shown) provided on the array substrate 110 on the inner side of a transparent second substrate 162, A data wiring 130 and a first black matrix 164a in a lattice shape to frame each pixel region P so as to cover a non-display region such as a thin film transistor Tr are formed. And a second black matrix (not shown) is formed in the non-display area. For convenience, the first and second black matrices 164a (not shown) are collectively referred to as a black matrix 164.

Green (G), and blue (B) color filter patterns, which are sequentially and repeatedly arranged in correspondence to the respective pixel regions P, in an area surrounded by the first black matrices 164a of the grid shape, A color filter layer 167 including the transparent electrodes 167a, 167b and 167c is formed on the transparent substrate 170. A transparent common electrode 170 corresponding to the display area is formed above the first black matrix 164 and the color filter layer 167 .

In order to prevent the leakage of the liquid crystal layer 180 interposed between the array substrate 110 and the color filter substrate 160, a sealant (an adhesive agent) is formed along the edges of the two substrates 110 and 160 And first and second alignment films (not shown) for imparting reliability in the molecular alignment direction of the liquid crystal are provided at boundaries between the array substrate and the color filter substrates 110 and 120 which are in contact with the liquid crystal layer 180, (152, 172).

In the liquid crystal display device 101 having such a configuration, on / off signal voltages of the thin film transistor Tr are sequentially applied to the gate wiring (not shown) An image signal voltage is applied to the pixel electrode 150 of the pixel region P selected by the ON state through the data line 130 and the voltage of the image signal generated between the pixel electrode 150 and the common electrode 170 The liquid crystal molecules in the liquid crystal layer 180 are driven by the electric field, and a full-color image can be displayed due to the light transmittance change caused by the driving of the liquid crystal molecules.

In order to manufacture the liquid crystal display device 101 having such a configuration, after the array substrate 110 and the color filter substrate 160 are manufactured, a liquid crystal layer 180 is formed between the two substrates 110 and 160, So that it is necessary to carry out the step of joining them together.

First, in the case of the array substrate 110, a low resistance metal material such as aluminum (Al), an aluminum alloy (AlNd), copper (Cu), a copper alloy, molybdenum (Mo), molybdenum alloy (MoTi), or the like to form a first metal layer (not shown) having a single layer or a bilayer structure.

Then, the first metal layer (not shown) is patterned by a mask process to form gate lines (not shown) extending in one direction and gate electrodes 115 connected to the gate lines (not shown).

Next, an inorganic insulating material such as silicon oxide (SiO ₂ ) or silicon nitride (SiNx) is deposited on the entire surface of the first substrate 112 over the gate wiring (not shown) and the gate electrode 115 to form a gate insulating film 118 ).

Then, a pure amorphous silicon layer (not shown), an impurity amorphous silicon layer (not shown) and a second metal layer (not shown) are formed on the gate insulating layer 118, and these are subjected to a single mask The active layer 120a of pure amorphous silicon corresponding to the gate electrode 115 in the pixel region P and the gate electrode 115 of the impurity amorphous silicon spaced apart from the active layer 120a by a predetermined distance, Source and drain electrodes 133 and 136 are formed on the contact layer 120b and the ohmic contact layer 120b.

At this time, the gate electrode 115, the gate insulating film 118, the semiconductor layer 120 including the active layer 120a and the ohmic contact layer 120b, which are sequentially stacked in each pixel region P, And the source and drain electrodes 133 and 136 which are spaced apart from each other constitute a thin film transistor Tr which is a switching element.

The source and drain electrodes 133 and 136 are formed and the data line 130 defining the pixel region P is formed on the gate insulating film 118 in a direction intersecting the gate line (not shown) do.

At this time, the source and drain electrodes 133 and 136 and the semiconductor layer 120 are formed through a single mask process so that the active layer 120a and the ohmic contact layer 120b are also formed under the data line 130 The first and second dummy patterns 121a and 121b are formed under the data line 130. The first and second dummy patterns 121a and 121b are formed on the semiconductor layer 120, And the source and drain electrodes 133 and 136 are formed through one mask process, respectively.

Then, the data line 130 and the source and drain electrodes (133, 136) over the substrate 101, an inorganic insulating material, for example silicon oxide (SiO ₂₎ or silicon nitride (SiNx) deposition, or insulating organic to the front The protective layer 140 is formed by applying a material.

Although the protective layer 140 is formed of an organic insulating material and has a flat surface, the protective layer 140 may include a first passivation layer (not shown) formed of an inorganic insulating material, And a second protective layer (not shown) having a flat surface made of an organic insulating material may be formed thereon.

The passivation layer 140 is provided with a drain contact hole 143 for exposing the drain electrode 136 of the thin film transistor Tr.

Next, a transparent conductive material such as indium-tin-oxide (ITO) or indium-zinc-oxide (IZO) is deposited on the entire surface of the passivation layer 140 to form a transparent conductive material layer (not shown) The pixel electrode 150 is formed in each pixel region P, thereby completing the array substrate 110.

 On the other hand, in the case of the color filter substrate 160, a black material layer (not shown) is formed by applying a black material to a second substrate made of a transparent insulating material, for example, A black matrix 164 is formed in correspondence with the boundary and non-display regions of the pixel regions P. In the case of such a black matrix 164, a second black matrix (not shown) for framing the display area and a grid pattern corresponding to the boundary area of each pixel area P, which are connected to the second black matrix (not shown) And a first black matrix 164a.

Next, red, green, and blue resists are successively applied on the black matrix 164 to form red, green, and blue resist layers (not shown), respectively, and patterned to form red , Green and blue color filter patterns 167a, 167b, and 167c are sequentially formed.

The color filter layer 167 is further provided with a white color filter pattern (not shown) in addition to the red, green, and blue color filter patterns 167a, 167b, and 167c so that red, green, blue, and white color filter patterns 167a, 167b, 167c, not shown).

A transparent conductive material is deposited on the color filter layer 167 and patterned to form the common electrode 170 in the display area, thereby completing the color filter substrate 160.

The array substrate 110 and the color filter substrate 160 manufactured as described above are configured to substantially form the twisted nematic mode liquid crystal display device 101. The pixel electrode 150 and the common electrode 170) may be formed in different positions and shapes to form a configuration of a transverse electric field mode liquid crystal display (201 in FIG. 4) or a fringe field switching mode liquid crystal display (301 in FIG. 5).

That is, in the case of the transverse electric field mode liquid crystal display (201 in Fig. 4), as shown in Fig. 4 (cross sectional view for one pixel region of the transverse electric field mode liquid crystal display) The structure of the lower portion of the pixel region 250 is the same as that of the array substrate for the twisted nematic mode liquid crystal display (110 in FIG. 3), and the pixel electrode 250 has a plurality of bar- And a bar-shaped common electrode 251 is provided so as to alternate with the pixel electrode 250 in the form of a bar.

In this case, the plurality of bar-shaped common electrodes 251 are connected to common wirings (not shown). These common wirings (not shown) are spaced apart from the gate wirings .

In the color filter substrate 260 for a transverse electric field mode liquid crystal display device facing the array substrate 210 for a transverse electric field mode liquid crystal display device having such a configuration, a common electrode is omitted, and the color filter layer 167, An overcoat layer 271 having a flat surface for protecting the color filter layer 167 is provided on the upper portion in place of the common electrode.

Referring to FIG. 5 (a sectional view of one pixel region of the fringe field mode liquid crystal display) in the case of the fringe field mode liquid crystal display device (301 in FIG. 5), in the array substrate 310, A common electrode 356 is further provided on the entire surface of the display area for displaying an image on the pixel electrode 150 with the insulating layer 354 interposed therebetween. And an opening op in the form of a bar corresponding to the electrode 150 is provided.

 The color filter substrate 360 facing the array substrate 310 for a fringe field mode liquid crystal display device has the same configuration as the color filter substrate 260 (FIG. 4) for the liquid crystal display device of the transverse electric field mode.

4, 210 and 5) and the color filter substrate (160 in Fig. 3, 260 in Fig. 4, 360 in Fig. 5) ) Is formed by interposing a liquid crystal layer 180 between these two substrates (110 in Fig. 3, 210 in Fig. 4, 310 in Fig. 5, 160 in Fig. 3, 260 in Fig. 4, The alignment layer 451 is formed to provide the initial alignment property of the liquid crystal layer 180 before the alignment.

Hereinafter, the orientation film forming method which is the most characteristic constitution in the present invention will be described.

Since the array substrate and the color filter substrate have already been described above, the array substrate and the array substrate are collectively referred to as a substrate, and the substrate The components other than the alignment layer are not shown in the drawing, and only the alignment layer is shown on the substrate by simplifying the drawing.

A method of forming an alignment layer according to an embodiment of the present invention includes a step of forming and curing a liquid alignment layer corresponding to a display area on a substrate using a printing apparatus equipped with a transfer plate, The laser beam is selectively irradiated to a predetermined width of the edge portion of the formed alignment film having a thicker thickness than other regions by the marginal development and then removed.

6A to 6C are cross-sectional views illustrating the steps of forming an alignment layer according to an embodiment of the present invention.

First, as shown in FIG. 6A, a substrate 440 (array or color filter) having the above-described components is placed on a stage 420 of an alignment film printing apparatus 410 on which a transfer plate 430 is mounted .

The alignment film printing apparatus 410 includes a printing stage 420 that reciprocates in one direction, a driving roller 416 that rotates in engagement with the printing stage 420, a transfer plate 416 that is mounted on the surface of the driving roller 416, An anilox roll 414 for transferring the alignment liquid to the transfer plate 430 and a doctor roll 412 for applying the alignment liquid evenly to the anilox roll 414 And a dispenser 418 for supplying an alignment liquid between the anilox roll 14 and the doctor roll 412 (or the doctor blade).

When the substrate 440 is placed on the printing stage 420, the printing stage 420 is moved at a uniform speed in one direction. At this time, the driving stage 420, which is engaged with the printing stage 420, The transfer plate 430 mounted on the platen 416 while rotating makes contact with the surface of the substrate 440 placed on the printing stage 420 to form an alignment liquid To the surface of the substrate 440.

In this way, a liquid-state alignment layer 450 having a predetermined viscosity is formed on the substrate 440.

On the other hand, in order to improve the productivity per unit time in the manufacture of the liquid crystal display device, the array substrate and the color filter substrate are not as large as liquid crystal display devices having one display area sold on the market, A plan view of a mother substrate used for fabricating an array substrate or a color filter substrate of a liquid crystal display according to an embodiment of the present invention) includes a plurality of active regions (not shown) on a substrate 440, which is defined as one mother substrate, A pixel electrode, a common electrode, a black electrode, and the like which are to be provided on the array substrate or the color filter substrate with respect to the mother substrate 440 in which the plurality of active areas AA are defined, A color filter layer and an overcoat layer are selectively formed on the active region AA, So that a unit liquid crystal display device is formed.

Each of these active areas AA is composed of a display area DA for displaying an image and a non-display area NA outside the display area DA.

At this time, a part of the non-display area NA located around each display area DA is electrically connected to a printed circuit board (not shown) including a driving circuit for driving the liquid crystal display device (not shown) .

6A and FIG. 7, the liquid crystal alignment layer 450 transferred onto the substrate 440 through the alignment film printing apparatus 410 may include a plurality of active regions (not shown) defined in the substrate 440, AA) More precisely, it is formed corresponding to a part of the non-display area NA excluding the front face of the display area DA among the active areas AA and the pad part (not shown).

In FIG. 7, four active areas AA are defined on the substrate 440, for example.

Alternatively, the active areas AA may be spaced apart from each other on the substrate 440, or the active area AA may be spaced apart in one direction And are spaced apart from each other in the other direction perpendicular to the one direction.

8A (a plan view showing a form in which an alignment film is formed by the alignment film formation method according to the embodiment of the present invention), and when the active area AA is formed on the substrate 440 so as to be spaced apart from each other, 8B (a plan view showing a form in which an alignment film is formed by an alignment film forming method according to an embodiment of the present invention) is formed while being separated from each active area AA by a liquid phase alignment film 450 transferred through the printing device 410. [ When the active regions AA are arranged in a substantially unaltered manner in one direction, the liquid-crystal alignment film 450 is also connected and formed between the neighboring active regions AA in the one direction without a spacing therebetween, And is spaced apart from each active area AA only in the other direction.

Next, as shown in Figs. 6B and 7, heat treatment is applied to the liquid crystal alignment film (450 in Fig. 6A) transferred through the alignment film printing apparatus (410 in Fig. 6A) and formed corresponding to each active area AA To remove water (or solvent) and simultaneously cure.

The edge portion 451b of each active region AA is transferred to each active region 451 by the last-mentioned phenomenon on the characteristics formed by transferring using the alignment film printing apparatus (410 in Fig. 6A) And has a thicker thickness than the central portion 451a of the antenna AA.

When the rubbing process proceeds on the substrate 440 having the orientation film 451 having the thickness difference for each position, the rubbing cloth or the like is damaged by the orientation film portion 451b formed to have a large thickness. By the rubbing process, The polymer chains (not shown) in the alignment layer 451 are not aligned in one direction but have different directionality, which causes a defect.

6A) formed with the transfer plate (430 in Fig. 6A) and formed in correspondence with the respective active areas AA on the substrate 440, The alignment layer 451 must be provided in the display area DA within each active area AA and the alignment layer 451 is formed on the substrate 440 in consideration of the error range. A pad portion (not shown) may be formed as a portion where the alignment layer 451 should not be formed.

Therefore, the formation of the alignment layer 451 on the substrate 440 through the alignment film printing apparatus 410 (see FIG. 6A) requires consideration of the above-described error range. Therefore, The width of the area NA must have a larger width by the error range, which is a problem in implementation of the narrow bezel.

Therefore, in the method of forming an alignment film according to the present invention, in order to solve the problem caused by forming the alignment film 451 for each active area AA on the substrate 440 by using the alignment film printing apparatus (410 of FIG. 6A) The laser beam irradiation step having a specific wavelength band and a specific energy density is further carried out as a post-process.

Referring to FIG. 6C, the laser beam irradiating device 460 used in the laser beam irradiation process irradiates a laser beam (LB) in the form of a pulse wave having a wavelength of 248 nm (KrF) Is an excimer laser device capable of being used.

The energy density per unit area of the laser beam LB irradiated through the laser beam irradiating device 460 that irradiates the laser beam LB of the pulse wave form having the wavelength of 248 nm is 200 To 700 mJ / cm < 2 >.

At this time, it is possible to reduce the thickness of the hardened alignment layer 451 or selectively remove only the alignment layer 451 by appropriately adjusting the energy density of the laser beam LB within the above-mentioned range, In addition, the material layer located underneath it, for example, the overcoat layer and / or the black matrix provided on the color filter substrate may be removed together.

In order to remove the overcoat layer or the black matrix together with the orientation film 451, the energy density of the laser beam irradiating device 460 is preferably about 1000 to 10000 mJ / cm 2.

In the method of forming an alignment layer according to an embodiment of the present invention, a laser beam (LB) using the laser beam irradiating device 460 is irradiated onto the substrate 440 on which the alignment layer 451 is formed, The incinerated substance itself 452 generated when the incision device 470 is positioned together with the laser beam irradiating device 460 and the alignment film 451 is incinerated by irradiating the laser beam LB, (Not shown) of the vaporizer.

That is, since the suction port 475 of the suction device 470 is located adjacent to the portion irradiated with the laser beam LB on the substrate 440, the alignment film (or the material layer located below the alignment layer) The incineration substances 452 and the vaporization residues (not shown) generated by the incineration are sucked and the generation of foreign matter is suppressed, and the cleaning process of the substrate 440 to be further advanced due to the incineration of the incineration substances 452 can be omitted Is another feature of the alignment film forming method according to the embodiment of the present invention.

At this time, the suction device 470 may have only a function of sucking only incineration substances by laser beam irradiation, or a gas which does not affect the alignment film to effectively remove the incineration substances, for example, nitrogen (N 2) or oxygen O2) gas may be further provided.

That is, as shown in Fig. 9 (schematic cross-sectional view of the suction device used in the orientation film forming method according to the embodiment of the present invention), the suction port 475 of the suction device 470 has a double structure, A gas discharge area 472 for blowing nitrogen or oxygen onto the substrate is provided and a suction area 474 surrounding the gas discharge area 472 and sucking and burning the incineration material may be provided.

When the alignment film is incinerated by laser beam irradiation, the substrate 440 may be maintained in a state of being adsorbed on the substrate 440. In this case, the incinerator material 452 may not be removed only by suction of the suction device 470.

Therefore, in this case, oxygen or nitrogen gas is strongly ejected by the gas discharge area 472 using the suction device 470 having the suction area 474 and the gas discharge area 472 as described above, 440 can be removed from the surface of the substrate 440 and sucked through the suction region 474 located around the gas discharge region 472 and removed on the substrate 440. [ have.

The suction device 470 is connected to the suction area 474 and further includes an exhaust pipe 478. The suction device 452 sucked from the substrate 440 and the specific device for treating the vaporization residue It is discharged to a specific place.

On the other hand, the removal of the incineration substances 452 and the vaporization residues from the substrate by using the suction apparatus 470 can be performed in such a manner that the incineration water 452 or the vaporization residue (not shown) generated by the irradiation of the laser beam LB, It acts as a particle during the process, thereby generating scratches on the surface of the alignment layer 451 and damaging the surface of the alignment layer 451.

The irradiation of the laser beam LB using the laser irradiating device 460 may be performed once by one laser irradiating device 460 or may be performed twice by using one or more laser irradiating devices 460 Or more.

In the case of removing only the alignment layer 451 itself or reducing the thickness of the alignment layer 451 on the substrate 440, the laser beam LB having an energy density of about 200 to 600 mJ / cm 2 is preferably irradiated once, Sectional view showing a method of forming an alignment film according to an embodiment of the present invention, as shown in the figure, which shows removal of both an alignment film, an overcoat layer and a black matrix on a color filter substrate provided with a black matrix, an overcoat layer and an alignment film) The laser beam LB is irradiated in a different energy density per unit area in the case where the overcoat layer 171 and / or the second black matrix 164b are further removed, It is experimentally confirmed that it is preferable to proceed more than two times.

Table 1 below shows an appropriate energy density range of a material layer and a laser beam irradiated to the material layer, which are removed when the laser beam is irradiated to the array substrate and the color filter substrate through the laser beam irradiation device. At this time, the alignment layer is based on a thickness of 700 Å ± 100 Å, which is formed on an array substrate and a color filter substrate of a general liquid crystal display device.

Substrate type Removal material layer Appropriate energy density (mJ / cm 2) Remarks Color filter substrate PI 200 to 600 PI + OC 1000 ~ 6000 Based on OC 17000 Å PI + OC + BM 2000 to 10000 Array substrate PI 200 to 600 When there is a planarization layer PI 200 to 700 When there is no planarization layer

(PI: orientation film, OC: overcoat layer, BM: black matrix)

When referring to Table 1, it can be seen that the laser beam irradiated in the case of removing only the alignment layer on the substrate by using the laser irradiation apparatus preferably has an energy density of about 200 to 600 mJ / cm 2. In addition to the alignment film, It is preferable that the energy density is about 1000 to 6000 mJ / cm 2 for the removal together.

In addition, in order to remove the black matrix made of the black resin together with the alignment film and the overcoat layer on the color filter substrate, a laser beam having an energy density of about 2000 to 10000 mJ / cm 2 should be irradiated.

On the other hand, as described above, when a laser beam is irradiated through a laser beam irradiating device to form an alignment film formed on an unnecessary portion of the substrate by a marginal phenomenon, When the margin portion of the alignment layer is removed, the portion having a greater thickness than the other region is removed. Thus, the alignment layer has a uniform thickness in each active region, so that the display quality deterioration due to unevenness in alignment layer thickness is suppressed. The damage of the rubbing cloth due to the formed alignment film can be suppressed, and the rubbing defect is suppressed.

In addition, since the marginal portion considering the error due to the transfer plate is removed, the width of the non-display area within each active area can be reduced, thereby achieving the implementation of a narrow bezel.

In addition, in the method of forming an alignment film according to an embodiment of the present invention, a liquid crystal display device having a color filter substrate in which an alignment film, an overcoat layer, and a black matrix are all removed by applying the alignment film forming method according to an embodiment of the present invention, Sectional view of the display device), the overcoat layer 271 and / or the black matrix 164 positioned below the alignment film 461 and more precisely the display area DA within each active area AA, A groove hm having a predetermined width is formed in the color filter substrate 260 and a sealant 290 as an adhesive is applied to the groove hm The adhesive force of the sealant 290 is improved and the width of the sealant 290 is smaller than that of the liquid crystal display device in which the groove hm is not formed when the sealant 290 is applied through a syringe (not shown) Can form Since there is an effect that it is possible to implement a more narrow bezel, it is possible to further reduce the width of the non-display area (NA) for the sealant 290 is formed.

That is, since the adhesion of the sealant 290 to the surface of the substrate 162 itself is superior to that of the alignment film 461, the overcoat layer 271 or the black matrix 164, the overcoat layer 171, together with the alignment film 461, Or the black matrix 164 is removed, the sealant 290 is brought into contact with the surface of the substrate 162, so that the adhesion can be improved.

Further, when a sealant is applied through a syringe without forming a groove between the array substrate and the color filter substrate during the manufacture of a general liquid crystal display device, and the array substrate and the color filter substrate are bonded together, the sealant spreads to a minimum of 600 to 1200 μm .

However, the alignment film forming method according to the embodiment of the present invention proceeds to irradiate the laser beam LB through the laser irradiator 460 to irradiate the alignment film 461 with the overcoat layer 171 or the black matrix 164 The groove hm may be in the range of 100 to 600 mu m through the adjustment of the width of the laser beam LB and in this case the sealant 290 may be removed from the groove hm so that the groove hm acts as a dam of the sealant 290 to suppress spreading.

Therefore, when the overcoat layer 271 and / or the second black matrix 164b are removed together with the alignment film 461 to provide the groove hm, the width of the sealant 290 is the width of the groove hm Since the width of the non-display area NA for forming the sealant 290 can be reduced, the width of the sealant can be further reduced to realize the narrow bezel. .

On the other hand, the sealant 290 is a sealant 290 that displays black by including a black resin having a high light absorptivity. The second black matrix 164b is removed at the portion where the sealant 290 is formed, so that light leakage may be generated through the portion.

6A to 6C, the alignment layer 450 is formed on the substrate 440 (array and color filter substrate (210, 260 in FIG. 4)) using the alignment film printing apparatus (410 in FIG. 6A) (The reference numerals 152 and 172 in FIG. 4) are formed. After the curing is performed, the laser beam LB is selectively irradiated onto the unnecessary portion of the hardened alignment film 451, After completing the alignment film forming process according to the embodiment of the present invention in which unnecessary portions of the alignment film 461 are removed without generating particles or the thickness of a portion formed thicker than other regions by the marginal phenomenon is completed, The array substrate 210 and the color filter substrate 260 are positioned such that the alignment layers 152 and 172 formed on the tops of the two substrates 210 and 260 face each other, (210, 260) A sealant (not shown) is applied along the rim of the substrate, and a liquid crystal layer 180 is laminated inside the sealant (not shown) so that the liquid crystal layer 180 is held therebetween. The liquid crystal display device 201 is completed by cutting the active area AA.

When the overcoat layer 171 and the black matrix 164 are removed together with the alignment film 172 in the color filter substrate 260 to provide a groove (not shown), the sealant (not shown) The sealant width can be reduced and at the same time the adhesive strength of the sealant can be improved.

On the other hand, in the method of forming an alignment film according to a comparative example, the alignment film is not formed in a form that is spaced apart from the active region only by using an alignment film printing apparatus, and the alignment film is formed on the mother substrate through a slit coating apparatus or a spin coating apparatus It is possible to remove unnecessary portions of the alignment film only through the laser irradiation apparatus after the alignment film is formed. However, in this comparative example, since the laser beam irradiation region is relatively wider than the alignment film forming method according to the embodiment of the present invention, There arises a problem that the processing time after irradiation of the beam increases.

In particular, in this comparative example, an alignment film having an insulating property must necessarily be removed from the non-display region of each active region to be electrically connected to the printed circuit board. In the pad portion, It is difficult to remove only the alignment film itself by reflecting the laser beam irradiated by the laser beam. Even if the alignment film is removed by laser beam irradiation, the pad electrode itself is damaged by the laser beam, And there is a lot of possibility that signal failure occurs when it is electrically connected.

Therefore, an alignment film is formed on the mother substrate in such a manner that an alignment film is not formed for each of the active regions, at least for the pad portion, by using an alignment film printing apparatus having a transfer plate, and then a laser beam irradiating apparatus having a specific wavelength and energy density A method of forming an orientation film according to an embodiment of the present invention, in which a laser beam of a pulsed wave type is irradiated and suction is simultaneously performed to selectively remove a thick or unnecessary portion by a marginal phenomenon, It is more effective in suppressing the defective rate and shortening the manufacturing time compared with the orientation film forming method.

440: substrate
451: Orientation film
460: laser irradiation device
470: Suction device
475:
AA: active area
LB: laser beam

Claims (15)

Printing an alignment film of a liquid phase through the alignment film printing apparatus for each of the active regions on a substrate on which a plurality of active regions having a display region and a non-display region around the display region are defined;
Curing the printed alignment film on the substrate;
A laser beam is irradiated to a portion of the cured alignment layer formed in each active region that is thicker or unnecessarily formed relative to the other region, and a laser beam is irradiated through the laser irradiating device. At the same time, A step of sucking and removing the incineration substances and the vaporization residues generated by the beam irradiation
And the thickness of the alignment layer irradiated with the laser beam is reduced or eliminated.
The method according to claim 1,
Wherein the laser irradiating apparatus uses KrF as a reactive gas so that the laser beam has a wavelength of 248 nm and the laser beam has a pulse shape.
3. The method of claim 2,
Wherein an energy density of the laser beam is 200 to 600 mJ / cm 2.
3. The method of claim 2,
Wherein:
An array substrate including a gate and a data line crossing each other in the active regions, a thin film transistor connected to the gate and the data line, and a pixel electrode connected to the thin film transistor,
Or a color filter substrate including a black matrix, a color filter layer and a common electrode in each of the active regions,
Or a color filter substrate comprising a black matrix, a color filter layer and an overcoat layer in each of the active regions.
5. The method of claim 4,
Wherein the overcoat layer alone or the overcoat layer and the black matrix located below the overcoat layer together with the alignment layer are removed together with the portion irradiated with the laser beam through the laser irradiation device.
6. The method of claim 5,
When the alignment layer and the overcoat layer are removed together, the energy density of the laser beam is 1000 to 6000 mJ / cm 2. When the black matrix is removed together with the alignment layer and the overcoat layer, the energy density of the laser beam is 2000 to 10000 mJ / cm < 2 >.
The method according to claim 6,
Wherein the portion irradiated with the laser beam through the laser irradiating device is irradiated with the overcoat layer alone or at least two times through the plurality of laser irradiating devices when the overcoat layer and the black matrix are removed together, Characterized in that a laser beam is irradiated.
The method according to claim 1,
The suction device may be provided only with suction means,
Or a gas exhausting means in addition to the suction means to separate the incineration substances and the vaporization residues generated by the laser beam irradiation on the substrate from the substrate through the gas exhausting means, And removing the incineration substances and the vaporization residues separated from the incineration substances and the vaporization residues.
Forming a color filter substrate having a plurality of active regions each having a display region and a non-display region in the periphery thereof, the array substrate having a thin film transistor and a pixel electrode in each active region, and a color filter layer in each active region; ;
Printing an alignment film of a liquid phase through the alignment film printing apparatus for each of the active regions on the array substrate and the color filter substrate;
Curing an alignment film printed on each of the array substrate and the color filter substrate;
A laser beam is irradiated to a portion of the cured alignment film formed on each of the array substrate and the color filter substrate for each of the active regions to form a thick or unnecessarily thick portion of the alignment film on the array substrate and the color filter substrate, Sucking and removing the incineration substances and the vaporization residues generated by the laser beam irradiation through the suction device in the vicinity of the irradiation of the laser beam;
The array substrate and the color filter substrate are positioned so as to face each other with the alignment film facing each other, the sealant is applied to the outside of each display region for each active region, and the array substrate and the color filter substrate are bonded together with the liquid crystal layer interposed therebetween, ;
Cutting the panel by each active region
And the second electrode is electrically connected to the second electrode.
10. The method of claim 9,
Wherein the laser irradiating device uses KrF as a reactive gas so that the wavelength of the laser beam is 248 nm and the laser beam is in the form of a pulse wave.
11. The method of claim 10,
Wherein the color filter substrate is provided with a first black matrix having a lattice shape inside the display region below the color filter layer and a second black matrix surrounding the display region, Layer,
The overcoat layer alone or the overcoat layer and the second black matrix located below the overcoat layer together with the alignment film are removed together at the portion irradiated with the laser beam through the laser irradiation device .
12. The method of claim 11,
In the case where only the alignment layer is removed or the thickness thereof is reduced by the laser beam irradiation, the energy density of the laser beam is 200 to 600 mJ / cm 2,
When the alignment layer and the overcoat layer are removed together by the laser beam irradiation, the energy density of the laser beam is 1000 to 6000 mJ /
Wherein when the second black matrix is removed together with the alignment layer and the overcoat layer by the laser beam irradiation, the energy density of the laser beam is 2000 to 10000 mJ / cm 2.
13. The method of claim 12,
Wherein when the overcoat layer alone or the overcoat layer and the second black matrix are removed together with the alignment film, the sealant is formed in a region from which the overcoat layer is removed.
14. The method of claim 13,
Wherein the sealant is a black sealant comprising a black-based resin material
10. The method of claim 9,
The suction device may be provided only with suction means,
Or a gas exhausting means in addition to the suction means to separate the incineration substances and the vaporization residues generated by the laser beam irradiation on the substrate from the substrate through the gas exhausting means, And removing the incineration substances and the vaporization residues separated from the incineration substances and the vaporization residues.

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