KR20070001725A - Apparatus and method of testing pattern of a liquid crystal display device - Google Patents

Abstract

An apparatus and a method for inspecting patterns of a liquid crystal display device are provided to grasp an accurate cause of inferiority of patterns by cutting the inferior patterns and observing a section with an electron microscope, thereby taking necessary measures to cope with the inferiority. Worktables(131a,131b) are installed to put a liquid crystal display device having bad patterns on the worktables. A cutter(132) is installed at one side of the worktables for cutting patterns. An electron microscope(136) is installed at the other side of the worktables for observing cut patterns.

Description

Pattern Inspection Apparatus and Method of Liquid Crystal Display Device {APPARATUS AND METHOD OF TESTING PATTERN OF A LIQUID CRYSTAL DISPLAY DEVICE}

1 is a cross-sectional view of a general liquid crystal display device.

2 is a flowchart showing a conventional method for manufacturing a liquid crystal display device.

3 is a flowchart showing a pattern inspection method of a liquid crystal display device according to the present invention;

4 is a diagram illustrating detecting a pattern defect of a liquid crystal panel by a camera.

5 is a view showing a pattern inspection apparatus according to the present invention.

Explanation of symbols on the main parts of the drawings

110: liquid crystal panel 116: camera

130: pattern inspection device 131a, 131b: work table

132: cutting wheel 136: electron microscope

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pattern inspection apparatus and a method of a liquid crystal display device, and more particularly, to a liquid crystal capable of inspecting a cross section of a pattern cut at the same time by cutting a pattern of a defective point by mounting a cutter for cutting a pattern on an electron microscope A pattern inspection apparatus and method for a display element.

Recently, with the development of various portable electronic devices such as mobile phones, PDAs, and notebook computers, there is a growing demand for flat panel display devices for light and thin applications. Such flat panel displays are being actively researched, such as LCD (Liquid Crystal Display), PDP (Plasma Display Panel), FED (Field Emission Display), VFD (Vacuum Fluorescent Display), but mass production technology, ease of driving means, Liquid crystal display devices (LCDs) are in the spotlight for reasons of implementation.

LCD is a device for displaying information on the screen using the refractive anisotropy of the liquid crystal. As shown in FIG. 1, the LCD 1 is composed of a lower substrate 5 and an upper substrate 3 and a liquid crystal layer 7 formed between the lower substrate 5 and the upper substrate 3. The lower substrate 5 is a drive element array substrate. Although not shown in the figure, a plurality of pixels are formed on the lower substrate 5, and a driving element such as a thin film transistor (hereinafter referred to as TFT) is formed in each pixel. The upper substrate 3 is a color filter substrate, and a color filter layer for real color is formed. In addition, a pixel electrode and a common electrode are formed on the lower substrate 5 and the upper substrate 3, respectively, and an alignment film for aligning liquid crystal molecules of the liquid crystal layer 7 is coated.

The lower substrate 5 and the upper substrate 3 are joined by a sealing material 9, and a liquid crystal layer 7 is formed therebetween to drive elements formed on the lower substrate 5. By driving the liquid crystal molecules by controlling the amount of light passing through the liquid crystal layer, information is displayed.

The manufacturing process of the liquid crystal display device can be largely divided into a driving element array substrate process of forming a driving element on the lower substrate 5, a color filter substrate process of forming a color filter on the upper substrate 3, and a cell process. However, the process of the liquid crystal display will be described with reference to FIG. 2.

First, a plurality of gate lines and data lines arranged on the lower substrate 5 to define a pixel region are formed by a driving element array process, and the gate line and the data are formed in each of the pixel regions. A thin film transistor which is a driving element connected to the line is formed (S101). In addition, the pixel electrode is connected to the thin film transistor through the driving element array process to drive the liquid crystal layer as a signal is applied through the thin film transistor.

In addition, the upper substrate 3 is formed with a color filter layer and a common electrode of R, G, B to implement the color by the color filter process (S104).

Subsequently, an alignment layer is applied to the upper substrate 3 and the lower substrate 5, respectively, and then the alignment control force or surface fixing force (ie, the liquid crystal molecules of the liquid crystal layer formed between the upper substrate 3 and the lower substrate 5). In order to provide a pretilt angle and an orientation direction, the alignment layer is rubbed (S102 and S105). Subsequently, a spacer is disposed on the lower substrate 5 to maintain a constant cell gap, and a sealing material 9 is applied to an outer portion of the upper substrate 3. And the upper substrate 3 by applying pressure (S103, S106, S107).

On the other hand, the lower substrate 5 and the upper substrate 3 is made of a large area glass substrate. In other words, a plurality of panel regions are formed on a large area glass substrate, and a TFT and a color filter layer, which are driving elements, are formed in each of the panel regions. Must be processed (S108). Thereafter, the liquid crystal is injected into the liquid crystal panel processed as described above through the liquid crystal inlet, and the liquid crystal inlet is encapsulated to form a liquid crystal layer, and then the liquid crystal panel is inspected to produce a liquid crystal panel (S109 and S110).

Inspection of the liquid crystal panel can be generally divided into appearance inspection and electrical lighting inspection. The lighting test applies a signal to the completed liquid crystal panel to check whether various electrical elements work without abnormality. The visual inspection is to inspect the liquid crystal panel visually by the operator for visual inspection.

In addition, the inspection of the liquid crystal panel includes a pattern inspection for inspecting a defect of a pattern. Such a pattern test may be performed at any time during the process of manufacturing a liquid crystal panel, unlike a normal test or lighting test. Pattern inspection is typically performed by an electron microscope, such as a scanning electronic microscope. In other words, the shape of the pattern is inspected by an electron microscope to check for abnormalities.

However, the pattern inspection apparatus as described above has the following problems. Examining the pattern with an electron microscope is to determine the shape of the formed pattern to inspect the stacked state of the pattern. Therefore, simply inspecting only the surface of the pattern does not accurately determine the cause of the failure of the pattern, and thus no measures can be taken to remove the defect in advance.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and the pattern inspection apparatus for a liquid crystal display device capable of identifying a precise cause of a defect and removing the defect in advance by observing the cross section of the pattern formed on the liquid crystal display device with an electron microscope; It is an object to provide a method.

It is another object of the present invention to provide a pattern inspection apparatus and method for a liquid crystal display device, in which an electron microscope and a cutter are integrally formed to cut a defective area of a pattern and observe the cross section at the same time to quickly and accurately determine the cause of a bad pattern of the pattern. To provide.

In order to achieve the above object, the pattern inspection apparatus of the liquid crystal display device according to the present invention is a work table on which a liquid crystal panel having a pattern in which a defect is formed is placed, a cutter installed at one side of the work table to cut a pattern, and the other side of the work table. It consists of an electron microscope that observes the cut pattern installed.

The cutting machine is a cutting wheel that rotates about a rotation axis and the electron microscope is a scanning electron microscope (SEM), the pattern of which is cut on the cutting wheel and the cross section of the pattern cut by the electron microscope is observed.

In addition, the pattern inspection method of the liquid crystal display device according to the present invention comprises the steps of inputting the coordinates of the defective area of the pattern of the liquid crystal panel, the step of aligning the pattern cutter and the electron microscope in the pattern according to the input coordinates, and the pattern cutter Cutting the pattern in which the defect has occurred, and observing the cross section of the cut pattern with an electron microscope.

The defect of the pattern is made by the camera, and the coordinates of the defective area are also detected and input to the pattern inspection apparatus.

In the present invention, by observing the cross section of the pattern of the liquid crystal panel in which the defect occurs with an electron microscope, it is possible to determine the exact cause of the defect. To this end, the present invention proposes a new pattern inspection apparatus, which does not simply observe the pattern with an electron microscope, but cuts a defective area of the pattern and observes the cut surface by an electron microscope. It is possible to grasp the stacking form and the deposition state. The cutting of such a pattern and the observation of its cross section are not performed by a separate device, but by using a pattern inspection apparatus in which a cutting machine for cutting the pattern and an electron microscope for observing the cross section are integrally formed.

Hereinafter, a pattern inspection apparatus and a pattern inspection room according to the present invention will be described in detail with reference to the accompanying drawings.

3 is a flowchart showing a pattern inspection method of a liquid crystal panel according to the present invention. As shown in FIG. 3, first, a check is performed on the liquid crystal panel on which the pattern is formed (S201). In this case, the liquid crystal panel may be a liquid crystal panel in which the process is completed, or may be a liquid crystal panel which is in progress (but has a pattern).

Such a pattern defect determination of the liquid crystal panel is made by a camera. That is, as shown in FIG. 4, when the process is completed or the process is in progress, the liquid crystal panel is placed on the work bench 110 and photographed using a camera 116 such as a CCD (Charge Coupled Device) camera. The image is transmitted to the image processor 120. The image processor 120 processes the input data to form a pattern image. The image processor 120 determines whether the pattern is defective based on the image of the pattern, and detects the coordinates of the defective area.

That is, by analyzing the image, if there is no abnormality, it is determined that no defect occurs in the pattern of the liquid crystal panel (i.e., judging suitability) (S202, S203), and if an abnormality occurs, the coordinate of the defective area is detected. (S202, S204).

When a defect occurs in the pattern, the liquid crystal panel 101 in which the defect is detected is transferred to the pattern inspection apparatus, and the coordinates of the detected defect region are transmitted to the pattern inspection apparatus (S204).

As shown in FIG. 5, the pattern inspection apparatus 130 includes work benches 131a and 131b on which the transferred liquid crystal panel 101 is located, cutting wheels 132 located below the work benches 131a and 131b, It consists of an electron microscope 136 located above the work bench (131a, 131b).

The cutting wheel 132 is formed in a disk shape, a cutting blade having a high hardness such as diamond is formed in the circumference and a rotating shaft 134 is formed in the center. The cutting wheel 132 is rotated at a high speed by rotating about the rotating shaft 134 to cut the liquid crystal panel 101 positioned on the working tables 131a and 131b. Of course, the cutting of the liquid crystal panel 101 is for cutting the defective area of the pattern, and from this point of view, it will be more accurate to consider that the cutting wheel 132 cuts the pattern.

As the electron microscope 136, any electron microscope can be used as long as the cut surface of the pattern can be observed (of course, a microscope other than the electron microscope can be used), but a scanning electron microscope is mainly used. The scanning electron microscope can be magnified and observed to a pattern of several nm. When electron beams are emitted and scanned on the surface of the liquid crystal panel 101 (that is, the surface of the pattern), secondary electrons are generated on the surface of the pattern. After the secondary electrons are amplified, they are input to the grid of the display unit 138 such as a television, and the image of the surface is enlarged and displayed on the screen.

As such, the pattern inspection apparatus 130 of the present invention is not simply provided with an electron microscope 136 for observing the pattern, but a cutting wheel 132 for cutting the pattern is formed by the microscope 136 to cut the pattern. The cross section of the pattern cut at the same time is enlarged and displayed by the electron microscope 136.

As the coordinates for the defective area of the pattern are input to the pattern inspection device 130, two work benches 131a and 131b are moved by driving a motor not shown in the drawing so that the defective area of the pattern is formed by the cutting wheel 132 and the electronics. It is aligned with the microscope 136 (S205). At this time, the two worktables 131a and 131b which are far apart and approach each other are positioned at set intervals, and the defective area of the pattern is located therebetween, so that the lower part of the defective area is exposed. Subsequently, after the cutting wheel 132 approaches the lower portion of the liquid crystal panel 101 in which the defective pattern is formed, the cutting wheel 132 is rotated at high speed to cut the pattern (S206).

As described above, the electron microscope 136 outputs an electron beam to the cross section of the pattern cut by the cutting wheel 132 in the state where the pattern is cut, and displays the image of the cut surface on the display unit 138 (S207). The operator observes the enlarged image of the cut surface displayed on the display unit 138, analyzes the shape of the pattern, the stacked state, and the like to determine the cause of the defect, thereby preventing the occurrence of the defect in the subsequent process.

As described above, in the present invention, when a defect occurs in the pattern of the liquid crystal panel, the cross section, not the surface thereof, is directly observed by the electron microscope 136, so that the shape of the defect, the cause of the defect, and the like can be accurately determined. Therefore, it is possible to prevent the defect in advance by accurate cause analysis according to the defect. At this time, the cutting wheel 132 and the electron microscope 136 is interlocked. That is, the cutting wheel 132 and the electron microscope 136 are not operated separately, but by interlocking, the cutting wheel 132 and the electron microscope 136 can be accurately cut and the cross section can be observed. Therefore, it is possible to observe the defective area quickly and accurately.

As described above, in the pattern inspection method of the liquid crystal panel according to the present invention, since the pattern of the defect is cut off and the cut surface is observed with an electron microscope, the cause of the exact defect can be identified. It becomes possible. Further, in the present invention, since the cutter and the microscope are integrally formed, the pattern can be cut and observed quickly and accurately according to the input coordinates.

Claims (11)

A work table on which a liquid crystal display device having a pattern in which a defect is formed is placed; A cutter installed at one side of the work table to cut a pattern; And The pattern inspection apparatus of the liquid crystal display device comprising an electron microscope for observing the cut pattern is installed on the other side of the work table. The apparatus of claim 1, wherein the work table comprises two tables that are separated from each other. The apparatus of claim 1, wherein the cutter is a cutting wheel that rotates about a rotation axis. The pattern inspection apparatus of claim 1, wherein the electron microscope is a scanning electron microscope (SEM). The apparatus of claim 1, wherein the cutter and the electron microscope are aligned with the pattern of the liquid crystal panel based on the coordinates of the defective area of the input pattern. Inputting coordinates of a defective area of a pattern of the liquid crystal panel; Arranging the pattern cutter and the electron microscope in the pattern according to the input coordinates; Cutting a pattern in which a defect has occurred using the pattern cutter; And A pattern inspection method of a liquid crystal display device comprising the steps of observing the cross section of the cut pattern with an electron microscope. 7. The method of claim 6, further comprising the step of photographing the pattern with a camera to determine the defect of the pattern. The method of claim 7, wherein the camera comprises a CCD (Charge Coupled Device) camera. The method of claim 6, wherein the inputting of the coordinates comprises: Detecting coordinates of a defective area based on an image photographed by a camera; And Pattern detection apparatus of the liquid crystal display device comprising the step of inputting the detected leftover. The apparatus of claim 6, wherein the pattern cutter is a cutting wheel that rotates about a rotation axis. 7. The apparatus of claim 6, wherein the electron microscope is a scanning electron microscope (SEM).

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