KR20070025326A - Device of forming color filter and method thereof - Google Patents

Abstract

An apparatus and a method of forming a color filter are provided to readily find a pixel, in which a sufficiently thick color filter is not formed, after injecting color ink. An apparatus for forming a color filter includes a stage(10), a support frame(20), a mask(30) and an injector(40). The stage allows a substrate to be mounted thereon. The support frame is disposed on the stage. The mask is mounted on the support frame and spaced apart from the substrate. The injector injects color ink onto the substrate. The substrate has a plurality of openings into which different colors of ink are inserted. The mask has a plurality of holes overlapping the openings and filled with the same colors of ink. The holes are separately formed along a region in which the holes overlap the openings. The holes are formed to include a region for connecting the openings in one direction.

Description

Device for forming color filter and forming method

1 is a configuration diagram of a color filter forming apparatus according to an embodiment of the present invention;

2 is a plan view of a light shielding film pattern formed on the substrate of FIG. 1,

3A and 3B are plan views of the mask of FIG. 1,

4A to 7A and 4B to 7B illustrate a method of forming a color filter according to an exemplary embodiment of the present invention.

♧ explanation of symbols for main parts of drawing

1-Substrate 2-Light Shading Pattern

5-opening 10-stage

20-Support 30-Mask

35-open hole 40-injector

100-color ink

The present invention relates to a color filter forming apparatus and a forming method, and more particularly, to an apparatus and method for forming a color filter by spraying a color ink.

In general, a flat panel display (FPD) is a display device that provides a thin and flat screen, and is typically used for a liquid crystal display device (LCD) or a large TV, which is widely used as a notebook computer monitor. Plasma Display Panels (PDPs) and the like. The flat panel display device is provided with a color filter for realizing color. Conventional color filters are formed by arranging color filters having different colors of red / green / blue corresponding to the three primary colors of light adjacent to each other.

The method for forming the color filter is variously classified according to the material used or the process method. The material constituting the color filter includes a dye method and a pigment method, and depending on the process method, there are a dyeing method, a dispersion method, and a printing method. According to a dispersion method using a pigment, which is a typical color filter formation method, a color filter is formed by coating a photoresist including a pigment on a substrate and then patterning it by a photolithography process. Recently, many inkjet printing methods have been used. The inkjet printing method is a method of forming a plurality of openings for each individual pixel on a substrate and then spraying color ink on the openings by an inkjet method. This method does not go through the process of coating / exposure / development, etc. has the advantage of shortening the process and material costs.

In inkjet printing technology, it is essential to properly control an injector such as a nozzle for ejecting the color ink to induce the color ink to be constantly and stably filled in the desired pixel openings. To do this, various variables such as driving voltage driving the injector or surface tension / viscosity / volatility of the color ink must be considered. However, it is not easy to control a plurality of variables as described above, and color mixing may occur between the color inks during the actual injection process. For example, in the case of a stripe-shaped color filter, red filters, green filters, and blue filters are alternately arranged side by side in one direction. When a red ink is injected into an opening to form a red filter, adjacent green filters or blue filters are disposed. A red ink may be inserted into the opening for forming the filter. In this case, since a part of the color ink to fill a specific opening fills another opening, the opening may have a small amount of color ink, thereby making the thickness of the color filter thin.

If the color ink is mixed or the thickness of the color filter is not constant as described above, the uniformity with respect to the color is reduced and the color difference between the pixels is increased.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a color filter forming apparatus and a forming method which can prevent color mixing between color inks.

In order to achieve the above technical problem, the present invention provides a color filter forming apparatus. The color filter forming apparatus of the present invention comprises: a stage on which a substrate is seated; A support disposed on the stage; A mask seated on the support to be spaced apart from the substrate; And an injector for injecting color ink onto the substrate.

An opening is formed in the mask, which corresponds to the color filter formed on the substrate. That is, the substrate is provided with a plurality of openings into which different colors of ink are inserted in each pixel according to the color filter, and the openings overlap the openings forming the color filter having the same color. Therefore, only the opening constituting the specific color filter is exposed by the mask, and color ink is inserted only to the opening of the specific color filter when the color ink is injected through the mask to the opening. In this case, it is possible to prevent the ink of different colors from being inserted into the same opening and mixing.

According to a specific embodiment of the present invention, the openings may be formed to be separated from each other along an area overlapping the respective openings, or the openings may be formed to include an area connecting the openings in one direction. .

According to the color filter forming method of the present invention, a color filter is formed using the mask as described above, and specifically, a plurality of openings are formed to insert ink of different colors into the substrate; Arranging a mask in which an opening is formed to be spaced apart from the substrate, wherein the opening is positioned to overlap with an opening into which ink of the same color is inserted among the openings; And spraying a color ink into the opening.

On the other hand, in the case of forming a color filter by injecting the color ink as described above, due to various variables in the process, a sufficient amount of the color ink may not be inserted into a specific opening, the thickness of the color filter may be formed thin. In addition, the color ink needs to be injected into the opening, and according to the present invention, it is easy to find the opening that requires re-injection. That is, in the case of using a mask, color inks that do not pass through the mask remain in an area adjacent to the opening and color the area. If the amount of color ink remaining in a specific area is large, it means that the amount of color ink that has passed through the opening is small, so that the thickness of the color filter formed in the opening can be determined based on the remaining amount of color ink on the mask. .

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be applied and modified in various forms. Rather, the following embodiments are provided to clarify the technical spirit disclosed by the present invention, and furthermore, to fully convey the technical spirit of the present invention to those skilled in the art having an average knowledge in the field to which the present invention belongs. Therefore, the scope of the present invention should not be construed as limited by the embodiments described below. In addition, in the drawings presented in conjunction with the following examples, the size of layers and regions are simplified or somewhat exaggerated to emphasize clarity, and like reference numerals in the drawings indicate like elements.

1 is a block diagram of a color filter forming apparatus according to an embodiment of the present invention.

Referring to FIG. 1, the present invention includes a stage 10, a support 20, a mask 30, and an injector 40. A substrate 1 is mounted on the stage 10, and a light shielding film pattern 2 having an opening 5 is formed on the substrate 1. The stage 10 is provided with a support 20, the mask 30 is seated on the support 20. Since the height of the support 20 is greater than the thickness of the substrate 1, the upper end of the support 20 is positioned higher than the upper surface of the substrate 1 seated on the stage 10. This is to separate the mask 30 and the substrate 1 from each other when the mask 30 is seated on the support 20. The support 20 may be disposed so as not to contact the substrate 1, and specifically, may be formed in an area outside the edge of the stage 10, that is, the area in which the substrate 1 is seated. The support 20 is not particularly limited as long as the mask 30 is stably seated. Therefore, it may be integrally formed along the edge of the stage 10, or may be formed in a plurality of to be separated from each other. If the support 20 is formed of a plurality of separated from each other, the number of the support 20 is determined in consideration of the size of the substrate (1). That is, since the size of the mask 30 also increases as the size of the substrate 1 increases, the number of the supports 20 supporting the same increases.

On the other hand, the support 20 may be formed to enable vertical movement. The substrate 1 may be vertically transported and seated at the top of the stage 10 or horizontally transported and seated at one side of the stage 10. In the case of the former, in the latter case, since the substrate 1 and the support 20 may physically collide during the transfer of the substrate 1, the vertically movable support 20 is preferable. That is, the support 20 is transferred to the substrate 1 in the horizontal direction while the support 20 is lowered downward, and the mask 30 may be seated after the substrate 1 is seated on the stage 10. Rises.

An opening hole 35 is formed in the mask 30, and the injector 40 sprays the color ink 100 onto the substrate 1 while moving in a state spaced apart on the mask 30. At this time, the color ink 100 may pass through only the area where the opening hole 35 is formed due to the mask 30, and as a result, the color ink may only pass to the area overlapping with the opening hole 35 in the substrate 1. 100 is reached. In other words, if the position where the opening hole 35 is formed is appropriately selected, it is possible to prevent the color ink 100 from being sprayed to an undesired area on the substrate 1 when the color ink 100 is sprayed. This will be described below with reference to the drawings.

FIG. 2 is a plan view of the light shielding film pattern formed on the substrate of FIG. 1, and a cross section taken along the opening in the column direction in FIG. 2 corresponds to the light shielding film pattern shown in FIG. 1.

Referring to FIG. 2, the light shielding film pattern 2 formed to block passage of light on the substrate 1 has a plurality of openings 5. The openings 5 correspond to individual pixels, and the insides of the openings 5 are colored in a specific color to form color filters. The color is composed of red, green, and blue, which are three primary colors of light, and each of the openings 5 is used for the red filter opening (R), the green filter opening (G), and the blue filter, depending on the color of the color ink filling them. It is divided into the opening part (B). The color filters may be arranged in various ways, and mainly arranged in a stripe shape. In this case, the red filter / green filter / blue filter are arranged alternately in the column direction, and as shown in Fig. 2, each color filter is composed of a plurality of openings 5 to be filled with inks of the same color in the row direction. Here, the direction of the color filter is limited to one direction for convenience of description, and the row direction and the column direction may be changed.

3A and 3B are plan views of the mask of FIG. 1, in which a cross section taken along an open hole in a column direction corresponds to the mask shown in FIG. 1. 3A and 3B are each according to different embodiments.

Referring to FIG. 3A, a plurality of openings 35a are formed in the mask 30 so as to be separated from each other. The opening hole 35a is formed at a position overlapping the opening 5 which is colored in the same color in the substrate 1. Accordingly, each mask 30 may be provided with an opening hole 35a overlapping the red filter opening R, the green filter opening G, and the blue filter opening B. Alternatively, in the case of forming a color filter in a band shape as shown in FIG. 2, since the openings 5 are regularly arranged, a single mask is formed to form a red filter / green filter / blue filter while changing the alignment position of the mask 30. (30) can also be used.

As shown in FIG. 2 and FIG. 3A, a mark 50 may be formed in the mask 30 and the substrate 1 to prevent misalignment between the opening hole 35a and the opening 5. If all of the color filters having different colors are formed using a single mask 30, a plurality of marks 50 corresponding to each color are required.

The size of the opening hole 35a is preferably at least equal to or larger than the opening 5. If the opening hole 35a is formed smaller than the opening 5, it is difficult to form a color filter having a sufficient thickness in the opening 5. When the opening hole 35a is formed larger than the opening 5, the opening hole 35a may overlap with a portion of the other opening 5 adjacent to the specific opening 5. At this time, the color ink 100 may be mixed when overlapped with the openings 5 colored in different colors. That is, in the embodiment of Fig. 3A, the length of the column direction is limited so that the opening hole 35a does not overlap with other openings 5 adjacent in the column direction. On the other hand, the opening 5 which is colored in the same color is filled with the same color ink 100, so that some portions may overlap. That is, in the embodiment of FIG. 3A, the opening hole 35a may overlap with other openings 5 adjacent in the row direction, and the row direction length is not limited.

In view of the size of the opening 35a as described above, considering that one opening 35a may overlap with another opening 5 filled with the same color ink 100, another embodiment of the present invention As a mask 30 as shown in Fig. 3b can be used.

Referring to FIG. 3B, the opening hole 35b is formed to overlap with the opening 5 in one direction having the same color. In this case, the opening hole 35b is composed of lines formed side by side spaced apart from each other by a predetermined interval, the advantages of such a structure is as follows.

First, the mask 30 is easy to manufacture. That is, since the openings 5 have a fine size corresponding to the pixels, the openings 35b having a wide linear area are formed rather than forming the openings 35a having a narrow area corresponding to the individual openings 5. ) Is easier to form.

Second, it is suitable for the line printing method. The color ink 100 is usually injected into the opening 5 in a state where the injector 40 is positioned on each opening 5. The color ink 100 includes a volatile solvent in addition to the pigment representing the color, and the solvent contained in the color ink 100 is mostly evaporated in the curing step after the color ink 100 is sprayed. However, when the color ink 100 is injected into the opening 5, the color filter formed inside the opening 5 may have a nonuniform thickness. This can be explained by the so-called coffee stain effect, which represents a mechanism when water droplets such as color ink 100 are dried in a space having a fixed contact surface such as opening 5. That is, when curing the color ink 100, the evaporation rate is large in the side wall portion of the opening 5, but the volume change is limited by the side wall. On the contrary, although the evaporation rate is low in the center part of the opening part 5, a large volume change is accompanied. In order to compensate for this difference, the fluid moves from the center to the edge, and as a result, the thickness of the color filter may be thinly formed at the center and sidewalls. This coffee stain effect may be overcome when the color ink 100 is sprayed along one direction in which the opening 5 is formed, instead of being limited to the opening 5. According to the mask 30 is suitable for the above line printing method.

The mask 30 having two types of open holes 35a and 35b has been described above with reference to FIGS. 3A and 3B. However, the opening holes 35a and 35b are not limited in shape or forming position as long as they prevent different colors of ink from being mixed when the color ink 100 is sprayed, and are formed differently from those shown in FIGS. 3A and 3B. May be

Hereinafter, a method of forming a color filter using the mask 30 as described above will be described. 4A to 7A and 4B to 7B illustrate a method of forming a color filter according to an exemplary embodiment of the present invention. 4B to 7B illustrate a plan view of a light blocking film pattern and a mask on the substrate shown in FIGS. 4A to 7A. Here, the cross section taken along the opening in the column direction or along the opening in the column direction in FIGS. 4B to 7B corresponds to the light shielding film pattern or mask shown in FIGS. 4A to 7A.

Referring to FIG. 4A, a substrate 1 having a plurality of openings 5 is prepared. The substrate 1 may be an insulating substrate 1 using transparent glass or plastic. The opening 5 may be formed using a light shielding film for blocking the passage of light. That is, it is necessary to block the passage of light to regions other than the individual pixels. For this purpose, after forming a light shielding film on the entire surface of the substrate 1, patterning the light shielding film so that the opening 5 is formed only in the region where the pixel is to be formed. do. The light shielding film may be formed by sputtering with a metal thin film such as chromium (Cr) or may be formed by applying an organic material.

Referring to FIG. 4B, a mask 30 having an opening hole 35b corresponding to the opening 5 together with the substrate 1 is prepared. The mask 30 may be made of acrylic resin, and the opening hole 35b may be formed by punching or the like. The opening holes 35b may be formed in a line shape connected in one direction or may be formed to be separated from each other according to the individual openings 5. Marks 50 for preventing misalignment are formed on the light shielding film pattern 2 and the mask 30.

Referring to FIG. 5A, the substrate 1 having the opening 5 is transferred to the color filter forming apparatus and then mounted on the stage 10. As the color filter forming apparatus, any apparatus to which a printing method is applied may be used, but FIG. 5A illustrates an example of using the color filter forming apparatus described above in the embodiment of the present invention.

When the substrate 1 is seated, the support 20 is raised to allow the mask 30 to be seated, and the mask 30 is transferred to the support as shown in FIG. 5B.

Referring to FIG. 6A, the mask 30 is seated on the upper portion of the support 20, and the mask 30 is placed on the substrate 1 due to the difference between the height of the support 20 and the thickness of the substrate 1. Spaced apart at regular intervals. This is because when the light blocking film pattern 2 on which the opening 5 is formed is made of an organic material or the like, the light blocking film pattern 2 may be damaged during direct contact between the light blocking film pattern 2 and the mask 30. The interval is preferably about 100 μm. If the spacing is too narrow, the substrate 1 may be damaged by the mask 30. If the spacing is too wide, the color ink 100 passing through the opening hole 35b is spread around and a part of the opening 5 is opened. This is because it can reach the adjacent area.

At this time, as shown in FIG. 6B, the opening hole 35b of the mask 30 and the opening 5 of the light shielding film pattern 2 correspond to each other. Therefore, after the alignment is completed, only the opening 5 through which the ink 100 of the same color is ejected by the opening hole 35b is exposed. In addition, as shown in the exemplary drawing, when the opening hole 35b is formed in a line shape, the light shielding film pattern 2 between the opening 5 and the opening 5 is also exposed in addition to the opening 5.

Referring to FIG. 7A, the color ink 100 is injected into each opening 5 while moving the injector 40 along the opening hole 35b. The color ink 100 may be sprayed along the opening 5 in one direction by spraying the individual openings 5 to the target or by a line printing method. In the latter case, however, a mask 30 having a line-shaped open hole 35b is required.

The spraying of the color ink 100 as described above is repeatedly performed in a predetermined order, for example, red / green / blue, and has a separate opening hole 35b at a different position according to the opening 5 corresponding to each color. Mask 30 is used. Alternatively, the single mask 30 may be used while changing the alignment position between the mask 30 and the substrate 1.

FIG. 7B shows a state in which the color ink 100 is injected onto the opening 5 through the opening hole 35b. Here, even if some of the color ink 100 is injected into the region outside the opening hole 35b, it may be confirmed that the color ink 100 is blocked by the mask 30 and thus cannot reach the substrate 1. In this case, the opening 5 of the corresponding region may not be filled with a sufficient amount of the color ink 100, and as a result, the thickness of the color filter may become thin. For these openings 5 additional jet of color ink 100 is required, the problem being to find these openings 5.

However, according to the present invention, it is possible to easily identify the opening portion 5 that needs to be re-injected as described above. That is, as shown in FIG. 7B, the color ink 100 not injected into the opening 5 is sprayed near the opening hole 35b in the region overlapping the opening 5 to color the mask 30. . If the degree of coloring of the mask 30 is high, it means that the amount of the color ink 100 passing through the open hole 35b in the vicinity thereof is small, which is an opening 5 overlapping the open hole 35b. ) Is not filled with a sufficient amount of color ink 100. Therefore, if the area around the opening hole 35b in the mask 30 is inspected for coloring with the color ink 100, and for the colored part, the degree of coloring according to the amount of the color ink 100 is measured. It is possible to easily identify the necessary opening 5.

As described above, according to the color filter forming apparatus and the forming method of the present invention, it is possible to prevent the ink of different colors from being mixed with each other in forming the color filter constituting the pixel by the printing method. In addition, the color ink needs to be jetted again to the pixel for which the color filter having a sufficient thickness is not formed after the color ink is ejected. According to the present invention, it is possible to easily find the pixel in which the color filter having the sufficient thickness is not formed.

Claims (10)

A stage on which the substrate is seated; A support disposed on the stage; A mask seated on the support to be spaced apart from the substrate; Including an injector for injecting a color ink on the substrate; And a plurality of openings into which the inks of different colors are inserted in the substrate, and opening holes formed in the mask so as to overlap with the openings filled with the same color. The method of claim 1, And the openings are formed to be separated from each other along an area overlapping each opening. The method of claim 1, The opening hole is a color filter forming apparatus, characterized in that formed to include a region connecting the opening in one direction. The method according to any one of claims 1 to 3, Color support forming apparatus, characterized in that the support is movable up and down. The method according to any one of claims 1 to 3, And the substrate and the mask include a mark for aligning the opening and the opening. Forming a plurality of openings to allow ink of different colors to be inserted into the substrate; Arranging a mask in which an opening is formed to be spaced apart from the substrate, wherein the opening is positioned to overlap with an opening into which ink of the same color is inserted among the openings; Color filter forming method comprising spraying a color ink into the opening. The method of claim 6, And the openings are formed to be separated from each other along an area overlapping each opening. The method of claim 6, The opening hole is a color filter forming method characterized in that it comprises a region for connecting the opening in one direction. The method according to any one of claims 6 to 8, And re-injecting the color ink into the opening in which the color ink is sprayed after the color ink is ejected. The method of claim 9, And the color ink ejected in the vicinity of the opening hole of the mask is inspected and identified by the opening in which the color ink is ejected little.

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