KR20150072827A - Flexible liquid crystal display device and method of fabricating the same - Google Patents

Abstract

The present invention provides a flexible liquid crystal display device which includes a first flexible substrate on which a plurality of pixel regions are defined, a second flexible substrate which faces the first flexible substrate, a pixel electrode which is located on the first flexible substrate, a common electrode which is located on either the first flexible substrate or the second flexible substrate and forms an electric field with the pixel electrode, a black matrix which is located on the second flexible substrate and includes a first opening part which corresponds to the pixel region and a second opening part which corresponds to the edge of the pixel region, a color filter layer which is located on the second flexible substrate to correspond to the first opening part and includes UV absorption particles, a liquid crystal layer which is located between the first and second flexible substrates and includes a liquid crystal molecule and a monomer, and a polymer partition which is located to correspond to the second opening part and maintains a distance between the first and second flexible substrates. The polymer partition is formed by the polymerization of the monomer by UV inputted through the second opening part.

Description

TECHNICAL FIELD [0001] The present invention relates to a flexible liquid crystal display device and a method of fabricating the flexible liquid crystal display device.

The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device capable of improving uniformity of a cell gap by forming a polymer barrier wall by curing a monomer of a liquid crystal by UV irradiation and capable of preventing an undesired monomer polymerization reaction in a pixel region And a method of manufacturing the same.

Generally, the driving principle of a liquid crystal display device utilizes the optical anisotropy and polarization properties of a liquid crystal. Since the liquid crystal has a long structure, it has a directionality in the arrangement of molecules, and the direction of the molecular arrangement can be controlled by artificially applying an electric field to the liquid crystal.

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 by optical anisotropy, so that image information can be expressed.

At present, an active matrix liquid crystal display (AM-LCD: hereinafter referred to as liquid crystal display) in which a thin film transistor and pixel electrodes connected to the thin film transistor are arranged in a matrix manner has excellent resolution and video realization capability, It is attracting attention.

Since an in-plane switching mode LCD (IPS-LCD) that drives a liquid crystal by a transverse electric field generated between a pixel electrode and a common electrode formed on one of the liquid crystal display devices has excellent viewing angle characteristics It is widely used.

Hereinafter, a cross-sectional view of a general transverse electric field type liquid crystal display device will be described with reference to Fig.

1, a conventional transverse electric field type liquid crystal display includes a first substrate 10, a second substrate 20 facing the first substrate 10, a first substrate 10 facing the first substrate 10, A liquid crystal layer 30 positioned between the first and second substrates 10 and 20 and a column spacer 90 for maintaining a distance between the first and second substrates 10 and 20,

On the first substrate 10, a pixel region P is defined by a gate wiring (not shown) and a data wiring 52 intersecting each other with a gate insulating film 46 interposed therebetween. In each of the pixel regions P, a thin film transistor, a pixel electrode 70 connected to the thin film transistor, and a common electrode 72 alternately arranged with the pixel electrode 70 are formed.

The thin film transistor includes a gate electrode 42, a gate insulating film 46 covering the gate electrode 42, a semiconductor layer 50 overlapping the gate electrode 42 on the gate insulating film 46, And a source electrode 54 and a drain electrode 56 which are spaced apart from each other on the semiconductor layer 50. [

The gate electrode 42 is connected to the gate wiring and the source electrode 54 is connected to the data wiring 52. That is, the thin film transistor is connected to the gate wiring and the data wiring 52.

A protective layer 60 having a drain contact hole 62 exposing a drain electrode 56 of the thin film transistor is formed covering the thin film transistor and the data line 52, And is connected to the drain electrode 56 through the drain contact hole 62 on the protection layer 60. The common electrode 72 is alternately arranged on the passivation layer 60 with the pixel electrode 70.

On the second substrate 20, a black matrix 82 for blocking light corresponding to the gate lines and the data lines 52 is formed. In other words, the black matrix 82 has a lattice shape having an opening corresponding to the pixel region P.

A color filter layer 84 is formed in the opening of the black matrix 82. The color filter layer 84 may include a red color filter pattern 84a, a green color filter pattern 84b, and a blue color filter pattern (not shown). An overcoat layer 86 is formed on the color filter layer 84.

The first and second substrates 10 and 20 are bonded together such that the color filter layer 84 faces the pixel electrode 70 and the common electrode 72 and the first and second substrates 10 and 20 The liquid crystal layer 30 is formed.

In addition, a column spacer 90 for maintaining the distance between the first and second substrates 10 and 20, that is, the cell gap, is formed. At this time, the column spacer 90 is generally formed in the process of forming the overcoat layer or the protective layer 60.

However, the column spacer 90 should be formed to have different heights in order to maintain a uniform cell gap since the protective layer 60 has a step. However, a height error occurs in the process of forming the column spacer 90, which causes a problem that the uniformity of the cell gap is lowered.

On the other hand, even when the protective layer 60 does not have a step, if the height of the column spacer 90 is non-uniform, there arises a problem that the cell gap uniformity is lowered.

Particularly, in a flexible display device using a flexible substrate, when the display device is bent due to the low adhesive force of the conventional column spacer 90, the column spacer 90 is separated, thereby causing a problem of cell gap maintenance.

The present invention aims at solving the problem of lowering the cell gap uniformity caused by the column spacer.

In order to solve the above problems, the present invention provides a display device comprising: a first flexible substrate on which a plurality of pixel regions are defined; A second flexible substrate facing the first flexible substrate; A pixel electrode located on the first flexible substrate; A common electrode which is disposed on one of the first and second flexible substrates and forms an electric field with the pixel electrode; A black matrix disposed on the second flexible substrate and having a first opening corresponding to each of the pixel regions and a second opening corresponding to the edge of the pixel region; A color filter layer positioned on the second flexible substrate and corresponding to the first opening and including UV absorbing particles; A liquid crystal layer disposed between the first and second flexible substrates and including liquid crystal molecules and a monomer; And a polymer barrier wall positioned corresponding to the second opening and maintaining a distance between the first and second flexible substrates, wherein the polymer barrier wall is formed by polymerization reaction of the monomer by UV incident through the second opening, And a flexible liquid crystal display device.

In the flexible liquid crystal display device of the present invention, the UV absorbing particles have a first transmittance with respect to the UV and a second transmittance with respect to visible light that is smaller than the first transmittance.

In the flexible liquid crystal display of the present invention, the UV has a wavelength of 360 to 370 nm.

In the flexible liquid crystal display device of the present invention, the UV absorbing particles have an absorption rate of 75% or more with respect to the UV.

In the flexible liquid crystal display device of the present invention, the second flexible substrate is characterized by being made of polyimide.

In another aspect, the present invention provides a method of manufacturing a semiconductor device, comprising: attaching a first flexible substrate on which a plurality of pixel regions are defined, onto a first carrier substrate; Forming a pixel electrode on the first flexible substrate; Attaching a second flexible substrate on a second carrier substrate; Forming a black matrix having a first opening corresponding to the pixel region and a second opening corresponding to an edge of the pixel region on a second substrate; Forming a color filter layer corresponding to the first opening on the second flexible substrate using a color filter material including a pigment and UV absorbing particles; Forming a common electrode on any one of the first flexible substrate and the second flexible substrate; Attaching the first flexible substrate and the second flexible substrate to each other with a liquid crystal molecule and a liquid crystal layer including a monomer interposed therebetween; Irradiating the second carrier substrate with UV light to form a polymer barrier wall corresponding to the second opening by the polymerization reaction of the monomer; And separating the first carrier substrate and the second carrier substrate from the first flexible substrate and the second flexible substrate.

In the method of manufacturing a flexible liquid crystal display device according to the present invention, the UV absorbing particles have a first transmittance with respect to the UV and a second transmittance with respect to a visible ray smaller than the first transmittance.

In the flexible liquid crystal display device manufacturing method of the present invention, the UV is characterized by having a wavelength of 360 to 370 nm.

In the method for manufacturing a flexible liquid crystal display device of the present invention, the UV absorbing particles have an absorption rate of 75% or more with respect to the UV.

In the flexible liquid crystal display device manufacturing method of the present invention, the second flexible substrate is characterized by being formed of polyimide.

The flexible liquid crystal display device of the present invention includes a monomer layer and a photoinitiator in a liquid crystal layer and forms a polymer barrier wall by irradiating UV light thereto. Since a polymer barrier wall is formed in a state where opposing substrates are bonded together, .

Further, the black matrix may be formed so as to have an opening with respect to the data wiring or the gate wiring, and UV rays having a low transmittance to the color filter layer may be irradiated to form a polymer barrier wall while preventing the light leakage problem caused by the black matrix.

In addition, a flexible liquid crystal display device capable of realizing a high-quality image by preventing a monomer polymerization problem in a pixel region by UV irradiation using a UV blocking layer having a low transmittance to UV and a high transmittance to visible light .

1 is a cross-sectional view of a general transverse electric field type liquid crystal display device.
2 is a schematic cross-sectional view of a flexible liquid crystal display device according to a first embodiment of the present invention.
3A to 3C are cross-sectional views illustrating a schematic manufacturing process of a flexible liquid crystal display device according to a first embodiment of the present invention.
4A and 4B are graphs showing the UV transmittance in the color filter layer, respectively.
5 is a schematic cross-sectional view of a flexible liquid crystal display device according to a second embodiment of the present invention.
6 is a schematic cross-sectional view of a flexible liquid crystal display device according to a third embodiment of the present invention.
7 is a graph for explaining the UV transmittance by UV absorbing particles used in the present invention.
8A to 8C are cross-sectional views showing a schematic manufacturing process of a flexible liquid crystal display device according to a second embodiment of the present invention.

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

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

The flexible liquid crystal display according to the first embodiment of the present invention includes a first flexible substrate 110, a second flexible substrate 120 facing the first flexible substrate 110, A liquid crystal layer 130 disposed between the substrates 110 and 120 and a polymer barrier 190 for maintaining a distance between the first and second flexible substrates 110 and 120, that is, a cell gap.

On the first flexible substrate 110, a pixel electrode 170 and a common electrode 172 are alternately formed, and when a voltage is applied to them, a transverse electric field is generated to drive the liquid crystal.

A pixel region P is defined on the first flexible substrate 110 by intersecting a gate wiring (not shown) and a data wiring 152 with a gate insulating film 146 interposed therebetween. In each pixel region P, a thin film transistor Tr is formed and the pixel electrode 170 is connected to the thin film transistor Tr.

For example, the thin film transistor Tr includes a gate electrode 142, a gate insulating film 146 that covers the gate electrode 142, and a semiconductor layer 142 that overlaps the gate electrode 142 on the gate insulating film 146. [ Layer 150 and a source electrode 154 and a drain electrode 156 that are spaced apart from each other on the semiconductor layer 150.

The semiconductor layer 150 may be formed of an active layer made of intrinsic amorphous silicon and an ohmic contact layer made of impurity-doped amorphous silicon, ≪ / RTI >

Although the thin film transistor Tr has a bottom gate structure, it may have a top gate structure.

The gate electrode 142 is connected to the gate line and the source electrode 154 is connected to the data line 152. That is, the thin film transistor Tr is connected to the gate wiring and the data wiring 152.

A protective layer 160 having a drain contact hole 162 exposing a drain electrode 156 of the thin film transistor Tr is formed to cover the thin film transistor Tr and the data line 152, The electrode 170 is connected to the drain electrode 156 through the drain contact hole 162 on the protection layer 160. In addition, the common electrode 172 is alternately arranged on the passivation layer 160 with the pixel electrode 170.

The first flexible substrate 110 on which the above-described components are formed is collectively referred to as an array substrate.

On the second flexible substrate 120, a black matrix 182 for blocking light corresponding to the gate lines and the data lines 152 is formed. In other words, the black matrix 182 is in a lattice shape having the first opening 182a corresponding to the pixel region P.

The black matrix 182 has a second opening 182b corresponding to at least one of the gate line and the data line 152. That is, the second opening 182b corresponds to the polymer barrier rib 190 by being positioned at the edge of the pixel region P.

A color filter layer 184 is formed on the first opening 182a of the black matrix 182. [ The color filter layer 184 may include a red color filter pattern 184a, a green color filter pattern 184b, and a blue color filter pattern (not shown). The red color filter pattern 184a, the green color filter pattern 184b and the blue color filter pattern (not shown) are spaced apart from each other so that the second opening 182b of the black matrix 182 is exposed. An overcoat layer 186 is formed on the color filter layer 184.

The second flexible substrate 120 having the above-described structure is collectively referred to as a color filter substrate.

The first and second flexible substrates 110 and 120 are bonded together such that the color filter layer 184 faces the pixel electrode 170 and the common electrode 172. The first and second flexible substrates 110 And 120, the liquid crystal layer 130 is formed. The liquid crystal layer 130 includes liquid crystal molecules, a monomer and a photo initiator.

In addition, a polymer barrier rib 190 is formed to maintain a distance between the first and second flexible substrates 110 and 120, that is, a cell gap. The polymer barrier ribs 190 are positioned corresponding to the second openings 182b of the black matrix 182. When UV is applied to the second flexible substrate 120 as described later, UV is irradiated to the liquid crystal layer 130 through the second opening 182b of the black matrix 182, and the liquid crystal layer 130 ) Monomer polymerization reaction occurs. Accordingly, the polymer barrier ribs 190 are formed corresponding to the second openings 182b of the black matrix 182.

That is, after the liquid crystal layer 130 is formed between the first and second flexible substrates 110 and 120, UV is irradiated through the second flexible substrate 120 to form the polymer barrier 190 ). Accordingly, the polymer barrier ribs 190 are formed to have the same thickness as the distances between the first and second flexible substrates 110 and 120 in a bonded state, and the cell gap irregularity due to the conventional spacer formation can be prevented.

2 shows a transverse electric field type flexible liquid crystal display device in which a pixel electrode 170 and a common electrode 172 are alternately arranged on a protective layer 160. However, And may be a fringe field type flexible liquid crystal display device having one opening. In addition, the pixel electrode and the common electrode may be configured to have a plate shape and be formed on different flexible substrates to form a vertical electric field. In other words, the flexible liquid crystal display device of the present invention does not limit the electrode structure.

The protective layer 160 and the overcoat layer 186 may also be omitted.

Hereinafter, a manufacturing method of a flexible liquid crystal display device will be described with reference to FIGS. 3A to 3C, which are cross-sectional views illustrating a schematic manufacturing process of the flexible liquid crystal display device according to the first embodiment of the present invention.

First, as shown in FIG. 3A, an array substrate and a color filter substrate are formed, and the first and second flexible substrates 110 and 120 are bonded together with the liquid crystal layer 130 interposed therebetween.

At this time, the array substrate is in a state in which the first flexible substrate 110 is attached to the first carrier substrate 101, and the color filter substrate is in a state in which the second flexible substrate 120 is attached to the second carrier substrate 102 State.

The liquid crystal display device of the present invention is a flexible liquid crystal display device using flexible substrates 110 and 120, and for example, a flexible substrate such as polyimide is used.

However, the flexible substrate used for providing flexible characteristics is difficult to apply to a conventional manufacturing apparatus for a display device, which is a glass substrate to be processed because of its weak heat characteristic.

In order to overcome this problem, the flexible substrate is attached to one side of a carrier substrate such as a glass substrate so that the substrate can be transported. Then, a general display device manufacturing process is performed to complete a flexible display device have.

A thin film transistor Tr, a pixel electrode 170, and a common electrode 172 are formed on the first carrier substrate 101 and then the first flexible substrate 110 is attached. To form an array substrate.

A sacrificial layer (not shown) or the like is formed on the second carrier substrate 101 and then a second flexible substrate 120 is attached to the second flexible substrate 120. A black matrix 182, An overcoat layer 184 and an overcoat layer 186 are formed to form a color filter substrate.

Next, a structure shown in Fig. 3A is obtained by interposing a liquid crystal layer therebetween and attaching the first and second flexible substrates 110 and 120 together.

More specifically, on the first flexible substrate 110 attached to the first carrier substrate 101, a thin film transistor Tr and a gate electrode (gate electrode) And a wiring and a data wiring 152 are formed.

Next, a passivation layer 160 is formed to cover the thin film transistor Tr and the data line 152, and the passivation layer 160 is patterned through a mask process to expose the drain electrode 156 of the thin film transistor The drain contact hole 162 is formed.

Next, a transparent conductive material such as indium-tin-oxide (ITO) or indium-zinc-oxide (IZO) is deposited on the passivation layer 160, The pixel electrode 170 and the common electrode 172 are formed. As described above, the pixel electrode 170 is connected to the drain electrode 156 through the drain contact hole 162, and the common electrode 172 is alternately arranged with the pixel electrode 170.

On the other hand, on the second flexible substrate 120 attached to the second carrier substrate 102, a black metal material, a black organic material, or a black inorganic material capable of blocking light is deposited or applied, A black matrix 182 having a first opening portion 182a corresponding to the pixel region P and a second opening portion 182b corresponding to the gate wiring and the data wiring 156 is formed. The second opening 182b is a region through which UV passes to form the polymer barrier ribs 190.

Next, a red color filter pattern 184a, a green color filter pattern 184b, and a blue color filter pattern (not shown) are formed on the second flexible substrate 120 on which the black matrix 182 is formed, (184). As described above, the red color filter pattern 184a, the green color filter pattern 184b, and the blue color filter pattern (not shown) are spaced apart so that the second opening 182b of the black matrix 182 is exposed. do.

Since UV for forming the polymer partition wall (190 in FIG. 2) is irradiated through the second opening portion 182b, the color filter layer 184 prevents UV blocking through the second opening portion 182b to be.

Next, an overcoat layer 186 is formed on the color filter layer 184.

Since the steps of forming the array substrate and the step of forming the color filter substrate are performed independently, the order is not limited.

Next, the first and second flexible substrates 110 and 120 are bonded together, and the liquid crystal layer 130 is injected therebetween. Alternatively, after the liquid crystal layer 130 is formed on the first flexible substrate 110 or the second flexible substrate 120, the first flexible substrate 110 and the second flexible substrate 120 may be bonded together .

At this time, the liquid crystal layer 130 includes liquid crystal molecules, a monomer, and a photo initiator.

Although not shown, a seal pattern for preventing the leakage of the liquid crystal layer 130 is formed at the edges of the first and second flexible substrates 110 and 120.

3B, after the exposure mask M having the transmissive area TA corresponding to the second opening 182b of the black matrix 182 is positioned, the second flexible substrate 120 ). ≪ / RTI > The UV is irradiated to the liquid crystal layer 130 through the second opening 182b of the black matrix 182. [ As described above, since the liquid crystal layer 130 includes a monomer and a photo initiator, polymerization reaction of the monomer occurs by UV irradiation, and a columnar polymer partition 190 is formed corresponding to the region irradiated with UV . Since the polymer barrier ribs 190 are formed to have the same thickness as the distance between the first and second flexible substrates 110 and 120 in a bonded state, a uniform cell gap is obtained.

At this time, considering the polymerization reaction of the monomer in the liquid crystal layer 130 and the transmittance of the second flexible substrate 120, the UV has a wavelength of about 360 to 370 nm.

That is, the UV for the polymerization of the monomer is irradiated to the liquid crystal layer 130 through the second carrier substrate 102 and the second flexible substrate 120, and the second flexible substrate (not shown) made of polyimide 120) has a high absorption ratio with respect to the UV of the wavelength range other than 360 to 370 nm.

Therefore, in order to polymerize the monomer by UV, it is necessary to use the UV of the wavelength band capable of sufficiently transmitting the second flexible substrate 120, that is, UV of about 360 to 370 nm. For maximum transmittance, the wavelength of the UV may be 365 nm.

Next, as shown in FIG. 3C, the first and second carrier substrates 101 and 102 are laser-irradiated to release the first and second carrier substrates 101 and 102, Thereby forming a flexible liquid crystal display device.

As described above, the polymer barrier ribs 190 can be formed by irradiating ultraviolet light having a wavelength range of 360 to 370 nm through the second openings 182b of the black matrix 182. According to such a process, undesired A polymerization reaction occurs to cause a problem of driving failure or display quality deterioration.

Referring to FIGS. 4A and 4B, which are graphs showing the UV transmittance in the color filter layer, the red and blue color filter layers have a transmittance of about 6% and the green color filter layer has a transmittance of about 1.25% Transmittance.

In the green pixel region in which a green color filter layer having a low transmittance (1.25%) against UV at 360 to 370 nm wavelength band is formed, the monomer polymerization reaction hardly occurs. However, in the red pixel region having a high transmittance (6%) against UV at 360 to 370 nm wavelength band And the red and blue pixel regions in which the blue color filter layer is formed, polymerization reaction of the monomers occurs and impurities in the liquid crystal layer 130 are formed.

3B, even if the exposure mask M having the transmissive region TA is used only for the second opening portion 182 of the black matrix 182, the UV is prevented from diffracting the color filter layer 184 The liquid crystal layer 130 of the pixel region P is irradiated.

In the general exposure process, only the distance (gap G in FIG. 3B) at which the exposure mask is spaced apart needs to be considered, so that the diffraction phenomenon may not be a big problem. However, in the flexible liquid crystal display device, since the distance from the exposure mask M is increased by the carrier substrate 102 having a larger thickness (T, about 630 micrometers) than the flexible substrate 120, (P) is irradiated with UV light to cause a polymerization reaction of the monomer.

To solve such a problem, a flexible liquid crystal display device will be described.

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

The flexible liquid crystal display device according to the second embodiment of the present invention includes a first flexible substrate 210, a second flexible substrate 220 facing the first flexible substrate 210, a second flexible substrate 220 A color filter layer 284 formed on the first and second flexible substrates 210 and 220 and including UV-absorbing particles 285; a liquid crystal layer 230 disposed between the first and second flexible substrates 210 and 220; And a polymer barrier rib 290 for maintaining a distance between the flexible substrates 210 and 220, that is, a cell gap.

On the first flexible substrate 210, a pixel electrode 270 and a common electrode 272 are alternately formed and when a voltage is applied thereto, a transverse electric field is generated to drive the liquid crystal.

A pixel region P is defined on the first flexible substrate 210 by intersecting a gate wiring (not shown) and a data wiring 152 with a gate insulating film 246 interposed therebetween. A thin film transistor Tr is formed in each of the pixel regions P and the pixel electrode 270 is connected to the thin film transistor Tr.

For example, the thin film transistor Tr includes a gate electrode 242, a gate insulating film 246 covering the gate electrode 242, and a semiconductor layer 246 overlapping the gate electrode 242 on the gate insulating film 246. [ Layer 250 and a source electrode 254 and a drain electrode 256 that are spaced apart from each other on the semiconductor layer 250.

The gate electrode 242 is connected to the gate wiring and the source electrode 254 is connected to the data wiring 252. That is, the thin film transistor Tr is connected to the gate wiring and the data wiring 252.

A protective layer 260 having a drain contact hole 262 for exposing the drain electrode 256 of the thin film transistor Tr is formed to cover the thin film transistor Tr and the data line 252, The electrode 270 is connected to the drain electrode 256 through the drain contact hole 262 on the passivation layer 260. The common electrode 272 is alternately arranged on the passivation layer 260 with the pixel electrode 270.

The first flexible substrate 210 on which the above-described components are formed is collectively referred to as an array substrate.

On the other hand, on the second flexible substrate 220, a black matrix 282 for blocking light corresponding to the gate lines and the data lines 252 is formed. In other words, the black matrix 282 is in a lattice shape having a first opening 282a corresponding to the pixel region P.

In addition, the black matrix 282 has a second opening 282b corresponding to at least one of the gate wiring and the data wiring 252. That is, the second opening 282b corresponds to the polymer barrier rib 290 by being positioned at the edge of the pixel region P.

A color filter layer 284 is formed in the first opening 282a of the black matrix 282. [ The color filter layer 184 may include a red color filter pattern 284a, a blue color filter pattern 284b, and a green color filter pattern (not shown). The red color filter pattern 284a, the blue color filter pattern 284b, and the green color filter pattern (not shown) are formed spaced apart to expose the second opening 282b of the black matrix 282.

The red color filter pattern 284a includes a red pigment (not shown) and UV absorbing particles 285. In addition, the blue color filter patterns 284a and 284b include a red pigment (not shown) and UV absorbing particles 285. The UV-absorbing particles 285 have a first absorption rate with respect to UV of 360 to 370 nm wavelength and a second absorption rate with respect to visible light that is smaller than the first absorption rate.

As described above, the UV for forming the polymer partition walls is transmitted through the red and blue color filter patterns to cause the polymerization reaction of the monomers in the pixel area, and the red and blue color filter patterns 284a and 284b are formed by the UV absorption By including the particles 285, such a problem can be prevented.

In other words, the typical red and blue color filter patterns have a transmittance of about 6% for UV at a wavelength of 360 to 370 nm, wherein the UV absorbing particles 285 are used to filter the red and blue color filter patterns 284a and 284b Is reduced to a level similar to the transmittance (1.25%) of the green color filter pattern to prevent the monomer polymerization in the pixel region (P).

At this time, the first absorption rate of the UV absorbing particles 285 with respect to the UV of 360 to 370 nm wavelength is 75% or more, and the red and blue color filter patterns 284a, 284b including the UV absorbing particles 285 The transmittance of ~ 370 nm wavelength UV is 1.25% or less.

On the other hand, a green color filter pattern (not shown) may further include the UV absorbing particles 285 to further lower the transmittance to UV of a wavelength of 360 to 370 nm.

That is, in the second embodiment of the present invention, since the color filter layer 284 includes the pigment and the UV absorbing particles 285, the monomer polymerization problem in the pixel region P that can occur in the flexible liquid crystal display device of the first embodiment .

Referring again to FIG. 5, an overcoat layer 286 is formed on the color filter layer 284.

The second flexible substrate 220 having the above-described structure is collectively referred to as a color filter substrate.

The first and second flexible substrates 210 and 220 are bonded together such that the color filter layer 284 faces the pixel electrode 270 and the common electrode 272. The first and second flexible substrates 210 And 220, the liquid crystal layer 230 is formed. The liquid crystal layer 230 includes liquid crystal molecules, a monomer, and a photo initiator.

In addition, a polymer barrier rib 290 is formed to maintain a distance between the first and second flexible substrates 210 and 220, that is, a cell gap. The polymer barrier ribs 290 are positioned corresponding to the second openings 282b of the black matrix 282. When UV is applied to the second flexible substrate 220 as described later, UV is irradiated to the liquid crystal layer 230 through the second opening 282b of the black matrix 282, and the liquid crystal layer 230 ) Monomer polymerization reaction occurs. Accordingly, the polymer barrier ribs 290 are formed corresponding to the second openings 282b of the black matrix 282.

That is, after the liquid crystal layer 230 is formed between the first and second flexible substrates 210 and 220, UV is irradiated through the second flexible substrate 220 to form the polymer barrier ribs 290 ). Therefore, the polymer barrier ribs 290 are formed to have the same thickness as the distance between the first and second flexible substrates 210 and 220 in the coalesced state, thereby preventing the cell gap unevenness due to the conventional spacer formation.

As described above, in the flexible liquid crystal display device according to the second embodiment of the present invention, since the color filter layer 284 includes the UV absorbing particles 285, the UV rays for forming the barrier ribs 290 Is sufficiently blocked with respect to the pixel region (P). Therefore, undesired monomer polymerization reaction in the pixel region P can be prevented from occurring.

6 is a schematic cross-sectional view of a flexible liquid crystal display device according to a third embodiment of the present invention.

6, a flexible liquid crystal display according to a third embodiment of the present invention includes a first flexible substrate 310, a second flexible substrate 320 facing the first flexible substrate 310, A UV absorbing material layer 380 formed on the second flexible substrate 320 and corresponding to the pixel region P and a liquid crystal layer 330 positioned between the first and second flexible substrates 310 and 320, And a polymer barrier wall 390 for maintaining a distance between the first and second flexible substrates 310 and 320, that is, a cell gap.

The flexible liquid crystal display device according to the third embodiment of the present invention differs from the flexible liquid crystal display device of the second embodiment shown in Fig. 5 and the UV absorbing material layer 380. Fig.

That is, in the flexible liquid crystal display device of the second embodiment, the UV absorbing particles 285 are included in the color filter layer 284, whereas in the flexible liquid crystal display device of the third embodiment, the UV absorbing material layer 380 is formed separately Layer.

As shown in FIG. 6, the UV absorbing material layer 380 is formed corresponding to the first opening 282a of the black matrix 282. That is, the UV absorbing material layer 380 is formed corresponding to the pixel region P.

The UV absorbing material layer 380 has the same function as the UV absorbing particles 285 of FIG. That is, the UV for forming the polymer partition wall 390 is incident on the pixel region P through the color filter layer 284, thereby preventing the polymerization reaction of the monomer in the pixel region P from occurring.

The UV absorber layer 380 has a first absorptance for UV at a wavelength of 360 to 370 nm and a second absorptivity for visible light that is less than the first absorptance.

The first absorption rate of the UV absorbing material layer 380 to UV at a wavelength of 360 to 370 nm is 75% or more. Therefore, the transmittance of 360 to 370 nm wavelength UV in the red and blue pixel regions is 1.25% or less.

That is, as described above, the red and blue color filter patterns 384a and 384b have a transmittance of about 6% with respect to UV at a wavelength of 360 to 370 nm, and a UV absorbing material layer 380 is formed in the red and blue pixel regions , The transmittance of 360 to 370 nm wavelength UV in the red and blue pixel regions is 1.25% or less. Therefore, the polymerization reaction of the monomer generated by irradiation of UV with the pixel region P can be suppressed.

The UV absorbing material layer 380 is formed not only in the red and blue pixel regions P but also in the green pixel region P so that the UV transmittance in the green pixel region P can be further reduced.

6 shows that the UV absorbing material layer 380 is positioned between the second flexible substrate 320 and the color filter layer 384 but the UV absorbing material layer 380 is located between the second flexible substrate 320 and the color filter layer 384. [ There is no limitation in its position as long as it is located between the layers 330.

That is, the UV absorbing material layer 380 may be located between the color filter layer 384 and the overcoat layer 386, or between the overcoat layer 386 and the liquid crystal layer 330.

In the flexible liquid crystal display device according to the third embodiment of the present invention, since the UV absorbing material layer 380 is included, the UV for forming the barrier ribs 390 is sufficiently blocked with respect to the pixel region P . Therefore, undesired monomer polymerization reaction in the pixel region P can be prevented from occurring.

As described above, the UV absorbing particles constituting the UV absorbing particles (285 in FIG. 5) or the UV absorbing material layer (380 in FIG. 6) have a high absorption ratio with respect to UV of 360 to 370 nm wavelength and a low Absorption rate.

The UV absorbing particles may be a material represented by the following formula.

7, which is a graph for explaining the UV transmittance by the UV absorbing particles represented by the above formula, the UV absorbing particles have an absorption rate of 75% or more with respect to UV of a wavelength of about 360 to 370 nm and have a very low transmittance Respectively.

Therefore, since the transmittance of the visible light is maintained while preventing the UV from entering the liquid crystal layer in the pixel region, generation of impurities in the liquid crystal layer in the pixel region can be suppressed without lowering the luminance.

8A to 8C are cross-sectional views showing a schematic manufacturing process of a flexible liquid crystal display device according to a second embodiment of the present invention.

First, as shown in FIG. 8A, the array substrate and the color filter substrate are formed, and the first and second flexible substrates 210 and 220 are bonded together with the liquid crystal layer 230 interposed therebetween.

At this time, the array substrate is in a state in which the first flexible substrate 210 is attached on the first carrier substrate 201, and the color filter substrate is in the state in which the second flexible substrate 220 is attached on the second carrier substrate 202 State.

The liquid crystal display device of the present invention is a flexible liquid crystal display device using flexible substrates 210 and 220, for example, a flexible substrate such as polyimide is used.

As described above, since the flexible substrate is weak against heat, the flexible substrate is attached to one surface of a carrier substrate such as a glass substrate, and then the display device manufacturing process proceeds.

A thin film transistor Tr, a pixel electrode 270, and a common electrode 272 are formed on the first carrier substrate 201, and then a first flexible substrate 210 is attached. To form an array substrate.

A sacrificial layer (not shown) or the like is formed on the second carrier substrate 201 and then a second flexible substrate 220 is attached to the second flexible substrate 220. A black matrix 282, A color filter substrate 284 and an overcoat layer 286 are formed to form a color filter substrate.

At this time, the color filter layer 284 includes UV absorbing particles 285. For example, the red color filter pattern 284a may comprise a red pigment and UV absorbing particles 285.

Next, a liquid crystal layer is interposed therebetween and the first and second flexible substrates 210 and 220 are bonded together, resulting in the structure shown in FIG. 8A. At this time, the liquid crystal layer 130 includes liquid crystal molecules, a monomer, and a photo initiator.

Next, UV is irradiated through the second carrier substrate 202 as shown in FIG. 8B. The UV is irradiated to the liquid crystal layer 230 through the second opening 282b of the black matrix 282. [ As described above, since the liquid crystal layer 230 includes a monomer and a photoinitiator, polymerization reaction of the monomer occurs by UV irradiation, and a columnar polymer barrier rib 290 is formed corresponding to the region irradiated with UV . Since the polymer barrier ribs 290 are formed to have the same thickness as the distance between the first and second flexible substrates 210 and 220 in a coupled state, a uniform cell gap is obtained.

At this time, considering the polymerization reaction of the monomer in the liquid crystal layer 230 and the transmittance of the second flexible substrate 220, the UV has a wavelength of about 360 to 370 nm.

Unlike the first embodiment of the present invention, in the second embodiment, an exposure mask (M in FIG. 3B) is not required and an unwanted monomer polymerization in the pixel region P does not occur.

In other words, since the color filter layer 284 includes the UV absorbing particles 285, no UV is irradiated to the liquid crystal layer 230 of the pixel region P even if UV is applied to the pixel region P without an exposure mask .

Next, as shown in Fig. 8C, the first and second carrier substrates 201 and 202 are laser-irradiated to release the first and second carrier substrates 201 and 202, Thereby forming a flexible liquid crystal display device.

On the other hand, the method for separating the first and second carrier substrates 201 and 202 is not limited to laser irradiation.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. It can be understood that

110, 210: first flexible substrate 120, 220: second flexible substrate
130, 230: liquid crystal layer 152, 252: data line
170, 270: pixel electrode 172, 272: common electrode
182, 282: black matrices 182a, 282a:
182b, 282b: second openings 184, 284: color filter layer
285: UV absorbing particle 380: UV absorbing material layer
190, 290: Polymer barrier

Claims (10)

A first flexible substrate on which a plurality of pixel regions are defined;
A second flexible substrate facing the first flexible substrate;
A pixel electrode located on the first flexible substrate;
A common electrode which is disposed on one of the first and second flexible substrates and forms an electric field with the pixel electrode;
A black matrix disposed on the second flexible substrate and having a first opening corresponding to each of the pixel regions and a second opening corresponding to the edge of the pixel region;
A color filter layer positioned on the second flexible substrate and corresponding to the first opening and including UV absorbing particles;
A liquid crystal layer disposed between the first and second flexible substrates and including liquid crystal molecules and a monomer;
And a polymer barrier wall positioned corresponding to the second opening and maintaining a distance between the first and second flexible substrates,
Wherein the polymer barrier is formed by polymerization of the monomer by UV incident through the second opening.
The method according to claim 1,
Wherein the UV-absorbing particles have a first transmittance with respect to the UV and a second transmittance with respect to visible light that is smaller than the first transmittance.
3. The method of claim 2,
Wherein the UV has a wavelength of 360 to 370 nm.
The method of claim 3,
Wherein the UV absorbing particles have an absorption rate of 75% or more with respect to the UV.
The method of claim 3,
Wherein the second flexible substrate is made of polyimide.
Attaching a first flexible substrate on which a plurality of pixel regions are defined on a first carrier substrate;
Forming a pixel electrode on the first flexible substrate;
Attaching a second flexible substrate on a second carrier substrate;
Forming a black matrix having a first opening corresponding to the pixel region and a second opening corresponding to an edge of the pixel region on a second substrate;
Forming a color filter layer corresponding to the first opening on the second flexible substrate using a color filter material including a pigment and UV absorbing particles;
Forming a common electrode on any one of the first flexible substrate and the second flexible substrate;
Attaching the first flexible substrate and the second flexible substrate to each other with a liquid crystal molecule and a liquid crystal layer including a monomer interposed therebetween;
Irradiating the second carrier substrate with UV light to form a polymer barrier wall corresponding to the second opening by the polymerization reaction of the monomer;
Separating the first carrier substrate and the second carrier substrate from the first flexible substrate and the second flexible substrate
Wherein the flexible liquid crystal display device is a flexible liquid crystal display device.
The method according to claim 6,
Wherein the UV absorbing particles have a first transmittance with respect to the UV and a second transmittance with respect to a visible ray that is smaller than the first transmittance.
8. The method of claim 7,
Wherein the UV has a wavelength of 360 to 370 nm.
9. The method of claim 8,
Wherein the UV absorbing particles have an absorption rate of 75% or more with respect to the UV.
9. The method of claim 8,
Wherein the second flexible substrate is made of polyimide.

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