Hole inspection system and method

Abstract

The present invention relates to a hole inspection system and method and, more specifically, to a system and method for inspecting the shape and position of a through-hole formed in a substrate. According to an embodiment, the hole inspection system for a substrate having a hole comprises: a substrate support device which supports a substrate; a camera disposed above or below the substrate to obtain an image of the substrate; a coaxial light source disposed on the same side as the camera relative to the substrate; a wide area light source disposed on the other side to the camera and illuminating a wider area than the coaxial light source; and an inspection module which inspects a hole on the basis of the image of the substrate obtained by the camera.

Description

Hole inspection system and method

[0001] The present invention relates to a hole inspection system and method, and more particularly, to a system and method for inspecting the shape and position of a through hole formed in a substrate.

[0002] To improve device integration, next-generation PIM (Processing In Memory) semiconductors are being developed, utilizing large-area glass substrates. To this end, systems and methods for inspecting through-holes formed in the substrate are needed.

[0003] In this regard, Japanese registration number 3859446, “Semiconductor substrate inspection device and semiconductor substrate inspection method”, discloses a technology for inspecting through holes by sequentially applying multiple direct current voltages, each having a different voltage value, to a semiconductor substrate.

[0004] This existing technology is a technique that can be applied after processing a conductor into a through hole, but has the limitation of being insufficient for inspection of the through hole itself, such as the shape or location of the through hole.

[0005] Meanwhile, the background technology described above is technical information that the inventor possessed for the purpose of deriving the present invention or acquired during the process of deriving the present invention, and cannot necessarily be said to be publicly known technology disclosed to the general public prior to the application for the present invention.

[0006] The problem to be solved by the present invention is to shorten the inspection time and improve accuracy when inspecting a hole formed on a substrate.

[0007] The problem to be solved by the present invention is to accurately and quickly perform inspection when inspecting at least one of the inner diameter, outer diameter, and position of a hole formed on a substrate.

[0008] The problem that the present invention seeks to solve is to construct a low-cost, high-efficiency system for inspecting holes formed on a substrate.

[0009] The tasks of the present invention are not limited to the tasks mentioned above, and other tasks not mentioned will be clearly understood by those skilled in the art from the description below.

[0010] According to one embodiment of the present invention for solving the above-described problem, a hole inspection system for a substrate having a hole may include a substrate support device for supporting the substrate, a camera arranged on an upper or lower portion of the substrate to obtain an image of the substrate, a coaxial light source arranged on the same side as the camera with respect to the substrate, a wide-area light source arranged on the other side of the camera to illuminate a wider area than the coaxial light source, and an inspection module for inspecting the hole based on an image of the substrate obtained by the camera.

[0011] A hole inspection system according to one embodiment may further include a camera movement module that supports the camera at a predetermined distance from the substrate and moves the camera reciprocally in a first direction parallel to the substrate, and the substrate support device may further include a substrate movement module that moves the substrate in a second direction parallel to the substrate but perpendicular to the first direction.

[0012] In a hole inspection system according to one embodiment, the substrate movement module may include a plurality of linear drive modules arranged on each side of the substrate to linearly move the substrate.

[0013] In a hole inspection system according to one embodiment, the wide-area light source may include a line light source installed to extend parallel to the first direction in which the camera reciprocates.

[0014] In a hole inspection system according to one embodiment, the line light source can irradiate an area of ​​(length corresponding to the width of the substrate) * (width corresponding to the FOV of the camera).

[0015] In a hole inspection system according to one embodiment, the wide-area light source may include a surface light source that irradiates an area corresponding to the entire area of ​​the substrate.

[0016] In a hole inspection system according to one embodiment, the inspection module may include an image processing unit that processes an image of the substrate based on a global mark corresponding to a point of the substrate and an alignment mark corresponding to each corner of a group formed by the holes.

[0017] In a hole inspection system according to one embodiment, the image processing unit can inspect at least one of the position of the group and the position of the hole included in the group based on the global mark and the alignment mark.

[0018] In a hole inspection system according to one embodiment, the global mark and the alignment mark are formed by radially arranging a plurality of points or circles, and the image processing unit can determine whether the image of the substrate is distorted based on the global mark and the alignment mark, and correct the image of the substrate.

[0019] In a hole inspection system according to one embodiment, the camera obtains a plurality of images by dividing the substrate into predetermined regions, and the image processing unit can obtain an image of the entire substrate by merging the plurality of divided images based on the global mark and the alignment mark.

[0020] In a hole inspection system according to one embodiment, the image processing unit can perform affine transformation on the divided plurality of images based on the global mark and the alignment mark, and merge them to match CAD, thereby obtaining an image for the entire substrate.

[0021] In a hole inspection system according to one embodiment, the camera obtains an image of the substrate including the inner and outer diameters of the hole simultaneously, and the inspection module can determine whether the hole is a good product based on the image of the substrate.

[0022] In a hole inspection system according to one embodiment, the image of the substrate may have a gray level difference of 10 or more inside and outside the boundary area of ​​the inner diameter.

[0023] A hole inspection method performed by a hole inspection system according to one embodiment of the present invention for solving the aforementioned problem may include a step of illuminating the substrate using a coaxial light source arranged on the same side as a camera based on the substrate and a wide-area light source arranged on the other side of the camera but illuminating a wider area than the coaxial light source, a step of acquiring an image of the substrate using the camera, and a step of inspecting the hole based on the acquired image of the substrate.

[0024] In a hole inspection method according to one embodiment, the inspecting step may include a step of correcting an image of the substrate based on a global mark corresponding to a point of the substrate and an alignment mark corresponding to each corner of a group formed by the hole, and a step of inspecting whether the hole is of good quality based on the corrected image of the substrate.

[0025] According to any one of the problem solving means of the present invention, when inspecting a hole formed on a substrate, the inspection time can be shortened and the accuracy can be improved.

[0026] According to any one of the problem solving means of the present invention, it is possible to accurately and quickly perform inspection when inspecting at least one of the inner diameter, outer diameter, and position of a hole formed on a substrate.

[0027] According to any one of the problem solving means of the present invention, a low-cost, high-efficiency system can be constructed for inspecting holes formed on a substrate.

[0028] The effects that can be obtained from the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by a person having ordinary skill in the art to which the present invention belongs from the description below.

[0029] Figure 1 is a cross-sectional view showing an example of a through hole formed in a substrate.

[0030] FIG. 2 is an exemplary diagram of an image of a substrate according to one embodiment of the present invention.

[0031] FIG. 3 is a side view illustrating a hole inspection system according to one embodiment of the present invention.

[0032] FIG. 4 is an exemplary diagram of a substrate having a plurality of holes according to one embodiment of the invention.

[0033] FIG. 5 is a top view illustrating a hole inspection system according to one embodiment of the present invention.

[0034] FIG. 6 and FIG. 7 are exemplary diagrams for explaining a light source of a hole inspection system according to one embodiment of the present invention.

[0035] Figure 8 is a flowchart for explaining a hole inspection method according to one embodiment of the present invention.

[0036] The advantages and features of the present invention, as well as the methods for achieving them, will become clearer with reference to the embodiments described in detail below, along with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various different forms. These embodiments are provided solely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention. In other words, the present invention is defined solely by the scope of the claims.

[0037] The shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for explaining embodiments of the present invention are exemplary, and therefore the present invention is not limited to the matters illustrated. In addition, in describing the present invention, if it is determined that a detailed description of a related known technology may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. When the terms “includes,” “has,” and “consists of” are used in this specification, other parts may be added unless “only” is used. When a component is expressed in the singular, it includes a case where the plural is included unless there is a specifically explicit description.

[0038] When interpreting components, it is interpreted as including the error range even if there is no separate explicit description.

[0039] Although terms like "first" and "second" are used to describe various components, these components are not limited by these terms. These terms are used merely to distinguish one component from another. Therefore, a "first" component referred to below may also be a "second" component within the technical scope of the present invention.

[0040] Unless otherwise specified, the same reference numerals refer to the same components throughout the specification.

[0041] The individual features of the various embodiments of the present invention can be partially or wholly combined or combined with each other, and as can be fully understood by those skilled in the art, various technical connections and operations are possible, and each embodiment can be implemented independently of each other or can be implemented together in a related relationship.

[0042] Hereinafter, the present invention will be described in detail with reference to the attached drawings.

[0043] First, Fig. 1 is a cross-sectional view illustrating an example of a through hole (20) formed in a substrate (10). Referring to Fig. 1, according to an embodiment, the cross-section of the hole (20) includes an upper diameter (21a) and a lower diameter (21b), and may include a waist diameter (22a). In addition, each hole (20) may be spaced apart by a certain distance, and in this case, the distance (23) between the through holes (20) may be defined as the distance between the centers of the holes (20).

[0044] According to FIG. 1, the cross-section of the hole (20) formed in the substrate (10) may be formed in an hourglass shape with wide ends and a narrow center, but may be implemented in various shapes, such as a tapered shape or a cylindrical shape, depending on the embodiment.

[0045] In addition, FIG. 2 is an exemplary diagram of an image of a substrate (10) according to one embodiment of the present invention. Referring to FIG. 2, the image of the substrate (10) observed from the upper or lower portion of the substrate (10) includes an image of a hole (20). According to FIG. 2, the hole (20) is implemented in a circular shape, but may be implemented in various shapes, such as an oval or a square, depending on the embodiment.

[0046] Referring to FIGS. 1 and 2, the upper diameter (21a) and the lower diameter (21b) of the hole (20) correspond to the upper and lower outer diameters (21) of the hole (20). In addition, the waist diameter (22a) of the hole (20) corresponds to the inner diameter (22) of the hole (20). At this time, the substrate (10) can be divided into an outer region of the outer diameter (21), a tapered region between the outer diameter (21) and the inner diameter (22), and a pupil region inside the inner diameter (22) based on the hole (20). At this time, since the reflectivity for the irradiated light is different due to the influence of the morphological characteristics of each region, a system for identifying and inspecting the inner and outer diameters (21, 22) of the hole (20) is disclosed.

[0047] In relation to this, FIG. 3 is a side view illustrating a hole inspection system (100) according to one embodiment of the present invention. Referring to FIG. 3, the hole inspection system (100) is for inspecting a hole (20) formed in a substrate (10), and can inspect, for example, a plurality of through holes (20) formed in a large-area glass substrate (10) for a PIM semiconductor.

[0048] According to one embodiment, a hole inspection system (100) may include a substrate support device (110) that supports a substrate (10), a camera (120) that is positioned above or below the substrate (10) to obtain an image of the substrate (10), a light source (130) that illuminates the substrate (10), and an inspection module (140) that inspects a hole (20) based on an image obtained by the camera (120).

[0049] At this time, the substrate support device (110) is configured to support the substrate (10) by coming into contact with the substrate (10) while performing hole (20) inspection, and according to an embodiment, the substrate (10) can be supported on both sides of the substrate (10), and for example, the edge area of ​​the substrate (10) where the hole (20) is not arranged can be supported.

[0050] According to an embodiment, the substrate support device (110) may include a substrate movement module (111), and the substrate movement module (111) may move the substrate (10) according to the process. Specific details regarding the movement of the substrate (20) will be described later in the relevant section.

[0051] Next, the camera (120) is configured to be placed on the upper or lower side of the substrate (10) to obtain an image of the substrate (10). FIG. 3 illustrates an embodiment in which the camera (120) is placed on the upper side of the substrate (10).

[0052] In this regard, the camera (120) may be configured as a line scan camera, for example, a tdi line scan camera, and thus, an image of the substrate (10) can be quickly scanned and acquired.

[0053] To this end, the camera (120) can be moved by the camera movement module (150) to obtain an image of the entire area of ​​the substrate (10). To this end, the camera movement module (150) supports the camera (120) at a predetermined distance from the substrate (10) and can move the camera (120) as the process progresses.

[0054] At this time, the hole inspection system (100) acquires an image of the substrate (10), but must acquire an image in which the hole (20) can be identified to the extent that hole (20) inspection is possible. Specifically, in order to identify and inspect the inner and outer diameters (21, 22) of the hole (20), an image of the substrate (10) in which the gray levels inside and outside the boundary area of ​​the inner and outer diameters (21, 22) differ by 10 or more must be acquired. Here, the gray level refers to a value in which the brightness of each pixel on the image is divided into 256 gray levels from 0 to 255 when the image of the substrate acquired through the camera (120) is digitized.

[0055] That is, the hole inspection system (100) can inspect the inner diameter (22) by acquiring an image of the substrate (10) in which the gray levels inside and outside the boundary area of ​​the inner diameter (22) differ by 10 or more, and can inspect the outer diameter (21) by acquiring an image of the substrate (10) in which the gray levels inside and outside the boundary area of ​​the outer diameter (21) differ by 10 or more.

[0056] For this purpose, the hole inspection system (100) may include a plurality of light sources (130). At this time, the light sources (130) may be arranged on the upper and lower portions of the substrate (10) as a configuration for illuminating the substrate (10). Specifically, the light sources (130) may include a coaxial light source (131) arranged on the same side as the camera (120) with respect to the substrate (10), and a wide-area light source (132) arranged on the other side of the camera (120) with respect to the substrate (10), but illuminating a wider area than the coaxial light source (131). At this time, the wide-area light source (132) may be arranged on a vertical line with respect to the camera (120), and the coaxial light source (131) and the wide-area light source (132) may provide light with strong straightness with respect to the substrate (10).

[0057] For example, when the camera (120) is placed on the upper part of the substrate (10) as shown in FIG. 3, the coaxial light source (131) is placed on the upper part of the substrate (10) to provide coaxial light for the camera (120) to the substrate (10). In addition, the wide-area light source (132) is placed on the lower part of the substrate (10) on the other side of the camera (120) with respect to the substrate (10) to illuminate a wider area than the coaxial light source (131).

[0058] The light emitted through these two light sources (130) can pass through the hole (20) and form an optical image through optical phenomena such as diffraction and interference with a refracted beam. Through this, the camera (120) can obtain an image of the substrate (10) including an image of the hole (20) to the extent that the shape, position, etc. of the hole (20) can be inspected. Specifically, an optical image can be obtained according to light incident on the camera (120) through optical phenomena such as reflection, diffraction, and interference from each of the outer region of the outer diameter (21), the tapered region between the outer diameter (21) and the inner diameter (22), and the pupil region inside the inner diameter (22).

[0059] At this time, the outer region of the outer diameter (21) has a high reflectivity for the irradiation light incident perpendicularly to the surface of the substrate (10), as the surface of the substrate (10), but the tapered region between the outer diameter (21) and the inner diameter (22) has a shape that is inserted and tilted from the surface of the substrate (10), and thus has a relatively low reflectivity for the irradiation light. Due to this difference in reflectivity, a significant difference occurs in the gray level of the image between the inner region and the outer region based on the outer diameter (21), so that the outer diameter (21) can be identified only with the irradiation light from the coaxial light source (131). On the other hand, the tapered region between the outer diameter (21) and the inner diameter (22) has a low reflectivity for the irradiation light from the coaxial light source (131) due to the morphological characteristic of being inserted and tilted from the surface of the substrate (10), making it difficult to distinguish it from the pupil region inside the inner diameter (22).

[0060] Therefore, by placing a wide-area light source (132) on the other side of the camera (120) and the coaxial light source (131) according to an embodiment, the inner diameter (22) can be identified. That is, when the irradiated light of the wide-area light source (132) passes through the hole (20) and enters the camera (120), a difference in gray level occurs in the taper area between the outer diameter (21) and the inner diameter (22) and the pupil area inside the inner diameter (22), thereby enabling the identification of the inner diameter (22).

[0061] Accordingly, the hole inspection system (100) can obtain an image of a substrate (10) in which the gray levels inside and outside the boundary line of the outer and inner diameters (21, 22) differ by 10 or more, and based on this, the inner and outer diameters (21, 22) can be inspected simultaneously, thereby shortening the inspection time and improving the accuracy of the inspection.

[0062] To explain this in more detail, if the hole inspection system (100) has only one coaxial light source (131), as described above, since the tapered area and the pupil area inside the inner diameter (22) in the image of the substrate (10) both have similar gray levels, only the outer diameter (21) can be inspected, and the inner diameter (22) cannot be inspected. In order to inspect the inner diameter (22), the coaxial light source (131) is moved to the side facing the camera (120), light is irradiated from the lower part of the substrate (10), and the light transmitted through the pupil area inside the inner diameter (22) is collected by the camera (120), thereby performing an inspection of the inner diameter (22). However, in this case, since the inspection of the outer diameter (21) and the inspection of the inner diameter (22) must be performed twice by separating them, there is a disadvantage in that the inspection time increases, and errors may occur during the two inspection processes, which may lower the accuracy of the inspection.

[0063] On the other hand, the hole inspection system (100) of the present invention can obtain a clear hole image for the inner and outer diameters by using a coaxial light source (131) and a wide-area light source (132), so it has the advantage of solving the above-described problem.

[0064] Meanwhile, the inspection module (140) inspects the hole (20) based on the image acquired by the camera (120), and may include a processor for image analysis. According to an embodiment, the inspection module (140) may extract the boundary lines of the inner and outer diameters (21, 22) and inspect whether the inner and outer diameters (21, 22) of the hole (20) are formed and the shape of the inner and outer diameters (21, 22), thereby determining whether the hole (20) is a good product. According to an embodiment, the inspection module (140) may process the image of the substrate (10) to increase the difference in gray levels inside and outside the boundary line area of ​​the inner and outer diameters (21, 22) in order to make the boundary lines of the inner and outer diameters (21, 22) clearer.

[0065] In addition, the inspection module (140) can measure the distance between holes (20) to determine whether the holes (20) are of good quality. For example, the center of the holes (20) is determined based on at least one of the inner diameter (22) and the outer diameter (21), and the distance (23) between the holes (20) is measured based on the center of each hole (20) to analyze the alignment state of the holes (20), thereby determining whether the holes (20) are of good quality.

[0066] In this regard, FIG. 4 is an exemplary diagram of a substrate (10) having a plurality of holes (20) according to one embodiment of the present invention. According to FIG. 4, the substrate (10) may form global marks (41, 42, 43) corresponding to a point of the substrate (10), for example, a corner of the substrate (10), and alignment marks (50) corresponding to each corner of a group (30) formed by a plurality of holes (20), or may be fixed with separate coordinate configurations forming the global marks (41, 42, 43) and the alignment marks (50). For example, when a group (30) formed by a plurality of holes (20) forms a square, the alignment marks (50) may be formed at positions corresponding to four corners of the group (30).

[0067] Accordingly, the inspection module (140) can measure the relative position of the alignment mark (50) based on the global mark (41, 42, 43), and can measure the position of each hole (20) included in a group (30) based on the alignment mark (50).

[0068] According to an embodiment, the global marks (41, 42, 43) and the alignment marks (50) may be formed by a plurality of points or circles arranged radially. For example, the global marks (41, 42, 43) and the alignment marks (50) may be formed by a point or circle arranged in the center, and a plurality of points or circles arranged at equal intervals in all directions around the point or circle arranged in the center.

[0069] In this regard, the inspection module (140) may include an image processing unit (not shown) that processes an image of the substrate (10) based on the global marks (41, 42, 43) and the alignment marks (50).

[0070] According to an embodiment, the image processing unit can determine whether the image of the substrate (10) is distorted based on the global marks (41, 42, 43) and the alignment marks (50). That is, the position and spacing of the global marks (41, 42, 43) and the alignment marks (50), the distortion of the points or circles included in the global marks (41, 42, 43) and the alignment marks (50) are measured, or the sizes of the points or circles included in the global marks (41, 42, 43) and the alignment marks (50) are compared, and based on this, distortion such as tilting or distortion of the image can be determined and corrected.

[0071] At this time, the image processing unit can perform an affine transformation that changes the entire image by changing the arrangement of pixels included in the image. For example, based on the global marks (41, 42, 43) and the alignment mark (50), the distortion such as tilt or distortion of the image can be determined, and the degree of distortion can be measured and corrected by changing the position of each pixel included in the image to translate or rotate the image, and the distortion can be corrected by converting the size of the image or adjusting the ratio of the image.

[0072] In addition, when the camera (120) acquires multiple images of a single substrate (10) divided into predetermined areas, the image processing unit can acquire an image of the entire substrate (10) by merging the multiple images divided based on the global marks (41, 42, 43) and the alignment marks (50). For example, the image processing unit can merge the multiple images by determining the relative positions between the multiple images based on the global marks (41, 42, 43) and the alignment marks (50).

[0073] In addition, the image processing unit may perform affine transformation on each of the plurality of images divided based on the global marks (41, 42, 43) and the alignment mark (50) and merge them. At this time, the image processing unit may perform affine transformation on each of the plurality of divided images and merge them to match the CAD. At this time, the CAD is a general term for the CAD file itself, the CAD image converted from the CAD file, and the data extracted from the CAD file or the CAD image. The data extracted from the CAD file or the CAD image includes, for example, information that can confirm the relative positions between the plurality of divided images, and as an example, may include coordinate information of the global marks (41, 42, 43) and the alignment mark (50) included in the CAD file or the CAD image. Accordingly, the image processing unit performs affine transformation so that the global marks (41, 42, 43) and alignment marks (50) included in the multiple images match the global marks (41, 42, 43) and alignment marks (50) included in the CAD, and merges them to obtain an image of the entire substrate (10).

[0074] Through this, the inspection module (140) can determine whether the hole (20) is a good product based on the image of the substrate (10). For example, the inspection module (140) can determine whether the position of the hole (20) is suitable based on the entire image of the substrate (10). Specifically, the inspection module (140) can inspect the position of a group (30) formed by a plurality of holes (20) based on the entire image of the substrate (10). At this time, the inspection of the position of a group (30) formed by a plurality of holes (20) may include an inspection of the alignment state of a group (30) formed by a plurality of holes (20), such as the position where a group (30) formed by a plurality of holes (20) is formed within the substrate (10), the distance between the groups (30), and the relative direction of the group (30) with respect to the global marks (41, 42, 43).

[0075] Specifically, the inspection module (140) inspects the position of each hole (20) included in a group (30) formed by a plurality of holes (20). The inspection module (140) assigns coordinates to each hole (20) based on alignment marks (50) corresponding to each corner of the group (30) and can inspect the position of each hole (20) based on the assigned coordinates. In addition, the inspection module (140) extracts a direction component for a group (30) formed by a plurality of holes (20) based on the alignment marks (50) and extracts a relative direction of the extracted direction component with respect to global marks (41, 42, 43), thereby inspecting the alignment state of a group (30) formed by a plurality of holes (20).

[0076] Next, FIG. 5 is a top view illustrating a hole inspection system (100) according to one embodiment of the present invention.

[0077] Referring to FIG. 5, the substrate (10) can be moved by the substrate movement module (111), and the camera (120) can be moved by the camera movement module (150) to obtain an image of the substrate (10). In addition, a wide-area light source (132) can be placed on the other side of the camera (120) with respect to the substrate (10), and at this time, the wide-area light source (132) can be placed on a vertical line with the camera (120).

[0078] Specifically, the camera movement module (150) can reciprocate the camera (120) in a first direction (x1) parallel to the substrate (10). In addition, the substrate movement module (111) can move the substrate (10) in a second direction (x2) parallel to the substrate (10) but perpendicular to the first direction (x1). To this end, the substrate movement module (111) may include a plurality of linear drive modules (not shown) arranged on each side of the substrate (10) to move the substrate (10). Accordingly, the camera (120) can acquire a plurality of images by dividing one substrate (10) into predetermined regions, and as a result, can quickly and simply acquire an image for the entire region of the substrate (10).

[0079] Additionally, the camera movement module (160) can move the coaxial light source (131) simultaneously with the camera (120) to continuously provide coaxial light while the camera (120) moves.

[0080] According to an embodiment, the wide-area light source (132) may include a line light source that is installed to extend parallel to the first direction (x1) in which the camera (120) reciprocates. In this case, the line light source may be arranged on a vertical line with the camera (120).

[0081] In this regard, FIG. 6 is an exemplary diagram for explaining a light source (130) of a hole inspection system (100) according to one embodiment of the present invention.

[0082] Referring to FIG. 6, the wide-area light source (132) is formed as a line light source (332) and can be placed on the other side of the camera (120) with the substrate (10) as the center. According to an embodiment, the line light source (332) can irradiate an area of ​​(length corresponding to the width of the substrate) * (width corresponding to the FOV of the camera) with respect to the substrate (10). Here, the FOV refers to the angle of view of the camera (120).

[0083] At this time, the length corresponding to the width of the substrate (10) may be a length corresponding to either the horizontal width or the vertical width of the substrate (10), and, depending on the embodiment, may be the width of the substrate (10) in a direction parallel to the first direction (x1) in which the camera (120) reciprocates on the substrate (10), or the width of an area where a hole (20) is formed on the substrate (10) in a direction parallel to the first direction (x1).

[0084] In addition, the length corresponding to the FOV of the camera (120) refers to the length corresponding to the area on the substrate (10) that the camera (120) can photograph at one time according to the FOV of the camera (120), and for example, it may be the length in the direction parallel to the second direction (x2) of the area on the substrate (10) that the camera (120) can photograph at one time according to the FOV of the camera (120).

[0085] As described above, the line light source (332) illuminates an area of ​​(length corresponding to the width of the substrate) * (width corresponding to the FOV of the camera) on the substrate (10), thereby allowing the line light source (332) to illuminate an area of ​​the substrate (10) corresponding to an image acquired by the camera (120) as it reciprocates.

[0086] In some embodiments, the wide area light source (132) may include a surface light source (432) that illuminates the entire area of ​​the substrate (10).

[0087] In this regard, FIG. 7 is an exemplary diagram for explaining a light source (130) of a hole inspection system (100) according to another embodiment of the present invention.

[0088] Referring to Fig. 7, the wide-area light source (132) is formed as a surface light source (432) and can be placed on the other side of the camera (120) with the substrate (10) as the center. At this time, the surface light source (432) is placed parallel to the substrate (10) in a vertical line with the camera (120) so as to irradiate an area corresponding to the entire area of ​​the substrate (10).

[0089] In an embodiment of the present invention, as illustrated in FIG. 6, when the wide-area light source (132) is configured as a line light source (332), light can be focused on a relatively narrow area, so that the light control performance is excellent, a clear image (i.e., an outline) of the inner diameter (22) of the hole (20) can be obtained, and there is an advantage of lowering the manufacturing cost for the hole inspection system (100).

[0090] In an embodiment of the present invention, as illustrated in FIG. 7, when the wide-area light source (130) is configured as a surface light source (432), light can be irradiated to the entire area of ​​the substrate (10), so that the illumination performance may be relatively low, but there is no need to match the scan area of ​​the camera (120) and the illumination area of ​​the wide-area light source (132), and the structure of the hole inspection system (100) can be simplified.

[0091] As described above, the hole inspection system (100) of the present invention has a coaxial light source (131) positioned coaxially with the camera (120) based on the substrate (20) and a wide-area light source (132) positioned on the other side of the camera (120), which is a line light source (332) or a surface light source (432), thereby having the advantage of being able to simultaneously measure the inner diameter (22) and outer diameter (21) of the hole.

[0092] In particular, the coaxial light source (131) is configured to be able to move together with the camera (120), and among the wide-area light sources (132), the line light source (332) irradiates an area of ​​(length corresponding to the width of the substrate) * (width corresponding to the FOV of the camera), and the surface light source (432) has the characteristic of illuminating the entire surface of the substrate (10). Therefore, the inner and outer diameters (21, 22) of the hole (20) can be quickly inspected only by moving the coaxial light source (131) and the camera (120) without moving the line light source (332) or the surface light source (432).

[0093] In addition, the line light source (332) or the surface light source (432) can provide sufficiently bright light so that the gray level difference between the inside and outside of the inner diameter (22) in the image of the substrate (10) is 10 or more, so that the inner region of the inner diameter (22) (i.e., pupil region) and the outer region of the inner diameter (22) (i.e., taper region) can be clearly distinguished, and through this, various inspections of the hole (20) such as the shape, size, and position of the inner diameter (22), and the misalignment of the inner diameter (22) and the outer diameter (21) can be made possible.

[0094] Next, FIG. 8 is a flowchart for explaining a hole inspection method according to one embodiment of the present invention.

[0095] Referring to FIG. 8, the hole inspection method performed by the hole inspection system (100) can illuminate the substrate (10) using a coaxial light source (131) placed on the same side as the camera (120) with respect to the substrate (10) and a wide-area light source (132) placed on the other side of the camera (120) but illuminating a wider area than the coaxial light source (131) (S801).

[0096] At this time, the wide-area light source (132) may include a line light source (130) that is installed to extend parallel to the first direction (x1) in which the camera (120) reciprocates, and according to an embodiment, the line light source (130) may irradiate an area of ​​(length corresponding to the width of the substrate (10))*(width corresponding to the FOV of the camera (120)).

[0097] As another embodiment, the wide-area light source (132) may include a surface light source (130) that irradiates an area corresponding to the entire area of ​​the substrate (10).

[0098] And the hole inspection system (100) can support the camera (120) at a predetermined distance from the substrate (10) through the camera movement module (150) and make the camera (120) reciprocate in a first direction (x1) parallel to the substrate (10).

[0099] In addition, the hole inspection system (100) can move the substrate (10) according to the movement of the camera (120), and can move the substrate (10) in a second direction (x2) that is parallel to the substrate (10) and perpendicular to the first direction (x1).

[0100] And the hole inspection system (100) can acquire an image of the substrate (10) using a camera (120) (S802). At this time, the image of the substrate (10) includes an image of the hole (20), and the gray levels inside and outside the boundary area of ​​the inner diameter (22) may differ by 10 or more.

[0101] In addition, when the hole inspection system (100) acquires an image of the substrate (10), as the camera (120) and the substrate (10) move in the first direction (x1) or the second direction (x2), the camera (120) can acquire multiple images that divide the substrate (10) into predetermined areas.

[0102] And the hole inspection system (100) can inspect the hole (20) based on the image of the acquired substrate (10) (S803).

[0103] According to an embodiment, the hole inspection system (100) can process an image of the substrate (10) based on global marks (41, 42, 43) corresponding to a point of the substrate (10) and alignment marks (50) corresponding to each corner of a group (30) formed by holes (20).

[0104] At this time, the global marks (41, 42, 43) and the alignment marks (50) may be formed on the substrate (10) itself by radially arranging multiple points or circles, and may be formed in a separate coordinate configuration and attached to the substrate (10) according to an embodiment.

[0105] According to an embodiment, the hole inspection system (100) can determine whether the image of the substrate (10) is distorted based on the global marks (41, 42, 43) and the alignment mark (50), correct the image of the substrate (10), and inspect whether the hole (20) is good based on the corrected image of the substrate (10).

[0106] For example, the hole inspection system (100) can inspect at least one of the positions of a group (30) formed by a plurality of holes (20) and the positions of each hole (20) included in the group (30) based on the global marks (41, 42, 43) and the alignment marks (50).

[0107] In addition, the hole inspection system (100) can acquire an image of the entire substrate (10) by merging multiple images divided into predetermined areas acquired through a camera (120) based on global marks (41, 42, 43) and alignment marks (50).

[0108] For example, the hole inspection system (100) can perform affine transformation on a plurality of images divided based on global marks (41, 42, 43) and alignment marks (50), and merge them to match CAD to obtain an image of the entire substrate (10).

[0109] The hole inspection system (100) of the present invention moves the line camera back and forth in the first direction (x1) while moving the substrate (10) in the second direction (x2) to obtain an image of the entire substrate (10), so that the inspection time is shortened and inspection is easily possible regardless of the size of the substrate (10) that is input.

[0110] Although the embodiments of the present invention have been described in more detail with reference to the attached drawings, the present invention is not necessarily limited to these embodiments, and various modifications may be implemented without departing from the technical spirit of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention, but to explain it, and the scope of the technical spirit of the present invention is not limited by these embodiments. Therefore, it should be understood that the embodiments described above are illustrative in all aspects and not restrictive. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within a scope equivalent thereto should be interpreted as being included in the scope of the rights of the present invention.

Claims

1. In a hole inspection system for a substrate having holes, A substrate support device supporting the above substrate; A camera positioned above or below the substrate to obtain an image of the substrate; A coaxial light source positioned on the same side as the camera based on the above substrate; A wide-area light source positioned on the other side of the above camera, illuminating a wider area than the coaxial light source; and A hole inspection system including an inspection module that inspects the hole based on an image of the substrate acquired by the camera.

2. In paragraph 1, Further comprising a camera movement module that supports the camera at a predetermined distance from the substrate and moves the camera reciprocally in a first direction parallel to the substrate. The above substrate support device, A hole inspection system further comprising a substrate moving module that moves the substrate in a second direction that is parallel to the substrate but perpendicular to the first direction.

3. In paragraph 2, The above substrate moving module, A hole inspection system comprising a plurality of linear drive modules arranged on each side of the substrate to move the substrate linearly.

4. In paragraph 1, The above wide area light source is, A hole inspection system including a line light source installed so as to extend parallel to a first direction in which the above camera reciprocates.

5. In paragraph 4, The above line light source is, A hole inspection system that examines an area of ​​(length corresponding to the width of the substrate) * (width corresponding to the FOV of the camera).

6. In paragraph 1, The above wide area light source is, A hole inspection system comprising a surface light source that irradiates an area corresponding to the entire surface area of ​​the substrate.

7. In paragraph 1, The above inspection module, A hole inspection system, comprising an image processing unit that processes an image of the substrate based on a global mark corresponding to a point of the substrate and an alignment mark corresponding to each corner of a group formed by the holes.

8. In paragraph 7, The above image processing unit, A hole inspection system that inspects at least one of the position of the group and the position of the hole included in the group based on the global mark and the alignment mark.

9. In paragraph 7, The above global mark and the above alignment mark are formed by arranging multiple points or circles radially, The above image processing unit, A hole inspection system that determines whether the image of the substrate is distorted based on the global mark and the alignment mark and corrects the image of the substrate.

10. In paragraph 7, The above camera, Acquire multiple images by dividing the above substrate into predetermined areas, The above image processing unit, A hole inspection system that acquires an image of the entire substrate by merging a plurality of divided images based on the global mark and the alignment mark.

11. In paragraph 10, The above image processing unit, A hole inspection system that performs affine transformation on the divided plurality of images based on the global mark and the alignment mark, and merges them to match the CAD to obtain an image for the entire substrate.

12. In paragraph 1, The above camera, Obtain an image of the substrate including the inner and outer diameters of the hole simultaneously, The above inspection module, A hole inspection system that determines whether the hole is good or bad based on an image of the substrate.

13. In paragraph 1, The image of the above substrate is, A hole inspection system in which the gray levels inside and outside the boundary area of ​​the above inner diameter differ by 10 or more.

14. A hole inspection method performed by the hole inspection system of Article 1, A step of illuminating the substrate using a coaxial light source positioned on the same side as the camera based on the substrate and a wide-area light source positioned on the other side of the camera but illuminating a wider area than the coaxial light source; A step of obtaining an image of the substrate using the camera; and A hole inspection method, comprising a step of inspecting the hole based on an image of the acquired substrate.

15. In paragraph 14, The above checking steps are: A step of correcting an image of the substrate based on a global mark corresponding to a point of the substrate and an alignment mark corresponding to each corner of a group formed by the holes; and A hole inspection method, comprising a step of inspecting whether the hole is of good quality based on an image of the corrected substrate.

Images