JP7173641B2 - LASER REPAIR AND INSPECTION METHOD FOR DISPLAY DEVICE PANEL AND REPAIR AND INSPECTION APPARATUS SUITABLE FOR THE SAME - Google Patents

Description

The present invention relates to laser repair for a display device panel, and more particularly, laser repair and inspection method capable of instantly confirming the result of laser repair of a display device panel to reduce the burden of inspection, and repair suitable for the same. and an inspection device.

Laser processing involves generating a single-wavelength beam with a high degree of synchronization, and irradiating a very small portion of the workpiece with a laser beam having high-density energy obtained by condensing the beam using a condenser lens. It is a processing method that performs operations such as cutting, ablation, vaporization, and melting.

Since the shape and size of the laser beam used in such laser processing is relatively easy to control, it is possible to process complex shapes and high-definition processing by controlling it with a numerical control device. Are suitable.

A universal laser processing apparatus includes a laser oscillator for generating a laser, an optical unit for guiding and focusing the laser beam emitted from the laser oscillator to a position of a processing operation, and a laser beam focused through the optical unit. It may also comprise a position controller or the like for causing the laser beam to reach a desired position on the workpiece.

FIG. 1 is a structural conceptual diagram schematically showing a structural example of a conventional laser repair apparatus.

Laser light emitted from the laser light source 10 is processed through the slit 20, the first beam splitter 91, the tube lens 40, the second beam splitter 81, the third beam splitter 51, and the objective lens 60. It reaches the processing area of the substrate 70 which is the object.

At this time, the slit covers the optical mask in a broad sense, and plays a role in determining the size and shape of the laser beam that passes through the slit and reaches the panel processing area. The tube lens 40 and the objective lens 60 work together to ensure that the laser light reaches the processing area of the panel 70 with the desired degree of focus to effect processing of the panel.

The image light source 53 shines light toward the third beam splitter 51 so that the light reflected therefrom illuminates the processing area of the substrate through the objective lens 60 . The light reflected and scattered from the working area is image light and passes back through the objective lens 60 with the image information of the working area and passes through the third beam splitter 51 , the second beam splitter 81 , the tube lens 40 . , the beam is reflected from the first beam splitter 91 and enters the imaging device 93 so that the imaging device can acquire an image of the processing area.

In such a configuration, the tube lens 40, together with the objective lens 60, constitutes a path for the processing laser light to reach the substrate and a path for transferring the image information of the panel processing area to the imaging device, thereby controlling the degree of convergence of the laser light. It plays a role of defining and a role of image formation and aberration correction of the image light emitted from the objective lens of the infinite optical system.

Also, part of the image light is reflected from the second beam splitter 81 and enters the autofocus sensor 83 beside it. The objective lens 60 for each magnification of the objective lens 60 for confirming the pattern processed on the upper surface (surface) of the panel 70 by laser light in order to smoothly confirm the processing process and result of the pattern processed in the corresponding area. Focus automatically.

A laser repair apparatus or laser processing apparatus having such a configuration has been widely used in the field of flat display manufacturing and the like due to the above-described convenience and high-definition processability. In particular, it is widely used for pixel repair in the field of flat displays such as liquid crystal displays (LCDs) and organic electroluminescence (OLEDs). For example, defective pixels are divided into bright pixels and dark pixels. Since the normally accepted criteria for bright pixels are stricter than those for dark pixels, the bright pixels are darkened. The yield rate of display device panels can be increased.

A typical method for darkening a bright pixel is to irradiate the black matrix with a laser to melt the black matrix, guide the melted black matrix material to the side of the foreign matter, and darken the bright pixel. and a method of directly irradiating the color filter in the area through which the light is transmitted to change the color of the color filter to black, thereby darkening the luminescent pixels.

On the other hand, the properties of polarized light and a focusing lens are used to focus the energy on a specific layer for darkening, such as the black matrix or color filter layer, without damaging other layers or parts of the panel during laser repair. A focal length of .

For example, Korean Patent No. 0981306 discloses a method for repairing a liquid crystal display panel using polarized light. The publication discloses a repair processing method in which a polarizing plate provided on the liquid crystal display panel itself is used to darken defective portions of pixels.

Conventionally, if a defect in the board is detected through a lighting inspection in the main production line after the panel is completed, the panel is transferred to a laser repair device and repaired. These are transferred to the main production line again, and a lighting inspection is performed to confirm whether the panel defects have been resolved. In this case, once the repair is done, it is often necessary to perform the repair completely through a lighting test, etc., and to re-inspect whether the panel defect has been completely cured. , re-inspection is indispensable when the success rate of repair for defects is low. Therefore, the panel is moved from the repair processing device to the inspection device, loaded, and, if necessary, set again.

In order to mitigate and reduce such inconveniences, if a defect occurs during the lighting inspection of the main production line, we will immediately perform laser repair and re-inspection, or re-inspect with the laser repair equipment. Techniques for combining equipment have been developed.

FIG. 2 is a partial structural conceptual diagram for schematically showing and explaining a part different from the repair apparatus of FIG. 1 in a repair apparatus capable of simultaneously performing repair and re-inspection.

In this case, in the reinspection, the lighting inspection is performed again, but under the illumination light from the image light source as shown in FIG. The light source illuminates the entire panel with light in the visible light region or white light.

At this time, if the problem pixel is a forced light emission pixel that always passes light, it can be easily found by preventing light from passing through the entire pixel if a lighting inspection is performed before repair. However, if image light and transmitted light are illuminated while performing a lighting inspection after repair, even if the problem pixel is not completely repaired, it is difficult to distinguish it as before. I have an inconvenience.

Further, in this case, there is a high possibility that a voltage or current is applied to the electrode or liquid crystal of the pixel for the lighting test, and the liquid crystal layer and the electrode are damaged during the test. In particular, when repairing a problem pixel automatically or manually at the same time as inspection, it is possible to darken the pixel by irradiating the laser beam while illuminating the image light and the transmitted light in the lighting state. This is good, but there is a high possibility that bubbles will occur in the liquid crystal or that the material will be denatured in such a process, which will increase the possibility of causing new problems in the pixel in question or adjacent pixels.

In short, these disadvantages reduce the repair success rate and the yield rate of the display panel process, and a proper solution to this problem is desired.

Korean Patent No. 0981306

The present invention relates to the above-described conventional panel repair processing and reinspection method using a laser, which can reduce the burden of being forced to perform reinspection, and can be performed in real time during panel repair processing. It is an object of the present invention to provide a laser repair and inspection method and an apparatus suitable for the laser repair and inspection method, in which the result of repair processing can be easily confirmed with accuracy.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a laser repair and inspection method and an apparatus suitable for the same, in which repair processing and inspection of the result thereof are performed substantially simultaneously, and repair reprocessing can be performed as necessary. .

The laser repair and inspection method of the present invention for achieving the above object is a panel repair apparatus using an existing laser that is irradiated with a laser beam and is an imaging target for checking the state of the lower part of the panel area (back surface). side) is equipped with an infrared transmission light source capable of illuminating the relevant area and penetrating the panel, and infrared light is emitted from the back surface of the panel without image light irradiation to the surface of the panel at the same time as the laser light irradiation for repair or after the laser light irradiation. is illuminated, the area is imaged for inspection, and the captured image is confirmed by an imaging device to confirm the success or failure of the repair process in the area.

As a result of confirming the success or failure of the method of the present invention, if it is not determined to be successful, a process of irradiating the region with laser light again and irradiating infrared light to re-inspect may be further performed.

In the method of the present invention, the irradiation of laser light and the irradiation of infrared light for repair are carried out together, but the irradiation of infrared light is carried out for a sufficient period of time for re-inspection, For the infrared light, a method may be adopted in which an infrared transmitting light source is continuously turned on regardless of the irradiation of the laser light.

The method of the present invention includes a lighting inspection for the entire panel to which the polarizing film has been attached, laser repair for the problem pixels confirmed in the lighting inspection, and an environment of only infrared transmitted light for checking the repair result. The non-lighting inspection may be performed by an in-situ method.

In the method of the present invention, the step of darkening the defective pixels is to focus the energy of the laser light on the color filter layer of the panel through adjusting the focal length of the polarizing film attached to the surface side of the panel and the objective lens system. It may be performed in the following manner.

The apparatus of the present invention is characterized in that an infrared transmission light source is arranged as a transmission light source for illuminating the panel from the back side of the panel, in addition to a normal repair device.

In the present invention, the imaging device as a whole is capable of recognizing infrared light with sufficient sensitivity, and an infrared rejection filter layer or filter material is provided on the path from the infrared transmission light source to the imaging device such as a camera. It is designed not to exist or to be replaced.

The apparatus of the present invention comprises at least one monitoring device or analysis means for displaying and automatically analyzing the illuminated area of interest in real time, such monitoring device or analysis means operating in real time. preferably.

According to the present invention, it is possible to reduce the burden of re-inspection for the results when laser repair processing is performed on a panel, and it is possible to easily confirm the results of repair processing immediately and with high accuracy. , and macroscopically increase the yield rate of manufacturing display panels such as liquid crystal displays (LCDs) and organic electroluminescence (OLEDs).

FIG. 2 is a conceptual diagram schematically showing the configuration of a conventional laser repair device; FIG. 2 is a structural conceptual diagram schematically showing the structure of a part compared with FIG. 1 in the structure of a conventional laser repair and reinspection apparatus; 1 is a structural conceptual diagram schematically showing the structure of a laser repair and inspection apparatus suitable for the present invention; FIG. 1 is a flowchart illustrating one embodiment of a laser repair and inspection method of the present invention; A photograph of the front side of the panel of the problem pixel part under irradiation with image light and visible transmitted light according to the conventional reinspection method, and a rear side (back side) of the panel after laser repair according to the laser repair inspection method of the present invention. 10 is a comparative photograph of the surface side of the panel in the portion of the problem pixel taken while the panel is irradiated with infrared light.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described more specifically with reference to embodiments of the present invention based on the accompanying drawings.

FIG. 3 is a schematic diagram of a laser repair processing and inspection apparatus suitable for implementing the method of the present invention.

The laser repair processing and inspection apparatus (hereinafter simply referred to as "apparatus") according to this embodiment includes a laser light source 110 that emits laser light, and adjusts the size and shape of the laser light while passing the laser light. a first tube lens 140 that can primarily adjust the laser beam that has passed through the slit; and irradiate the panel, which is the object to be processed, and pass the image light of the object to be processed in the opposite direction while adjusting the degree of convergence of the image light, and the object to be processed through the objective lens system. An illumination light source (image light source) 153 that emits illumination light for illuminating the display device panel, a second tube lens 240, and an imaging device that receives image light that has passed through the second tube lens and obtains an image of the object to be processed. 193 and are deployed.

Here, the laser light source 110 is a concept that includes accessory elements required for emitting laser light, such as a laser oscillator and a shutter.

The slit 120 is a broad concept including a portion that forms a gap through which the laser beam passes to determine the size of the laser beam and a pattern mask that determines the shape of the laser beam. to limit the size and shape of

Here, the laser beam that has passed through the slit is reflected by the reflecting mirror 125 to change its path and enter the first tube lens 140 . As the first tube lens 140, one having a focal length of 200 mm is normally used. A slit illuminator 120 a that provides illumination to the slit 120 may be provided at the front end of the optical path of the slit 120 .

After passing through the first tube lens, the laser beam is reflected from the beam splitter 127, passes through the objective lens system 160, is refocused, and is irradiated onto a predetermined position of the display device panel. Thereby, the substance of the color layer of the pixel of the color filter can be blackened.

On the other hand, illumination light is emitted from the illumination light source 153, reflected from the beam splitter 151 through the optical system, transmitted through the beam splitter 127, and passed through the objective lens system 160 to the display device panel 170 which is repaired by laser light. It illuminates, reflects and scatters to form an image light with image information about the working condition of the working area.

Such image light passes through the objective lens system 160 in the opposite direction, is converged, passes through the beam splitters 127 and 151 and is directed to the second tube lens 240 .

The second tube lens adjusts the image light while allowing the incident image light to pass through and directs the image light to the imaging device 193 . As a result, the imaging device can acquire a focused and suitable image. The imaging device can display an image using a computer and a monitor connected thereto, and the displayed image can be used to confirm the processed state of the area during the laser repair process.

Between the second tube lens and the imaging device, a color filter 197 and a polarizing filter 195 are arranged to reduce the amount of light when the amount of light is too high or to limit the image to a wavelength band suitable for the imaging device. good too.

Further, here, unlike the conventional case shown in FIG. 2, an infrared transmission light source 330 is arranged together with the visible light transmission light source 310 on the back side (lower portion) of the display device panel. The infrared transmission light source 330 is arranged together with the visible light transmission light source 310 that produces visible transmission light, and can emit only visible transmission light, only infrared transmission light, or both transmission light as required. I'm trying to irradiate both. Although the transmitted light source may illuminate only a partial area of the panel, here, a transmitted light source that illuminates the entire panel is used.

Furthermore, the image light and the laser light may not be applied to the surface of the panel when the infrared transmitted light is applied.

On the other hand, in the above apparatus configuration, in order to clearly confirm the repair result on the surface of the panel when the infrared transmitted light is irradiated, it is necessary, as a matter of course, to hold the surface side of the substrate while the transmitted light is transmitted through the panel. from the infrared light to the imager so that there is no problem of blocking or seriously weakening the infrared light.

To do so, each optical element in its path is either free of a filtering layer that rejects infrared radiation, or is repositioned so that it can be removed from the path as needed. It must be replaced with an optical element that is specialized for infrared illumination and that can perform the function while smoothly transmitting infrared rays. For example, among the filters, there should be no infrared ray exclusion filter, among the lens coatings and filters attached to the camera constituting the imaging device, there should be no infrared ray exclusion filter, and whether the beam splitter should have an infrared ray exclusion coating, Alternatively, such substances must be kept out of the body components.

Also, although not explicitly shown in FIG. 3, an autofocus device may typically be provided above the image light path, and in such an autofocus device infrared imaging with transmitted light is also facilitated. preferably be able to recognize and drive

On the other hand, considering that the present invention can be performed together with the laser repair, when the laser beam is used to repair the overall structure of the optical system, the laser beam may be an infrared transmission light source or other components in the panel. It is preferred that the structure of the layers be as unaffected as possible to the optical elements within the device.

A series of processes performed in the laser repair and inspection apparatus having such a configuration can be briefly described based on the flow chart of FIG.

The repair and inspection equipment is installed in the path for the lighting inspection after the display panel is completed (see FIG. 3). The completed display panel, which has been pasted up to the surface polarizing film through the previous steps, is loaded and loaded into this machine.

First, an overall lighting inspection is performed on the panel (S10). When performing such an inspection, visible light or white light is illuminated from the visible light transmission light source 310 on the back side of the panel, image light is illuminated from the front side of the panel, and an image seen from the front side of the panel is transferred to an imaging device. be done.

At this time, if a voltage is applied to prevent light from passing through all the pixels, the entire screen is displayed black, but the light passes through the defective pixels and can be clearly recognized. Accordingly, forced emission defective pixels are recognized through this process. Recognition using such an image may be performed visually, or may be performed by an automatic image analysis method through image processing (S20).

Since the device is equipped with a laser repair device, even if a defect is detected, the laser repair device is driven in situ without moving the panel to darken and blacken the defective pixels. (S30).

That is, the position of such a defective pixel is confirmed, and laser light is irradiated to each position to thermally denature the material forming the color filter layer at that position. At this time, an objective lens is used to increase the degree of laser beam convergence in the color filter layer to improve the processing efficiency of the laser beam, and the polarizing filter and the properties of polarized light are used to maximize the deterioration of other components of the panel. Prevention is preferred.

Normally, this material forms a heat-modified black opaque layer with which light cannot pass, but some light leakage may be found if the laser repair is not done correctly.

Such problems may be found in the next step, the results inspection step for laser repair. In the result inspection, unlike the first lighting inspection step, only an infrared transmission light source is used as a transmission light source, and a non-lighting inspection is performed in a state where image light (illumination light) is not applied to the surface side. Therefore, the light from the infrared transmission light source is transmitted through the liquid crystal layer in each pixel without applying an electrical load to the panel (S40).

Infrared light, in normal pixels, passes through the color filter material layer and presents a relatively bright morphology in the image perceived in an imaging device that is sensitive to infrared light, and is darkened using laser repair. Cracked pixels appear dark because they cannot pass through the thermally denatured layer, resulting in a relatively sharp difference between normal and defective pixel areas.

This point can be confirmed using the comparative photographs of FIGS. 5(a) and 5(b). FIG. 5(a) is a comparative example, and FIG. 5(b) is this embodiment. On the other hand, in the photograph of FIG. 5(a), when visible transmitted light is illuminated while performing re-inspection after performing conventional repair, image light on the surface side is still illuminated, and in that state, problem pixels and normal pixels are separated. It can be seen that there is no large difference in brightness between

According to the method of the present invention as described above, since the lighting inspection is not performed after the pixel darkening process using the laser repair, voltage or current is applied to the electrodes and the liquid crystal of the pixel for the lighting inspection after the repair. It is possible to prevent the problem that the liquid crystal layer and electrodes are damaged during the inspection due to the voltage applied, and the problem that occurs when the lighting is continued for the subsequent lighting inspection after the repair even in the laser repair process can be prevented. can be prevented.

According to the method of the present invention as described above, panel lighting inspection, laser repair processing, and post-repair inspection can be performed in situ. It is possible to accurately check whether the problem pixel has been sufficiently darkened according to the repair process, and if necessary, perform further repair, thereby increasing the overall repair success rate. As a result, the yield rate of panels can be increased.

Although the present invention has been described above with reference to limited embodiments, this is merely an exemplary description to aid understanding of the present invention, and the present invention may be It is not intended to be limited to any particular embodiment. Therefore, a person who has ordinary knowledge in the field to which the invention belongs should be able to implement various modifications and applications based on the present invention, and these modifications and applications are not limited to patent claims. It goes without saying that it falls within the scope of

Claims (4)

a laser light source that emits laser light;
a slit for adjusting the size and shape of the laser beam while passing the laser beam;
a first tube lens that passes the laser light that has passed through the slit and primarily adjusts the degree of convergence; a second tube lens that passes image light to the panel;
The laser light that has passed through the first tube lens is received and passed through, the degree of convergence is adjusted secondarily, and the panel is irradiated with the laser light, and the degree of convergence of the image light is passed while the image light from the panel is passed. an objective lens system for adjusting
an illumination light source that emits illumination light that illuminates the panel through the objective lens system;
an imaging device that receives image light that has passed through the second tube lens to obtain an image of the panel;
a visible light transmission light source and an infrared transmission light source disposed on the opposite side of the objective lens system with respect to the panel and illuminating the panel;
provided with,
Further, a color filter or a polarizing filter is positioned between the second tube lens and the image pickup device to reduce the amount of light to the image pickup device or to limit the image to a wavelength band suitable for the image pickup device. including
A lighting test is performed on the panel while illuminating the front side of the panel with illumination light from the illumination light source and irradiating the back side of the panel with transmitted light from the visible light transmission light source, and performing the lighting inspection. After confirming forced light emission defective pixels on the panel through which light constantly passes using the image acquired by the imaging device, the confirmed defective pixels on the panel are irradiated with laser light from a laser light source to darken the defective pixels. ,
without applying an electrical load to the panel and without irradiating the surface of the panel with the illumination light source and the visible light transmission light source, performing a non-lighting inspection of irradiating the panel with infrared rays using only the infrared transmission light source; A laser repair and inspection apparatus, wherein additional repair is performed using the laser light source in an in situ manner when the defective pixels are not darkened. 2. The infrared transmitting light source and the visible light transmitting light source are arranged on the opposite side of the objective lens system, and irradiate the back side of the panel with visible light instead of or together with the infrared transmitting light source. The laser repair and inspection device according to . A laser repair and inspection method using the laser repair and inspection apparatus according to claim 2,
performing a lighting inspection on the panel while irradiating the front side of the panel with illumination light from the illumination light source and irradiating the back side of the panel with transmitted light from the visible light transmission light source;
using the image acquired by the imaging device through the lighting inspection to check forced emission defective pixels through which light constantly passes on the panel;
a step of irradiating the confirmed defective pixels of the panel with laser light to darken the defective pixels;
A non-lighting inspection is performed by irradiating the panel with infrared rays using only the infrared transmission light source in a state where the panel surface is not irradiated with the illumination light source and the visible light transmission light source without applying an electrical load to the panel. confirming whether or not the defective pixel has been accurately darkened using the image acquired by the imaging device;
If the darkening of the defective pixels has not been treated, the laser repair and inspection method further comprising performing additional repair using the laser light source in an in situ manner. The step of darkening the defective pixels includes adjusting the focal length of the polarizing film attached to the surface of the panel and the objective lens system so that the energy of the laser light is concentrated on the color filter layer of the panel. 4. The laser repair and inspection method according to claim 3, wherein the laser repair and inspection method is performed as follows.

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