KR102077935B1 - Method of laser repair and test for display panel and apparatus suit for the same - Google Patents

Abstract

Disclosed are a laser repair and inspection method for a display device panel and a repair and inspection device appropriate thereto. According to the present invention, a laser beam is irradiated from a panel repair device using a laser and an infrared transmission light source capable of irradiating a corresponding area to penetrate a panel is disposed on the other surface of a panel region to be photographed for state confirmation such that infrared light is irradiated from the other surface of the corresponding region without irradiating lighting or visible transmission light for a surface of the panel simultaneously with or after laser irradiation for repair, and a photographing process for inspecting the corresponding region is performed and the photographed image is checked in a photographing device, thereby checking whether a repair process for the corresponding region is successful. Accordingly, a burden for re-inspecting a result in a laser repair process for a panel can be reduced and the result of the laser repair process can be easily and immediately confirmed with high accuracy, thereby increasing efficiency and utilization of the laser repair process.

Description

FIELD OF LASER REPAIR AND TEST FOR DISPLAY PANEL AND APPARATUS SUIT FOR THE SAME}

The present invention relates to a laser repair technology for a display panel, and more particularly, a laser repair and inspection method capable of immediately checking the results of a laser repair on a display panel to reduce an inspection burden, and a repair and inspection suitable therefor. Relates to a device.

Laser processing generates a single wavelength light beam with high degree of synchronization, and irradiates a very small portion of the workpiece with high-density energy obtained by condensing with a condenser lens, thereby cutting, ablation, and evaporation. Refers to a processing method for performing operations such as melting and the like.

Since the laser beam used in the laser processing is relatively easy to control the shape or size, it is suitable for the processing of complex shapes or the fine micro-machining by controlling through the numerical control device.

The general laser processing apparatus includes a laser oscillator for generating a laser, an optical unit for guiding and concentrating a laser beam generated by the laser oscillator to a machining work position, and a laser beam focused through the optical unit at a desired position of a workpiece. Or a position controller for reaching.

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

The laser light starting from the laser light source 10 includes 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. ) Reaches the processing region of the substrate 70 to be processed.

At this time, the slit is a concept including a wide photomask, and determines the size and shape of the laser beam passing through the slit to reach the panel processing area. The tube lens 40 and the objective lens 60 work together to allow the laser beam to reach the processing region of the panel 70 at a desired collecting speed so that the panel processing can be performed.

In the image light source 53, the light is directed toward the third beam splitter 51 so that the light reflected from the image light source 53 illuminates the processing region of the substrate through the objective lens 60. The light reflected and scattered in the processing area passes through the objective lens 60 with the image information of the processing area as the image light, and then passes through the third beam splitter 51, the second beam splitter 81, and the tube lens 40. ) Is reversed, reflected by the first beam splitter 91 and input to the image pickup device 93 so that the image pickup device can acquire an image of the processing area.

In this configuration, the tube lens 40, together with the objective lens 60, constitutes a path through which the laser beam for processing reaches the substrate and a path through which image information of the panel processing area is transferred to the imaging device, and determines the focal velocity of the laser beam. And the Infinite Optical System, which plays a role in image formation and aberration correction of the image light emitted from the objective lens.

In addition, a part of the image light is reflected by the second beam splitter 81 and input to the auto focus sensor 83 on the side thereof, and the auto focus sensor 83 is a panel 70 which is an object to be processed through the imaging device 93. Objectives 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 check the processing process and results of the pattern processed in the corresponding area of the The lens 60 is automatically focused.

The laser repair apparatus or laser processing apparatus having such a configuration has been widely used in the field of flat panel display manufacturing and the like because of the above-mentioned convenience and precision workability. In particular, it is widely used for pixel repair in the field of flat panel display including LCD and OLED. For example, a bad pixel may be divided into a bright pixel and a dark pixel. In general, a standard of the bright pixel is allowed to be stricter than that of the dark pixel, thereby increasing the yield of the display panel by darkening the bright pixel.

Such a conventional method for darkening a bright pixel is a method of irradiating a black matrix with a laser to melt the black matrix, and inducing the melted black matrix material toward the foreign material to darken the bright pixel and a color of a region where light is transmitted. There is a method of darkening the bright pixels by irradiating the filter directly to discolor the color of the color filter.

On the other hand, when performing laser repair, the property of polarization and the focal length of the focusing lens can be used to concentrate energy in a specific layer for darkening such as a black matrix or color filter layer without damaging other layers or parts of the panel. .

For example, Korean Patent No. 0981306 discloses a repair method of a liquid crystal display panel using polarization. Here, the repair processing method of the system which darkens the defective part of a pixel using the polarizing plate provided in the liquid crystal display panel itself is disclosed.

Conventionally, when inspecting a board defect through a lighting test in the main production line after panel completion, if a board defect is detected, such a panel is moved to a laser repair apparatus for repair, and then, these panels are moved to the main production line to perform a lighting test. Through this, it is checked whether the defect of the panel is eliminated. In this case, once the repair is made, repairs are completely completed through lighting checks, etc., and it is often necessary to recheck whether the panel defects have healed as a whole, and in particular, when the repair success rate for defects is lowered. Becomes essential. Therefore, there was a lot of trouble, time, and process efficiency such as moving the panel from the repair processing apparatus to the inspection apparatus for loading and updating the settings as necessary.

To alleviate this problem, a technology has been developed to correct the laser repair, retest, or combine the process equipment to perform a retest on the laser repair device if a failure occurs during the lighting test of the main production line.

FIG. 2 is a partial configuration conceptual view schematically illustrating and explaining a portion different from the repair apparatus of FIG. 1 among repair apparatuses capable of repair and retest at the same time.

In this case, in the re-inspection, the lighting test is performed again. The visible light transmitting light source 310 under the panel 70 (back side) is further provided under the illumination light by the image light source as shown in FIG. Light from the area or white light shines through the panel.

In this case, the problem pixel can be easily detected by preventing the entire pixel from passing through the light if it is a forced light emitting pixel that constantly passes the light when the lighting test is performed before repairing. Even if the problem pixel is not completely repaired, there is a problem that it is difficult to distinguish clearly as before.

In this case, a voltage or a current may be applied to the electrodes or the liquid crystals of the corresponding pixels for the lighting inspection, thereby increasing the possibility that the liquid crystal layer and the electrodes may be damaged during the inspection. In particular, when repairing a problem pixel automatically or manually at the same time as the inspection, the pixel darkening may be attempted by irradiating a laser beam while illuminating the image light and the transmitted light in the lit state. The likelihood of occurrence or material deterioration increases, thereby increasing the possibility of generating new problems in the corresponding pixel or adjacent pixels.

As a result, the repair success rate and the process yield of the display panel are lowered due to these problems, and thus, an appropriate solution is required.

Republic of Korea Patent No. 10-0981306 Republic of Korea Patent Publication No. 10-2006-0028186 Republic of Korea Patent No. 10-1358884

The present invention can reduce the burden of re-inspection with respect to the panel repair processing and re-inspection method using the conventional laser described above, it is easy to check the performance of the repair process with high accuracy in real time during panel repair processing It is an object of the present invention to provide a laser repair and inspection method and a device suitable therefor.

SUMMARY OF THE INVENTION An object of the present invention is to provide a laser repair and inspection method and apparatus suitable for the repair processing and the inspection thereof, which can be carried out substantially simultaneously and, if necessary, repaired.

In the laser repair and inspection method of the present invention for achieving the above object, a laser beam is irradiated from a panel repair apparatus using a conventional laser, and the corresponding region is placed on the lower portion (back side) of the panel region to be imaged to check the state. Infrared light source that can penetrate the panel to illuminate the infrared light at the back of the panel without irradiating the surface of the panel at the same time as the laser light irradiation for repair or after the laser light irradiation, and imaging for inspection of the area Proceed to, characterized in that to confirm the success of the repair process in the region by checking the captured image in the imaging device.

If it is determined that the success in the method of the present invention, the success is not determined, the process of re-irradiating the laser light irradiation on the corresponding area and irradiating infrared light may be further performed.

In the method of the present invention, the laser light irradiation and the infrared light irradiation for the repair are performed together, but the infrared light irradiation is performed for a sufficient time for re-inspection, or the infrared light continuously turns on the infrared transmitted light source irrespective of the laser light irradiation. Can be used in a way.

In the method of the present invention, the lighting test for the entire panel where the polarizing film is attached is completed, the laser repair for the problem pixels identified in the lighting test, and the non-lighting test performed only in the environment of infrared rays transmitted for checking the repair result in an in situ manner It may be to proceed.

The darkening of the defective pixel in the method of the present invention may be performed by focusing the energy of the laser light on the color filter layer of the panel by adjusting the focal length of the polarizing film attached to the surface side of the panel and the objective lens system.

The apparatus of the present invention is characterized in that an infrared transmission light source is provided as a transmission light source that illuminates the panel on the back side of the panel in addition to the usual repair apparatus.

In the present invention, the imaging device is capable of recognizing infrared light with sufficient sensitivity as a whole, and is made so that the infrared exclusion filter layer or the filter material may be missing or replaced on the path from the infrared transmission light source to the imaging device such as a camera.

The apparatus of the present invention is provided with at least one monitor or analysis means capable of showing or automatically analyzing the corresponding area being illuminated in real time, and such a monitor device or analysis means is preferably operated in real time.

According to the present invention, it is possible to reduce the re-examination burden on the results of the laser repair processing on the panel, and to immediately check the performance of the repair processing with high accuracy, thereby increasing the efficiency and utilization of the laser repair processing. In addition, the manufacturing yield of a display panel such as a liquid crystal display (LCD) or an organic light emitting display (OLED) may be increased.

1 is a configuration conceptual diagram schematically showing a configuration of a conventional laser repair apparatus;
2 is a configuration conceptual view schematically showing a configuration of a portion compared to FIG. 1 among the configurations of a conventional laser repair and retesting apparatus;
3 is a configuration conceptual diagram schematically showing the configuration of a laser repair and inspection apparatus suitable for the present invention;
4 is a flowchart showing an embodiment of a laser repair and inspection method of the present invention;
Fig. 5 is a photograph photographing a panel surface side of a problem pixel portion in a state in which image light and visible transmitted light are irradiated according to a conventional retest method, and rearward (back side) to a panel after laser repair according to the laser repair inspection method of the present invention. ) Is a comparative image obtained by photographing the panel surface side of the problem pixel portion in the state of irradiating infrared light.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

3 is a schematic conceptual view showing 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 'device') according to the present embodiment includes a laser light source 110 for emitting a laser light, a slit 120 for adjusting the size and shape of the laser light while passing the laser light, The first tube lens 140, which can primarily control the laser beam passing through the slit, receives the light passing through the first tube lens, and adjusts the collecting speed to the panel, which is the object to be processed. The objective lens system 160 through which the image light adjusts the focusing speed while passing the image light in the reverse direction, an illumination light source (image light source 153), and a second tube that emits illumination light that illuminates the display device panel to be processed through the objective lens system. An imaging device 193 is provided to receive an image light passing through the lens 240 and the second tube lens to obtain an object image.

Here, the laser light source 110 is a concept that includes all the accessories necessary for emitting laser light, such as a laser oscillator and a shutter.

The slit 120 forms a gap through which the laser light passes to determine the size of the laser light, and includes a pattern mask for determining the shape of the laser light. The slit 120 defines the size and shape of the laser light passing therethrough. Do it.

In this case, the laser beam passing through the slit is reflected by the reflection mirror 125 to change the path and enter the first tube lens 140. The first tube lens 140 typically uses a focal length of 200 mm. A slit illumination 120a for providing illumination to the slit 120 may be provided at the front end of the slit 120 on the optical path.

The laser beam passing through the first tube lens is reflected by the beam splitter 127 and then focused again through the objective lens system 160 and irradiated to a predetermined position on the display device panel. As a result, the color layer material of the pixel of the color filter may be blackened.

On the other hand, the illumination light source 153 is emitted from the illumination light is reflected by the beam splitter 151 through the optical system is transmitted through the beam splitter 127 is repaired by the laser light through the objective lens system 160 170 Reflecting, scattering, and scattering light to form image light having image information about the processing state of the processing region.

Such image light is focused while passing in the reverse direction of the objective lens system 160 to pass through the beam splitters 127 and 151 to the second tube lens 240.

In the second tube lens, the image light is adjusted while being passed through the input image light so as to be directed to the imaging device 193. As a result, the imaging apparatus can obtain a focused and suitable image. The imaging apparatus can display an image through a computer and a monitor connected thereto, and can confirm the processing state of the corresponding region during the laser repair process through the displayed image.

A color filter 197 or a polarization filter 195 may be provided between the second tube lens and the image pickup device to reduce the amount of light or limit the image to a wavelength band suitable for the image pickup device when the amount of light is too large.

In addition, unlike the conventional case as shown in FIG. 2, the infrared transmitting light source 330 is provided on the side (lower side) of the display device panel together with the visible light transmitting light source 310. The infrared transmission light source 330 is installed together with the visible light transmission light source 310 for generating visible transmission light, so as to irradiate only visible transmission light, only infrared transmission light, or irradiate both transmitted light as necessary. The transmitted light source may be only a part of the area of the panel, but the overall transmitted light source is used.

In addition, when irradiating infrared transmitted light, the image light and the laser light may be operated so as not to irradiate the panel surface.

On the other hand, in the above device configuration, it is natural to clearly confirm the repair result on the panel surface when irradiating infrared transmitted light, but in the state where the transmitted light is transmitted through the panel, the infrared light is blocked from the substrate surface side to the imaging device, or There should be no serious weakening problems.

In order to do so, each optical element on its path can be devoid of a filter function layer that excludes infrared light, or can be repositioned to remove it on the path if necessary, or can be replaced and specialized in infrared illumination, particularly transmitting well in infrared light. At the same time, it should be possible to install and replace with an optical element that can perform the function. For example, there should be no infrared exclusion filter in the filter, no infrared exclusion filter in the lens coating or filter attached to the camera constituting the imaging device, and the infrared splitter coating in the beam splitter should not be mixed with the body components. do.

In addition, although not explicitly illustrated in FIG. 3, an auto focusing apparatus may be generally included on the image light path, and it is preferable to make it easy to recognize and drive an infrared image by transmitted light in such an auto focusing apparatus.

On the other hand, considering that the present invention can be made with a laser repair, when the repair operation by the laser light is performed in the overall configuration of the optical system, the laser light is an infrared transmission light source, another layer structure in the panel, optical elements in the device. It is desirable to ensure that there is no impact to the maximum.

The series of processes performed in the laser repair and inspection apparatus having such a configuration can be arranged in a simple form through the flowchart of FIG. 4.

The repair and inspection apparatus is installed in a path for performing lighting inspection after the display panel is completed (see FIG. 3). The completed display panel attached to the surface polarizing film through the previous steps is fed into and loaded into the device.

First, an overall lighting test on the panel is performed (S10). In performing such an inspection, visible light or white light is emitted from the visible light transmitting light source 310 on the rear surface side of the panel, and image light is emitted from the panel surface side so that the image seen from the panel surface side is transmitted to the imaging device.

In this case, when the voltage is applied to prevent the light from passing through all the pixels, the entire screen appears black, but the light passes through the defective pixels as it is and can be clearly recognized. Therefore, the forced emission defective pixel is recognized through this process. Recognition through such an image may be performed through the naked eye, or may be performed by an automatic image analysis method through image processing (S20).

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

That is, the position of the defective pixel is identified and the laser beam is irradiated at each position to thermally denature the material forming the color filter layer at the position. At this time, it is preferable to increase the processing speed of the laser light by increasing the focusing speed of the laser light in the color filter layer through the objective lens, and to prevent the deterioration of other components of the panel to the maximum by using the polarization filter and the polarization property.

Typically this material is a thermally denatured black opaque layer that prevents light from passing through it, but some laser light leaks can be found if the laser repair is not done correctly.

This problem can be found in the next step, the results inspection for laser repair. In the result inspection, unlike the initial lighting inspection step, only the infrared transmission light source is used as the transmission light source, and the non-lighting inspection is performed without the image light (illumination light) irradiation on the surface side. Accordingly, the light of the infrared ray transmitting light source is transmitted through the liquid crystal layer as it is without applying an electrical load to the panel (S40).

Infrared light passes through the color filter material layer in the normal pixel, and is relatively bright in the image recognized by the image sensing device that detects infrared well. Infrared light does not pass through the thermally denatured layer in the dark ignition process through laser repair. It appears dark, so that the difference between the normal area and the bad pixel area is relatively apparent.

This can be confirmed through the comparison pictures of FIGS. 5A and 5B. (A) of FIG. 5 is a comparative example, (b) is a present Example. On the other hand, the photograph of FIG. 5 (a) shows that the visible light is still shining on the surface side when the visible transmission light is reflected while re-inspecting the conventional repair, and in that state, there is no significant difference in brightness between the problem pixel and the normal pixel. You can see that.

According to the method of the present invention as described above, since the lighting test is not performed after the pixel darkening processing through laser repair, a voltage or a current is applied to the electrode or the liquid crystal of the pixel to check the lighting after repair, thereby resulting in the liquid crystal layer and the electrode. The problem of damage during the inspection can be prevented, and in the laser repair process, it is possible to prevent the problem caused by continuing the lighting for the lighting inspection after the subsequent repair.

According to the method of the present invention as described above, the panel lighting inspection, laser repair processing, and post-repair inspection can be performed in-situ, thereby reducing the burden on the process, and using the infrared transmission light source, Accurately confirm that the darkening process has been sufficiently performed, and if necessary, additional repairs can be performed to increase the overall repair success rate and, ultimately, to increase the panel yield.

In the above described the present invention through a limited embodiment, but this is only illustrative for the purpose of understanding the present invention, the present invention is not limited to these specific embodiments. Accordingly, one of ordinary skill in the art to which the present invention pertains may implement various modifications or applications based on the present invention, and such modifications and applications belong to the appended claims.

10, 110: laser light source 20, 120: slit
40: tube lens 51, 81, 91, 127, 151, 281: beam splitter
53, 153: illumination light source (video light source) 60, 160: objective lens (objective lens system)
70, 170: Panel 83: auto focus sensor
93, 193: imaging device 125: reflective mirror
140: first tube lens 240: second tube lens
310: visible light transmitted light source 330: infrared light transmitted light source

Claims (6)

A laser light source that emits laser light,
A slit that controls the size and shape of the laser light while passing the laser light,
Tube lens for passing the laser light passed through the slit to adjust the focusing speed primarily, and pass the video light for the panel,
An objective lens system for controlling the focusing speed of the image light while passing through the laser beam passing through the tube lens and controlling the focusing rate to the second panel, and passing the video light to the panel;
An illumination light source for emitting illumination light shining on the panel through the objective lens system;
An imaging device which receives an image light passing through the tube lens and acquires an image of the panel;
A visible light transmitting light source and an infrared light transmitting light source provided on the panel opposite to the objective lens system to illuminate the panel;
Conducting a global lighting test on the panel using the visible light transmitting light source, wherein, in the overall lighting test, a voltage is applied to all of the pixels to prevent light of the visible light transmitting light source from passing through all the pixels; If a bad pixel is recognized according to the inspection, after repairing the bad pixel, the panel is irradiated with infrared rays by using only the infrared transmission light source with no image light or illumination light irradiated on the surface side of the panel. Laser repair and inspection device that inspects the results of the laser repair by performing a non-lighting test that does not put an electrical load on the panel. The method of claim 1,
Further comprising a color filter or a polarizing filter between the objective lens system and the image pickup device to reduce the amount of light to the image pickup device or to limit the image to a specific wavelength band of the image pickup device,
Laser repair and inspection apparatus for performing additional repair using the laser light source in situ if the darkening of the defective pixel is not processed after the non-lighting inspection of the repair processing result using the infrared transmission light source. . Illuminating the panel of the display device by illuminating the illumination light by the illumination light source on the front surface side and irradiating the transmitted light from the visible light transmission light source on the back side of the panel;
Identifying a forced light emitting defective pixel through which light of the panel always passes, based on an image obtained by the lighting apparatus through the lighting test;
Irradiating a laser beam to the identified defective pixels of the panel to darken the defective pixels, and
The image obtained by the imaging apparatus by performing a non-illumination test that irradiates only infrared rays from an infrared transmitted light source and does not apply an electric load to the panel in a state where the illumination light source and the visible light transmitted light source are not irradiated with respect to the panel. Checking whether the dark ignition for the defective pixel is normally performed through,
After the non-illumination inspection of the repair processing result using the infrared transmission light source, if the darkening of the defective pixel is not processed further comprising the step of performing an additional repair using a laser light source in situ (in situ) method Repair and inspection method. delete The method of claim 3, wherein
The darkening of the defective pixel is performed by focusing energy of a laser beam on a color filter layer of the panel by adjusting a focal length of a polarizing film and an objective lens system attached to the surface side of the panel. Way. A laser repair and inspection method using the laser repair and inspection apparatus according to claim 1 or 2,
Irradiating a laser beam to the identified defective pixels of the panel to darken the defective pixels;
Irradiating infrared rays from the infrared transmitted light source to the panel to determine whether the darkening of the defective pixel is made correctly;
Laser repair and inspection method for performing additional repair using the laser light source in situ method when the darkening of the defective pixel is not processed after the non-lighting inspection of the repair processing result using the infrared transmission light source. .

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