KR101064756B1 - Photomask for Color filter and Using method of the same - Google Patents

Abstract

The present invention relates to a photomask for manufacturing a color filter, the present invention comprising at least one black matrix region formed on a substrate and at least one color filter formed on the black matrix region in the photomask for manufacturing a color filter. The color filter may include a protruding region protruding from a portion of the black matrix, and at least one transmittance adjusting unit corresponding to a horizontal width of the protruding region of the color filter is provided.

Color Filter, Transmittance Control Unit, Variable Area

Description

Photomask for Color Filter and Using Method of the Same

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photomask used in a color filter manufacturing process and a process for manufacturing a color filter using the same, wherein an edge portion of a pattern during exposure of color filter layers R, G, and B constituting an LCD color filter is exposed. A photomask with a halftone or optical pattern layer (OPC) is used to eliminate the protrusion of the color filter layer caused by the thickness of the black matrix layer, thereby reducing the variation in the thickness of the color filter layer, thereby reducing the light leakage phenomenon of the LCD. It relates to a method of using a photomask that can produce a color filter that significantly reduces it.

BACKGROUND ART A liquid crystal display (LCD) is a device that can display an image by using electro-optical characteristics of liquid crystal molecules generally forming a liquid crystal layer. The liquid crystal display device includes a thin film transistor substrate and a color filter substrate facing each other with a liquid crystal layer interposed therebetween. In particular, the color screen of the TFT-LCD is achieved through the operation of the TFT and the liquid crystal (Cell), which controls the transmittance of the white light of the backlight, and the additive mixed color of three primary colors transmitted through the color filters of Red, Green, and Blue.

The basic process in the manufacture of the LCD is a thin film transistor process for forming a basic positive electrode, a color filter manufacturing process, a cell process and a module process for bonding the substrates through the above two processes.

The thin film transistor process is the process of forming the basic electrode, which is the most basic and essential process to form the electrode of each cell. First, the gate electrode is formed, the insulating film semiconductor film is formed, the data electrode is generated, the protective film, the pixel. The electrode is formed. Of course, each of the above steps requires one or more pattern processes, and is basically performed through a process of deposition and cleaning, photosensitive material coating, exposure, development, etching, and peeling.

In addition, the manufacturing of the color filter (CF) is generally implemented in a similar manner. In the case of LCD, each cell does not emit light like PDP or OLED, but the brightness of the light is controlled by adjusting the arrangement of the liquid crystal in each cell with a constant light from the backlight. In particular, since the backlight itself is white light, the amount of light is controlled by changing the liquid crystal array, but the color filter CF plays an important role in making R, G, and B to realize color.

The color filter is located on the upper panel of the LCD panel and is made through a process separate from the thin film transistor process. Of course, the above-mentioned pattern process is generally required also in such a color filter process.

This process is briefly described with reference to FIGS. 1A and 1B.

The process of forming a black matrix (BM) pattern (2) on the glass (1) (S 1), which requires a pattern process in the order of deposition, cleaning, photosensitive material coating, exposure, development, etching, peeling Done. Since each pixel has three cells of red, green, and blue, a separate pattern process is required for each cell to form each cell. In general, the pattern process is different from the above-described two processes, and the photosensitive material having a color is applied without the need for deposition and cleaning processes to be exposed and developed (S 2 to S 4). Then, it is common to produce a transparent electrode material 4 such as ITO through a pattern process like the BM process (S 5). In this process of coloring, a photosensitive material is added to the dye-soluble water-soluble polymer material to be photosensitive and patterned to a desired shape by a photolithography process, followed by forming a coloring pattern. When this process is repeated three times, a colored layer of red (R), green (G) and blue (B) is formed.

However, in the case of forming the R, G, and B layers, which are the color filters formed in the above-described process, a step is formed in the edge portions of the R, G, and B patterns due to the thickness of the black matrix to generate the protruding region. In other words, the protrusion area P is generated as much as the thickness of the black matrix, which causes distortion of the liquid crystal array due to the protrusion area when the liquid crystals are arranged later. As a result, light leakage occurs to deteriorate the quality of the LCD. This is a problem, which represents a limitation in LCDs having a black matrix structure. In particular, in order to eliminate the problem caused by the protruding region formed at the edge of the color filter, a flattening layer is coated on the upper part of the color filter to eliminate the step of the upper part of the overall color filter, and a separate transparent electrode is formed on the upper part of the color filter. This problem has been solved by forming process, but this has led to a problem that is contrary to the trend of the liquid crystal display device aiming for thinning, and in particular, additional manufacturing process increases the manufacturing cost and delays the production process. It is causing a problem. Therefore, there is an urgent need for an efficient manufacturing method that can solve the fatal limitation of the color filter while still using the conventional manufacturing process of the liquid crystal display device.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a photomask having a transmittance control unit for removing the formation of the protrusion pattern of the color filter of the color filter for LCD, thereby providing the presence of the protrusion pattern. It is possible to remove the light leakage caused by the twisting of the liquid crystal, to provide a photomask for manufacturing a color filter that can produce a color filter of excellent quality and to provide a technology for manufacturing a color filter using the same.

In the present invention, as a means for solving the above-described problem, in the photomask for LCD color filter manufacturing, at least one black matrix region formed on a substrate and at least one color filter formed in the black matrix region, The color filter includes a protruding region protruding from a portion of the black matrix, and at least one transmittance adjusting unit corresponding to a horizontal width w ₁ of the protruding region of the color filter is provided. To provide a photomask for the.

In particular, in order to remove the protruding region of the color filter in a simple continuous process in the original production line by providing a transmittance adjusting portion in the photomask generally used in the manufacturing process of the color filter, the above-described transmittance adjusting portion is semi-transmissive It may be formed of an optical pattern portion having a slit or formed of a material, or a combination of the two.

In particular, the transmittance of the transmittance adjusting unit is formed so that the corresponding color filter is changed according to the height of protrusion of the protruding region so that at least two fluctuation regions having different transmittances are included, more preferably in forming the fluctuation region. It is preferable to form a minimum transmittance at the maximum height of the protruding region and a maximum transmittance at the minimum height.

In addition, the horizontal width (w ₂ ) of the transmittance adjusting portion according to the present invention is preferably formed to be less than the horizontal width (w ₁ ) of the projecting area, and adjust the transmittance of the transmittance adjusting portion in the range of 5 to 80%. You can do that.

Particularly, in the present invention, Cr, Si, Mo, Ta, Ti, Al as a main element, at least two or more of the main element material or the main elements are mixed or the main element or composite material It may be formed of a material to which at least one of C 0 _x , O _x , and N _x is added.

The photomask for the color filter as described above may be used in the following manner to be used in the manufacture of a color filter in which the protruding areas are removed in the R, G, and B areas of the color filter.

That is, by using a photomask having a transmittance adjusting part having a horizontal width w ₁ corresponding to the protruding region, the LCD color filter including the protruding region of the R, G, and B color filters formed in the black matrix region. It is possible to provide a color filter of excellent quality that eliminates the problem of light leakage through the use of a color filter photomask, which is characterized by forming the protrusion height H 'by developing / exposure.

In particular, the protrusion height (H ') of the color filter formed using the color filter photomask according to the present invention, the height of the protrusion portion (h ₃ ') of the color filter protrusion area formed on the upper surface of the black matrix is a color. It is possible to provide a method of using a color filter photomask, characterized in that formed in 10 to 80% of the height (h ₁ ') of the flat portion of the filter.

According to the present invention, by providing a photomask having a transmittance adjusting portion for removing the formation of the projection pattern of the color filter for LCD, it is possible to eliminate the light leakage phenomenon due to the distortion of the liquid crystal in the presence of the projection pattern, There is an effect that can produce a color filter substrate.

Hereinafter, with reference to the accompanying drawings will be described in detail the configuration and operation of the present invention.

The photomask for a color filter according to the present invention is basically based on a color filter structure, and particularly in a region corresponding to the position of the protruding regions of the color filters R, G, and B due to the black matrix pattern of the color filter substrate. The gist of the present invention has a structure provided with a transmittance adjusting portion for adjusting transmittance.

2A and 2B are conceptual views illustrating the structure of a color filter according to the present invention.

Referring to FIG. 2A, a conceptual diagram of a color filter positioned below the photomask according to the present invention is a structure adopted to explain the protruding region. FIG. 2A illustrates a structure of a photomask including one of color filters including a protruding region and a flat region of any one of R, G, and B formed on a color filter substrate, and a transmittance control unit according to the present invention. It is an enlarged conceptual diagram showing.

The photomask according to the present invention includes a transmittance adjusting part 120, a light transmitting part 130 through which light is completely transmitted, and a light blocking part 110 through which light is blocked. In particular, the transmittance adjusting unit 120 may be formed to be disposed at a position corresponding to the width w1 of the protruding region X of any one of R, G, and B of the color filter.

As shown in the drawing, the conventional color filter has a protruding pattern. Specifically, the protruding region of the color filter forms a step that protrudes as much as the thickness of the black matrix B formed below. Due to the protruding region X, light leakage due to twisting of the liquid crystal cell occurs later. The protruding region X may be conceptualized as a starting point X ₁ abutting the upper surface of the black matrix B, a highest point X ₂ , and an end point Y ₁ abutting the flat region Y of the color filter. .

Although the illustrated protrusions are described with a uniform structure of the starting point, the highest point, and the ending point, the actual protrusion area may include these three points, but may have a more irregular structure or a structure having a constant curvature. To define the structure of the photomask of the present invention.

The protruding region X of the color filter is defined to correspond to the starting point Y ₁ of the flat region Y starting from the upper surface X1 of the black matrix pattern and passing through the highest height point X ₂ . It should be noted that the flat region Y is a relative concept having a certain flatness compared to the projecting region which is not perfect flatness.

In particular, the transmittance adjusting unit 120 is to adjust the transmittance of light to be partially transmitted, not completely transmitted, so that it can be formed through the semi-transmissive material in this embodiment. The transmittance control unit 120 controls the amount of light transmitted during exposure to perform a function of transmitting only a portion of the light, not perfect transmission. As described above, the transflective material is Cr, Si, Mo, Ta, Ti, Al as the main element, at least two or more of the main element material or the main element is a mixed material, or in the main element or the composite material of C0 _x , O _x , N _x At least one may be made of the added material. For example, it is possible to control the transmittance with a semi-transmissive material such as Cr _x O _y , Cr _x Co _y , Cr _x Co _y N _z , Si _x N _y , Mo _x Si _y , and in the present preferred embodiment 5 to 80 It is preferable to form to have a transmittance of%.

That is, the width w ₂ of the transmittance adjusting unit 120 of the photomask according to the present invention is preferably formed to be equal to or less than the width w ₁ of the protruding region X of the corresponding color filter. The length of the adjusting unit 120 is more preferably formed so as not to exceed the starting point (Y ₁ ) of the flat region (Y).

In particular, at the highest point X ₂ of the protruding region, it is preferable to form a transmittance lower than other points so that more height is removed.

That is, the photomask according to the present invention is preferably formed such that the transmittance of the transmittance adjusting unit is adjusted so that the corresponding color filter is changed according to the projecting height of the protruding region so that at least two fluctuation regions Z having different transmittances are included. . That is, in order to remove more protruding portions of the protruding region, the fluctuating region has a minimum transmissive region (Z ₂ ) so as to have a minimum transmittance at the maximum height of the protruding region, and a maximum transmittance at the minimum height. It is preferable to provide the maximum variation zone Z ₁ or Z ₃ .

Although the protrusion region illustrated in FIG. 2A is illustrated as having a constant flatness at the highest point X, the protrusion region is more generally formed in an irregular structure formed with a constant curvature, as shown in FIG. 3A. The arrangement is preferably formed in a structure that can be formed in at least two or more to compensate for the more precise step difference.

2B is a diagram illustrating a method of using the photomask for color filters according to the present invention having the above-described structure, and an operation example thereof.

Referring to (a), (a) is arranged to correspond to the structure in which the protruding area of the conventional color filter described above the photomask 100 according to the present invention is presented to explain the application example of the present invention easily Conceptual diagram. Therefore, the color filter substrate 200 shown in (a) shows a conventional structure, and the color filter substrate shown in (b) is manufactured according to the present invention manufactured by applying the photomask 100 according to the present invention. The structure of the result is shown.

The photomask 100 according to the present invention is disposed on the upper portion of the color filter substrate, and the transmittance adjusting part and the protruding region X of the color filter correspond to each other. This considers the height H of the highest point X ₂ of the protruding region X from the lowest surface of the flat region Y of the color filter, the height of the flat region Y and the height of the protruding region h ₁ . ₃ ), the black matrix height (h ₂ ) can be classified, and in the present invention, the height (h ₃ ) of the protruding region is exposed / developed using light transmitted through the transmittance control unit 120 to significantly lower the height. It becomes possible to manufacture.

Specifically, in the manufacturing process using the photomask according to the present invention can be formed with the protrusion height (H ') shown in (b) of the height significantly lower than the overall height (H) of the conventional color filter shown in (a). Will be. Most preferably, the protrusion height H 'may be lowered by the height h ₂ ′ of the black matrix, or lowered by the height h ₁ ′ of the color filter in the flat region.

Referring to (b) of FIG. 1, the photomask 100 according to the present invention forms a structure having a protrusion height H ′ that is significantly lower than the overall height H of a conventional color filter. It is shown.

The protrusion height H 'of the color filter according to the present invention may be lowered by the height h ₂ of the black matrix of the conventional structure, or compared to the color filter of the originally formed flat area, as compared with the conventional color filter structure. Can be as low as height h ₁ . Therefore, preferably, the protrusion height H 'of the protruding region may be formed as the height h ₂ of the black matrix or the height h _{1 of} the color filter flat region in consideration of the structure of a conventional color filter. have. Most preferably, the protrusion height h ₃ ′ of the protrusion region has a height of h ₃ '= h ₁ ′. The protrusion height H 'of the protruding region is preferably 10 to 80% of the height h ₁ ' of the flat portion of the color filter.

3A and 3B, another embodiment of a color filter photomask according to the present invention will be described. The photomask of FIG. 3A is in accordance with the present invention, and the color filter substrate at the bottom is employed to describe the application example of the present invention by employing a color filter having a conventional structure.

Transmittance control unit 121 according to the present embodiment is formed by the optical pattern layer (OPC) to form a predetermined slit in addition to the transmissive control unit formed of a semi-transparent material as in the embodiment of FIG. It may also be formed in a composite structure in which the transmission slit is formed on the semi-transparent material layer. The photomask according to the present invention includes a transmittance adjusting part 121, a light transmitting part 131 through which light is completely transmitted, and a light blocking part 111 through which light is blocked.

In particular, the transmittance adjusting unit 121 may be formed to be disposed at a position corresponding to the width w ₁ of the protruding region X of one of the color filters R, G, and B of the color filter.

Referring to FIG. 3A, in the structure having the protruding region X and the flat region Y of the color filter formed on the black matrix B as shown in FIG. 2A, the starting point X ₁ and the highest point X in the protruding region are shown. ₂ ), the structure having the end point Y ₁ is the same. That is, the protruding region of the conventional color filter is formed with a predetermined curvature from the starting point (X ₁ ) of the upper surface of the black matrix pattern to the highest point (X ₂ ), the starting point (Y ₁ ) of the flat region (Y). Of course, as shown in the example, the heights of the points of X ₁ and Y ₁ may be different. In the present embodiment will be described by introducing a structure having a irregular curved protrusion area.

In the present embodiment, the transmittance adjusting unit 131 is different from the above-described embodiment in that the optical pattern layer OPC is provided instead of the semi-transparent material. The optical pattern layer (OPC) is formed in a structure having a plurality of slits, it is possible to adjust the amount of light transmitted through the slit. In particular, the transmittance of the transmittance adjusting unit 121 may be adjusted so that the corresponding color filter is changed according to the height of the protrusion of the protrusion area so that at least two variation zones Z having different transmittances are included. In order to remove more protruding portions, the fluctuation area may include a minimum fluctuation area Z ₂ to have a minimum transmittance at the maximum height of the protrusion area, and a maximum fluctuation area to have a maximum transmittance at the minimum height. Z ₁ or Z ₃ ) as described above can be formed in a structure having.

In addition, in the present invention, the optical pattern layer of the transmittance adjusting unit may be implemented in a manner of adjusting the transmittance of light by arranging a plurality of light transmitting slits in a specific material layer, and of course, the specific material layer itself is formed of a semi-transparent material. It can also be formed as a composite structure to form the transmissive slit.

FIG. 3B illustrates a concept of a manufacturing process capable of significantly lowering the protruding area of the color filter using the photomask for the color filter according to the present invention having the structure shown in FIG. 3A.

(a) is a schematic diagram in which the photomask according to the present invention is positioned to correspond to the structure in which the protruding region of the color filter 200 according to the conventional manufacturing technique is formed. And (b) shows the result of forming a height similar to the height of the flat area (Y) of the color filter by compensating the height of the protruding region through the photomask 100 and the transmittance adjusting unit 121 according to the present invention. have. As in the structure shown in (b), the color filter substrate manufactured by using the photomask according to the present invention has a significantly low projecting area at the edge of the color filter, thereby eliminating the problem of light leakage due to twisting of the liquid crystal. The benefits of doing so are implemented.

That is, when compared with the height (h ₃ ) of the protrusion area shown in the conventional color filter structure posted in (a), it is reduced to a significantly lower protrusion height (h ₃ '), in which case the protrusion height (h ₃ ') is As shown in the drawing, the height h ₂ 'up to the upper surface ① of the black matrix or the height h ₁ ' up to the upper surface ② of the flat region of the color filter can be formed.

More preferably, the height h ₃ ′ of the protrusion of the color filter protrusion region may be 10 to 80% of the height h ₁ ′ of the flat portion of the color filter. Similarly, when compared with the height h ₃ of the protrusion area of the conventional color filter, the protrusion height h ₃ ′ according to the present invention may be formed at a height of 10 to 80% of the height h ₃ . Will be.

The color filter substrate manufactured using the color filter photomask according to the present invention can form a structure in which the height of the protruding region formed in the color filters R, G, and B is minimized. Injecting and disposing the liquid crystals enables the liquid crystal cell to be distorted significantly, thereby minimizing light leakage of recently generated LCD products.

In addition, it is possible to provide an efficient manufacturing method capable of eliminating the photomask for a color filter according to the present invention having a transmittance control unit to the fatal limitation of the color filter while using the conventional manufacturing process of the liquid crystal display device.

In the foregoing detailed description of the present invention, specific examples have been described. However, various modifications are possible within the scope of the present invention. The technical idea of the present invention should not be limited to the embodiments of the present invention but should be determined by the equivalents of the claims and the claims.

1 is a conceptual diagram illustrating a manufacturing process of a color filter according to the prior art.

2A and 2B are conceptual views illustrating a manufacturing process of a color filter photomask and a color filter using the same according to a preferred embodiment of the present invention.

3A and 3B are conceptual views illustrating a manufacturing process of a color filter photomask and a color filter using the same according to another embodiment of the present invention.

Claims (10)

In a color filter photomask used in the manufacture of a color filter having a structure overlapping a portion of the black matrix region formed on the substrate, and having a protrusion region in the overlapping portion, At least one transmittance adjusting part corresponding to the horizontal width w ₁ of the protruding region of the color filter is provided. The transmittance of the individual transmittance adjusting unit is adjusted to vary according to the height of protrusion of the protruding region of the corresponding color filter, so that at least two fluctuation regions having different transmittances are included. The transmittance adjusting portion is formed of a semi-transparent material or consists of an optical pattern portion having a slit, or a combination of the two color filter photomask. delete delete The method according to claim 1, wherein the variation region, The photomask for the color filter is formed to have a minimum transmittance at the maximum height of the protrusion area, the maximum transmittance at the minimum height. The method according to claim 4, The horizontal width (w ₂ ) of the transmittance control unit is a color filter photomask, characterized in that formed below the horizontal width (w ₁ ) of the protruding region. The method according to claim 4, The photomask for color filters, characterized in that the transmittance of the transmittance adjusting portion is adjusted in the range of 5 to 80%. The method according to claim 4, The transmittance control unit is made of Cr, Si, Mo, Ta, Ti, Al as a main element, or a composite material in which at least two or more of the main element materials or the main elements are mixed, or C0 to the main element or composite material. At least one of _x , O _x , N _x is made of a material added to the color filter photomask. (Where the subscript x is a natural number) In the color filter for LCD provided with the protruding area of the R, G, B color filter formed in the black matrix area, By developing / exposure using the photomask of any one of claims 1 and 4 having a transmittance adjusting part having a horizontal width w ₁ corresponding to the protruding region, The height (h ₃ ') of the protrusion of the color filter projecting area formed on the upper surface of the black matrix is 10 to 80% of the height (h ₁ ') of the flat portion of the color filter. delete A color filter having a structure in which protrusion areas of R, G, and B color filters manufactured by the method of using the photomask of claim 8 are compensated for.

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