KR100983162B1 - Equipments for light exposure for large substrate - Google Patents

Abstract

An exposure apparatus including a light source, an optical system for processing light of a light source, a pattern mask, and a work table on which a substrate is placed, wherein the pattern mask is formed to be wider to completely cover the substrate, and the work table is used during the exposure operation. The table surface is installed vertically as a whole, and the substrate mounting jaw is formed in a closed curve along the position where the substrate edge is placed so as to adsorb the periphery of the substrate. Disclosed is an exposure apparatus comprising a mask mounting jaw formed to form a closed curve along a position at which the periphery of the pattern mask is placed outside the jaw, and a mask side vacuum suction port provided between the substrate mounting jaw and the mask mounting jaw.

Description

Exposure device {Equipments for light exposure for large substrate}

1 is an explanatory diagram showing that a deviation in pattern size occurs due to a gap between the pattern mask and the substrate and the divergence angle of light;

2 is an explanatory diagram showing a deflection phenomenon of a large area pattern mask in a conventional planar mounting method;

3 is a schematic diagram illustrating an exposure method of vertically mounting a substrate and a pattern mask;

4 is an explanatory diagram in which the problem of the vertical table is enlarged and expressed in the exposure method as shown in FIG. 3;

5 is a plan view schematically illustrating a work table configuration, a mounting position of a substrate, and a pattern mask of an exposure apparatus according to an embodiment of the present invention;

6 and 7 are partial cross-sectional views for explaining a state in which a substrate and a pattern mask are fixed to a work table by the action of a vacuum in one embodiment of the exposure apparatus of the present invention installed vertically.

* Explanation of symbols for the main parts of the drawings

10: pattern mask 20: substrate

30,300: Work table 32,38,39: Vacuum passage                 

33: mask mounting jaw 34: mask side vacuum suction port

35: substrate side vacuum suction port 36: substrate mounting jaw

37: Opening 41: First space

43: second space

The present invention relates to an exposure apparatus, and more particularly, to an exposure apparatus table for forming a precise pattern on a large area substrate (panel) of a large-screen display such as a PDP.

With the trend toward the larger screens of display devices, large area sizes exceeding 40 inches are accelerating in display devices such as PDPs. At the same time, high definition of the screen is required. In order to form a pixel or other pattern uniformly and with high precision on a large area substrate or substrate filter, an exposure process for forming pixels is also required to be made with high precision over the entire area. In particular, these demands are growing in pursuit of multifaceted processes to reduce process costs and increase productivity.

Generally, an exposure process is performed by apply | coating an exposure substance to a target surface, and exposing a coating film by shining light through a pattern mask on a coating film. Such an exposure process generally requires an exposure apparatus including an optical system for processing a light source and the light of the light source to a desired state, and a work table on which an exposure mask and a substrate are placed.

Unlike exposure to a small area such as a semiconductor, when exposing to a large area such as a PDP panel, it is difficult for the light source to be parallel light. In addition, although the light may be subjected to a collimator so that the light is close to parallel light, the divergence angle is present even when collimated.

Therefore, when the distance between the substrate surface on which the coating film is formed and the pattern mask for exposure is increased, the pattern larger than the pattern on the mask is larger than the pattern on the mask even under exposure in which the light is passed through the transparent portion of the mask and the size is transferred 1: 1. Is formed. 1 is an explanatory diagram for explaining this phenomenon. Here, the length dX in which the pattern of the coating film of the substrate 20 is increased compared to the mask pattern is approximately proportional to the product of the distance Z between the pattern mask 10 and the coating film of the substrate 20 and the divergence angle θ (radian). Able to know. This is achieved without major problems because the general divergence angle is a degree sufficiently smaller than the right angle.

On the other hand, the current PDP EMI filter is required to form a precise pattern width of about 10 ± 2um, the current process requires a precision that the deviation dX is less than 1um in this pattern width. In order to fall within such a deviation range, the divergence angle should not exceed 5.87 degrees when the gap between the pattern mask and the substrate coating film is 10 μm, and when the gap is 20 μm. In order to fall within the desired deviation range, there is a method of reducing the divergence angle or reducing the distance Z between the pattern mask and the substrate coating film. However, reducing the divergence angle, which is an optical characteristic value, is difficult due to limitations due to the size of the lens, mirror, etc. constituting the optical system. This reality requires that there be substantially no gap between the pattern mask and the substrate coating film.

However, in the conventional large area batch exposure method using ultraviolet light for forming the display panel, the area of the pattern to be exposed is large while the thickness of the pattern mask to be used is only a few [mm]. Therefore, in the exposure apparatus, when the pattern mask 10 is positioned on the substrate 20 for exposure as shown in FIG. 2, the substrate 20 is placed on the work table 30 while the pattern mask 10 is supported only at the periphery thereof. The gap between the pattern mask 10 and the substrate 20 coating film could not be kept constant.

In order to solve the problem of the pattern mask sagging caused by gravity, a method of mounting the pattern mask 10 vertically and fixing the substrate 20 to the vertical work table 30 has been introduced. 3 is a diagram showing a schematic configuration for explaining such an exposure method.

In order to use the method shown in FIG. 3, the substrate 20 must be fixed to the vertical work table 30, and vacuum adsorption is usually used as the fixing method. If the substrate 20 is vacuum-adsorbed to the work table 30, the substrate surface is in close contact with the table surface. By the way, in the table processing technology, the plane precision that can be obtained by grinding and surface treatment of a square table of about 2m on one side is about 50um. That is, the difference between the most prominent part and the recessed part may have a difference of about 100um.

Fig. 4 is an explanatory diagram in which the problems of the vertical work table 30 described above are exaggerated in large-area exposure, and Fig. 32 shows a vacuum passage. In this state, even if the surface of the pattern mask 10 is perpendicular to the ground, the surface of the substrate 20 is curved, so that the gap between the surface of the pattern mask 10 and the surface of the substrate 20 is not constant. Therefore, even when parallel light is used, it is difficult to form a uniform and precise pattern over the entire surface of the substrate 20 by an exposure process, and the precision pattern uses a step exposure method, which causes a cost increase.

SUMMARY OF THE INVENTION The present invention solves the problems caused by the precision of the substrate surface in the vertical front exposure of the large area substrate described above, and keeps the gap between the pattern mask and the substrate below a certain level by bringing the pattern mask and the substrate surface into close contact with each other. It is an object of the present invention to provide an exposure apparatus that enables high-definition pattern exposure.

SUMMARY OF THE INVENTION An object of the present invention is to provide an exposure apparatus capable of transferring a mask pattern having a desired shape and size to a substrate even when a divergence angle of light used for exposure is large by substantially eliminating the gap between the pattern mask and the substrate.

The present invention for achieving the above object,

In the exposure apparatus provided with the light source, the optical system which processes the light of a light source, a pattern mask, and the work table on which a board | substrate is placed,

The pattern mask is formed wider to completely cover the substrate,

The work table is installed so that the table surface is perpendicular to the entire surface during the exposure operation, at least one substrate mounting jaw formed in a closed curve along the position where the substrate peripheral portion is placed so as to absorb the peripheral portion of the substrate, the substrate mounting At least one mask mounting hole formed on the table surface inside the outermost substrate mounting jaw of the jaw, at least one mask mounting formed to form a closed curve along the position where the periphery of the pattern mask is placed outside the outermost substrate mounting jaw. And at least one mask side vacuum suction port provided on the table surface between the jaw, the outermost substrate mounting jaw and the outermost mask mounting jaw among the mask mounting jaws.

In the present invention, when the substrate mounting jaw is made up of two or more, and the substrate side vacuum suction port is formed between these substrate mounting jaws, it is preferable because the substrate holding jaw can be more efficiently grasped and the deflection of the substrate can be reduced. . In this case, a hole may be formed in the central portion of the inner working table of the innermost substrate mounting jaw to allow the outside air to act on the inner surface of the substrate.

In the present invention, the substrate mounting jaw and the mask mounting jaw are made of a soft hermetic material that does not leak when the vacuum is applied to the vacuum suction port while being in close contact with the substrate. On the other hand, the mounting jaw is made of a material having a certain mechanical strength and elasticity, when the vacuum is applied to the vacuum inlet it is preferable that the height is reduced by the force when the substrate or mask is pulled toward the work table. With such a material, it is possible to use foam rubber having excellent elasticity.

In the present invention, the substrate mounting jaw is preferably formed lower than the mask mounting jaw.

In the present invention, the vacuum inlets may be formed of one or a plurality of openings, and are preferably installed to form a closed curve on the work table in parallel with the mounting jaw.

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

Figure 5 is a plan view of a work table in one embodiment of the exposure apparatus of the present invention, Figure 6 is a state in which the substrate is fixed to the work table by vacuum suction while the work table is vertically positioned in one embodiment of the exposure apparatus of the present invention. 7 is a cross-sectional view showing a state in which the work mask is vertically positioned and the pattern mask is fixed to the work table by vacuum suction and closely adhered to the substrate in one example of the exposure apparatus of the present invention.

Referring to the drawings, in the present embodiment, it is assumed that it has a conventional light source and an optical system, and in the conventional exposure apparatus, the pattern mask 10 and the work table serving as the substrate 20 holder are separately installed, whereas the pattern mask 10 is also mounted on the work table 300. The pattern mask 10 is formed wider than the substrate 20, and the work table 300 is also formed wide enough to place the pattern mask 10. The work table 300 is installed so that the table surface is perpendicular to the ground as a whole during the exposure operation.

On the work table 300, two substrate mounting jaws 36 are positioned along the position where the periphery of the substrate 20 is placed, that is, along the edge of the substrate 20 so as to absorb the periphery of the substrate 20. It is installed. Each substrate mounting jaw 36 is a closed curve, the jaw height is made the same size. The substrate side vacuum suction port 35 is installed on the surface of the work table 300 between the two substrate mounting jaws 36 to form a closed curve alongside the jaw. Therefore, when a vacuum is applied to the substrate side vacuum suction port 35, the space surrounded by the two jaws 36, the surface of the substrate 20, and the work table 300 becomes a vacuum while the substrate 20 is driven by the external atmospheric pressure. It is pressed toward the 300 and is in close contact with the substrate mounting jaw 36.

Since the substrate holding jaw 36 is made of a soft material such as rubber, airtightness is likely to be maintained as the substrate 20 comes in close contact with the substrate 20. Since no vacuum acts on the central portion of the substrate 20, the substrate 20 is not deformed toward the work table 300 by atmospheric pressure. Since the substrate mounting jaw 36 is an elastic body, the height is reduced by the action of atmospheric pressure. The decreasing height can be adjusted according to the degree of vacuum.

A mask mounting jaw 33 is formed outside the substrate mounting jaw 36 on the work table 300 to form a closed curve along a position at which the periphery of the pattern mask 10 is placed. The mask side vacuum suction hole 34 is provided on the work table surface between the outer side of the substrate holding jaws 36 and the mask mounting jaw 33. A plurality of mask mounting jaws 33 are also provided, and a mask side vacuum suction port 34 may be provided between the mask mounting jaws 33, but the close contact between the pattern mask 10 and the substrate 20 is illustrated. It can be harder than yes.

Looking at the process in which the substrate 20 and the pattern mask 10 is installed on the work table 300 for exposure in the illustrated embodiment, first, the substrate on the substrate mounting jaw 36 of the work table 300 installed vertically ( The substrate 20 is approached to the work table 300 such that the periphery of 20 is reached. As the degree of vacuum applied to the first space 41 between the two substrate holding jaws 36, the substrate 20, and the work table 300 is increased by the substrate side vacuum suction hole 35, the substrate 20 is placed on the substrate mounting jaw. The substrate 20 is fixed to the work table 300 while being closely adhered to the 36, and the height of the substrate mounting jaw 36 decreases.

Subsequently, the pattern mask 10 approaches the work table 300 such that the periphery of the pattern mask 10 is placed on the mask mounting jaw 33 of the work table 300. As the vacuum is applied to the mask side vacuum suction port 34, the pattern mask is in close contact with the mask mounting jaw 33 and fixed to the work table 300. The degree of vacuum applied to the space between the substrate 20 and the pattern mask 10 and the second space 43 between the substrate mounting jaw 36 and the mask mounting jaw 33 is increased by the mask side vacuum inlet 34. As a result, the air pressure pushing the substrate 20 from the outside of the substrate toward the work table 300 becomes small. The first space 41 is slightly expanded and reduced as the height of the substrate mounting jaw 36 is gradually recovered, the substrate 20 is partially moved toward the pattern mask 10.

On the other hand, as the vacuum degree of the inner second space 43 increases, the force pushing the pattern mask 10 toward the substrate 20 from the outside gradually increases. Since the pattern mask 10 is supported only at the periphery, the center portion is convexly deformed toward the substrate under atmospheric pressure. On the other hand, at the periphery of the mask mounting jaw 33 is reduced in height. When the gap between the substrate 20 and the pattern mask 10 gradually decreases and the vacuum degree of the second space 43 reaches a predetermined level, there is substantially no gap between the substrate 20 and the pattern mask 10.                     

However, if the vacuum degree of the substrate side vacuum suction port 35 is too low and the vacuum degree of the mask side vacuum suction port 34 is high, when the vacuum is applied to the mask side vacuum suction port 34, the substrate 20 will be removed from the substrate mounting jaw 36. The degree of vacuum must be controlled as there is a risk of separation and dropping. In addition, since the height and elasticity of the substrate mounting jaw 36 or the mask mounting jaw 33 affect the deformation of the pattern mask 10 and the adhesion between the substrate 20 and the pattern mask 10, the degree of vacuum is controlled and adjusted. Should be. Typically, the substrate mounting jaw may be slightly lower than or equal to the mask mounting jaw.

On the other hand, the space between the central portion of the substrate 20 and the work table 300 may be a vacuum of the same degree of vacuum as the first space 41, depending on the configuration of the table or the relative height of the substrate mounting jaw 36, It may be at atmospheric pressure or higher than atmospheric pressure. When the opening 37 connecting the space and the external atmosphere is formed on the work table 300 surface, the work table 300 of the substrate 20 when the substrate 20 and the pattern mask 10 are in close contact with each other as shown in FIG. Since atmospheric pressure acts on both the side surface and the outer surface of the pattern mask 10, the exposure may be more precise in that the substrate surface is vertical.

When the substrate and the pattern mask are substantially in contact with each other, the amount of fine gap between them may be determined as an interference fringe generated between the contacted substrate and the pattern mask. Even in the presence of a fine gap, this gap does not need to be measured since there is no problem in forming a pattern having a pattern size of 10 ± 2 μm with a precision of about 1 μm of deviation from a light having a normal divergence angle.

If a plurality of mask mounting jaws are provided and a mask side vacuum suction port is installed between the mask mounting jaws, the close contact between the pattern mask and the substrate is only to reduce the height of the mask mounting chuck by increasing the degree of vacuum in the space between the mask mounting jaws. Will be done by Therefore, there will be a constraint that the vacuum degree is very high or the masking jaw should be used with a more elastic material.

On the other hand, in the present invention, since the pattern mask is in direct contact with the substrate surface, a strong material such as chromium should be used as the material of the film forming the pattern mask, and care must be taken in preparation for contamination.

According to the present invention, in a large-area exposure using a large-area mask and a substrate, the pattern mask and the substrate surface are substantially adhered to each other, thereby maintaining a gap between the pattern mask and the substrate at a predetermined level, thereby enabling high-definition pattern exposure. However, even when the divergence angle of light is large due to the characteristics of large area exposure, a mask pattern having a desired shape and size can be transferred to the substrate.

Claims (7)

An exposure apparatus comprising a light source, an optical system for processing light of the light source, a pattern mask, and a work table on which a substrate is placed. The pattern mask is formed wider than the substrate so as to completely cover the substrate, The work table is installed so that the table surface is perpendicular to the entire surface during the exposure operation, at least one substrate mounting jaw formed in a closed curve along the position where the substrate peripheral portion is placed so as to absorb the peripheral portion of the substrate, the substrate mounting jaw At least one substrate side vacuum suction port installed on the table surface inside the outermost substrate mounting jaw, and at least one mask mounting jaw formed to form a closed curve along a position where the periphery of the pattern mask is placed outside the outermost substrate mounting jaw. And at least one mask side vacuum suction port provided on the table surface between the outermost substrate mounting jaw and the outermost mask mounting jaw among the mask mounting jaws. The method of claim 1, And the substrate mounting jaw and the mask mounting jaw are made of a foam rubber which is a soft elastic material. The method of claim 1, The vacuum suction ports are formed of a plurality of openings or in parallel with the mounting jaw is installed to form a closed curve on the work table surface. The method of claim 1, The pattern mask is an exposure apparatus, characterized in that the chrome mask. The method of claim 1, The mask mounting jaw is made of a plurality, And the mask side vacuum suction port is formed between the mask mounting jaws. The method of claim 1, The substrate mounting jaw is made of a plurality, And the substrate side vacuum suction port is formed between the substrate holding jaws. The method of claim 6, And a hole is formed in the table surface inside the innermost substrate mounting jaw among the substrate mounting jaws so that outside air can act on the substrate.

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