KR101902606B1 - Method of inspecting pixel position accuracy - Google Patents

Abstract

A method of inspecting pixel position accuracy of a display cell is disclosed. The method includes the steps of: detecting a reference pattern of a display cell formed on a substrate using an image obtaining unit and predetermined reference position coordinates; and detecting a reference pattern of the reference pattern and the image The method comprising the steps of: correcting a relative horizontal position and a vertical position between acquisition units; detecting an inspection pattern of the display cell using a horizontal position correction value and a predetermined inspection position coordinate with respect to the reference pattern; And performing a pixel position accuracy check using the pattern.

Description

Field of the Invention < RTI ID = 0.0 > [0001] <

Embodiments of the present invention relate to a method of inspecting pixel position accuracy. More particularly, the present invention relates to a method of checking pixel position accuracy for display cells such as organic light emitting device (OLED) cells formed on a substrate.

The OLED device used as a flat panel display device is widely used in portable display devices, smart phones, tablet PCs, and the like, as well as being widely used as a next-generation display device due to its large size, having a wide viewing angle, excellent contrast and high response speed . In particular, the OLED device has advantages such as brightness, driving voltage, response speed, etc., and is capable of multi-coloring as compared with an inorganic light emitting display device.

In the manufacturing process of the OLED device, a TFT (Thin Film Transistor) layer is formed on the substrate through various film formation processes and etching processes, and a lower electrode and an organic film layer (for example, a hole transport layer, An electron transport layer) and an upper electrode may be formed. Then, the OLED device can be completed by sealing the TFT layer and the substrate on which the organic light emitting layer is formed using an encapsulating substrate.

In particular, a plurality of OLED cells may be formed on the substrate, and after the sealing process is completed, individual OLED cells may be individualized through a cutting process to complete the OLED device.

Meanwhile, after the sealing process is completed, an inspection process for OLED cells formed on the substrate may be performed. In the inspection process, a function test of the TFT layer, a correction circuit inspection, an image quality inspection, a spectral inspection, an image inspection, and the like may be performed by applying an inspection signal to the OLED cells. However, since the inspecting process is performed after the sealing process is completed as described above, the loss due to the defective OLED devices in the inspecting process may be increased.

In order to solve the above problems, Korean Patent Registration Nos. 1435323 and 10-1452118 filed and filed by the applicant of the present application have found that image quality, brightness, color coordinates, color temperature, thin film A method and an apparatus for inspecting an alignment state of patterns and the like are disclosed. In particular, the inspection apparatus includes an inspection camera for inspecting the image quality, brightness, etc. of the display cells, a spectroscope for checking the color coordinates, color temperature, etc. of the display cells, For example, a fluorescence microscope.

On the other hand, each display cell may have a reference pattern and inspection patterns for checking the pixel position accuracy. The pixel position accuracy inspection may be performed by sequentially detecting the reference pattern and the inspection patterns using the fluorescence microscope and obtaining an image of the inspection patterns. For example, each of the display cells may include one reference pattern and a plurality of inspection patterns adjacent to the reference pattern, and the reference patterns and the inspection patterns may be arranged in a line on an edge of the display cell .

The reference pattern and the inspection patterns may be detected by the fluorescence microscope at predetermined position coordinates. However, it may be difficult to detect the reference pattern and the inspection patterns due to the mechanical error of the driving unit used for adjusting the position of the substrate and the position of the fluorescence microscope. To solve this problem, A vertical and horizontal alignment of the fluorescence microscope with the substrate may be performed.

However, the reference pattern or the inspection pattern may not be detected at the predetermined position coordinates, and it takes a considerable time to perform the alignment for the reference pattern and each inspection pattern in the inspection for each display cell as described above . As a result, the total time required for the inspection of the display cells can be greatly increased.

In order to solve the above-described problems, it is an object of the present invention to provide a new method for shortening the time required for pixel position accuracy inspection.

According to an aspect of the present invention, there is provided a method of inspecting a pixel position accuracy, comprising: detecting a reference pattern of a display cell formed on a substrate using an image obtaining unit and predetermined reference position coordinates; Correcting a relative horizontal position and a vertical position between the reference pattern and the image acquiring unit for alignment between the pattern and the image acquiring unit, using a horizontal position correction value for the reference pattern and a predetermined inspection position coordinate Detecting an inspection pattern of the display cell, and performing a pixel position accuracy check using the detected inspection pattern.

According to embodiments of the present invention, the method may further include correcting a relative vertical position between the inspection pattern and the image obtaining unit for alignment between the inspection pattern and the image obtaining unit.

According to embodiments of the present invention, the method further includes the steps of: correcting the reference position coordinate using a horizontal position correction value and a vertical position correction value for the reference pattern; The horizontal position correction value, and the vertical position correction value for the inspection pattern.

According to embodiments of the present invention, the vertical position with respect to the reference pattern can be corrected through focusing of the image obtaining unit.

According to embodiments of the present invention, focusing of the image acquisition unit may be achieved by vertical movement of the substrate.

According to embodiments of the present invention, the horizontal position with respect to the reference pattern can be corrected by moving the substrate in a first horizontal direction and moving the image obtaining unit in a second horizontal direction perpendicular to the first horizontal direction have.

According to embodiments of the present invention, a fluorescent microscope can be used as the image acquiring unit.

According to another aspect of the present invention, there is provided a method of inspecting pixel position accuracy, comprising: detecting reference patterns of display cells formed on a substrate using an image obtaining unit and preset reference position coordinates; Correcting relative horizontal positions and vertical positions between the reference patterns and the image obtaining unit for alignment between the reference pattern and the image obtaining unit, Detecting inspection patterns of the display cells using coordinates, and performing a pixel position accuracy check using the detected inspection patterns. At this time, an inspection pattern adjacent to the reference pattern of the second display cell among the inspection patterns of the first display cell may be detected using the horizontal position correction value for the reference pattern of the second display cell.

According to the embodiments of the present invention as described above, vertical and horizontal alignment between the reference pattern and the image obtaining unit is performed, and inspection patterns are detected using the horizontal position correction value for the reference pattern, Can be greatly shortened.

In addition, by correcting the reference position coordinates and the inspection position coordinates using the vertical and horizontal position correction values for the reference pattern and the vertical position correction values for the inspection patterns, the time required for the alignment in the inspection process for the subsequent substrate The inspection time for the substrates can be further shortened since the correction values can be optimized in the process of inspecting the plurality of substrates.

In addition, among the inspection patterns, the inspection pattern positioned closer to the reference pattern of the adjacent display cell than the reference pattern of the display cell may be detected using the horizontal position correction value for the reference pattern of the adjacent display cell, The inspection reliability for the display cells can be greatly improved.

FIG. 1 is a flowchart illustrating a pixel position accuracy checking method according to an exemplary embodiment of the present invention. Referring to FIG.
FIG. 2 is a schematic diagram for explaining an inspection apparatus for performing the pixel position accuracy inspection shown in FIG. 1; FIG.
3 is a schematic view for explaining display cells formed on a substrate.
4 is a schematic view for explaining a display cell shown in FIG.
5 is a schematic diagram for explaining the pixel position accuracy checking method shown in FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention should not be construed as limited to the embodiments described below, but may be embodied in various other forms. The following examples are provided so that those skilled in the art can fully understand the scope of the present invention, rather than being provided so as to enable the present invention to be fully completed.

In the embodiments of the present invention, when one element is described as being placed on or connected to another element, the element may be disposed or connected directly to the other element, . Alternatively, if one element is described as being placed directly on another element or connected, there can be no other element between them. The terms first, second, third, etc. may be used to describe various items such as various elements, compositions, regions, layers and / or portions, but the items are not limited by these terms .

The terminology used in the embodiments of the present invention is used for the purpose of describing specific embodiments only, and is not intended to be limiting of the present invention. Furthermore, all terms including technical and scientific terms have the same meaning as will be understood by those skilled in the art having ordinary skill in the art, unless otherwise specified. These terms, such as those defined in conventional dictionaries, shall be construed to have meanings consistent with their meanings in the context of the related art and the description of the present invention, and are to be interpreted as being ideally or externally grossly intuitive It will not be interpreted.

Embodiments of the present invention are described with reference to schematic illustrations of ideal embodiments of the present invention. Accordingly, changes from the shapes of the illustrations, e.g., changes in manufacturing methods and / or tolerances, are those that can be reasonably expected. Accordingly, the embodiments of the present invention should not be construed as being limited to the specific shapes of the regions described in the drawings, but include deviations in the shapes, and the elements described in the drawings are entirely schematic and their shapes Is not intended to describe the exact shape of the elements and is not intended to limit the scope of the invention.

FIG. 1 is a flowchart for explaining a pixel position accuracy inspection method according to an embodiment of the present invention, and FIG. 2 is a schematic diagram for explaining an inspection apparatus for performing pixel position accuracy inspection shown in FIG. 1 .

Referring to FIGS. 1 and 2, a method of inspecting a pixel position accuracy according to an exemplary embodiment of the present invention may be used to perform a pixel position accuracy check on a display cell 20 (see FIG. 3) such as an OLED cell.

As an example, display cells 20, such as OLED cells, may be formed on a substrate 10 (see Figure 3) through a cell process. Specifically, a TFT array layer may be formed on the substrate 10, and an organic light emitting layer may be formed on the TFT array layer. The organic light emitting layer may include a lower electrode layer, a hole transporting layer, a light emitting layer, an electron transporting layer, an upper electrode layer, and the like.

FIG. 3 is a schematic view for explaining display cells formed on a substrate, and FIG. 4 is a schematic view for explaining a display cell shown in FIG. 3. FIG.

Referring to FIGS. 3 and 4, the display cells 20 formed on the substrate 10 may be arranged in a plurality of rows and columns. Each of the display cells 20 may include a plurality of test pads 22 electrically connected to the TFT array layer and may include a reference pattern 30 and test patterns 32 for checking pixel position accuracy . Although the inspection pads 22 and the reference and inspection patterns 30 and 32 are disposed in opposite directions to each other, the inspection pads 22 and the reference and inspection patterns 30 and 32 The position may be variously changed, so that the scope of the present invention is not limited thereto.

The reference pattern 30 may be used to detect a pixel position accuracy inspection position, and a plurality of inspection patterns 32 may be arranged in a line on one side of the reference pattern 30, depending on the color.

Referring to FIG. 2, an inspection apparatus 100 for performing a pixel position accuracy inspection method according to an embodiment of the present invention includes a substrate stage 110 for holding the substrate 10, An image acquisition unit 120 may be included. As the image obtaining unit 120, a fluorescence microscope can be used. Although not shown, the inspection apparatus 100 includes a probe card contacting the inspection pads 22 to light up the display cells 20, a probe card for inspecting the image quality of the display cells 20, A camera, and a spectroscope for checking color coordinates, color temperature, and the like.

Also, although not shown in detail, the substrate stage 110 may be configured to be movable in the first horizontal direction and the vertical direction by the first driving unit 112, (122) to be movable in a second horizontal direction and a vertical direction perpendicular to the first horizontal direction. As an example, the substrate stage 110 may be configured to be movable in the X-axis direction, and the image acquisition unit 120 may be configured to be movable in the Y-axis direction.

5 is a schematic diagram for explaining the pixel position accuracy checking method shown in FIG.

Referring to FIGS. 1 and 5, in step S100, the reference pattern 30 of the display cell 20 on the substrate 10 is detected using the image obtaining unit 120 and predetermined reference position coordinates. For example, the reference position coordinates may include an X axis coordinate of the substrate stage 110 and a Y axis coordinate and a Z axis coordinate of the image obtaining unit 120.

Subsequently, in step S110, the relative horizontal position and vertical position between the reference pattern 30 and the image obtaining unit 120 are corrected for alignment between the reference pattern 30 and the image obtaining unit 120. For example, in order to obtain a clearer image of the reference pattern 30, the vertical position between the reference pattern 30 and the image obtaining unit 120 is corrected first, The horizontal position between the image acquisition units 120 can be corrected. That is, by performing the focusing of the image acquisition unit 120, a clearer image of the reference pattern 30 can be obtained, and the horizontal position correction can be performed using the image of the reference pattern 30 have.

According to an embodiment of the present invention, the focusing of the image acquisition unit 120 may be performed by vertical movement of the substrate 10. [ That is, the first driving unit 112 may perform focusing of the image obtaining unit 120 by adjusting the height of the substrate stage 110, that is, the vertical direction. The horizontal position correction is performed by moving the substrate 10 in the first direction, for example, the X-axis direction so that the optical axis of the image obtaining unit 120 is aligned with the central portion of the reference pattern 30, For example, by moving the image acquisition unit 120 in a second direction, e.g., the Y-axis direction.

The horizontal position correction value and the vertical position correction value for the reference pattern 30 may be stored in a separate storage device. Also, although not shown, the step of correcting the reference position coordinates for the reference pattern 30 using the horizontal position correction value and the vertical position correction value may be performed. The corrected reference position coordinates may be used in a subsequent inspection process of the second substrate.

In step S120, the inspection pattern 32 is detected using the horizontal position correction value and the predetermined inspection position coordinates of the reference pattern 30, and in step S130, An accuracy check can be performed. For example, when the substrate 10 is moved in the first direction or the image obtaining unit 120 in a state where the relative horizontal position and the vertical position of the reference pattern 30 and the image obtaining unit 120 are corrected, Can be moved by a predetermined distance in the second direction. Since the horizontal position correction value for the reference pattern 30 is reflected in the coordinates of the previously set inspection position, the inspection pattern 32 can be detected more easily.

Meanwhile, when the inspection position is moved to the inspection position for detecting the inspection pattern 32, the focusing state of the image acquisition unit 120 is changed due to a mechanical error of the first and second driving units 112 and 122 . According to an embodiment of the present invention, although not shown, the distance between the inspection pattern 32 and the image acquisition unit 120 for vertical alignment between the inspection pattern 32 and the image acquisition unit 120 May be performed.

The vertical alignment between the inspection pattern 32 and the image acquisition unit 120 may be substantially the same as the vertical alignment with respect to the reference pattern 30. That is, focusing of the image obtaining unit 120 with respect to the inspection pattern 32 can be performed by moving the substrate 10 in the vertical direction.

The vertical position correction value for the inspection pattern 32 may be stored in a separate storage device. Although not shown, the step of correcting the inspection position coordinates for the inspection pattern 32 using the horizontal position correction value for the reference pattern 30 and the vertical position correction value for the inspection pattern 32 Can be performed. The corrected inspection position coordinates may be used in a subsequent inspection process of the second substrate.

As described above, since the alignment of the inspection pattern 32 is made only in the vertical direction, the time required for the alignment between the inspection pattern 32 and the image obtaining unit 120 can be greatly shortened.

The inspection pattern detection step S120 and the pixel position accuracy inspection step S130 may be repeatedly performed on the remaining inspection patterns 32 of the display cell 20 and the reference pattern S100 may be repeatedly performed. (S110), the inspection pattern detection step (S120), and the pixel position accuracy inspection step (S130) are repeatedly performed on the remaining display cells (20) of the substrate (10) .

In addition, the corrected reference position coordinates and the corrected inspection position coordinates can be used in the following pixel position accuracy inspection for the second substrate, so that in the pixel position accuracy inspection process, the reference pattern 30 and the inspection patterns 32 and the image acquiring unit 120 can be greatly shortened. In addition, the vertical and horizontal position correction values for the reference pattern 30 and the vertical position correction values for the inspection patterns 32 may be repeatedly performed on the plurality of substrates 10 So that the time required for the pixel position accuracy check can be further shortened.

According to another embodiment of the present invention, although not shown, a method of detecting a pixel position accuracy may be performed by using the image acquisition unit 120 and the reference of the display cells 20 formed on the substrate 10 using predetermined reference position coordinates Patterns 30 and relative horizontal positions between the reference patterns 30 and the image acquisition unit 120 for alignment between the reference patterns 30 and the image acquisition unit 120. [ And detecting the inspection patterns 32 of the display cells 20 using the horizontal position correction values and predetermined inspection position coordinates of the reference patterns 30 , And a second step of performing a pixel position accuracy check using the detected inspection patterns 32.

Specifically, the first step includes the steps of: detecting a reference pattern 30 of the first display cell 20A (see FIG. 5) using reference position coordinates; ) Relative to the remaining display cells (20), including the second display cell (20B) adjacent to the first display cell (20A) And performing the vertical position correction step repeatedly.

After obtaining the vertical and horizontal position correction values for the reference patterns 30 on the substrate 10 as described above, the vertical and horizontal position correction values may be stored in the storage device. The detailed steps of the first step are substantially the same as those described above with reference to FIGS. 1 and 5, so that detailed description thereof will be omitted.

In the second step, the inspection patterns 32 may be detected using horizontal position correction values for the reference patterns 30 obtained as described above. Particularly in the case of the inspection pattern 32 positioned closer to the reference pattern 30 of the display cell 20B adjacent to the reference pattern 30 of the display cell 20A, Can be detected using the horizontal position correction value for the pattern 30. [ 5, the reference pattern 30A of the first display cell 20A and the reference pattern 30B of the second display cell 20B are different from the reference pattern 30A of the first display cell 20A among the inspection patterns 32 of the first display cell 20A, In the case of the inspection pattern 32E adjacent to the pattern 30B, it is preferable to detect using the horizontal position correction value for the reference pattern 30B of the second display cell 20B.

More specifically, when the first display cell 20A has five inspection patterns 32A to 32E, the fifth inspection pattern 32E may have a larger size than the reference pattern 30A of the first display cell 20A. The second display cell 20B may be located closer to the reference pattern 30B of the second display cell 20B so that the fifth display 20B may be positioned closer to the reference pattern 30B using the horizontal position correction value for the reference pattern 30B of the second display cell 20B. It may be more accurate to detect the pattern 32E.

According to the embodiments of the present invention as described above, vertical and horizontal alignment between the reference pattern 30 and the image obtaining unit 120 is performed, and a horizontal position correction value for the reference pattern 30 is used The time required for the detection of the inspection patterns 32 can be greatly shortened by detecting the inspection patterns 32. FIG.

Further, by correcting the reference position coordinates and the inspection position coordinates by using the vertical and horizontal position correction values for the reference pattern 30 and the vertical position correction values for the inspection patterns 32, The time required for the alignment can be greatly shortened and the inspection time for the substrates 10 can be further shortened since the correction values can be optimized in the process of inspecting the plurality of substrates 10. [

In addition, the inspection pattern 32E positioned closer to the reference pattern 30B of the adjacent display cell 20B than the reference pattern 30A of the display cell 20A in the inspection patterns 32 is adjacent to the adjacent display cell 20B using the horizontal position correction value for the reference pattern 30B so that the inspection reliability for the display cells 20 can be greatly improved.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention as defined by the following claims It can be understood that

10: substrate 20: display cell
30: reference pattern 32: inspection pattern
100: inspection apparatus 110: substrate stage
112: first driving unit 120: image acquisition unit
122:

Claims (8)

Detecting a reference pattern of a display cell formed on the substrate using the image acquisition unit and predetermined reference position coordinates;
Correcting relative horizontal and vertical positions between the reference pattern and the image acquisition unit for alignment between the reference pattern and the image acquisition unit;
Detecting an inspection pattern of the display cell using a horizontal position correction value for the reference pattern and a predetermined inspection position coordinate;
Correcting a relative vertical position between the inspection pattern and the image acquisition unit for alignment between the inspection pattern and the image acquisition unit;
Performing a pixel position accuracy check using the detected inspection pattern;
Correcting the reference position coordinate using a horizontal position correction value and a vertical position correction value for the reference pattern; And
And correcting the inspection position coordinates using a horizontal position correction value for the reference pattern and a vertical position correction value for the inspection pattern. delete delete 2. The method of claim 1, wherein the vertical position with respect to the reference pattern is corrected through focusing of the image acquisition unit. 5. The method of claim 4, wherein the focusing of the image acquisition unit is by vertical movement of the substrate. The apparatus according to claim 1, wherein the horizontal position with respect to the reference pattern is corrected by moving the substrate in a first horizontal direction and moving the image obtaining unit in a second horizontal direction perpendicular to the first horizontal direction How to check pixel position accuracy. The method of claim 1, wherein the image acquisition unit is a fluorescence microscope. A) detecting reference patterns of display cells formed on a substrate using an image obtaining unit and preset reference position coordinates, and for detecting an alignment between the reference patterns and the image obtaining unit, Correcting relative horizontal positions and vertical positions between the horizontal and vertical positions; And
B) detecting inspection patterns of the display cells using horizontal position correction values and predetermined inspection position coordinates for the reference patterns, and performing pixel position accuracy inspection using the detected inspection patterns However,
Wherein the inspection pattern adjacent to the reference pattern of the second display cell among the inspection patterns of the first display cell is detected using the horizontal position correction value for the reference pattern of the second display cell.

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