KR20060079039A - Apparutus for inspecting array board of liquid crystal display - Google Patents

Abstract

The present invention relates to an array substrate inspection apparatus of a liquid crystal display device capable of shortening the inspection time.

An array substrate inspection apparatus of a liquid crystal display according to the present invention includes a chamber in which a thin film transistor substrate, which is a substrate to be inspected, is mounted, a driving circuit for applying test data to the thin film transistor substrate, and an upper portion of the chamber. And a plurality of inspectors for inspecting the operation of the pixel electrodes of the substrate, and a movable body for horizontally and vertically moving the plurality of inspectors across the entire surface of the thin film transistor substrate.

Description

Apparatus for Inspecting Array Board of Liquid Crystal Display

1 is a view showing a conventional liquid crystal display device.

2 is a block diagram showing a process for manufacturing a substrate of a liquid crystal display device.

3A and 3B illustrate a step of inspecting an array substrate of a conventional liquid crystal display device.

4 is a view showing an inspection apparatus of an array substrate according to an embodiment of the present invention.

FIG. 5 is a diagram illustrating the tester shown in FIG. 4.

FIG. 6 is a diagram illustrating a step of inspecting an array substrate using the inspection apparatus illustrated in FIG. 4.

7 is a diagram illustrating a step of inspecting an array substrate according to another exemplary embodiment.

<Description of the code | symbol about the principal part of drawing>

1: lower substrate 6: gate insulating film

8: protective layer 10, 12: alignment film

11: upper substrate 14: common electrode

16 color filter 22 pixel electrode

23 contact hole 24 liquid crystal

25 gate electrode 26, 27 semiconductor layer

28 source electrode 29 drain electrode

31 TFT array substrate 33 Reflector

35 PDLC layer 37 substrate

39: modulator 41: PBSP

43: light source 45: CCD camera

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection apparatus for an array substrate of a liquid crystal display device, and more particularly, to an array substrate inspection apparatus capable of shortening an inspection time and increasing production efficiency.

In general, a liquid crystal display (LCD) displays an image corresponding to a video signal on a liquid crystal substrate on which liquid crystal cells are arranged in a matrix by adjusting light transmittance of liquid crystal cells according to a video signal. In the active matrix liquid crystal display device, a thin film transistor (hereinafter referred to as TFT) is mainly used as a switching element. Such liquid crystal display devices can be miniaturized compared to CRTs, and are widely used in personal computers and notebook computers, as well as office automation devices such as photocopiers, mobile devices such as cell phones and pagers. .

Referring to FIG. 1, a conventional liquid crystal display device includes a color filter substrate including a color filter 16, a common electrode 14, and an alignment layer 12 sequentially formed on an upper substrate 11, and a lower substrate 1. A TFT array sequentially formed on the substrate, a TFT array substrate composed of the pixel electrode 22 and the alignment film 10, a spacer (not shown) for maintaining a gap between the color filter substrate and the TFT array substrate, and a color filter substrate. And a liquid crystal 24 injected into the inner space provided by the TFT array substrate and the spacer.

In the color filter substrate, color filters 16 of red, green, and blue primary colors are sequentially formed on the upper substrate 11. In this case, each of the three primary color filters 16 is formed by coating and then patterning a material that absorbs a white light source on the front surface of the upper substrate 11 to transmit only a light having a specific wavelength (red, green, or blue). The common electrode 14, which is a transparent conductive film to which a ground potential is supplied, is formed on the upper substrate 11 on which the color filter 16 is formed. The alignment film 12 is formed by applying polyimide on the common electrode 14.

The TFT for switching the driving of the liquid crystal cell in the TFT array substrate includes a gate electrode 25 protruding from a gate line (not shown), a source electrode 28 protruding from a data line (not shown), and a contact hole 23. A drain electrode 29 connected to the pixel electrode 22 is provided. In addition, the TFT is formed by the gate insulating film 6 for insulating the gate electrode 25, the source electrode 28, and the drain electrode 29, and the source electrode 28 by the gate voltage supplied to the gate electrode 25. The semiconductor layers 26 and 27 are further provided to form conductive channels between the drain electrodes 29. This TFT selectively supplies the data signal from the data line to the pixel electrode 22 in response to the gate signal from the gate line. The liquid crystal rotates by the voltage difference between the data signal supplied through the TFT and the common voltage Vcom supplied to the common electrode 14, and the light transmittance is determined according to the degree of rotation of the liquid crystal. The pixel electrode 22 is formed of a transparent conductive material having a high light transmittance and positioned in a cell region divided by a data line and a gate line. The pixel electrode 22 is formed on the passivation layer 8 applied to the entire lower substrate 1 and electrically connected to the drain electrode 29 through the contact hole 23 formed in the passivation layer 8. After the alignment layer 10 is coated on the lower substrate 1 on which the pixel electrode 22 is formed, a rubbing process is performed.

2 is a block diagram showing a manufacturing process for manufacturing a substrate of such a liquid crystal display device.

Referring to FIG. 2, a manufacturing process for manufacturing a substrate of a liquid crystal display device may include a substrate cleaning process, a substrate patterning process, an alignment film forming / rubbing process, a substrate bonding / liquid crystal injection process, a mounting process, an inspection process, a repair process, and the like. Go through the process.

In the substrate cleaning process, foreign substances contaminated on the substrate surface of the liquid crystal display device are removed with a cleaning liquid.

In the substrate patterning process, the upper substrate (color filter substrate) and the lower substrate (TFT-array substrate) are divided into patterning. A color filter, a common electrode, a black matrix, and the like are formed on the upper substrate. Signal lines such as data lines and gate lines are formed on the lower substrate, and TFTs are formed at intersections of the data lines and gate lines, and pixel electrodes are formed in the pixel region between the data lines and gate lines connected to the source electrodes of the TFTs. Is formed.

In the alignment film forming / rubbing process, an alignment film is applied to each of the upper substrate and the lower substrate, and the alignment film is rubbed with a rubbing cloth or the like.

In the substrate bonding / liquid crystal injection process, the upper substrate and the lower substrate are bonded using a real material, the liquid crystal and the spacer are injected through the liquid crystal inlet, and then the liquid crystal inlet is sealed.

In the liquid crystal substrate mounting process, a tape carrier package in which integrated circuits such as a gate drive integrated circuit and a data drive integrated circuit are mounted is connected to a pad portion on a substrate. Such a drive integrated circuit may be directly mounted on a substrate by a chip on glass method in addition to the tape automated bonding method using the aforementioned TCP.

The inspection process includes an electrical inspection performed after various signal wirings and pixel electrodes are formed on the lower substrate, and an electrical inspection and a visual inspection performed after the substrate bonding / liquid crystal injection process. In particular, the electrical inspection process of the signal wiring and the pixel electrode of the lower substrate prior to the bonding of the substrate is very important in that the defect rate and disposal can be reduced, and the defective substrate in a relatively repairable state can be detected early.

The repair process restores the substrate that is determined to be repairable by the inspection process. Meanwhile, defective substrates that cannot be repaired in the inspection process are disposed of.

After completing the TFT array on the array substrate of the liquid crystal display device during the above process, the inspection process for confirming whether or not the TFT of each pixel operates properly is performed using a TFT array substrate inspection apparatus including a modulator. The inspector of the inspection apparatus of the array substrate inspects all the pixel electrodes through the front surface of the substrate while moving horizontally and vertically on the array substrate.

3A and 3B are diagrams illustrating a modulator step sequence for inspecting a plurality of TFT array substrates using such an array substrate inspection apparatus.

Referring to FIG. 3A, in order to inspect six TFT array substrates, one modulator inspects the A substrate and then moves horizontally to inspect the B substrate and again moves diagonally to inspect the C substrate. In this way, the A to F substrates are sequentially examined.

Referring to FIG. 3B, according to another modulator step sequence for inspecting six TFT array substrates, one modulator inspects the C substrate and the E substrate after the A substrate is inspected in the longitudinal direction, and then moves in the horizontal direction. After the F board is inspected, the board is moved back to the vertical direction to inspect the D and B boards.

As described above, according to the inspection apparatus of a conventional TFT array substrate, a plurality of substrates are inspected in a certain order by using one modulator. The modulator is usually 70 × 70 mm in size, which requires considerable inspection time for full area inspection involving multiple TFT array substrates.

Therefore, as the mass production, the number of inspection apparatus required for inspecting a plurality of array substrates increases, so that the apparatus cost is high and the space required for installing the apparatus also needs to be secured.

Accordingly, an object of the present invention is to provide an array substrate inspection apparatus of a liquid crystal display device which can efficiently inspect the array substrate.

In order to achieve the above object, the liquid crystal display inspection modulator according to the present invention includes a chamber in which a thin film transistor substrate, which is a substrate to be inspected, is mounted, a driving circuit for applying test data to the thin film transistor substrate, and an upper portion of the chamber. And a plurality of inspectors for inspecting the operation of the pixel electrode of the thin film transistor substrate, and a movable body for horizontally and vertically moving the plurality of inspectors across the entire surface of the thin film transistor substrate.

The array substrate inspecting apparatus of the liquid crystal display includes two inspectors.

The array substrate inspecting apparatus of the liquid crystal display device includes as many inspectors as the thin film transistor substrates.

The movable body moves the inspectors in the same pattern.

The inspector includes a light source for generating light, a modulator installed on a TFT array substrate, a polarization separation prism for selectively reflecting light from the light source and sending the light to the modulator, and whether the pixel electrode is defective by the detected light. A Charged Couple Display (CCD) camera is provided.

Other objects and features of the present invention in addition to the above object will be apparent from the description of the embodiments with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 4 to 7.

Referring to FIG. 4, an inspection apparatus for a TFT array substrate includes a chamber 52 in which a thin film transistor substrate, which is a substrate to be inspected, is mounted, a driving circuit (not shown) for applying test data to the thin film transistor substrate, and the chamber. A plurality of inspectors 52 positioned on top of the 52 and inspecting the operation of the pixel electrode of the thin film transistor substrate, and for moving the plurality of inspectors 52 horizontally and vertically so as to pass through the front surface of the thin film transistor substrate; A moving body (not shown) is provided.

FIG. 5 is a diagram illustrating the inspector 52 shown in FIG. 4.

Referring to FIG. 5, the optical inspector of the TFT array substrate includes a TFT array substrate 31 to be inspected, a light source 43 for generating light, a modulator 39 provided on the TFT array substrate 31, Polarizing Beam Splitter Prism (hereinafter referred to as " PBSP ") 41 for selectively reflecting light from the light source 43 and sending it to the modulator 39, and a CCD (Charged Couple Display) camera 45 Equipped.

The optical inspector moves while maintaining a distance of about 10 to 20 µm from the TFT array substrate 31 to inspect the defect of the TFT array substrate 31.

In the optical inspector, the PBSP 41 selectively transmits and reflects light. The PBSP 41 reflects the linearly polarized S-waves of the light generated from the light source 43 and proceeds to the modulator 39.

The modulator 39 is composed of a polymer dispersed liquid crystal (hereinafter referred to as "PDLC") 35 injected between the substrate 37 on which the transparent electrode is installed and the reflecting plate 33. As shown in FIG. 3, the PDLC layer 35 is formed of a circular liquid crystal droplet 53 by mixing the liquid crystal and the polymer 51 to irradiate ultraviolet rays and then separating the liquid crystal from the polymer 51. The material of the PDLC layer 35 is an epoxy resin composed of a resin and a curing agent. The PDLC layer 35 is driven by the voltage difference between the transparent electrode formed on the substrate 37 of the modulator 39 and the pixel electrode 22 formed on the TFT array substrate 31. In other words, when the voltage is not applied, that is, when the voltage difference applied to the transparent electrode and the pixel electrode 22 is less than or equal to the threshold voltage Vth, the liquid crystal droplets are arranged in random order to scatter the incident light. . This is because light is scattered due to a mismatch between the refractive index of the liquid crystal droplets and the polymer refractive index. On the other hand, when the voltage difference between the transparent electrode and the pixel electrode 22 is greater than or equal to the threshold voltage Vth, the liquid crystal molecules in the liquid crystal droplets of the PDLC layer 35 are arranged in parallel with the electric field to transmit incident light.

By using the principle of the PDLC layer 35, the TFT array substrate is inspected for defects.

When the pixel electrodes 22 of the TFT array substrate 31 operate properly so that the PDLC layer 35 is arranged side by side in the electric field, the S-waves through the PDLC layer 35 are reflected by the reflector of the modulator 39 without polarization change. The process proceeds to PBSP 41. Since there is no polarization change, the light of the S wave is reflected from the PBSP 41 toward the light source 43. As a result, light cannot be detected by the CCD camera 45.

When a defect occurs in the pixel cell of the TFT array substrate 31, no voltage difference occurs between the transparent electrode and the pixel electrode 22, so that the PDLC layer 35 is not driven. That is, the S wave from the light source 43 via the PDLC layer 35 is converted into a P wave and transmitted through the PBSP 41 so that light is detected by the CCD camera 45. Accordingly, it can be seen that the pixel cells on the TFT array substrate 31 on which light is detected by the CCD camera 45 are blue pixels.

6 is a view showing an inspection step of the array substrate by the TFT array substrate inspection apparatus according to the present invention.

Referring to FIG. 6, an inspection apparatus for a TFT array substrate according to an exemplary embodiment of the present disclosure includes two inspectors to inspect a plurality of substrates.

The first and second inspectors are positioned on the upper left plates of the A and B substrates, respectively, to move horizontally and vertically by one moving object and inspect the A and B substrates, respectively.

After the inspection of the A and B substrates is completed, the movable body moves diagonally so that the first and second inspectors are located at the upper left of the C and D substrates. The first and second inspectors perform horizontal and vertical movements starting from the upper left of the C and D substrates and inspect the C and D substrates.

In this process, the first and second inspectors inspect the A to F substrates.

7 is a view showing an inspection step of the array substrate by the TFT array substrate inspection apparatus according to another embodiment of the present invention.

Referring to FIG. 7, an inspection apparatus for a TFT array substrate according to an exemplary embodiment of the present disclosure includes an inspector for the number of array substrates to inspect a plurality of substrates.

The first to N inspectors are positioned at the upper left of each substrate to inspect the substrate while moving in the horizontal and vertical directions by the moving body.

In this way, if the number of substrates is provided, the number of substrates can be inspected by the time required for inspecting one substrate in the related art, thereby significantly reducing the inspection time in the aspect of the substrate.

In addition, the number of inspection apparatuses can be reduced, thereby reducing the apparatus cost and the space required for installing the apparatus.

On the other hand, the inspection apparatus of the TFT array substrate according to the present invention can be implemented through various embodiments.

For example, in the first embodiment, the inspecting step of the TFT array substrate through a plurality of inspectors may be performed by inspecting vertically positioned substrates simultaneously and vertically moving substrates simultaneously and horizontally inspecting them. You can also use In addition, the number of inspectors or the modulator step sequence may be implemented in various forms according to the number of array substrates.

As described above, the liquid crystal display according to the present invention can shorten the time required to inspect the array substrate using a plurality of inspectors.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (5)

A chamber on which a thin film transistor substrate, which is a substrate to be inspected, is seated; A driving circuit for applying test data to the thin film transistor substrate; A plurality of inspectors positioned above the chamber and inspecting the operation of the pixel electrode of the thin film transistor substrate; And a movable body for horizontally and vertically moving the plurality of inspectors across the entire surface of the thin film transistor substrate. The method of claim 1, The array substrate inspection device of the liquid crystal display device comprises two of the inspection device. The method of claim 1, And the array substrate inspecting apparatus of the liquid crystal display comprises as many inspectors as the thin film transistor substrate. The method of claim 1, And the movable body moves the inspectors in the same pattern. The method of claim 1, The checker A light source for generating light; A modulator provided on the TFT array substrate; A polarization splitting prism for selectively reflecting light from the light source and sending it to the modulator; An array substrate inspection apparatus of a liquid crystal display device comprising a CCD (Charged Couple Display) camera for determining whether the pixel electrode is defective by the detected light.

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