Substrate and method of inspecting substrate
By using a multi-camera system and alignment mark correction methods, the problems of image distortion and misalignment in display device manufacturing were solved, achieving high-precision foreign object detection.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-15
- Publication Date
- 2026-04-10
Smart Images
Figure CN121843489A_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to a substrate, a method for inspecting a substrate, and an electronic device including the substrate. More specifically, this disclosure relates to a substrate for providing visual information, a method for inspecting a substrate, and an electronic device including the substrate. Background Technology
[0002] With technological advancements, display products are becoming smaller, lighter, and more efficient, while achieving superior performance. Specifically, high-resolution display devices, such as plasma display devices, liquid crystal display devices, and organic light-emitting diode display devices, are gaining attention.
[0003] In the manufacturing of display panels included in such display devices, optical inspection devices can be used to detect defects in the display panels. However, depending on the inspection conditions, the captured images may be distorted or misaligned, leading to reduced inspection accuracy. To address this issue, various efforts are continuously being made to improve inspection accuracy. Summary of the Invention
[0004] One object of this disclosure is to provide a method for inspecting a substrate with improved reliability.
[0005] Another object of this disclosure is to provide a substrate for use in a method of inspecting a substrate.
[0006] Another object of this disclosure is to provide an electronic device including a substrate.
[0007] A method for inspecting a substrate according to an embodiment of the present disclosure includes: placing a substrate comprising a plurality of units, a first alignment mark, and a second alignment mark spaced apart from the first alignment mark in a plan view on a stage; performing a first correction to correct misalignment of a first camera using the first alignment mark; obtaining a first image by capturing an image of the substrate using the first camera; detecting foreign objects in the first image; moving the stage such that the substrate is superimposed on a second camera in a plan view; performing a second correction to correct misalignment of the second camera using the second alignment mark; and obtaining a second image by capturing an image of one of the plurality of units in which foreign objects were detected using the second camera.
[0008] In an embodiment, the substrate may include a first region and a second region adjacent to the first region, and the first alignment mark includes a first first alignment mark disposed in the first region and a first second alignment mark disposed in the second region.
[0009] In an embodiment, the step of capturing the substrate using a first camera may include a first camera and a second camera. The step of capturing the substrate using the first camera may include: capturing a first region using the first camera; and capturing a second region using the first second camera.
[0010] In one embodiment, a first camera can be used to capture an image of the substrate in a line scan manner.
[0011] In an embodiment, the substrate may further include a plurality of third alignment marks corresponding one-to-one with the plurality of units.
[0012] In an embodiment, each of the plurality of third alignment marks may be positioned at the center of one side of the corresponding unit among the plurality of units.
[0013] In an embodiment, each of the first alignment mark, the second alignment mark, and the third alignment mark may have a cross shape in the plan view.
[0014] In an embodiment, the method may further include: performing a third correction to correct misalignment of the second camera using a third alignment mark included among a plurality of third alignment marks before acquiring a second image by capturing it with a second camera, wherein the third alignment mark corresponds to a unit among a plurality of units in which a foreign object is detected.
[0015] In an embodiment, a third correction may be performed using a pre-stored first grayscale of the third alignment mark and a second grayscale of the third alignment mark determined based on an image of the third alignment mark captured by a second camera.
[0016] In the embodiments, Formula 1 can be used to perform the third correction.
[0017]
[0018] Where f(x,y) is the second gray level of each region of the third alignment mark, and is the average value of f(x,y), g(x,y) is the pre-stored first gray level of each region of the third alignment mark, and It is the average value of g(x,y).
[0019] In an embodiment, a third correction may be performed until the value of the normalized grayscale (f,g) is equal to or greater than about 0.85.
[0020] In an embodiment, the step of detecting foreign objects in a first image may include: matching the first images of each of a plurality of units with each other; and determining that a region with a grayscale value difference greater than a preset threshold includes foreign objects.
[0021] In an embodiment, the step of matching the respective first images of multiple units may include: matching using a third alignment mark.
[0022] In one embodiment, the first calibration may include verifying whether the first alignment mark is positioned at the center of the screen of the first camera.
[0023] In one embodiment, the second calibration may include verifying whether the second alignment mark is positioned at the center of the screen of the second camera.
[0024] In one embodiment, the resolution of the second camera may be higher than that of the first camera.
[0025] The substrate according to an embodiment of the present disclosure includes: a cell region in which a plurality of cells are disposed; and a peripheral region surrounding at least a portion of the cell region, wherein the substrate includes: a first alignment mark disposed in the peripheral region; a second alignment mark disposed in the peripheral region and spaced apart from the first alignment mark in a plan view; and a third alignment mark disposed in the cell region and corresponding one-to-one with the plurality of cells, wherein each of the third alignment marks is disposed on one side of the corresponding cell among the plurality of cells.
[0026] In an embodiment, the substrate may include a first region and a second region adjacent to the first region, and the first alignment mark may include: a first alignment mark disposed in the first region; and a first second alignment mark disposed in the second region.
[0027] In an embodiment, each of the first alignment mark, the second alignment mark, and the plurality of third alignment marks may have a cross shape in a plan view.
[0028] An electronic device according to an embodiment of the present disclosure includes a display device and a processor configured to drive the display device, wherein the display device is inspected by a method of inspecting a substrate, the method comprising: placing a substrate including a plurality of units, a first alignment mark and a second alignment mark spaced apart from the first alignment mark in a plan view on a stage; performing a first correction using the first alignment mark to correct misalignment of a first camera; obtaining a first image by capturing an image of the substrate using the first camera; detecting foreign objects in the first image; moving the stage such that the substrate is superimposed on a second camera in a plan view; performing a second correction using the second alignment mark to correct misalignment of the second camera; and obtaining a second image by capturing an image of one of the plurality of units in which foreign objects are detected using the second camera.
[0029] Therefore, even when the substrate is enlarged (e.g., enlarged beyond a predetermined size), distortions in the first and second cameras can be corrected through first, second, and third corrections. Thus, the location of foreign objects can be accurately identified, and the coordinates of the foreign objects captured by the first camera can be magnified and accurately determined by the second camera. Consequently, the technique described herein supports accurate location determination of foreign objects and overcomes problems in the substrate manufacturing process by analyzing foreign objects via the first and second cameras. Attached Figure Description
[0030] The accompanying drawings are included to provide a further understanding of the inventive concept, and are incorporated in and form part of this specification. The drawings, together with the description, illustrate embodiments of the inventive concept.
[0031] Figure 1 This is a cross-sectional view showing a first camera according to a disclosed embodiment.
[0032] Figure 2 It is shown Figure 1 A plan view of an embodiment of the substrate.
[0033] Figure 3 It is shown Figure 1 Perspective view of the first camera and the first alignment mark.
[0034] Figure 4 and Figure 5 It is shown Figure 3 The first corrected plan view of the first camera.
[0035] Figure 6 It shows the captured Figure 2 A planar view of the first image of the base.
[0036] Figure 7 This is a perspective view showing the second camera and the second alignment mark.
[0037] Figure 8 and Figure 9 It is shown Figure 7 The second correction plan view of the second camera.
[0038] Figure 10 , Figure 11 and Figure 12 It is shown Figure 7 The third corrected view from the second camera.
[0039] Figure 13 This is a flowchart illustrating a method for examining a substrate according to a disclosed embodiment.
[0040] Figure 14 It is shown Figure 13 The flowchart shows the steps for detecting foreign objects.
[0041] Figure 15 This is a block diagram illustrating an electronic device according to an embodiment of the present disclosure.
[0042] Figure 16 It is based on Figure 15 Schematic diagrams of electronic devices in various embodiments. Detailed Implementation
[0043] Regarding the embodiments disclosed herein, the specific structural and functional descriptions are illustrative for the purpose of explaining the embodiments of this disclosure, and the embodiments of this disclosure can be implemented in various forms and should not be construed as limited to the embodiments described herein.
[0044] Because this disclosure can be modified and take many forms, specific embodiments will be shown in the accompanying drawings and described in detail herein. However, this is not intended to limit this disclosure to the particular form disclosed, and it should be understood to include all modifications, equivalents, and substitutions included within the spirit and technical scope of this disclosure.
[0045] Terms such as "first," "second," etc., may be used to describe various components, but these components should not be limited by these terms. The terms above may be used for the purpose of distinguishing one component from another. For example, without departing from the scope of this disclosure, a first component may be referred to as a second component, and similarly, a second component may be referred to as a first component.
[0046] It will be understood that when an element is referred to as “connected” or “joined” to another element, the element may be directly connected to or joined to said other element, or an intermediary element may be present. Conversely, when an element is referred to as “directly connected” or “directly joined” to another element, no intermediary element is present. Other terms used to describe the relationship between elements (e.g., “between” vs. “directly between”, “adjacent to” vs. “directly adjacent to”, etc.) should be interpreted in a similar manner.
[0047] The terminology used herein is for the purpose of describing particular exemplary embodiments and is not intended to limit the embodiments of this disclosure. As used herein, unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” are also intended to include the plural forms. It will also be understood that when the terms “comprising” and / or “including” are used in this specification, it indicates the presence of the stated features, integrals, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof.
[0048] Terms such as “below,” “at the bottom,” “down,” “below,” “above,” “at the top,” “on top,” and “on top” are used to explain the relationships between the components shown in the accompanying drawings. The terms are relative concepts and are interpreted based on the directions indicated in the drawings.
[0049] The terms “about” or “approximately” as used herein include the stated value and, taking into account the measurement being discussed and the errors associated with the measurement of the specific quantity, include an appropriate range of deviations for the specific value as determined by one of ordinary skill in the art. For example, the terms “about” or “approximately” may mean within one or more standard deviations, or within ±30%, ±20%, ±10%, ±5% of the stated value.
[0050] As used herein, the term "substantially" means approximately or actually. The term "substantially equal" means approximately or actually equal. The term "substantially identical" means approximately or actually identical. The term "substantially perpendicular" means approximately or actually perpendicular. The term "substantially parallel" means approximately or actually parallel.
[0051] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which the inventive concept pertains. It will also be understood that terms (such as those defined in a general dictionary) shall be interpreted as having the meaning consistent with their meaning in the context of the relevant field, and shall not be interpreted in an idealized or overly formalized sense, unless expressly defined herein.
[0052] In the following description, embodiments will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used for the same components, and redundant descriptions of the same components will be omitted.
[0053] In this specification, a plane may be defined by a first direction D1 and a second direction D2 intersecting the first direction D1. For example, the second direction D2 may be perpendicular to the first direction D1. In some aspects, a third direction D3 may be the normal direction of the plane. That is, the third direction D3 may be perpendicular to the plane formed by the first direction D1 and the second direction D2.
[0054] Figure 1 This is a cross-sectional view showing a first camera according to a disclosed embodiment.
[0055] Reference Figure 1 The inspection device STD may include a stage ST, a first camera CA1, and a first processor HD1. The first processor HD1 may include a storage unit SR, a grayscale extraction unit SE, an alignment unit SU, an image extraction unit IE, and a defect determination unit DJ.
[0056] The base SUB, used as an inspection target for determining the occurrence of defects using the inspection device STD, can be mounted on the ST. For example, the base SUB can be a display device comprising multiple units (e.g., Figure 2 The base of the unit CL in the middle.
[0057] The first camera CA1 can capture images of the substrate SUB set on the stage ST. Therefore, the first camera CA1 can obtain captured images of the substrate SUB.
[0058] In an embodiment, the first camera CA1 may be a charge-coupled device (CCD) camera. That is, the first camera CA1 may be a device that uses light to capture an image of the substrate SUB. The first camera CA1 may capture an image of the substrate SUB in one direction. For example, the first camera CA1 may move in a first direction D1 while illuminating the substrate SUB and capturing a reflected image.
[0059] The storage unit SR can store captured images obtained by the first camera CA1.
[0060] The grayscale extraction unit SE can obtain the grayscale values of the captured image. For example, the grayscale extraction unit SE can generate grayscale values by converting the captured image obtained by the first camera CA1 into grayscale. In an embodiment, the grayscale extraction unit SE can analyze the captured image and generate grayscale values ranging from 0 to 255.
[0061] The alignment unit SU can align the captured image. In an embodiment, a captured image can be obtained by capturing an image of the base SUB using the first camera CA1 while changing the relative position of the first camera CA1 with respect to the base SUB. In this case, for example, alignment errors may occur in the captured image due to errors in the moving device that moves the first camera CA1 or the stage ST. The alignment unit SU can correct the alignment errors in the captured image.
[0062] The image extraction unit (IE) can extract the target image and at least one comparison image that matches the target image from the captured image.
[0063] The defect determination unit DJ can determine whether a defect has appeared in the captured image. For example, the defect determination unit DJ can compare the inspection target image extracted by the image extraction unit IE with a comparison image to determine whether a defect exists in a region of the captured inspection target image. However, the disclosed embodiments are not limited to this. The defect determination unit DJ can also determine the defect based on the grayscale analyzed by the grayscale extraction unit SE.
[0064] Figure 2 It is shown Figure 1 A plan view of an embodiment of the substrate.
[0065] Reference Figure 1 and Figure 2 The base SUB may include a cell region CLA with multiple cells CL and a peripheral region SA surrounding at least a portion of the cell region CLA. Figure 2In the diagram, the base SUB is shown as having a rectangular shape in a planar view; however, the disclosed embodiments are not necessarily limited to this. The planar shape of the base SUB can include various forms such as circles, ellipses, or other polygons.
[0066] Multiple cells CL can be arranged within the cell region CLA of the substrate SUB. The cells CL can be arranged in a matrix along a first direction D1 and / or a second direction D2. The cells CL can be a unit substrate included in a display device (e.g., a smartphone, tablet, etc.). Figure 2 In the diagram, each of the elements CL is shown as having a rectangular shape in a planar view; however, the disclosed embodiments are not necessarily limited to this. The elements CL can have various planar shapes, such as circles, ellipses, or other polygons.
[0067] In an embodiment, the base SUB may define a first region A1, a second region A2, and a third region A3. The first region A1, the second region A2, and the third region A3 may be defined along a first direction D1. Specifically, the second region A2 may be adjacent to the first region A1 in the first direction D1, and the third region A3 may be adjacent to the second region A2 in the first direction D1.
[0068] In an embodiment, the substrate SUB may include a first alignment mark AK1. The first alignment mark AK1 may include a first alignment mark AK1-1, a first second alignment mark AK1-2, and a first third alignment mark AK1-3. The first alignment mark AK1 may be disposed on one side of the peripheral region SA of the substrate SUB. Figure 2 In the illustration, the first alignment mark AK1 is shown as comprising three alignment marks; however, the disclosed embodiments are not necessarily limited to this. The first alignment mark AK1 may comprise two or fewer, or four or more alignment marks.
[0069] For example, a first alignment mark AK1 can be disposed in a first region A1, a second region A2, and a third region A3 of the substrate SUB. Specifically, a first alignment mark AK1-1 can be disposed in the first region A1 of the substrate SUB. A first second alignment mark AK1-2 can be disposed in the second region A2 of the substrate SUB. A first third alignment mark AK1-3 can be disposed in the third region A3 of the substrate SUB.
[0070] The second alignment mark AK2 can be further disposed in the peripheral region SA of the base SUB. The second alignment mark AK2 can be spaced apart from the first alignment mark AK1 in a plan view. For example, as... Figure 2 As shown, the second alignment mark AK2 can be positioned in the region rotated clockwise from the first alignment mark AK1. However, the disclosed embodiments are not limited to this.
[0071] Multiple third alignment marks AK3 can be disposed in the cell region CLA of the base SUB. The third alignment marks AK3 can be disposed in a matrix form along the first direction D1 and / or the second direction D2. The third alignment marks AK3 can be disposed in a one-to-one correspondence with the cell CL. For example, each of the third alignment marks AK3 can be disposed on one side of each of the cells CL.
[0072] In an embodiment, such as Figure 2 As shown, the first alignment mark AK1, the second alignment mark AK2, and the third alignment mark AK3 can have a cross shape in the plan view. However, the disclosed embodiments are not limited to this. The first alignment mark AK1, the second alignment mark AK2, and the third alignment mark AK3 can have various shapes in the plan view, such as triangles, rectangles, or ellipses.
[0073] Figure 3 It is shown Figure 1 Perspective view of the first camera and the first alignment mark.
[0074] Reference Figure 1 , Figure 2 and Figure 3 The first camera CA1 may include a first camera CA1-1, a first second camera CA1-2, and a first third camera CA1-3. However, the disclosed embodiments are not limited thereto. The first camera CA1 may include two or fewer, or four or more cameras.
[0075] In this embodiment, the first camera CA1-1, the first second camera CA1-2, and the first third camera CA1-3 can correspond one-to-one with the first region A1, the second region A2, and the third region A3 of the substrate SUB. When the substrate SUB is defined as three regions along the first direction D1, the first camera CA1 can include three cameras to capture images of each region. That is, if the substrate SUB is defined as four or more regions along the first direction D1, the first camera CA1 can also include four or more cameras.
[0076] In this embodiment, the first camera CA1 can capture images of the entire surface of the substrate SUB. Specifically, the first camera CA1 can capture images of cells CL disposed in the cell region CLA of the substrate SUB. For example, the first camera CA1 can capture images of the substrate SUB in a line scan manner along the second direction D2. That is, the first camera CA1 can move along the second direction D2 while capturing images of the substrate SUB. However, the disclosed embodiments are not limited to this.
[0077] Figure 4 and Figure 5 It is shown Figure 3The first calibrated plan view of the first camera. Specifically, Figure 4 and Figure 5 It can be shown that the first camera CA1-1 captures the first alignment mark AK1-1 on the screen (e.g., what the user sees as displayed by the camera).
[0078] although Figure 4 and Figure 5 The first camera CA1-1 and the first alignment mark AK1-1 are described as central elements, but the first second camera CA1-2 and the first second alignment mark AK1-2, as well as the first third camera CA1-3 and the first third alignment mark AK1-3, can perform substantially the same functions as the first camera CA1-1 and the first alignment mark AK1-1. Therefore, overlapping details can be omitted or summarized.
[0079] Reference Figure 3 , Figure 4 and Figure 5 Before the first camera CA1 captures the substrate SUB using a line scan method, a first correction can be performed. The first correction is a process of checking and correcting any misalignment of the first camera CA1 on its screen using a first alignment mark AK1 before moving along the second direction D2. With this first correction, the first camera CA1 can capture a first image of the substrate SUB without distortion.
[0080] For example, such as Figure 4 As shown, the first camera CA1-1 can capture an image of the first alignment mark AK1-1. In an example where the first alignment mark AK1-1 has a cross shape, the first camera CA1-1 can check whether the first and second axes of the first alignment mark AK1-1, which intersect each other, are parallel to the first direction D1 and the second direction D2, respectively. In some aspects, through a first correction, the technique described herein can check whether the first alignment mark AK1-1 is positioned at the center of the screen of the first camera CA1-1.
[0081] The first calibration can continue until the first axis and the second axis of the first alignment mark AK1-1 become parallel to the first direction D1 and the second direction D2, respectively, on the screen of the first camera CA1-1. Furthermore, the first calibration can continue until the first alignment mark AK1-1 is located at the center of the screen of the first camera CA1-1. Therefore, when the first axis and the second axis of the first alignment mark AK1-1 are parallel to the first direction D1 and the second direction D2, respectively, and the first alignment mark AK1-1 is located at the center of the screen of the first camera CA1-1, the first camera CA1 can begin capturing the substrate SUB.
[0082] Figure 6 It shows the captured Figure 2 A planar view of the first image of the base.
[0083] Reference Figure 2 , Figure 3 and Figure 6 After completing the first calibration, the first camera CA1 can capture an image of the substrate SUB to obtain a first image. This first image can be used to detect foreign objects (DEF) included in the substrate SUB. (See later...) Figure 14 Describe a method for detecting foreign objects (DEF) in a first image using a first camera CA1.
[0084] like Figure 6 As shown, each unit CL disposed on the substrate SUB may include a foreign object DEF. For example, one unit CL in the unit CL may include a first foreign object DEF1, and another unit CL spaced apart from said one unit CL in the unit CL may include a second foreign object DEF2. Although Figure 6 The presence of a first foreign object DEF1 and a second foreign object DEF2 is shown, but the disclosed embodiments are not necessarily limited thereto.
[0085] The coordinates of the foreign object DEF included in the first image can be sent to the first processor (e.g., Figure 1 The first processor (HD1) can further send the coordinates of the sent foreign object DEF to the second processor (e.g., Figure 7 The second processor (HD2). Foreign matter DEF can be dust on the substrate SUB or an area affected by wiring short circuits, etc. However, the disclosed embodiments are not limited to this.
[0086] Figure 7 This is a perspective view showing the second camera and the second alignment mark.
[0087] Reference Figure 6 and Figure 7 The stage ST can move the base SUB so that the base SUB is superimposed on the second camera CA2 in a planar view. Specifically, the stage ST can move the base SUB so that the second alignment mark AK2 of the base SUB is superimposed on the second camera CA2 in a planar view. Therefore, the second camera CA2 can capture an image of the second alignment mark AK2.
[0088] Figure 8 and Figure 9 It is shown Figure 7 The second camera's second calibration plan view. Specifically, Figure 8 and Figure 9 The screen shows the second camera CA2 capturing the second alignment mark AK2.
[0089] Reference Figure 6, Figure 7 , Figure 8 and Figure 9 Before capturing each of the cells CL containing the foreign object DEF in the substrate SUB, the second camera CA2 can perform a second correction. That is, the second correction is a process of checking and correcting any screen misalignment before the second camera CA2 moves to the position of the cell CL that detected the foreign object.
[0090] The resolution of the second camera CA2 can be higher than that of the first camera CA1. Therefore, the second camera CA2 can more accurately determine the type of foreign object (DEF) detected in the first image captured by the first camera CA1.
[0091] For example, the second camera CA2 can capture an image of the second alignment mark AK2. In some aspects, according to one or more embodiments of this disclosure, the second alignment mark AK2 may have a cross shape in a plan view, which can support checking whether the third axis of the second alignment mark AK2 and the fourth axis intersecting the third axis are parallel to the first direction D1 and the second direction D2, respectively. In some aspects, the techniques described herein can check whether the second alignment mark AK2 is positioned at the center of the screen of the second camera CA2 through a second correction.
[0092] like Figure 7 As shown, when the second camera CA2 captures the second alignment mark AK2, the third and fourth axes of the second alignment mark AK2 do not necessarily need to be parallel to the first direction D1 and the second direction D2. When correcting this misalignment of the second camera CA2, a second correction can be performed until the third and fourth axes of the second alignment mark AK2 become parallel to the first direction D1 and the second direction D2, respectively. Furthermore, the second correction can continue until the second alignment mark AK2 is positioned at the center of the screen of the second camera CA2.
[0093] When the third and fourth axes of the second alignment mark AK2 are parallel to the first direction D1 and the second direction D2 respectively, and the second alignment mark AK2 is positioned at the center of the screen of the second camera CA2, the second camera CA2 can begin to capture the substrate SUB.
[0094] Figure 10 , Figure 11 and Figure 12 It is shown Figure 7 The third corrected view from the second camera. Specifically, Figure 10 This is a perspective view showing the second camera CA2 capturing the substrate SUB. Figure 11 This is a plan view showing one of the units CL and one of the third alignment marks AK3. Figure 12 This is an enlarged plan view showing one of the third alignment marks AK3.
[0095] Before capturing each of the cells CL containing foreign objects (DEF) in the substrate SUB, the second camera CA2 can perform a third correction. That is, the third correction is a process of checking and correcting any screen misalignment after the second camera CA2 moves to the position of the cell CL and before capturing each cell CL.
[0096] Reference Figure 6 and Figure 10 The stage ST can move the base SUB so that the second camera CA2 can capture an image of the unit CL, including the foreign object DEF. Specifically, the stage ST can move the base SUB so that the third alignment mark AK3, which is located on one side of the unit CL including the foreign object DEF, is superimposed on the second camera CA2 in the plan view.
[0097] Further reference Figure 11 and Figure 12 The second camera CA2 can capture images of the third alignment mark AK3, which is set on one side of each of the third alignment marks AK3 in the unit CL. That is, as Figure 12 As shown, the second camera CA2 can capture an image of one of the third alignment marks AK3, such that the third alignment mark AK3 is positioned at the center of the screen of the second camera CA2.
[0098] In an embodiment, such as Figure 11 As shown, each of the third alignment marks AK3 can be positioned at the center of one side of each of the units CL. Specifically, each of the third alignment marks AK3 can be positioned along an imaginary line parallel to the first direction D1 and passing through the center of each of the units CL. However, the disclosed embodiments are not limited to this. Each of the third alignment marks AK3 can also be arranged along an imaginary line parallel to the second direction D2 and passing through the center of each of the units CL.
[0099] The third correction can be performed by comparing the first grayscale of the third alignment mark AK3 set on one side of the unit CL that detects the foreign object DEF with the second grayscale obtained by capturing the third alignment mark AK3 using the second camera CA2.
[0100] Specifically, the first grayscale value of one of the pre-stored third alignment marks AK3 can refer to the grayscale value obtained by capturing one of the third alignment marks AK3 using the second camera CA2 before detecting the foreign object DEF. That is, the first grayscale value of each of the third alignment marks AK3 can be stored as data. For example, as... Figure 12 As shown, the first gray level can be the average gray level of the 64 divided regions.
[0101] Similarly, relative to the 64 segmented regions captured by the second camera CA2, which includes the third alignment marker AK3, the second grayscale can be the average grayscale among the 64 segmented regions. Figure 12 In this embodiment, the screen of the second camera CA2 is divided into 64 regions; however, the disclosed embodiments are not necessarily limited to this. Since the second camera CA2 is capable of capturing high-resolution images, the regions can include millions or tens of millions of partitions (i.e., millions or tens of millions of areas).
[0102] Subsequently, a second grayscale can be obtained, which is the grayscale of the third alignment mark AK3 set on one side of the unit CL that detects the foreign object DEF.
[0103] The first and second gray levels can be normalized using the following equation: [Formula 1]
[0104] Here, f(x,y) is for each region of the third alignment mark AK3 (e.g., Figure 12 The second grayscale value of the 64 divided regions shown, and It is the average value of f(x,y). Similarly, g(x,y) is the first gray value of each region of the third alignment mark AK3, and It is the average value of g(x,y).
[0105] The third correction can be performed by normalizing the first and second gray levels using Formula 1 until the value derived from Formula 1 is equal to or greater than 0.85. That is, when the value derived from Formula 1 is 0.85 or greater, the second camera CA2 can determine that the misalignment has been corrected for use in each of the capture units CL. Therefore, by comparing the gray levels of the third alignment mark AK3 with each image of the directly corrected unit CL, the correction process can be performed in a relatively simple manner.
[0106] As a result, even when the substrate SUB is large (i.e., the substrate SUB has an area larger than a predetermined size), embodiments of this disclosure support performing the first, second, and third corrections described herein in association with correcting misalignments in the first camera CA1 and the second camera CA2. Therefore, the location of the foreign object DEF can be accurately identified, which allows the second camera CA2 to magnify and precisely determine the coordinates of the foreign object DEF detected in the first image captured by the first camera CA1. Ultimately, the first camera CA1 and the second camera CA2 can analyze the foreign object DEF to accurately identify and resolve problems in the manufacturing process of the substrate SUB.
[0107] Figure 13This is a flowchart illustrating a method for examining a substrate according to a disclosed embodiment.
[0108] In the description of the methods and processes herein, operations may be performed in a different order than those shown and / or described, or in a different order or at different times. Some operations may also be omitted from the flowchart, one or more operations may be repeated, or additional operations may be added. The descriptions of "can be set," "can be formed," "can be moved," etc., elements include methods, processes, and techniques for setting, forming, moving, etc., based on the examples described herein.
[0109] Reference Figures 1 to 13 The method may include setting (i.e., placing) a substrate SUB including a first alignment mark AK1 and a second alignment mark AK2 on a stage ST (S100). Before capturing an image of the substrate SUB using a first camera CA1 (described later with reference to S300), the method may include performing a first correction to verify that the screen of the first camera CA1 is not misaligned (S200).
[0110] Once the first correction is completed, the method may include positioning a first alignment mark AK1 at the center of the screen of the first camera CA1. In some aspects, the first axis and the second axis of the first alignment mark AK1 may be parallel to the first direction D1 and the second direction D2, respectively. The method may then include capturing an image of the substrate SUB using the first camera CA1 via a line scan method (S300) (i.e., obtaining a first image as described herein). Since the position and misalignment of the first camera CA1 are corrected by the first correction, the coordinates of the foreign object DEF within each of the cells CL can be obtained more accurately.
[0111] After capturing the substrate SUB using the first camera CA1, the method may include detecting foreign objects (DEFs) in each of the cells CL disposed on the substrate SUB using an inspection device STD (S400). The method may then include sending the coordinates of the foreign objects (DEFs) to a second processor HD2 by the inspection device STD. To identify the foreign objects (DEFs) included in the cells CL, the method may include moving a stage ST associated with the moving substrate SUB such that the substrate SUB is superimposed on the second camera CA2 in a plan view (S500). The foreign objects (DEFs) may be dust on the substrate SUB or defects caused by wiring short circuits, etc. However, the disclosed embodiments are not necessarily limited to this.
[0112] Before capturing an image of each cell CL, the method may include performing a second correction to verify that the screen of the second camera CA2 is not misaligned (S600). Once the second correction is complete, the method may include positioning a second alignment mark AK2 at the center of the screen of the second camera CA2. In some aspects, the third and fourth axes of the second alignment mark AK2 may be parallel to the first direction D1 and the second direction D2, respectively. Since the position and misalignment of the second camera CA2 are corrected in the second correction, the second camera CA2 can be precisely moved to the coordinates of each of the cells CL.
[0113] Subsequently, the method may include using a second camera CA2 to capture an image of a third alignment mark AK3 positioned on one side of the unit CL in which the foreign object DEF was detected. In an example where the second camera CA2 moves from the position of the second alignment mark AK2 to the coordinates of one of the third alignment marks AK3, mechanical errors may cause the second camera CA2 to fail to align precisely with the coordinates. To address this problem, the method may include performing a third correction (S700). Finally, after completing the first, second, and third corrections, the method may include obtaining a second image by using the second camera CA2 to capture an image of the unit CL in which the foreign object DEF was detected (S800). Therefore, the method can determine the type of the foreign object DEF accordingly based on the steps described herein.
[0114] Figure 14 It is shown Figure 13 A flowchart of the steps for detecting foreign objects (DEF) (S400). Specifically, Figure 14 This is a flowchart illustrating the process of extracting the coordinates of a foreign object (DEF) from a first image.
[0115] Reference Figures 1 to 14 Detecting a foreign object DEF from the first image (S400) may include obtaining a first image (S410) representing each of the units CL using the first camera CA1. That is, the first image may not be an image of the entire upper surface of the substrate SUB, but rather an image of each individual unit CL included in the substrate SUB.
[0116] The method may then include extracting the grayscale of each first image by a grayscale extraction unit SE included in the first processor HD1 (S420). After extracting the grayscale of each first image, the method may include matching the respective first images to each other by an alignment unit SU (S430). The first images may be matched using each of the third alignment marks AK3 respectively set on one side of each of the units CL. After matching the first images, the method may include comparing the grayscale of the respective first images to determine a grayscale difference (S440).
[0117] In response to determining that the grayscale difference exceeds a threshold, the defect determination unit DJ can determine that a foreign object DEF has appeared in the first image (S450, S470) (i.e., a foreign object DEF exists or has been detected). In response to determining that the grayscale difference is below a threshold, the defect determination unit DJ can determine that no foreign object DEF has appeared (S460) (i.e., no foreign object DEF exists or no foreign object DEF has been detected). In response to detecting a foreign object DEF, the method may include obtaining the coordinates of the foreign object DEF and sending the coordinates of the foreign object DEF to a second processor HD2 connected to the second camera CA2.
[0118] Figure 15 This is a block diagram illustrating an electronic device according to an embodiment of the present disclosure.
[0119] Reference Figure 2 and Figure 15 The substrate SUB examined in the embodiments can be applied to various electronic devices 10. The electronic device 10 according to the embodiments may include the substrate SUB described herein and additional modules or devices with other functions.
[0120] The electronic device 10 may include a display module 11, a processor 12, a memory 13, and a power module 14.
[0121] The processor 12 may include at least one of a central processing unit (CPU), an application processor (AP), a graphics processing unit (GPU), a communication processor (CP), an image signal processor (ISP), and a controller.
[0122] The memory 13 can store data or information for the operation of the processor 12 or the display module 11. In an example where the processor 12 executes an application stored in the memory 13, video data signals and / or input control signals can be sent to the display module 11. The display module 11 can process the received signals and output visual information through a display screen.
[0123] The power module 14 may include a power module such as a power adapter or battery device, and may include a power conversion module that converts the power supplied by the power module to generate power for the operation of the electronic device 10.
[0124] At least one of the components described herein may be included within the display device according to an embodiment. In some aspects, some components that are functionally included in a single module may be partially included in the display device and partially provided separately. For example, the base SUB may include the display module 11, while the processor 12, memory 13, and power module 14 may be configured as part of another device within the electronic device 10 instead of the base SUB.
[0125] Figure 16 It is based on Figure 15 Schematic diagrams of electronic devices in various embodiments.
[0126] Reference Figure 15 and Figure 16 The various electronic devices 10 including the base SUB according to the embodiments may include image display devices such as smartphones 10_1a, tablet PCs 10_1b, laptop computers 10_1c, TVs 10_1d, or desktop monitors 10_1e. In some aspects, it may also include wearable electronic devices including display modules, such as smart glasses 10_2a, head-mounted displays 10_2b, or smartwatches 10_2c. It may also include automotive electronic devices 10_3 including display modules, such as central information displays (CID), dashboard displays, or interior mirror displays.
[0127] However, these examples are illustrative, and the electronic device 10 according to embodiments of this disclosure is not necessarily limited thereto. For example, the electronic device 10 may be implemented as a mobile phone, video phone, smart tablet, smartwatch, tablet PC, vehicle display, computer monitor, laptop computer, or head-mounted display device. In some aspects, the electronic device 10 may be a television, monitor, laptop computer, or tablet computer. Furthermore, the electronic device 10 may also be a vehicle.
[0128] While the disclosure has been specifically shown and described with reference to its embodiments, those skilled in the art will understand that various changes in form and detail may be made therein without departing from the spirit or scope of the disclosure as defined by the appended claims.
Claims
1. A method for examining a substrate, the method comprising: A base comprising multiple units, a first alignment mark, and a second alignment mark spaced apart from the first alignment mark in a plan view is placed on the stage; Perform a first correction using the first alignment mark to correct the misalignment of the first camera; A first image is obtained by capturing an image of the substrate using the first camera; Detect foreign objects in the first image; The stage is moved such that the base is superimposed on the second camera in a plan view; Perform a second correction using the second alignment mark to correct the misalignment of the second camera; as well as A second image is obtained by capturing an image of the unit among the plurality of units in which the foreign object is detected using the second camera.
2. The method according to claim 1, wherein: The substrate includes a first region and a second region adjacent to the first region, and The first alignment mark includes a first alignment mark disposed in the first region and a first second alignment mark disposed in the second region.
3. The method according to claim 2, wherein: The first camera includes a first camera and a second camera, and The step of capturing the substrate using the first camera includes: The first area is captured using the first camera; and The second region is captured using the first and second cameras.
4. The method according to claim 1, wherein, The substrate also includes a plurality of third alignment marks that correspond one-to-one with the plurality of units.
5. The method according to claim 4, further comprising: Before acquiring the second image using the second camera, a third correction is performed, which uses a third alignment mark included among the plurality of third alignment marks to correct misalignment of the second camera, wherein the third alignment mark corresponds to one of the plurality of units that detected the foreign object.
6. The method according to claim 5, wherein, The third correction is performed using the following: The pre-stored first grayscale of the third alignment mark; and The second grayscale of the third alignment mark is determined based on the image of the third alignment mark captured by the second camera.
7. The method according to claim 6, wherein, The third correction is performed using Formula 1. Formula 1 in: f(x,y) is the second gray level of each region of the third alignment mark. It is the average value of f(x,y). g(x,y) is the pre-stored first grayscale value for each region of the third alignment mark, and It is the average value of g(x,y).
8. The method according to claim 7, wherein, The third correction is performed until the value of the normalized grayscale (f,g) is equal to or greater than 0.
85.
9. The method according to claim 4, wherein, The steps for detecting the foreign object in the first image include: Match the first image of each of the plurality of units to each other, and The region with a grayscale difference greater than a preset threshold is determined to include the foreign object.
10. A substrate, the substrate comprising: A unit area, wherein multiple units are provided in the unit area; and the surrounding area, including at least a portion of the unit area. The substrate includes: A first alignment mark is set in the peripheral area; A second alignment mark is disposed in the peripheral region and spaced apart from the first alignment mark in the plan view; and A plurality of third alignment marks are disposed in the cell region and correspond one-to-one with the plurality of cells, wherein each of the plurality of third alignment marks is disposed on one side of the corresponding cell among the plurality of cells.