KR20070079820A - Slit coater for manufacturing display device and manufacturing method of display device using the same - Google Patents

Abstract

A slit coater for manufacturing a display device is provided to form a coating layer with uniform quality, especially even thickness. A slit coater for manufacturing a display device comprises: a coating solution feeder; and a slit nozzle(15) which includes an injecting part injected with a coating solution from the coating solution feeder, an elongated slit part for applying the coating solution onto a target substrate, and a cavity(14) formed between the injecting part and the slit part and having a volume of 0.13-0.5cc per 1mm of the slit part.

Description

SLIT COATER FOR MANUFACTURING A DISPLAY DEVICE AND MANUFACTURING METHOD OF THE DISPLAY DEVICE USING THE SAME {SLIT COATER FOR MANUFACTURING DISPLAY DEVICE AND MANUFACTURING METHOD OF DISPLAY DEVICE USING THE SAME}

1 is a perspective view of a slit coater according to a first embodiment of the present invention,

2 is a cross-sectional view taken along II-II of FIG. 1,

3 is a cross-sectional view taken along III-III of FIG. 1,

4A and 4B are views for explaining a slit coating using a slit coater according to the first embodiment of the present invention,

5 is a graph for explaining the relationship between the cavity volume of the slit coater and the thickness distribution of the coating layer,

6A to 6C are graphs for explaining Experimental Example 1 of the present invention carried out on a patternless substrate,

7A and 7B are graphs for describing Experimental Example 2 of the present invention performed on a substrate on which a black matrix is formed.

8a and 8b are graphs for explaining Experimental Example 3 of the present invention carried out by varying the coating speed,

9A to 9F are views for explaining a method of manufacturing a display device using a slit coater according to a first embodiment of the present invention.

10 and 11 are cross-sectional views of the slit coater according to the second and third embodiments of the present invention, respectively.

Explanation of Signs of Major Parts of Drawings

10: slit nozzle 11, 12: sub body

13 injection part 14 cavity

15 nozzle part 20 coating liquid supply part

21: coating liquid tank 22: mass flow controller

The present invention relates to a slit coater for manufacturing a display device and a method of manufacturing the display device using the same.

Recently, a flat panel display such as a liquid crystal display (LCD), a plasma display panel (PDP), or an organic light emitting diode (OLED) has been used in place of the conventional CRT.

In the manufacture of these flat panel display devices, a process of forming a coating layer by coating a thin film such as a photosensitive material on the entire substrate is used. The coating layer is patterned through exposure, development, and the like as necessary.

Methods of forming such a coating layer include spin coating and slit coating. Slit coating is a method of discharging a coating liquid through a nozzle while moving a slit coater having an elongated nozzle on a substrate.

Recently, as the size of the display device has increased, the length of the slit coater has also increased. However, as the length of the slit coater increases, the degree of ejection becomes uneven according to the position, thereby causing a problem in that the quality of the coating layer, in particular, the thickness is not constant.

Accordingly, an object of the present invention is to provide a slit coater for manufacturing a display device capable of forming a coating layer of uniform quality.

Another object of the present invention is to provide a method of manufacturing a display device using a slit coater for manufacturing a display device capable of forming a coating layer of uniform quality.

The purpose of the coating liquid supply unit; An injection portion into which the coating liquid from the coating liquid supply portion is injected and an elongated slit portion for coating the coating liquid on a substrate to be treated; between 0.13 cc and 0.5 cc per 1 mm of length of the slit portion between the injection portion and the slit portion It is achieved by a slit coater for manufacturing a display device comprising a slit nozzle having a cavity having a volume of.

The injection portion is located at the center of the slit nozzle, the cavity is preferably provided symmetrically around the injection portion.

Preferably, the cavity is inclined downward as it moves away from the injection portion.

Preferably, the cross section of the cavity becomes wider as it moves away from the injection portion.

The gap of the nozzle is preferably 60 μm to 140 μm.

The object of the present invention and the coating liquid supply; The coating liquid is supplied from the coating liquid supply unit, and the coating liquid into which the coating liquid is injected is passed through an elongated cavity having a volume of 0.13 cc to 0.5 cc per 1 mm of discharge width. Is achieved.

Another object of the present invention includes an injection portion into which the coating liquid is injected and an elongated slit portion for coating the coating liquid on the substrate to be treated, and between 1.3 cc per 1 mm length of the slit portion between the coating liquid supply portion and the slit portion. Coating a coating layer on the insulating substrate by using a slit coater including a slit nozzle having a cavity having a volume of 5 cc; It is achieved by a method for manufacturing a substrate for a display device comprising patterning the coating layer.

And forming a lattice black matrix on the insulating substrate, wherein the coating layer is formed on the black matrix, and the coating layer comprises a color filter material.

The viscosity of the coating solution is preferably 2cP to 6cP.

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

In the following examples, the same reference numerals refer to the same components. The same components are representatively described in the first embodiment and may be omitted in other embodiments.

A liquid crystal display according to a first exemplary embodiment of the present invention will be described with reference to FIGS. 1 to 3.

1 is a perspective view of a slit coater according to a first embodiment of the present invention, FIG. 2 is a sectional view taken along II-II of FIG. 1, and FIG. 3 is a sectional view taken along III-III of FIG.

The slit coater 1 according to the first embodiment of the present invention includes a slit nozzle 10 and a coating liquid supply part 20.

The slit nozzle 10 is elongated and receives the coating solution from the coating solution supply unit 20 to form a coating solution on the substrate. The length W of the slit nozzle 10 may be about 800 mm to 2000 mm.

The slit nozzle 10 includes a first sub main body 11 and a second sub main body 12 coupled to each other. The first sub main body 11 has an intricate shape compared to the second sub main body 12, and forms the injection part 13, the cavity 14, and the nozzle part 15.

The injection unit 13 is connected to the coating solution supply unit 20 and receives the coating solution. The injection part 13 is located in a substantially center portion in the longitudinal direction of the slit nozzle 10.

The cavity 14 is connected to the injection part 13 and extends in both directions about the injection part 13. The cavity 14 is symmetrically formed at both sides about the injection part 13.

The coating liquid supplied through the injection part 13 passes through the cavity 14 and then proceeds to the nozzle part 15. The cavity 14 has a larger volume than the nozzle unit 15, and has a volume of about 0.13 cc to 0.5 cc per 1 mm of the nozzle unit 15. For example, when the length W of the slit nozzle 10 is about 1200 mm, the cavity 14 has a volume of about 156 cc to 600 cc. The reason why the volume of the cavity 14 has this value will be described later.

The cavity 14 is also lowered away from the injection part 13 about the injection part 13. The angle of inclination, ie, the hanger angle θ, may be around 1 degree.

The first sub main body 11 and the second sub main body 12 face each other with a small gap g therebetween to form the nozzle unit 15. The nozzle unit 15 is connected to the cavity 14, and the gap g of the nozzle unit 15 may be 60 μm to 140 μm.

The orifice length L of the nozzle portion 15 depends on the position of the cavity 14. That is, the orifice length L of the nozzle unit 15 is the longest in the center of the slit nozzle 10 in which the cavity 14 is located at the top, and the slit nozzle 10 in which the cavity 14 is located at the bottom thereof. It is the shortest at both ends of. The orifice length L at both ends of the shortest slit nozzle 10 may be 10 mm to 60 mm.

The coating liquid supply unit 20 includes a coating liquid tank 21 and a mass flow controller.

The slit coater 1 as described above coats the supplied coating liquid on a substrate with a uniform thickness regardless of the position. That is, to form a coating layer having a uniform thickness in both the portion close to the injection portion 13 or the portion away from the injection portion 13.

This is because the coating liquid flows uniformly by the cavity 14 having a large volume. This is because the orifice length L of the nozzle portion 15 decreases as the distance from the injection port 13 decreases, and the discharge resistance decreases.

Hereinafter, the cavity volume of the slit coater will be described with reference to FIGS. 4A to 5.

4A and 4B are views for explaining a slit coating using a slit coater according to the first embodiment of the present invention, Figure 5 is a graph for explaining the relationship between the cavity volume of the slit coater and the thickness distribution of the coating layer. .

As shown in FIG. 4A, the slit nozzle 10 forms the coating layer 110 while passing through the substrate 100 in the vertical direction of the extension direction. The extending direction of the slit nozzle 10 is called TD, and the advancing direction of the slit nozzle 10 is called MD.

The coating layer 110 may be formed in a non-uniform thickness, of which thickness non-uniformity in the MD direction is determined by the performance of the coating liquid supply unit 20, or the composition of the coating liquid. On the other hand, the thickness nonuniformity in the TD direction is determined according to the performance of the slit nozzle 10. In particular, the thickness difference between the center portion A and the edge portion B of the slit nozzle 10 becomes a problem.

When bending occurs in the coating layer 110 as shown in Figure 4b, there is a problem that the stain is recognized according to the width (dx) of the bending and the height of the bending (dy). The spot is observed when dy / dx is above a certain level. If the width of the bend (dx) is small for the same height of dying (dy), it is recognized as a stain. If the width of the bend (dx) is large, it is not recognized as a stain. .

On the other hand, the height change (dy) of the bending may be expressed in dBy indicating a change in position on the NTSC color coordinate when the coating layer 110 is a blue color filter material. This is because it is easier to measure the color characteristics of the coating layer 110 than directly measuring the thickness of the coating layer (110). A dBy of 0.0012 means about 365 dB of dy, and a large dBy means a large dy.

Table 1 below shows dBy / dx * 1000 values (hereinafter referred to as “staining index”) according to the width of the curve (dx) and the height of the curve (dBy).

   Table 1

In Table 1, stains are not recognized when the stain index is about 0.25 or less, and stains are recognized when the stain index is about 0.7 or more. Hereinafter, the staining index 0.7 will be described based on the generation of defects.

5 is a graph for explaining the relationship between the cavity volume of the slit nozzle and the thickness distribution of the coating layer.

In the experiment, when the length W of the slit nozzle 10 was 1100 mm, the coating liquid flow rates of the central portion and the edge portion were measured while changing the volume of the cavity 14 of the slit nozzle 10.

5, it can be seen that the smaller the volume of the cavity 14 is, the larger the flow rate Qcenter at the center portion is compared to the flow rate Qedge at the edge portion. In this case, the thickness of the coating layer is different from the center portion and the edge portion, and the bending becomes severe, causing stains.

As the volume of the cavity 14 increases, the difference between the flow rate Qcenter at the center portion and the flow rate Qedge at the edge portion decreases, and when the volume of the cavity 14 reaches about 150 cc or more, the difference almost disappears. .

This is considered to be because when the volume of the cavity 14 is about 150 cc or more, the cavity 14 effectively plays a buffer role and makes the pressure at the end of the nozzle portion 15 constant regardless of the position.

The volume of the cavity 14 in which the flow rate is constant irrespective of the position can be expressed as a ratio with respect to the length W of the slit nozzle 10. Through experiments, this value is 150cc / 1100mm, which is about 0.13cc / mm.

Even if the volume of the cavity 14 increases to 150 cc or more, the effect of keeping the flow rate constant regardless of the position is maintained. However, when the volume of the cavity 14 is larger than about 0.5 cc / mm, problems due to the stagnation of the coating liquid may occur, so the volume of the cavity 14 is preferably smaller than about 0.5 cc / mm.

Hereinafter, the performance of the slit coater 1 according to the present invention will be described through experiments.

Experimental Example 1

The experiment was carried out by coating a blue color filter on a glass substrate having no pattern. The viscosity of the blue color filter was about 4.2 cP and the length of the slit nozzle was 1100 mm.

Table 2 summarizes the conditions of the slit nozzle used in the experiment.

  TABLE 2

As shown in Table 2, the nozzle coater according to the present invention has a cavity having a volume of about 202 cc, that is, 0.183 cc / mm, and the nozzle coater of the comparative example has a cavity having a volume of about 26 cc, that is, 0.023 cc / mm. Formed.

6a to 6c show the results of Experimental Example 1 and showed By values along the TD direction. 6a and 6b are for the comparative example and shows the thickness distribution when one sheet is coated and 480 sheets are coated. FIG. 6B is an enlarged view of a portion “C” of FIG. 6A. Figure 6c shows the thickness distribution of the case of coating one sheet and the case of 120 sheets coated for the Example.

6A and 6B of the comparative example, the spot where the speckle index (dBy / dx * 1000) exceeds 0.7 is observed. In particular, the edges of staining index were 0.6 in the case of 1 sheet, but increased to 1.0 in the case of 580 sheets.

On the other hand, in FIG. 6C for the embodiment, although the thickness change at the edge is somewhat large, since it is changed over a wide range, the stain index has a value within the standard such as 0.1 or 0.35. In the case of one sheet or 120 sheets, the thickness distribution was almost the same.

Experimental Example 2

The experiment was carried out by coating a blue color filter on a glass substrate having a black matrix formed thereon. The viscosity of the blue color filter was about 4.2 cP and the length of the slit nozzle was 1100 mm. The nozzle coater used was the same as in Experiment 1.

7A and 7B show the results of the experimental example and showed By values along the TD direction. Figure 7a is for the comparative example and shows the thickness distribution in the case of coating one sheet and 400 sheets. Figure 7b shows the thickness distribution for the case of coating one sheet, coated 400 sheets, coated 600 sheets and coated 800 sheets.

Referring to FIG. 7A for the comparative example, the staining index of 0.5 to 0.55 level is observed when 400 sheets are coated. In particular, it can be seen that the coating of 400 sheets is more severe in thickness change than the first coating.

On the other hand, in Figure 7b for the embodiment, although the thickness change at the edge is somewhat large, because it was changed over a wide range, the staining index shows a level of 0.33. In particular, the thickness profile was almost constant regardless of the number of coatings.

Table 3 puts together the result of Example 1 and Example 2 mentioned above.

 Table 3.

Looking at Table 3 it can be seen that the nozzle coater according to the embodiment has a small number of inflection points that can cause staining and a staining index of 0.35 or less regardless of the number of coatings. In addition, the nozzle coater shows excellent performance regardless of the substrate having no pattern or the substrate having the black matrix formed thereon.

Experimental Example 3

In this experiment, the coating speed was changed to 120 mm / sec and 150 mm / sec for the nozzle coater according to the example. In addition, after coating for a predetermined time at 150m / sec, the experiment was performed to coat again at 150mm / sec after 2 hours coating stop.

8A illustrates the results of Experimental Example 3, and shows By values according to the TD direction. Referring to FIG. 8A, the thickness is slightly different in three cases, but the overall thickness profile is similar.

FIG. 8B shows the staining index for the six points where the bending is indicated by a rectangle in FIG. 8A. The staining index is all 0.3 or less, it can be seen that it is within the standard. Therefore, it can be seen that the nozzle coater according to the embodiment may be used at 150 cc / sec, which corresponds to the operation speed of the conventional nozzle coater.

On the other hand, the conventional nozzle coater has a problem that contamination occurs at the interface between the nozzle portion inner wall surface and the coating liquid during the coating standby. However, according to Experiment 3, the nozzle coater according to the embodiment does not cause such a contamination problem.

9A to 9F illustrate a method of manufacturing a display device using a slit coater according to a first embodiment of the present invention. 9A to 9F illustrate a method of manufacturing a color filter substrate used in a liquid crystal display.

First, a lattice-like black matrix 121 is formed on the insulating substrate 120 as shown in FIGS. 9A and 9B.

Next, a blue color filter 122a is formed on the insulating substrate 120 on which the black matrix 121 is formed as shown in FIG. 9C by using the slit coater 1 according to the present invention, and the blue color filter coated as shown in FIG. 9D. Pattern 122a.

Next, the red color filter 122b is coated on the patterned blue color filter 122a using the slit coater 1 as shown in FIG. 9E.

Subsequently, when the red color filter 122b is patterned and the green color filter 122c is subjected to the same process, the color filter substrate shown in FIG. 9F is completed. The color filter 122 of the completed color filter substrate has a constant thickness irrespective of the position, so that spots are reduced.

In the above, the slit coater 1 of the present invention is limited to that used for the formation of the color filter, but the slit coater 1 may be used to form various organic layers, protective films, and the like used in the display device. The display device in the present invention includes a liquid crystal display device, an organic light emitting display device, a PDP, and the like.

10 and 11 are cross-sectional views of the slit coater according to the second and third embodiments of the present invention, respectively.

In the second embodiment shown in FIG. 10, the diameter of the cavity 14 increases toward the edge. That is, the diameter R2 of the edge portion is larger than the diameter R1 of the center portion. Accordingly, the volume per unit length of the cavity 14 also increases toward the edge, thereby making the discharge pressure at the edge portion constant.

In the third embodiment shown in Fig. 11, no hanger angle is formed in the cavity 14, and thus the orifice length L of the nozzle portion 15 is constant regardless of the position.

Although some embodiments of the invention have been shown and described, those skilled in the art will recognize that modifications can be made to the embodiments without departing from the spirit or principles of the invention. . It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents.

As described above, according to the present invention, there is provided a slit coater for manufacturing a display device capable of forming a coating layer of uniform quality.

In addition, a method of manufacturing a display device using a slit coater for manufacturing a display device capable of forming a coating layer of uniform quality is provided.

Claims (9)

A coating liquid supply unit; An injection portion into which the coating liquid from the coating liquid supply portion is injected and an elongated slit portion for coating the coating liquid on a substrate to be treated; between 0.13 cc and 0.5 cc per 1 mm of length of the slit portion between the injection portion and the slit portion A slit coater for manufacturing a display device comprising a slit nozzle having a cavity having a volume of about. The method of claim 1, The injection portion is located in the center of the slit nozzle, The cavity is a slit coater for manufacturing a display device, characterized in that provided in the left and right symmetry around the injection portion. The method of claim 2, And the cavity is inclined downward as it moves away from the injection portion. The method of claim 2, The slit coater for manufacturing a display device, wherein the cross section of the cavity becomes wider as it moves away from the injection portion. The method of claim 1, The gap of the nozzle is a slit coater for manufacturing a display device, characterized in that 60㎛ to 140㎛. A coating liquid supply unit; A slit coater for manufacturing a display device comprising a slit nozzle which receives a coating liquid from the coating liquid supplying part and is discharged after passing the elongated cavity having a volume of 0.13 cc to 0.5 cc per 1 mm of discharge width. A cavity having an injection portion into which a coating liquid is injected and an elongated slit portion for coating the coating liquid on a substrate to be treated, and having a volume of 1.3 cc to 5 cc per 1 mm length of the slit portion between the coating liquid supply portion and the slit portion. Coating a coating layer on the insulating substrate using a slit coater including a slit nozzle formed thereon; And patterning the coating layer. The method of claim 7, wherein Forming a lattice-like black matrix on the insulating substrate, wherein the coating layer is formed on the black matrix, The coating layer of claim 1, wherein the display device comprises a color filter material. The method of claim 7, wherein The viscosity of the coating solution is a manufacturing method of the display device, characterized in that 2cP to 6cP.

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