KR20070079879A - Manufacturing method of black matrix for color filters - Google Patents

Abstract

A method for producing a black matrix for color filters is disclosed. According to the disclosed method of manufacturing a black matrix, forming a light blocking layer made of an organic material having a repulsive force against ink on a surface of a transparent substrate, forming a black matrix by patterning the light blocking layer, and forming a photomask on an upper surface of the black matrix. And irradiating ultraviolet rays on top of the black matrix while heating the black matrix on which the photomask is formed.

Description

Method of manufacturing black matrix for color filter {Method of fabricating black matrix of color filter}

1 is a view illustrating a phenomenon in which ink filled in a black matrix for a conventional color filter is mixed;

2 is a view illustrating a phenomenon in which light leaks because ink is not completely filled in a conventional black matrix for color filters;

3 and 4 are views showing a conventional method for manufacturing a black matrix for color filters,

5a to 5d are views for explaining a method of manufacturing a black matrix for a color filter according to an embodiment of the present invention,

Figure 6a is a photograph taken of the color filter made by filling the color ink in the black matrix does not increase the ink wettability of the side,

FIG. 6B is a graph of a cross section of the color filter shown in FIG. 6A;

Figure 7a is a photograph of the color filter produced by filling the color ink in the black matrix of the ink wettability of the side according to the embodiment of the present invention,

FIG. 7B is a graph of a cross section of the color filter shown in FIG. 7A. FIG.

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

100 ... Transparent substrate 110 ... Shading layer

111 black matrix 120 barrier layer

The present invention relates to a method for producing a black matrix for color filters, and more particularly, to a method for producing a black matrix for color filters that can improve the uniformity of luminance.

Conventionally, CRT monitors have been mainly used to display information of TVs and computers, but recently, as the screen size increases, a liquid crystal display (LCD), a plasma display panel (PDP), and an organic Flat display devices such as EL (Electro Luminescence), light emitting diodes (LEDs), and field emission displays (FEDs) are used. Among such flat panel display devices, power consumption is low, and liquid crystal displays (LCDs), which are mainly used for computer monitors and notebook PCs, are in the spotlight.

In general, a liquid crystal display is provided with a color filter that passes through white light modulated by the liquid crystal layer to form an image of a desired color. Here, the color filter has a structure in which a plurality of red (R), green (G), and blue (B) pixels are arranged in a predetermined shape on a transparent substrate, and these pixels have a black matrix. Partitioned by

1 is a view illustrating a phenomenon in which ink filled in a black matrix for a conventional color filter is mixed, and FIG. 2 is a view illustrating a phenomenon in which light leaks because ink is not completely filled in a conventional black filter for a color filter.

Referring to FIG. 1, the black matrix 11 is formed by applying a light shielding layer on a transparent substrate 10 to a predetermined thickness, then baking the pattern and patterning the light shielding layer into a predetermined shape.

When the black matrix 11 has a small repulsive force with the ink and the contact angle is small, the ink 13 overflows with the surrounding pixels, and color mixture with other inks 14 occurs.

In order to solve the above problems, it is necessary to make the black matrix 11 to increase the repulsive force with the ink to increase the contact angle, and the black matrix 21 having such repulsive force is shown in FIG. 2.

Referring to FIG. 2, since the black matrix 21 is made to have a high repulsive force with the ink, it is possible to prevent the ink from overflowing with the surrounding pixels and mixing with other inks, but the ink is uniform on the transparent substrate 20. There is a problem that is not applied to one thickness.

As a result, light leakage occurs in the vicinity of the side surface of the black matrix 21, and as a result, the luminance of light emitted from each pixel of the color filter becomes nonuniform.

In order to solve this problem, a method of applying the ink flat on the transparent substrate is shown in Figures 3 to 4b. FIG. 3 is a view illustrating "Ink-jet printing method and apparatus for manufacturing color filters" disclosed in US Patent Publication No. 2003-0030715, and FIGS. 4A to 4B are disclosed in US Patent Publication No. 2003-0108804 FIG. Is a diagram illustrating "Ink-jet manufacturing process and device for color filters".

Referring to FIG. 3, after the black matrix 31 is formed on the transparent substrate 30, the ink 32 is applied to the pixels partitioned by the black matrix 31, and then air is blown through the air nozzle 33. It is soaked in ink 32 so that the ink is evenly applied to the pixels.

4A and 4B, after forming a pixel partitioned by the printing frame 41 on the transparent substrate 30, a shielding film 42 is installed on the printing frame 41, and the printing frame 41 is interposed therebetween. Electrodes 51 and 52 are provided.

After applying the ink 60 to the pixel and applying an electric voltage 50 to the electrodes 51 and 52 to form an electric field, the ink becomes flat as shown in FIG. 4B while the contact angle decreases with time. do.

However, the method of applying the ink evenly to the pixels by pouring air into the ink through the air nozzle as described above is difficult to supply the air for flattening the dryness of each pixel before the ink is dried. Rather, there is a problem that can worsen planarization.

The method of flattening the ink by applying an electric field to the pixel has a limitation in that it has to use a conductive ink, and thus there is a limitation in practical use.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object thereof is to provide a method for producing a black matrix for color filters which can improve the uniformity of brightness while preventing mixing of ink.

In order to achieve the above object, the present invention provides a method of manufacturing a color filter, the method including: forming a light blocking layer made of an organic material having a repulsion diameter on ink on a surface of a transparent substrate;

Patterning the light blocking layer to form a black matrix;

Forming a photomask on an upper surface of the black matrix; And

And irradiating ultraviolet rays on top of the black matrix while heating the black matrix on which the photomask is formed.

According to the present invention, the side surface of the black matrix is exposed to ultraviolet rays to increase surface energy by reacting moisture in the air with oxygen.

According to the invention, the black matrix is heated to a temperature of at least 100 ° C.

According to the present invention, the method may further include removing a photomask formed on an upper surface of the black mattress after irradiating ultraviolet rays to the upper portion of the black matrix.

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

5A to 5D are views for explaining a method of manufacturing a black matrix for a color filter according to an embodiment of the present invention.

 Referring to FIG. 5A, a light blocking layer 110 is formed by applying a hydrophobic organic material to a surface of the transparent substrate 100 to a predetermined thickness and then soft baking the same. Here, a glass substrate is generally used as the transparent substrate 100, but a plastic substrate may be used. The organic material may be applied to the surface of the transparent substrate 100 by spin coating, die coating, or dip coating.

Referring to FIG. 5B, a black matrix 111 is formed by patterning the light blocking layer 110 in a predetermined shape. When the light blocking layer 110 is formed of a photosensitive material, the light blocking layer 110 is exposed to light using a photo mask (not shown) having a predetermined pattern. Meanwhile, when the light blocking layer 110 is formed of a non-photosensitive material, a photoresist (not shown) is applied to the surface of the light blocking layer 110 and then patterned by a photolithography process. The light blocking layer 110 is etched using the patterned photoresist as an etching mask.

Referring to FIG. 5C, a blocking layer 120 is formed on an upper surface of the black matrix 111. The blocking layer 120 is preferably a photo mask.

Referring to FIG. 5D, ultraviolet rays are irradiated to the upper side of the black matrix 111 while heating the black matrix 111. The black matrix 111 is heated because only the ultraviolet rays are irradiated to the black matrix 111 so that the contact angle of the black matrix 111 does not change as easily as desired. Therefore, the contact angle can be easily changed by heating the black matrix 111 while irradiating ultraviolet rays. Here, the heating temperature of the black matrix 111 may be 100 ° C or more.

Through the above process, the contact angle of the portion of the surface of the black matrix 111 exposed to ultraviolet rays and the contact angle of the portion not exposed are different from each other.

That is, the side surface of the black matrix 111 exposed to ultraviolet rays reacts with moisture and oxygen in the air to increase the surface energy, so that the repulsive force with the ink is lost, and conversely, the wettability with the ink is increased. However, since the ultraviolet rays are blocked by the blocking layer 120 and are not exposed to ultraviolet rays, the upper surface of the black matrix 111 maintains a repulsive force against ink as it is.

Table 1 shows experimental data in which the surface energy of the side surface of the black matrix 111 irradiated with ultraviolet light and the contact angle of the side surface of the black matrix 111 change with water or ink. It shows experimental data that changes over time.

TABLE 1

0 sec 40 seconds 60 seconds 120 seconds Surface energy (mN / m) 29.1 37.6 39.2 41.5 Contact angle water 89.5 75.8 73.2 69.5 Ink A 29.0 28.2 26.2 4.0 Ink B 25.7 26.2 25.4 4.0 Ink C 25.2 24.2 21.6 4.0

Referring to Table 1, it can be seen that the surface energy of the side surface of the black matrix 111 irradiated with ultraviolet rays gradually increases with time. In addition, the contact angle of the side surface of the black matrix 111 exposed to ultraviolet rays is gradually decreased in the case of water, and in the case of ink, although there is a slight difference depending on its composition, it was generally 20 degrees or more before the ultraviolet rays were irradiated. As it is irradiated, it gradually becomes smaller and eventually turns out to be smaller than 4 degrees.

Therefore, the surface energy of the black matrix 111 exposed to ultraviolet rays increases in surface energy and the contact angle decreases, so that the repulsive force against the ink disappears. However, the upper surface of the black matrix 111 blocked by ultraviolet rays by the blocking layer 120 has a repulsive force against the ink as it is.

Therefore, the color ink filled in the black matrix 111 is prevented from being mixed with other adjacent color inks due to the repulsive force on the ink of the upper surface of the black matrix 111, and the side surface of the black matrix 111 Due to the increased wettability of the ink can be filled with a uniform thickness can prevent light leakage.

As described above, the result of the increased wettability of the side surface of the black matrix 111 according to the present invention can be clearly confirmed through the following photograph and the profiled graph.

FIG. 6A is a photograph of a color filter manufactured by filling a color ink into a black matrix having no ink wettability increase treatment on its side surface, and FIG. 6B is a graph illustrating a cross-sectional profile of the color filter shown in FIG. 6A, and FIG. 7A is According to an embodiment of the present invention, a photograph of a color filter manufactured by filling a color ink into a black matrix having increased ink wettability of a side surface is shown. FIG. 7B is a graph illustrating a profile of a cross section of the color filter illustrated in FIG. 7A.

6A and 6B, when the color ink is filled in the black matrix 111 having the repulsive force against the ink, the contact angle of the color ink increases due to the repulsive force against the ink. It can be seen that this leak can occur.

However, referring to FIGS. 7A and 7B, when the repulsive force on the side of the black matrix 111 is removed by using ultraviolet rays, that is, when the wettability of the ink is increased, the color filled in the black matrix 111 is increased. It can be seen that the ink is filled flat. This is because the contact angle of the side of the black matrix 111 is reduced, thereby preventing light leakage.

As described above, in the method of manufacturing a color filter according to the present invention, the upper surface of the black matrix may prevent color mixing of the color ink by maintaining a repulsion force against the ink by using a photomask, and the side of the black matrix may be By eliminating the repulsive force it is possible to fill the color ink with a uniform thickness in the areas partitioned by the black matrix has the effect of preventing light leakage.

Although the present invention has been described with reference to one embodiment shown in the drawings, this is merely exemplary and will be understood by those of ordinary skill in the art that various modifications and variations can be made therefrom. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

Claims (5)

Forming a light blocking layer made of an organic material having a repulsive force against ink on the surface of the transparent substrate; Patterning the light blocking layer to form a black matrix; Forming a blocking layer on an upper surface of the black matrix; And And irradiating ultraviolet rays to the upper portion of the black matrix while heating the black matrix on which the photomask is formed. The method of claim 1, The side surface of the black matrix is exposed to ultraviolet rays to react with moisture and oxygen in the air surface energy increases black matrix manufacturing method characterized in that the increase. The method of claim 1, The black matrix is a method for producing a black matrix for color filters, characterized in that heated to a temperature of 100 ℃ or more. The method of claim 1, The blocking layer is a black matrix manufacturing method for a color filter, characterized in that the photomask. The method of claim 1, And removing the photomask formed on the upper surface of the black mattress after the step of irradiating ultraviolet rays to the upper portion of the black matrix.

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