KR20100027560A - Apparatus and method for inspecting tft array substrate of falt panel display - Google Patents

Abstract

PURPOSE: A device and a method for inspecting a TFT array substrate for a flat panel display are provided, which can improve precision of the inspection of the TFT array substrate. CONSTITUTION: A device for inspecting a TFT array substrate for a flat panel display comprises a polarized light device(110), a stage(120), a modulator(130), an analyzer(140), and a CCD camera(150). The polarized light device irradiates the light of the light source(100) to the TFT array substrate(200) in the first polarization direction. The TFT array substrate can be put on the stage and can be adjusted in location. The modulator modulates the optical property of the light through the TFT array substrate proportionally to the pressure distribution of the TFT array substrate surface. The CCD camera takes a photograph of the light through the analyzer.

Description

TFT array substrate inspection apparatus and method for flat panel display {Apparatus and method for inspecting TFT array substrate of falt panel display}

The present invention relates to a TFT array substrate inspection apparatus and method for a flat panel display that can inspect a TFT array without contacting the TFT array substrate.

In general, a flat panel display includes a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP), and an electroluminescence (Electroluminescence). : EL), and most of them are commercially available and commercially available.

In particular, LCD (Liquid Crystal Display: hereinafter referred to as 'liquid crystal display') is utilized as a monitor of desktop computers and other office or home appliances.

A liquid crystal display is an apparatus that expresses an image by using optical anisotropy and birefringence characteristics of liquid crystal molecules. When an electric field is applied, a liquid crystal array is changed, and a light transmission characteristic is also changed according to the changed liquid crystal array direction.

Looking at the basic characteristics of the liquid crystal, most of the liquid crystal molecules are thin and long shape, the nematic phase (Smectic phase) and cholesteric depending on the alignment direction of the liquid crystal molecules and the regularity of the arrangement Classified as Cholesteric phase.

In this case, the molecules forming the liquid crystal phase are all in the form of thin and long rods, and all the physical properties in the direction parallel to the long axis of the molecule and in the direction perpendicular to each other have optical anisotropy.

In addition to having anisotropic properties, the liquid crystal molecules have a feature that the orientation direction of the molecules is easily changed by working with an external field such as an electric field, a magnetic field, or a stress.

The liquid crystal display includes a first substrate; A second substrate facing the first substrate; It consists of the liquid crystal layer formed between the said 1st board | substrate and a 2nd board | substrate.

The first substrate is a substrate on which a thin film transistor, which is a driving element, is formed, and a plurality of pixels are formed, and each pixel is formed of a thin film transistor.

The second substrate is a color filter substrate, and a color filter layer for implementing color is formed.

The first substrate and the second substrate are bonded together by a sealing material along a sealing portion along an outer portion of the substrate, and a liquid crystal layer is formed therebetween so that the liquid crystal is formed by a driving element formed on the first substrate. The information is displayed by driving the molecules to control the amount of light passing through the liquid crystal layer.

The sealing material is formed on the outer periphery of the first substrate and the second substrate and serves as an adhesive for bonding the first substrate and the second substrate, as well as the liquid crystal between the bonded first substrate and the second substrate leaks to the outside. Prevent it.

In order to manufacture a flat panel display, a substrate cleaning process, an array substrate forming process, a thin film pattern inspection process, a substrate bonding process, a defective pixel inspection process, a repair process, and the like are performed.

Among these processes, the thin film pattern inspection process is a process of confirming that the thin film patterns formed on the thin film transistor array substrate are normally formed. Recently, various methods for accurate inspection have been studied as the flat panel display panel becomes larger.

This invention solves the problem that the precision falls at the time of inspection of a large area panel.

According to a first preferred embodiment of the present invention,

Transmitting light to a TFT array substrate in which TFT cells having non-transmissive gate electrodes are arrayed and non-transmissive data lines are formed;

Photographing the non-transmissive gate electrode and data line with a CCD camera;

Aligning positions of the TFT cells and cells of a CCD camera with the photographed non-transmissive gate electrode and data line;

A method of inspecting a TFT array substrate for a flat panel display comprising modulating optical characteristics of light through the TFT array substrate using a modulator, photographing the modulated light with the CCD camera, and measuring a voltage of the TFT cells. Is provided.

According to a second preferred embodiment of the present invention,

A light source, a polarizer for emitting the light of the light source to the TFT array substrate in a first polarization direction, a stage on which the TFT array substrate is placed and adjusted, and a voltage distribution on the surface of the TFT array substrate Modulator for modulating optical characteristics of light through the TFT array substrate, an analyzer for emitting light modulated by the modulator in a second polarization direction different from the first polarization direction, and light through the analyzer Preparing a TFT array substrate inspection apparatus for a flat panel display comprising a CCD camera for photographing;

Placing a TFT array substrate on which the TFT cells having non-transmissive gate electrodes are arranged on the stage and on which non-transmissive data lines are formed;

Emitting light from the light source to photograph the non-transmitted gate electrode and data line through a polarizer, a TFT array substrate, a modulator and an analyzer with a CCD camera;

Aligning positions of the TFT cells with cells of a CCD camera with the photographed non-transmissive gate electrode and data line;

Emitting light from the light source to modulate the optical characteristics of the light through the polarizer and the TFT array substrate in the modulator, photographing the modulated light through the analyzer with the CCD camera, and measuring the voltage of the TFT cells A configured TFT array substrate inspection method for a flat panel display is provided.

According to a third preferred embodiment of the present invention,

A light source, a polarizer for emitting the light of the light source to the TFT array substrate in a first polarization direction, a stage on which the TFT array substrate is placed and adjusted, and a voltage distribution on the surface of the TFT array substrate Modulator for modulating optical characteristics of light through the TFT array substrate, an analyzer for emitting light modulated by the modulator in a second polarization direction different from the first polarization direction, and light through the analyzer Preparing a TFT array substrate inspection apparatus for a flat panel display comprising a CCD camera for photographing;

Placing a TFT array substrate on the stage;

Emitting light from the light source and photographing the TFT array substrate with the CCD camera through the polarizer, the TFT array substrate, the modulator, and the analyzer;

Performing an image inspection on the obtained image of the TFT array substrate;

Emit light from the light source to modulate the optical characteristics of the light through the polarizer and the TFT array substrate in the modulator, photograph the modulated light through the analyzer with the CCD camera, and measure the voltage of the TFT cells to perform electrical inspection Provided is a TFT array substrate inspection method for a flat panel display, comprising the steps of:

According to a fourth preferred embodiment of the present invention,

A light source;

A polarizer emitting light from the light source to the TFT array substrate in a first polarization direction;

A stage on which the TFT array substrate is placed and which can be adjusted;

A modulator for modulating optical characteristics of light through the TFT array substrate in proportion to the voltage distribution on the surface of the TFT array substrate;

An analyzer configured to emit light modulated by the modulator in a second polarization direction different from the first polarization direction;

Provided is a TFT array substrate inspection device for a flat panel display composed of a CCD camera for photographing light through the analyzer.

According to the present invention, after the position correction of the TFT cells and the cells of the CCD camera using the image of the non-transmissive region of the TFT array substrate without applying the reference voltage to the modulator, the voltage of the arrayed TFTs is applied by applying a reference voltage to the modulator. By detecting and inspecting the TFTs, there is an effect of not having to use a very large precision stage even when inspecting a large area TFT array.

In addition, since the present invention can correct the voltage of the TFT cells by correcting the positions of the TFT cells and the cells of the CCD camera, the accuracy of inspection of the TFT array substrate can be improved.

Further, the present invention has the effect of inspecting the TFT array without contacting the TFT array substrate.

In addition, the present invention has the effect that the inspection of the electrical inspection and the appearance quality of the TFT array substrate can be performed in one device.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

1 is a schematic view for explaining the configuration of a TFT array substrate inspection apparatus for a flat panel display according to the present invention, comprising: a light source 100; A polarizer (110) for emitting the light of the light source (100) to the TFT array substrate (200) in a first polarization direction; A stage 120 on which the TFT array substrate 200 is placed and which can be adjusted; A modulator (130) for modulating optical characteristics of light through the TFT array substrate (200) in proportion to the voltage distribution on the surface of the TFT array substrate (200); An analyzer (140) for emitting light modulated by the modulator (130) in a second polarization direction different from the first polarization direction; It consists of a CCD camera 150 for taking light through the analyzer 140.

Here, the first and second polarization directions are polarization directions perpendicular to each other.

In the TFT array substrate inspection apparatus, the TFT array substrate 200 is positioned between the polarizer 110 and the modulator 130 to photograph the modulated light of the modulator 130 with a CCD camera. By inspecting the voltages of the TFTs arrayed in the array substrate 200, it is possible to detect whether there is a defect.

In this case, the modulator 130 modulates light through the TFT array substrate 200 when a reference voltage is applied, but transmits light through the TFT array substrate 200 when a reference voltage is not applied. It is preferable that it is an optical modulator.

The reference voltage is to prepare an electric field between the conductive layer of the modulator 130 and the surface of the TFT array substrate 200 in preparation for the voltage distribution to be formed on the upper surface of the TFT array substrate 200.

An arbitrary voltage source may be connected to apply the reference voltage, but it is preferable to ground it.

In addition, the image photographed by the CCD camera 150 may be analyzed by the image processor 210 according to a conventional image processing technique to determine the voltage distribution formed on the surface of the TFT array substrate.

This image processing is a known technique, and further description thereof will be omitted.

Therefore, after correcting the position of the TFT cells and the cells of the CCD camera with the image of the non-transmissive region of the TFT array substrate 200 without applying the reference voltage to the modulator 130, By inspecting the TFTs by detecting the voltages of the arrayed TFTs by applying a reference voltage, there is an advantage of not having to use a very large precision stage even when inspecting a large-area TFT array.

Here, aligning the positions of the TFT cells of the TFT array substrate 200 and the cells of the CCD is as shown in Figure 1, the TFT array substrate 200 is mounted on the stage 120, the stage The TFT array substrate 200 is adjusted to 120 to align the positions of the TFT cells and the cells of the CCD.

In this case, the stage 120 should be provided with a light transmission area through which the light of the light source 100 is incident on the TFT array substrate 200.

The TFT array substrate inspection apparatus for flat panel display of the present invention is a device capable of inspecting a TFT array without contacting the TFT array substrate.

Therefore, by using the inspection apparatus arranged in the transmission optical system, the present invention is capable of non-contact inspection of the TFT array substrate.

FIG. 2 is a schematic flowchart illustrating a TFT array substrate inspection method for a flat panel display according to a first embodiment of the present invention. First, TFT cells having non-transmissive gate electrodes are arrayed, and non-transmissive data lines are formed. The light is transmitted through the TFT array substrate (step S100).

Thereafter, the non-transmissive gate electrode and the data line are photographed by the CCD camera (S110).

Next, the TFT cells and the cells of the CCD camera are aligned with the photographed non-transmissive gate electrode and data line (step S120).

Subsequently, the optical characteristics of the light through the TFT array substrate are modulated using a modulator, and the modulated light is photographed by the CCD camera to measure the voltages of the TFT cells.

Here, the map information of the TFT cells of the TFT array substrate, which are stored in advance, before the step S200 of transmitting the light to the TFT array substrate having the non-transmissive gate electrodes arrayed and the non-transmissive data line formed thereon. Positioning the TFT cells in the cells of the CCD camera with the stage is preferably further provided.

And aligning the positions of the TFT cells and the cells of the CCD camera with the photographed non-transmissive gate electrode and data line may include the aligned TFT cells with respect to the photographed non-transmissive gate electrode and data line. And correcting the positions of the cells of the CCD camera.

FIG. 3 is a schematic flowchart illustrating a method of inspecting a TFT array substrate for a flat panel display according to a first embodiment of the present invention, wherein the light source shown in FIG. 1 and the light of the light source are moved to the TFT array substrate in a first polarization direction. A polarizer for outputting, a stage on which the TFT array substrate is placed and adjustable, a modulator for modulating optical characteristics of light through the TFT array substrate in proportion to the voltage distribution on the surface of the TFT array substrate, A flat panel display TFT array substrate inspection apparatus comprising an analyzer configured to emit light modulated by a modulator in a second polarization direction different from the first polarization direction, and a CCD camera for photographing light through the analyzer. (Step S200)

Thereafter, TFT cells having non-transmissive gate electrodes are arrayed on the stage, and a TFT array substrate on which non-transmissive data lines are formed is placed (step S210).

Next, the light is emitted from the light source to photograph the non-transmitted gate electrode and the data line through the polarizer, the TFT array substrate, the modulator, and the analyzer (S220).

Subsequently, the TFT cells and the cells of the CCD camera are aligned with the photographed non-transmissive gate electrode and data line (step S230).

Subsequently, the light is emitted from the light source to modulate the optical characteristics of the light through the polarizer and the TFT array substrate in the modulator, and the modulated light through the analyzer is photographed by the CCD camera to measure the voltage of the TFT cells. (Step S240)

4A to 4D are schematic flowcharts for explaining a method of inspecting a TFT array substrate for a flat panel display according to a second embodiment of the present invention, and FIG. 4A is a map information of TFT cells of a TFT array substrate stored in advance. to be.

These TFT cells and the cells of the CCD camera are aligned through the stage (FIG. 4B).

That is, since the TFT cells are aligned at the positions of the cells of the CCD camera, the defective TFT cells in the image photographed by the CCD camera can be easily detected only by knowing the cell positions of the CCD camera.

Then, as in the above-described step S230, the positions of the TFT cells and the cells of the CCD camera are corrected based on the non-transmissive gate electrode and data line photographed (FIG. 4C).

Therefore, the present invention has the advantage that the accuracy of inspection of the TFT array substrate can be improved because the accurate voltage measurement can be made for the TFT cells by correcting the positions of the TFT cells and the cells of the CCD camera.

Subsequently, the voltages of the TFT cells taken by the CCD camera are measured. (FIG. 4D).

FIG. 5 is a schematic flowchart illustrating a method of inspecting a TFT array substrate for a flat panel display according to a third embodiment of the present invention, wherein the light source shown in FIG. 1 and the light from the light source are moved to the TFT array substrate in a first polarization direction. A polarizer for outputting, a stage on which the TFT array substrate is placed and adjustable, a modulator for modulating optical characteristics of light through the TFT array substrate in proportion to the voltage distribution on the surface of the TFT array substrate, A flat panel display TFT array substrate inspection apparatus comprising an analyzer configured to emit light modulated by a modulator in a second polarization direction different from the first polarization direction, and a CCD camera for photographing light through the analyzer. (Step S300)

Thereafter, the TFT array substrate is placed on the stage (step S310).

Subsequently, light is emitted from the light source and the TFT array substrate is photographed by the CCD camera through the polarizer, the TFT array substrate, the modulator, and the analyzer (S320).

Next, an image inspection is performed on the obtained image of the TFT array substrate (S330).

The light emitted from the light source is modulated by the modulator to modulate the optical characteristics of the light through the polarizer and the TFT array substrate, the modulated light through the analyzer is photographed by the CCD camera, and the voltage of the TFT cells is measured. Perform an electrical test (step S340).

In the method for inspecting the TFT array substrate for flat panel displays of the first to third embodiments of the present invention described above, it is preferable to further include a step of repairing defective TFT cells after measuring the voltage of the TFT cells.

In the third embodiment of the present invention, after performing the image inspection, if there are TFT cells with foreign substances, it is not necessary to repair the TFT cells determined as defective in the electric inspection, and to perform the process of removing the foreign substances. desirable.

6 is a schematic partial cross-sectional view for explaining the configuration of an example of a flat panel display TFT array substrate to be inspected according to the present invention, and an example of a flat panel display TFT array substrate is a TFT array substrate constituted in a liquid crystal display panel.

Here, the liquid crystal display panel, as shown in Figure 6, the first substrate 301; A second substrate 302 facing the first substrate 301; The liquid crystal layer 303 is formed between the first substrate 301 and the second substrate 302.

A plurality of pixels, which are driving elements, are formed on the first substrate 301, thin film transistors are formed on each pixel, and color filters are formed on the second substrate 302.

That is, the present invention inspects the first substrate 301 in which the thin film transistors are arrayed.

FIG. 7 is a conceptual view illustrating a modulator applied according to the present invention. The modulator of the present invention is an electro-optic modulation sensor of a transmission optical system, and is driven in a mode capable of obtaining an image of a TFT array substrate when a reference voltage is not applied. Thus, the image inspection of the TFT array substrate can be performed.

When the reference voltage is applied, the electric field is driven in a mode capable of measuring the electric field of the TFT array substrate, thereby performing the electric inspection of the TFT array substrate.

Therefore, the present invention is advantageous in that it is possible to perform electrical inspection and image inspection for inspecting the appearance quality of the TFT array substrate in one apparatus.

Although the invention has been described in detail only with respect to specific examples, it will be apparent to those skilled in the art that various modifications and variations are possible within the spirit of the invention, and such modifications and variations belong to the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view for explaining the configuration of a TFT array substrate inspection apparatus for a flat panel display according to the present invention.

2 is a schematic flowchart for explaining a method for inspecting a TFT array substrate for a flat panel display according to a first embodiment of the present invention.

3 is a schematic flowchart for explaining a method for inspecting a TFT array substrate for a flat panel display according to a first embodiment of the present invention;

4A to 4D are schematic flowcharts for explaining a method for inspecting a TFT array substrate for a flat panel display according to a second embodiment of the present invention.

5 is a schematic flowchart for explaining a method for inspecting a TFT array substrate for a flat panel display according to a third embodiment of the present invention.

6 is a schematic partial cross-sectional view for explaining the configuration of an example of a TFT array substrate for a flat panel display to be inspected according to the present invention.

7 is a conceptual diagram illustrating a modulator applied according to the present invention.

Claims (8)

Transmitting light to a TFT array substrate in which TFT cells having non-transmissive gate electrodes are arrayed and non-transmissive data lines are formed; Photographing the non-transmissive gate electrode and data line with a CCD camera; Aligning positions of the TFT cells and cells of a CCD camera with the photographed non-transmissive gate electrode and data line; And modulating the optical characteristics of the light through the TFT array substrate using a modulator, photographing the modulated light with the CCD camera, and measuring the voltage of the TFT cells. The method according to claim 1, Before the step of transmitting light to the TFT array substrate on which the TFT cells having the non-transmissive gate electrode are arrayed and the non-transmissive data line is formed, And aligning the cells of the CCD camera and the TFT cells in the map information of the TFT cells of the TFT array substrate which are stored in advance through the stage. Aligning the positions of the TFT cells and the cells of the CCD camera with the photographed non-transmissive gate electrode and data line, And correcting positions of the aligned TFT cells and the cells of the CCD camera based on the photographed non-transmissive gate electrode and data line. A light source, a polarizer for emitting the light of the light source to the TFT array substrate in a first polarization direction, a stage on which the TFT array substrate is placed and adjusted, and a voltage distribution on the surface of the TFT array substrate Modulator for modulating optical characteristics of light through the TFT array substrate, an analyzer for emitting light modulated by the modulator in a second polarization direction different from the first polarization direction, and light through the analyzer Preparing a TFT array substrate inspection apparatus for a flat panel display comprising a CCD camera for photographing; Placing a TFT array substrate on which the TFT cells having non-transmissive gate electrodes are arranged on the stage and on which non-transmissive data lines are formed; Emitting light from the light source to photograph the non-transmitted gate electrode and data line through a polarizer, a TFT array substrate, a modulator and an analyzer with a CCD camera; Aligning positions of the TFT cells with cells of a CCD camera with the photographed non-transmissive gate electrode and data line; Emitting light from the light source to modulate the optical characteristics of the light through the polarizer and the TFT array substrate in the modulator, photographing the modulated light through the analyzer with the CCD camera, and measuring the voltage of the TFT cells A method for inspecting a TFT array substrate for a configured flat panel display. The method according to claim 3, The alignment of the TFT cells and the cells of the CCD camera is performed by adjusting the position of the TFT array substrate using the stage to arrange the TFT array substrate for a flat panel display. A light source, a polarizer for emitting the light of the light source to the TFT array substrate in a first polarization direction, a stage on which the TFT array substrate is placed and adjusted, and a voltage distribution on the surface of the TFT array substrate Modulator for modulating optical characteristics of light through the TFT array substrate, an analyzer for emitting light modulated by the modulator in a second polarization direction different from the first polarization direction, and light through the analyzer Preparing a TFT array substrate inspection apparatus for a flat panel display comprising a CCD camera for photographing; Placing a TFT array substrate on the stage; Emitting light from the light source and photographing the TFT array substrate with the CCD camera through the polarizer, the TFT array substrate, the modulator, and the analyzer; Performing an image inspection on the obtained image of the TFT array substrate; Emit light from the light source to modulate the optical characteristics of the light through the polarizer and the TFT array substrate in the modulator, photograph the modulated light through the analyzer with the CCD camera, and measure the voltage of the TFT cells to perform electrical inspection The TFT array substrate inspection method for a flat panel display comprising the step of performing. The method according to claim 5, In the performing of the image inspection, a reference voltage is not applied to the modulator. And a reference voltage is applied to the modulator in the performing of the electrical inspection. The method of claim 1, wherein And measuring a voltage of the TFT cells, and then repairing the defective TFT cells. A light source; A polarizer emitting light from the light source to the TFT array substrate in a first polarization direction; A stage on which the TFT array substrate is placed and which can be adjusted; A modulator for modulating optical characteristics of light through the TFT array substrate in proportion to the voltage distribution on the surface of the TFT array substrate; An analyzer configured to emit light modulated by the modulator in a second polarization direction different from the first polarization direction; A TFT array substrate inspection device for a flat panel display, comprising a CCD camera for photographing light through the analyzer.

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