KR100817124B1 - Apparatus for exposing light in fabricating lcd - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to exposure equipment for manufacturing LCDs, and more particularly to a pre-align chuck used in the pre-alignment stage of a substrate. In the exposure apparatus for manufacturing an LCD according to the present invention, the pre-align chuck used in the pre-alignment step injects nitrogen gas through a hole formed in the pre-align chuck, thereby reducing friction applied to the substrate, thereby easily freezing the substrate. Can be. However, the conventional free alignment chuck does not sufficiently remove the friction generated on the substrate, which causes the substrate to bend. In the pre-aligned chuck of the present invention, the size of the hole formed in the chuck to inject nitrogen gas is small in the center, and the size of the hole increases in the edge thereof to minimize the frictional force acting on the substrate.

Description

Exposure equipment for LCD manufacturing {APPARATUS FOR EXPOSING LIGHT IN FABRICATING LCD}

1 is a view schematically illustrating a color filter substrate and a thin film transistor substrate constituting a liquid crystal panel.

2 is a schematic diagram illustrating exposure equipment for alignment and exposure;

3A is a view showing a state where a substrate is mounted on a conventional free alignment chuck.

FIG. 3B is a diagram showing the generation of a gradient of force gradient due to friction due to deformation of the substrate.

4 is a view showing a hole formed in a conventional free alignment chuck.

5 is a view showing a hole formed in the pre-aligned chuck according to the exposure equipment for manufacturing LCD of the present invention.

6 is a cross-sectional view showing a cross section of the X-axis in FIG.

** Explanation of symbols for main parts of drawings **

11: thin film transistor substrate 12: color filter substrate

13: liquid crystal layer 14: pixel electrode

15: thin film transistor 15b: storage capacitor

16: sealant 18: color filter

19: ITO 20: spacer

21: alignment film 23: light collecting system                 

24: Reticle 25: Lens

26 plate 28 reticle alignment system

29: plate alignment system 30: laser interferometer

31: reference pin 33: pre-aligned chuck

34: substrate 41: hole

The present invention relates to exposure equipment for LCD manufacturing, and more particularly, to a pre-align chuck used in the pre-alignment step of the pre-exposure step.

Recently, a variety of large screen, high-definition display equipment has been developed in addition to the CRT, and PDP, LCD, and projection displays are representative. Among them, LCDs are widely used with LEDs because of their relatively low manufacturing cost, thin thickness, and low heat generation, and are widely used as electronic wrist watches, TV screen displays, and outdoor full-color displays. .

The cross section of the TFT-LCD panel is manufactured in the form of the liquid crystal layer 13 formed between the TFT array substrate (Thin Film Transistor) substrate 11 and the C / F (color filter) substrate 12 as shown in FIG. The TFT substrate 11 is provided for each pixel, and has a TFT 15 for switching and applying a signal voltage to the liquid crystal. The TFT substrate 11 applies a signal voltage applied through the TFT 15 to the liquid crystal cell. A pixel electrode 14 and a storage capacitor 15b for maintaining a signal voltage applied to the pixel electrode 14 of the pixel for a predetermined time. The C / F substrate 11 has a light blocking film (not shown) formed between the color filters, and ITO on the C / F layer 18 of several red (R), green (G), and blue (B) films formed with the light blocking film. and a common electrode 19 formed of indium tin oxide.

On the upper surfaces of the C / F substrate 11 and the TFT substrate 12, an alignment film 21 is formed to align the liquid crystal with a thin organic film made of polyimide.

A spacer 20 is disposed between the C / F substrate 11 and the TFT substrate 12 so as to inject liquid crystal so that a space having a predetermined height is formed. The sealant 16 located at the edge of the panel constitutes a cell region and serves as an adhesive for fixing the C / F substrate 11 and the TFT substrate 12.

In order to manufacture the C / F substrate 11 and the TFT substrate 12, various processes such as thin film deposition, photolithography, and etching are performed.

In particular, the photolithography process is an important factor that determines yield in the process of manufacturing TFT-LCD, and is a series of processes in which a pattern drawn on a mask is transferred and formed on an organic substrate on which a thin film is deposited. Photo Resist (PR Coating), Align & Exposure, and Develop steps are the main processes.

The alignment and exposure equipment uses an ultra-high pressure mercury lamp 35 as an illumination light source as shown in FIG. 2, and condenses the light with an ellipsoidal mirror 22 to filter a wavelength filter, an integrator lens, and a condenser. The pattern on the reticle 24 is uniformly illuminated by a light collecting system 23 including a condenser lens or the like.

The pattern on the illuminated reticle 24 is imaged on the surface of the substrate 26 via the projection lens 25 and exposed on the resist.

The substrate 26 is located on the XY stage 27, and is moved and positioned on the stage 27, and the exposure is repeated.

In addition, the stage 27 has a laser interferometer 30 capable of measuring coordinates, and can measure position coordinates in units of 0.02 μm.

Then, there are a reticle alignment system 28 and a plate alignment system 29.

The reticle alignment system 28 grasps the center of the alignment mark on the reticle 24 with respect to the Y, θ, and X directions of the crosshairs as a photoelectric signal, so that the attitude and position of the reticle 24 with respect to the plate stage coordinate system can be precisely determined. Match it. This method is simple and high in stability and the reticle 24 is automatically positioned by the reticle alignment system 28.

With respect to the plate alignment system 29, the mark for alignment is transferred onto the plate 26 in the first exposure, passes through the process, and the mark is formed. For this reason, the alignment sensor is required to have high process compatibility.

The substrate alignment is precisely aligned with the X axis of the plate stage coordinate system in the rotational direction by detecting alignment marks in the Y, θ, and X directions provided on the substrate 26, and on the plate stage coordinate system in the X and Y directions. This is done by measuring the position.

Before the precise alignment process is performed, the step of first placing the substrate to be mechanically exposed on the alignment chuck is performed. In other words, the substrate is pushed and roughly pre-aligned before exposure.

However, as the size of the substrate increases, the size of the chuck does not match the size of the substrate, so when the substrate is placed on the pre-aligned chuck, the substrate is bent and friction occurs. In order to reduce this friction, nitrogen gas is blown from the rear of the aligning chuck, and friction occurs due to deformation of the substrate, which causes the substrate to be hardly pushed.

Hereinafter, a problem occurring in the pre-alignment step will be described in detail with reference to the accompanying drawings.

As shown in FIG. 3A, a reference pin 31 for positioning a substrate on a pre-align chuck 33 is installed to be adjusted according to the size of the substrate 34. In order to align the substrate 34, the push pin 32 is pushed so that the substrate is aligned with the set reference pin 31 by the force of F1 and F2 in the long direction and the short direction of the substrate.

At this time, since the deformation occurs in the longitudinal direction more than the short direction of the substrate, the pre-aligned chuck 33 and the substrate ( The frictional force F1` at the part where the long direction of 34) touches is larger. In other words, the F1 force pushing the substrate should be larger than the F2 force for the uniform gradient of the force. However, due to the structure of the equipment, F1 and F2 cannot be applied separately.

That is, as shown in FIG. 3B, as the substrate is deformed in the longitudinal direction of the substrate 34, friction occurs at the edge portion of the pre-aligned chuck 33. In order to reduce the friction, the pre-aligned chuck 33 Nitrogen gas is injected into the substrate from the back by forming a hole in the substrate, but when the friction occurs due to the deformation of the substrate, the substrate is not pushed well.
In the conventional pre-aligned chuck, as shown in FIG. 4, the holes 41 formed in the pre-aligned chuck 33 have the same size from the center to the edge with respect to the X and Y axes of the pre-aligned chuck. That is, the diameters of the holes formed along the X axis of the prealign chuck are the same in size from the center R3 to the edges R2 to R1. (R1 = R2 = R3) The diameters of the holes are also the same in size from the center (R3 ') to the edges (R2' to R1 ') (R1' = R2 '= R3').
However, when the substrate is placed on the pre-aligned chuck, the frictional force generated by the deformation of the substrate along the long direction of the substrate, that is, the X axis direction is greater than the short direction of the substrate, that is, the Y axis, and thus a uniform gradient of force is not achieved.

Accordingly, the present invention has been made to solve the above problems of the prior art, an object of the present invention is to provide an exposure apparatus for manufacturing LCD for preventing the deformation of the substrate placed on the pre-aligned chuck.

In addition, another object of the present invention to provide an exposure apparatus for manufacturing LCD for reducing the friction between the pre-aligned chuck and the substrate.

Other objects and features of the present invention will be described in detail in the configuration and claims of the following invention.

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The pre-aligned chuck of the present invention for achieving the above object is characterized in that the size of the hole formed for nitrogen injection in order to secure a uniform force gradient is smaller in the center of the pre-aligned chuck and larger as it moves away from the center. It is done.

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Hereinafter, an exposure apparatus for manufacturing an LCD according to the present invention will be described in detail with reference to the accompanying drawings.

Figure 5 shows a hole formed in the pre-aligned chuck according to the present invention.

As shown in FIG. 5, the size R of the hole 41 formed in the pre-aligned chuck 33 is the center of the pre-aligned chuck 33 in the X-axis at which the long direction portion of the substrate 34 is raised. At R3 and at the edge R1 of the prealign chuck. That is, the size of the hole 41 increases from the center R3 to the edges R2 to R1 (R1 '>R2'> R3 ').
The size of the hole where the unidirectional portion of the substrate is raised, that is, the hole formed in the Y axis of the prealign chuck 33, is the same from the center R3 'to the edges R2' to R1 '(R1'). = R2` = R3`). The overall area of the pore size is the same as before.

When the substrate to be aligned is placed on the pre-aligned chuck 33 thus formed, the amount of nitrogen gas injected from the larger hole is increased, thereby preventing the substrate from bending in the long direction.

That is, as shown in FIG. 6, the nitrogen gas injected from the hole formed at the edge of the prealign chuck 33 is larger than the nitrogen gas injected from the hole formed at the center of the prealign chuck 33. Nitrogen gas is injected. That is, the force capable of supporting the substrate 34 on the prealign chuck 33 is increased.
Therefore, nitrogen gas injection from the large hole formed at the edge of the prealignment chuck 33 prevents the substrate 34 from bending in the longitudinal direction of the substrate.

As a result, the substrate 34 is properly floated by varying the amount of nitrogen gas injected into the edge of the prealign chuck 33 and the amount of nitrogen gas injected into the center of the prealign chuck 33. It is possible to align the substrate freely by setting the frictional forces F1` and F2` that were applied to 0, and to ensure the reproducibility of the position coordinates of the substrate.

As described above, according to the exposure apparatus for manufacturing LCD according to the present invention, by increasing the size of the hole formed in the pre-align chuck from the center to the edge, the uniform force gradient through minimizing the frictional force acting on the substrate It is possible to ensure the reproducibility of the position coordinates of the substrate.

Claims (5)

A pre-align chuck for aligning the substrate in advance before the precise alignment is made; And And a plurality of holes formed in the pre-aligned chuck and having a larger diameter from the center toward the edge. The method of claim 1, And a plurality of holes in the position where the short direction of the substrate is placed among the plurality of holes have the same size, and the plurality of holes in the position where the longitudinal direction of the substrate is placed have different sizes. delete delete The method of claim 1, LCDs, characterized in that the plurality of holes in the position where the short direction of the substrate is placed among the plurality of holes has the same size, the plurality of holes in the position where the long direction of the substrate is placed has a larger diameter from the center to the edge Exposure equipment for manufacturing.

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