KR20060062094A - Color filter substrate for liquid crystal display device and method of fabricating the same - Google Patents

Abstract

In general, when manufacturing a color filter substrate by thermal transfer, first, a black matrix is formed on each subpixel boundary region on the substrate, and then a color filter substrate is completed by transferring a color filter layer of each color included in the transfer film onto the substrate. Since the formation of the black matrix is formed through a photolithography process, the formation process is complicated, and since the equipment required for forming the black matrix, for example, deposition equipment and exposure apparatus, is required, There is little benefit in the initial equipment investment compared with the production of the color filter using the pigment dispersion method.

In manufacturing a color filter substrate for a liquid crystal display device by a thermal transfer method according to the present invention, a color filter substrate having a structure replacing the black matrix by forming a thick layer of each color filter pattern overlapping a boundary area of each subpixel, and a manufacturing method thereof To provide.

Therefore, the manufacturing process can be simplified by omitting the black matrix, and the cost can be reduced since the initial investment of the equipment required for forming the black matrix is not required.

Thermal Transfer, Color Filter Substrate, Black Matrix

Description

Color filter substrate for liquid crystal display device and manufacturing method thereof {Color filter substrate for liquid crystal display device and method of fabricating the same}             

1A to 1I are cross-sectional views of a manufacturing process of a color filter substrate for a liquid crystal display device by a conventional thermal transfer method.

2A to 2I are cross-sectional views of a process for manufacturing a color filter substrate for a liquid crystal display device by a thermal transfer method according to the present invention;

<Description of the symbols for the main parts of the drawings>

130 substrate 140 first red color filter pattern

141: second red color filter pattern 142: first green color filter pattern

143: second green color filter pattern 144: first blue color filter pattern

145: second blue color filter pattern 146: planarization film

148: common electrode

R, G, B: Red, Green, Blue Subpixel Area

BA1, BA2, BA3: boundary area between each subpixel

The present invention relates to a color filter substrate for a liquid crystal display device and a method for manufacturing the same, and more particularly, to a color filter substrate and a method for manufacturing the same by a thermal transfer method.

Recently, with the rapid development of the information society, the necessity of flat panel displays having excellent characteristics such as thinning, light weight, and low power consumption has emerged. Among them, liquid crystal displays have a resolution, It is excellent in color display and image quality, and is actively applied to notebooks and desktop monitors.

In general, a liquid crystal display device arranges two substrates on which one electrode is formed so as to face a surface on which the electrodes are formed, injects a liquid crystal between the two substrates, and bonds the voltages to electrodes formed on the substrates. By moving the liquid crystal molecules by the electric field generated by the application, the image is expressed by the transmittance of light that varies accordingly.

The lower substrate of the liquid crystal display is formed of an array substrate including a thin film transistor for applying a signal to a pixel electrode, and the upper substrate is a substrate including a common electrode and a color filter layer. The color filter layer is a red, green, or blue color. The patterns are arranged repeatedly in sequence.

At this time, the formation of the color filter pattern on the color filter substrate, which is the upper substrate, is generally used in the pigment dispersion method is excellent in fineness and good reproducibility. However, the manufacturing process of the color filter substrate by the pigment dispersion method is a long and complicated manufacturing process line because it repeats the manufacturing process, such as coating, exposure, development, curing of the color resist.

Therefore, in order to solve the problem of manufacturing the color filter substrate by the pigment dispersion method described above, a method of manufacturing the color filter substrate by the thermal transfer method has been proposed as a new method.

In the thermal transfer method, a color filter transfer film formed of a color filter layer, a photothermal conversion layer, and a support film is brought into close contact with a substrate, and a color filter layer on a color filter transfer film is transferred onto a substrate by irradiating a light source such as a laser to the transfer film. How to form.

Here, the general color filter transfer film used for the thermal transfer method will be briefly described.

The color filter transfer film consists of three layers. That is, it is formed of a support film made of a material having excellent light transmittance and a light to heat convert (LTHC) for converting light energy into heat energy over the support film and a color filter layer which is a transfer layer over the light heat change layer.

In this case, the support film is composed of a polymer film, such as polyester, polyethylene, a colorless transparent material to support the color filter layer and the light-heat conversion layer as well as to pass the laser light to the light-heat conversion layer, the light-heat conversion layer is Since the light incident through the laser must be converted into thermal energy, it is composed of a material having high photothermal conversion ability. In addition, the color filter layer is composed of a material layer to be transferred, typically composed of a red, green, blue pigment.

The manufacturing method of the color filter substrate by the thermal transfer method using the above-mentioned color filter transfer film is demonstrated with reference to FIGS. 1A-1I.

First, as shown in FIG. 1A, a black matrix layer 31 is formed by depositing a metal material, for example, chromium (Cr) or chromium oxide (CrOx), on a transparent substrate 30 to the entire surface, and forming the black matrix. The photoresist is applied to the entire surface over the layer 31 to form the photoresist layer 32.

Subsequently, a mask 90 having a light transmitting region and a blocking region is positioned on the photoresist layer 32 and subjected to exposure.

Next, as illustrated in FIGS. 1B and 1C, the exposed photoresist layer (32 of FIG. 1A) is developed to form a photoresist pattern 33, and the black matrix exposed to the outside of the photoresist pattern 33. The layer 32 is etched to form a black matrix 35 with openings. In this case, although the photoresist used to selectively etch the black matrix layer 32 is shown to use a negative type having a characteristic in which light-receiving portions remain during development, a positive type having the opposite characteristic ( It is also possible to pattern the black matrix layer using a positive photoresist.

Next, as shown in FIG. 1D, the photoresist pattern (33 in FIG. 1C) remaining on the black matrix 35 is removed by stripping or ashing.

Next, as illustrated in FIG. 1E, the substrate on which the black matrix 35 is formed may be formed on the first color filter transfer film 10 including the support film 10a, the photothermal conversion layer 10b, and the color filter layer 10c. The color filter layer 10c is positioned to correspond to the substrate 30 on which the black matrix 35 is formed at a predetermined interval from 30, and then the color of the substrate 30 and the first color filter transfer film 10 is disposed. The filter layer 10c is brought into close contact.

Next, as shown in FIG. 1F, a substrate including the adhered first color filter transfer film 10 is positioned in a laser irradiation apparatus, and a stage on which the laser head 50 or the substrate 30 is located (not shown). ) And the laser is irradiated only to the region A, which is a portion where the color filter pattern should be formed on the first color filter transfer film 10 positioned on the substrate 30.

In the first color filter transfer film 10 irradiated with the laser light, the photothermal conversion layer 10b in the first color filter transfer film 10 absorbs the light emitted by the irradiated laser to heat the light energy. The color filter layer 10c is transferred from the photothermal conversion layer 10b onto the substrate 30 by the heat by dissipating heat to the color filter layer 10c in exchange for energy.

Next, as shown in FIG. 1G, after the laser irradiation, the first color filter transfer film (10 of FIG. 1F) is removed, and transferred by thermal transfer from the first color filter transfer film (10 of FIG. 1F). The first color filter pattern 40 is formed on the substrate 30 by the color filter layer (10c of FIG. 1F).

Next, as shown in FIG. 1H, the second color and the third color are repeatedly performed by using the second color filter transfer film and the third color filter transfer film in the manner described above with reference to FIGS. 1E to 1G. And third color filter patterns 42 and 44 on the substrate 30.

Subsequently, the substrate 30 having the first, second and third color filter patterns 40, 42, and 44 formed thereon may be formed using a curing apparatus such as an oven in which an atmosphere of 200 ° C. to 300 ° C. is maintained. (40, 42, 44) is cured.

Next, as shown in FIG. 1I, the color filter patterns 40, 42, and 44 are disposed on the color filter patterns 40, 42, 44 on the substrate 30 on which the curing process of the color filter patterns 40, 42, 44 is completed. The planarization film 46 is formed to protect 42 and 44 and to eliminate the step. Thereafter, an indium tin oxide (ITO) or indium zinc oxide (IZO), which is a transparent conductive material, is deposited on the planarization layer 46 to form a common electrode 48, thereby completing a color filter substrate.

In the above-described color filter substrate, the black matrix 35 is formed between the red, green, and blue color filter patterns 40, 42, and 44 to form a color separation between the color filter patterns and to form a liquid crystal display device. As another element, it is formed to block abnormal light caused by the liquid crystal driving abnormally on the data wiring and the gate wiring on the array substrate corresponding to the color filter substrate, and typically has an OD (optical density) value of 4 or more. It is formed by using a metal material of To form such a black matrix requires a photolithography process as described above.

Therefore, in order to form the black matrix, a material for forming the black matrix is deposited, and a series of processes such as exposure and development by a photolithography process are performed, and thus the formation process is complicated, and an example of equipment necessary for forming the black matrix is required. For example, since the deposition equipment, the exposure apparatus, and the like are required, the initial investment cost for the manufacturing is not much advantageous in the initial equipment investment compared with the production in which the color filter using the pigment dispersion method is formed.

An object of the present invention is to provide a color filter substrate that can prevent light leakage while eliminating the process of forming a black matrix, which is devised to solve the above-described conventional problems.

In addition, another object of the present invention is to provide a manufacturing method of a color filter substrate which can save the initial investment cost of an exposure apparatus or the like by omitting the patterning process by the photolithography method.

According to an aspect of the present invention, there is provided a color filter substrate for a liquid crystal display device, comprising: a substrate in which red, green, and blue colors are sequentially repeated, and a boundary region having a predetermined width between the subpixels is defined; A first color filter pattern of red, green, and blue which is sequentially repeated for each subpixel and has a first thickness; And a second color filter pattern having a second thickness in the boundary region and formed by overlapping red, green, and blue.

In addition, a planarization film covering the red, green, and blue color filter patterns and the overlapped color filter pattern and having a third thickness on the front surface is further configured, and a common electrode is further configured on the front surface of the planarization film.

In addition, the first thickness is preferably 1 μm to 2 μm, the second thickness is 3 μm to 6 μm, and the third thickness is 3 μm to 6 μm.

A method of manufacturing a color filter substrate for a liquid crystal display according to the present invention includes a red color filter layer on a substrate on which red, green, and blue subpixels which are sequentially repeated, and boundary regions having a predetermined width between the subpixels are defined. (A) contacting the color filter transfer film; (B) transferring the red color filter layer to the substrate by irradiating a laser onto the first color filter transfer film adhered to the substrate corresponding to the red subpixel and a boundary area; (C) forming first and second red color filter patterns on the red subpixel and the boundary area by removing the first color filter transfer film from the substrate; Repeatingly applying steps (a) to (c) to the second and third color filter transfer films each including the green and blue color filter layers, respectively, the first green and the first blue color corresponding to the green and blue subpixels. (D) forming a filter pattern, and forming a second green color filter pattern and a second blue color filter pattern overlapping the second red color filter pattern in the boundary region.

In this case, after step (d), the method may further include forming a planarization layer on the entire surface of each color filter pattern, and further comprising forming a common electrode on the planarization layer.

In addition, the step (c) further comprises the step of curing the red, green or blue color filter pattern formed by transferring from the transfer film onto the substrate.

Hereinafter, a method of manufacturing a color filter substrate by a thermal transfer method according to an embodiment of the present invention will be described with reference to the accompanying drawings.

2A to 2I are sectional views of the manufacturing process showing the manufacturing of the color filter substrate by the thermal transfer method according to the present invention.

First, as shown in FIG. 2A, the support film 110a, the photothermal conversion layer 110b, and the color filter layer are disposed on the transparent substrate 130 on which the first to third color subpixel regions R, G, and B are defined. After positioning the first color filter transfer film (110c) consisting of (110c), the color filter layer (110c) of the first color filter transfer film 110 by using a transfer device having a transfer roll to the substrate 130 Close contact to avoid bubbles.

At this time, the color filter layer 110c in the first color filter transfer film 110 may be any color among red, green, and blue, but for convenience of description, in the present embodiment, the color filter layer in the first color filter transfer film 110 is used. It is assumed that 110c is a red color filter layer 110c.

Next, as illustrated in FIG. 2B, a laser scan is performed on the substrate 130 on which the first color filter transfer film 110 including the red color filter layer 110c is in close contact with the laser irradiation apparatus 170. As a result, on the transfer film 110 corresponding to the red subpixel area R in which the red color filter pattern is to be formed and the boundary BA1, BA2, BA3 having a predetermined width of each subpixel R, G, and B, respectively. Irradiate the laser.

In this case, within the first color filter transfer film 110 corresponding to the laser irradiated area, that is, the red subpixel area R and the boundary areas BA1, BA2, and BA3 of each subpixel R, G, and B. The photothermal conversion layer 110b converts the light energy of the irradiated laser into thermal energy, and emits the converted heat to the red color filter layer 110c, thereby providing a red color filter layer adhered to the photothermal conversion layer 110b. The 110c is separated from the photothermal conversion layer 110b and transferred to the substrate 130 to be firmly fixed.

 Next, as shown in FIG. 2C, the first color filter transfer film (110 of FIG. 2B) irradiated with a laser is removed from the substrate 130. In this case, since the red color filter layer (110c of FIG. 2B) of the laser regions R, BA1, BA2, and BA3 is supplied with heat from the photothermal conversion layer (110b of FIG. 2B), it is firmly fixed on the substrate 130. When the transfer film (110 of FIG. 2B) is removed from the substrate 130, the transfer film (110 of FIG. 2B) remains on the substrate 130, and the first red color filter pattern 140 and each of the first red color filter pattern 140 are disposed on the red subpixel region R on the substrate 130. A second red color filter pattern 141 having a predetermined width is formed in the boundary areas BA1, BA2, and BA3 of the subpixel.

On the other hand, in the red color filter layer 110c of the regions G and B, which are not irradiated with laser, light is not supplied to the photothermal conversion layer (110b of FIG. 2B) corresponding to the regions G and B. It does not occur to maintain a state adhered to the photothermal change layer (110b of FIG. 2b) on the transfer film (110 of FIG. 2b), and is not fixed to the substrate 130, the photothermal conversion layer (110b of FIG. 2b) It is removed in the state adhered to.

Thereafter, the first and second red color filter patterns 140 and 141 are heated by heating the substrate 130 on which the first and second red color filter patterns 140 and 141 are formed to an appropriate temperature in a curing apparatus such as an oven. Harden. In this case, the thickness of the first and second red color filter patterns 140 and 141 in the cured state is preferably 1 μm to 2 μm.

Next, as shown in FIG. 2D, a color different from the color filter layer in the first color filter transfer film on the substrate 130 on which the first and second red color filter patterns 140 and 141 are formed (for convenience of description below). The second color filter transfer film 111 having the color filter layer 111c of green), and the green color filter layer 111c of the second color filter transfer film 111 through a transfer device having a transfer roll. ) Is brought into contact with the substrate 130 and closely adhered so as not to generate bubbles.

Next, as shown in FIG. 2E, the laser irradiation apparatus 170 is disposed on the substrate 130 on which the second color filter transfer film 111 is in close contact, more precisely, on the second color filter transfer film 111. Perform a laser scan. In this case, the second color filter transfer film 111 corresponding to an area where a green color filter pattern is to be formed during the laser scanning, that is, a boundary area BA1, BA2, BA3 between the green subpixel area G and each subpixel. Only the laser is irradiated.

Next, as shown in FIG. 2F, after the laser scanning is performed, the second color filter transfer film 111 is removed from the substrate 130, where the laser is irradiated (G, BA1, BA2, BA3). The green color filter layer 111c in the second color filter transfer film 111 corresponding to the first color filter pattern 142 is transferred to the substrate 130 in the green subpixel area G on the substrate 130. The second green color filter pattern 143 is formed to overlap the second red color filter pattern 141 in the boundary areas BA1, BA2, and BA3 of each subpixel. Thereafter, the first and second green color filter patterns 142 and 143 are cured by heating the substrate 130 on which the first and second green color filter patterns 142 and 143 are formed in a curing apparatus. In this case, the cured first and second green color filter patterns 142 and 143 may be formed to have a thickness of 1 μm to 2 μm.

Next, as shown in FIG. 2G, the first, second red and green color filter patterns 140, 141, and 142, 143 are formed on the substrate 130 on which the first and second green color filter patterns 142 and 143 are formed. Heat transfer is also performed on the third color filter transfer film (not shown) in the same manner as the method of forming a)) to transfer the first blue color filter pattern 144 to the blue subpixel area B on the substrate 130. At the same time, a second blue color filter pattern 145 is formed by overlapping the second green color filter pattern 143 on the boundary areas BA1, BA2, and BA3 of each subpixel. Thereafter, the substrate on which the first and second green color filter patterns are formed is cured using a curing device to cure the first and second green color filter patterns on the substrate. In this case, the thickness of the cured first and second green color filter patterns 144 and 145 on the substrate is preferably 1 μm to 2 μm.

Next, as illustrated in FIG. 2H, first red, green, and blue color filter patterns 140, 142, and 144 are formed in each of the subpixel regions R, G, and B, respectively, and the boundary of each subpixel is formed. A transparent organic material, for example, photo acryl, is disposed on the front surface of the substrate 130 on which the second red, green, and blue color filter patterns 141, 143, and 145 are overlapped in the areas BA1, BA2, and BA3. It is applied to form a planarization layer 146. In this case, the planarization layer 146 is formed sufficiently thicker than the heights of the second red, green, and blue color filter patterns 141, 143, and 145 formed by overlapping the subpixel boundary areas BA1, BA2, and BA3. It is preferably formed so as to cover the second red, green, blue color filter pattern (141, 143, 145) of the overlapped state, the thickness satisfying this is preferably 3㎛ to 6㎛. .

Next, as shown in FIG. 2I, a color conductive substrate is completed by forming a common electrode 148 by depositing a transparent conductive material such as ITO on the entire surface of the substrate 130 on which the planarization layer 146 is formed.

In this case, the above-described embodiment shows that the red, green, and blue color filter patterns are formed after the respective red, green, and blue color filter patterns are formed, but the red, green, and blue color filter patterns are all formed on the substrate. After forming, the red, green, and blue color filter patterns may be cured by performing one hardening process.

The color filter substrate for the liquid crystal display device having the structure as described above has a thickness three times thicker than the first red, green, and blue color filter patterns formed in each subpixel at the boundary of each subpixel, and the second red, green, and blue colors. As the color filter patterns are overlapped, the second red, green, and blue color filter patterns of the overlapped shape serve as a black matrix to prevent light leakage. In this case, the second red, green, and blue color filter patterns of the overlapped form are displayed in black because red, green, and blue are combined at the same ratio.

Therefore, when light passes through the region from the bottom, it is recognized as black, which is the same as blocking light, and thus has the same effect as forming a black matrix that serves to block the conventional light.

In the present invention, in forming a color filter pattern on a transparent substrate using a color filter transfer film by thermal transfer method, a black matrix is formed by superimposing red, green, and blue color filter patterns on the boundary of each subpixel. By replacing it, there is an effect of simplifying the color filter substrate manufacturing process using the thermal transfer method.

In addition, it is possible to reduce the initial equipment investment cost for the equipment for forming the black matrix by omitting the formation of the black matrix.

Claims (10)

A substrate in which red, green and blue colors are sequentially repeated, and a boundary area having a predetermined width between the subpixels is defined; A first color filter pattern of red, green, and blue which is sequentially repeated for each subpixel and has a first thickness; A second color filter pattern having a second thickness in the boundary region and formed by overlapping red, green, and blue colors; Color filter substrate for a liquid crystal display device comprising a. The method of claim 1, And a planarization film having a third thickness on the front surface of the red, green, and blue color filter patterns and the overlapping color filter pattern. The method of claim 2, And a common electrode further formed on the entire surface of the planarization layer. The method of claim 1, The first thickness is 1㎛ 2㎛ color filter substrate for a liquid crystal display device. The method of claim 1, And a second thickness of 3 μm to 6 μm. The method of claim 2, And a third thickness of 3 μm to 6 μm. (A) contacting a first color filter transfer film including a red color filter layer on a substrate in which red, green, and blue subpixels which are sequentially repeated, and a boundary region having a predetermined width between the subpixels are defined; (B) transferring the red color filter layer to the substrate by irradiating a laser onto the first color filter transfer film adhered to the substrate corresponding to the red subpixel and a boundary area; (C) forming first and second red color filter patterns on the red subpixel and the boundary area by removing the first color filter transfer film from the substrate; Repeatingly applying steps (a) to (c) to the second and third color filter transfer films each including the green and blue color filter layers, respectively, the first green and the first blue color corresponding to the green and blue subpixels. (D) forming a filter pattern, and forming a second green color filter pattern and a second blue color filter pattern overlapping the second red color filter pattern in the boundary region. Method of manufacturing a color filter substrate for a liquid crystal display device comprising a. The method of claim 7, wherein And forming a planarization film on the entire surface of the color filter pattern after the step (d). The method of claim 8, A method of manufacturing a color filter substrate for a liquid crystal display, further comprising forming a common electrode on the planarization layer. The method of claim 7, wherein And after the step (c), curing the red, green or blue color filter pattern formed by transferring the transfer film from the transfer film onto the substrate.

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