Defect inspection device for glass substrate, and method for manufacturing glass substrate

Abstract

To provide a defect inspection device for a glass substrate that inspects a defect in a glass substrate, and a method for manufacturing a glass substrate including an inspection step using the defect inspection device, the defect inspection device for a glass substrate and the method for manufacturing a glass substrate with which the presence or absence of a defect in an outer peripheral edge part of the glass substrate can be accurately inspected.SOLUTION: A defect inspection device for a glass substrate comprises: a stage 10 that supports a glass substrate G; imaging means 20 that picks up an image of the glass substrate G from a side of one principal surface (front face Ga); and a control unit 50 that determines the state of the outer peripheral end face Gd of the glass substrate G on the basis of image data picked up by the imaging means 20. The stage 10 has a support surface 11a1 that supports the outer peripheral edge part Gc of the glass substrate G from a side of the other principal surface (rear face Gb) of the glass substrate G. The support surface 11a1 has a contact area 11c that is provided along the outer peripheral end face Gd of the glass substrate G, and is in contact with the glass substrate G at a position away from the outer peripheral end face Gd toward the center of the glass substrate G.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a defect inspection apparatus for a glass substrate and a method for manufacturing a glass substrate including an inspection process using the defect inspection apparatus.

Background Art

[0002] Conventionally, in the manufacturing process of a thin plate-shaped glass substrate, a defect inspection apparatus for a glass substrate that inspects the presence or absence of defects in the manufactured glass substrate is known. For example, as an example, in Patent Document 1, a support part (stage) that supports a glass workpiece (glass substrate) in a slightly inclined vertical posture, a light irradiation part (lighting means) that irradiates light to the glass substrate supported by the stage for illumination, an image information acquisition part (imaging means) that images the glass substrate illuminated by the lighting means to acquire image data, and a determination control part (control part) that inspects the presence or absence of defects in the glass substrate based on the image data acquired by the imaging means are provided. An inspection apparatus (defect inspection apparatus) is disclosed.

[0003] In the above defect inspection apparatus, the glass substrate is supported by the stage in a state where one main surface (hereinafter, appropriately referred to as the "front surface") faces the imaging means. Further, the glass substrate is supported by the stage in a state where a part of the outer peripheral edge portion is in contact with the stage on the other main surface (hereinafter, appropriately referred to as the "back surface").

[0004] Then, based on the image data in which the outer peripheral edge portion of the glass substrate is imaged, the defect inspection apparatus performs, for example, binarization processing or the like to extract a contour line tracing the shape of the end surface (outer peripheral end surface) of the outer peripheral edge portion. When a breakage point or the like is confirmed on the contour line, it is determined that there are defects such as scratches, chips, and stains on the outer peripheral end surface of the glass substrate.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In the above-described conventional defect inspection apparatus, for example, due to aging or the like, if defects such as peeling of paint or fine scratches occur at a location where the outer peripheral edge portion of the back surface of the glass substrate on the stage comes into contact, when the glass substrate is imaged by the imaging means, the light irradiated from the illumination means is reflected by the defect, and the reflected light may unexpectedly be reflected at a position overlapping the outer peripheral end surface on the image data. In this case, on the image data subjected to binarization processing, the contour line of the outer peripheral end surface of the glass substrate is extracted in a state of being broken by the above-described reflected light.

[0007] As a result, the defect inspection apparatus erroneously determines the broken portion of the contour line due to the reflected light as a defect occurring on the outer peripheral end surface of the glass substrate, and there is a possibility that it is difficult to accurately inspect the presence or absence of defects on the outer peripheral edge portion of the glass substrate.

[0008] The present invention has been made in view of the above-described current problems, and a glass substrate defect inspection apparatus for inspecting defects of a glass substrate, and a glass substrate manufacturing method including an inspection process using the defect inspection apparatus, which can accurately inspect the presence or absence of defects on the outer peripheral edge portion of the glass substrate, are provided.

Means for Solving the Problems

[0009] The problems to be solved by the present invention are as described above. Next, means for solving these problems will be described.

[0010] That is, the glass substrate defect inspection apparatus according to Aspect 1 of the present invention is a glass substrate defect inspection apparatus for inspecting defects of a glass substrate, comprising a stage for supporting the glass substrate, imaging means for imaging the glass substrate supported by the stage from one main surface side, and a control unit for determining the state of the outer peripheral edge portion of the glass substrate based on the image data imaged by the imaging means. The stage has a support surface for supporting the outer peripheral edge portion of the glass substrate from the other main surface side of the glass substrate, the support surface is provided along the outer peripheral end surface of the glass substrate, and has a contact region in contact with the glass substrate at a position away from the outer peripheral end surface toward the central side of the glass substrate. According to the glass substrate defect inspection apparatus of the present invention having such a configuration, in the support surface of the stage that supports the outer peripheral edge portion of the glass substrate, the contact region in contact with the glass substrate is provided at a position away from the outer peripheral end surface of the glass substrate toward the central side of the glass substrate. Thus, for example, even when defects such as peeling of the coating or fine scratches due to aging or the like occur in the contact region, it is possible to suppress the reflected light reflected by the defect from being imaged at a position overlapping the outer peripheral end surface of the glass substrate in the image data. Therefore, for example, on the image data subjected to binarization processing, it is possible to prevent the occurrence of breakage points caused by reflected light on the contour line of the outer peripheral end surface of the extracted glass substrate, and accurately inspect the presence or absence of defects at the outer peripheral edge portion of the glass substrate.

[0011] Further, the glass substrate defect inspection apparatus according to Aspect 2 of the present invention is characterized in that, in the above Aspect 1, the stage supports the glass substrate in an inclined vertical posture. By having such a configuration, for example, it is possible to suppress the glass substrate from bending so as to protrude downward due to its own weight as in the case of supporting the outer peripheral edge portion of the glass substrate in a horizontal posture, and more accurately inspect the presence or absence of defects at the outer peripheral edge portion of the glass substrate.

[0012] Further, in the glass substrate defect inspection apparatus according to Embodiment 3 of the present invention, in the above Embodiment 1 or Embodiment 2, the support surface in the state where the glass substrate is supported by the stage is provided at a position overlapping the outer peripheral end surface of the glass substrate when viewed from the one main surface side, and has a groove portion formed along the outer peripheral end surface. By having such a configuration, when viewed from the one main surface side, it is possible to more reliably avoid the contact area on the support surface of the stage from overlapping the outer peripheral end surface of the glass substrate via the groove portion. Therefore, according to the defect inspection apparatus of the present invention, on the image data captured by the imaging means, it is possible to more reliably suppress the reflected light reflected from the defect generated in the contact area from being reflected at a position overlapping the outer peripheral end surface of the glass substrate, and it is possible to stably and accurately inspect the presence or absence of defects at the outer peripheral edge portion of the glass substrate.

[0013] Further, in the glass substrate defect inspection apparatus according to Embodiment 4 of the present invention, in any one of the above Embodiments 1 to 3, the dimension between the outer peripheral end surface of the glass substrate and the first end surface on the outer peripheral end surface side in the contact area, when viewed from one main surface side of the glass substrate in the state where the glass substrate is supported by the stage, is 0.5 mm or more and 3 mm or less. By having such a configuration, according to the defect inspection apparatus of the present invention, on the image data captured by the imaging means, it is possible to more reliably suppress the reflected light reflected from the defect generated in the contact area from being reflected at a position overlapping the outer peripheral end surface of the glass substrate, while stably supporting the glass substrate by the stage, and it is possible to more stably and accurately inspect the presence or absence of defects at the outer peripheral edge portion of the glass substrate.

[0014] Further, in the glass substrate defect inspection apparatus according to Embodiment 5 of the present invention, in any one of the above Embodiments 1 to 4, the width dimension between the first end surface on the outer peripheral end surface side of the glass substrate and the second end surface on the central side of the glass substrate in the contact area of the support surface is 0.5 mm or more and 3 mm or less. By having such a configuration, according to the defect inspection apparatus of the present invention, while stably supporting the glass substrate by the stage, on the image data captured by the imaging means, the reflected light reflected by the defect generated in the contact region is more reliably prevented from being imaged at a position overlapping the outer peripheral end face of the glass substrate, and the presence or absence of defects at the outer peripheral edge of the glass substrate can be more stably and accurately inspected.

[0015] Further, the glass substrate defect inspection apparatus according to Aspect 6 of the present invention is, in any one of the aspects from Aspect 1 to Aspect 5, in a state where the glass substrate is supported by the stage, the support surface is provided at a position overlapping the outer peripheral end face of the glass substrate as viewed from the one main surface side, and is formed along the outer peripheral end face, and has a separation region separated from the other main surface side of the glass substrate with respect to the contact region, and the separation dimension between the contact region and the separation region is 1 mm or more. By having such a configuration, according to the defect inspection apparatus of the present invention, on the image data captured by the imaging means, the reflected light reflected by the defect generated in the separation region is more reliably prevented from being imaged at a position overlapping the outer peripheral end face of the glass substrate, and the presence or absence of defects at the outer peripheral edge of the glass substrate can be more stably and accurately inspected.

[0016] Further, the method for manufacturing a glass substrate according to Aspect 7 of the present invention includes a molding step of molding a glass substrate, and after the completion of the molding step, using the defect inspection apparatus described in any one of the aspects from Aspect 1 to Aspect 6, with the obtained glass substrate as an inspection object, an inspection step of inspecting the defects of the glass substrate. By having such a configuration, according to the method for manufacturing a glass substrate of the present invention, the presence or absence of defects at the outer peripheral edge of the glass substrate can be accurately inspected, and a high-quality glass substrate can be obtained.

Effects of the Invention

[0017] As an effect of the present invention, the following effects are obtained. That is, according to the glass substrate defect inspection apparatus and the glass substrate manufacturing method according to the present invention, it is possible to accurately inspect the presence or absence of defects in the outer peripheral edge portion of the glass substrate.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0019] Next, an embodiment of the present invention will be described with reference to FIGS. 1 to 5. In the following description, for convenience, the front-rear direction, left-right direction, and up-down direction of the glass substrate G defect inspection apparatus 1 are defined and described according to the directions of the arrows shown in FIGS. 1 to 3.

[0020] [Overall Configuration of Glass Substrate G Defect Inspection Apparatus 1] First, the overall configuration of the glass substrate G defect inspection apparatus 1 (hereinafter simply referred to as "defect inspection apparatus 1") in the present embodiment will be described with reference to FIGS. 1 and 5.

[0021] The defect inspection device 1 is provided in the manufacturing process of a thin plate-shaped glass substrate G, and is a device that inspects whether there are defects in the manufactured glass substrate G.

[0022] Here, the shape of the glass substrate G is not particularly limited, such as a disk shape, an elliptical shape, a rectangular shape, a polygonal shape, etc. In this embodiment, for example, it is a disk-shaped glass substrate. Also, the thickness of the glass substrate is preferably set, for example, within the range of 0.2 mm or more and 1.0 mm or less.

[0023] Furthermore, a functional film may be formed on at least one of the two main surfaces (the front surface Ga and the back surface Gb, which will be described later) of the glass substrate G. Examples of the type of the functional film include a dielectric multilayer film used as an antireflection film or the like, and a transparent conductive film used as an electrode or the like. Also, the film thickness of the functional film is preferably set, for example, within the range of 10 nm or more and 2000 nm or less.

[0024] As shown in FIG. 5, the glass substrate G is mainly manufactured by a manufacturing process including a forming step S01 and an inspection step S02 that are performed in order over time.

[0025] The forming step S01 is a step of forming the glass substrate G. In the forming step S01, for example, a long strip-shaped glass ribbon is formed from molten glass made of a molten glass raw material by using a down-draw method typified by an overflow down-draw method, a slot down-draw method, and a redraw method. The formed glass ribbon is once cut into a rectangular plate-shaped glass original plate by scribing or the like, and a plurality of or a single primary glass substrate having a predetermined shape (in this embodiment, a disk shape) is cut out from the cut glass original plate. Thereafter, each of the cut primary glass substrates is subjected to a polishing operation, a cleaning operation, etc., and is finished as the glass substrate G that is the final product.

[0026] After the forming step S01, the inspection step S02 is a step of inspecting for defects in the obtained glass substrate G with the glass substrate G as an object to be inspected. In the inspection step S02, using the defect inspection apparatus 1 in the present embodiment, the presence or absence of defects such as scratches, chips, and dirt is inspected on the end surface of the outer peripheral edge portion Gc of the obtained glass substrate G (hereinafter, appropriately referred to as "outer peripheral end surface Gd"; see FIG. 2).

[0027] Thus, in the present embodiment, the manufacturing process (manufacturing method) for manufacturing the glass substrate G includes a forming step S01 for forming the glass substrate G, and after the forming step S01, using the defect inspection apparatus 1, with the obtained glass substrate G as an object to be inspected, an inspection step S02 for inspecting for defects in the glass substrate G.

[0028] By having such a configuration, according to the manufacturing method of the glass substrate G in the present embodiment, as will be described later, the presence or absence of defects on the outer peripheral end surface Gd of the glass substrate G can be accurately inspected, and a high-quality glass substrate G can be obtained.

[0029] As shown in FIG. 1, the defect inspection apparatus 1 mainly includes a stage 10 for supporting the glass substrate G, an imaging means 20 disposed on one side (front side in the present embodiment) of the stage 10, a first illumination means 30 disposed between the stage 10 and the imaging means 20, a second illumination means 40 disposed on the other side (rear side in the present embodiment) of the stage 10, and a control unit 50 for controlling the operation of the entire defect inspection apparatus 1.

[0030] The stage 10 supports the glass substrate G in an inclined vertical posture state. Here, the "inclined vertical posture state" means a state in which the maximum amount of deflection due to the self-weight of the glass substrate G is suppressed so as to be 0.1 mm or less, and the glass substrate G is erected such that the angle on the acute angle side of the main surface of the glass substrate G with respect to the virtual horizontal plane is in the range of 70° or more, preferably 80° or more, more preferably 85° or more, and 90° or less.

[0031] The stage 10 includes a stage substrate 11 which is a main body, and a plurality (two in this embodiment; however, only one is shown in the side view in FIG. 1) of support pins 12·12 arranged in a state of protruding forward from the stage substrate 11.

[0032] Then, the glass substrate G is placed on the two support pins 12·12 in a vertical posture, and at a plurality of locations (five locations in this embodiment) on the outer peripheral edge portion Gc of the main surface on the other side (the rear side in this embodiment; hereinafter, appropriately referred to as the "back surface Gb"), it contacts the stage substrate 11 and is supported by the stage 10 in a state of being inclined at a predetermined angle.

[0033] Note that the support posture of the glass substrate G by the stage 10 is not limited to this embodiment, and as long as it is supported via the outer peripheral edge portion Gc of the glass substrate G, it may be, for example, a horizontal posture or the like. However, by supporting the glass substrate G in an inclined vertical posture as in this embodiment, for example, like the case where the outer peripheral edge portion Gc of the glass substrate G is supported in a horizontal posture, it is possible to suppress the glass substrate G from bending downward due to its own weight, and it is possible to more accurately inspect the presence or absence of defects on the outer peripheral end surface Gd of the glass substrate G.

[0034] Details of the configuration of the stage 10 will be described later.

[0035] The imaging means 20 images the glass substrate G supported by the stage 10 from one main surface side (the front main surface side in this embodiment; hereinafter, the front main surface is appropriately referred to as the "front surface Ga") to acquire image data.

[0036] The imaging means 20 can be configured by, for example, a so-called digital camera using an imaging element such as a CCD image sensor or a CMOS image sensor. Also, the image data acquired by the imaging means 20 may be either color or monochrome.

[0037] The imaging means 20 is arranged with its imaging direction facing the stage 10 side (the rear side in this embodiment). Also, the imaging means 20, together with the first illumination means 30 and the second illumination means 40 described later, is configured such that the relative position between the glass substrate G supported by the stage 10 can be adjusted by the movement of the imaging means 20 or by the movement of the stage 10.

[0038] Then, the imaging means 20 reciprocally scans the surface Ga of the glass substrate G in a direction parallel to the surface Ga (more specifically, the vertical direction and the horizontal direction) to acquire overall image data including the contour line of the glass substrate G.

[0039] The first illumination means 30 illuminates the glass substrate G supported by the stage 10 from the surface Ga side (i.e., the front side). The first illumination means 30 is constituted by, for example, a ring illumination composed of white LED illumination. It is arranged from the front side of the stage 10 with the irradiation direction of the light La facing the stage 10 side (the rear side in this embodiment) so as not to obstruct the field of view of the imaging means 20 and to fit within the inner space of the field of view.

[0040] On the other hand, the second illumination means 40 illuminates the glass substrate G supported by the stage 10 from the back surface Gb side (i.e., the rear side). Similar to the first illumination means 30, the second illumination means 40 is also constituted by, for example, a ring illumination composed of white LED illumination. It is arranged from the rear side of the stage 10 with the irradiation direction of the light Lb facing the stage 10 side (the front side in this embodiment).

[0041] Note that the difference between the central wavelength of the first illumination means 30 and the central wavelength of the second illumination means 40 is preferably set within a range of, for example, 10 nm or less.

[0042] As described above, the control unit 50 controls the operation of the entire defect inspection apparatus 1 and determines the state of the outer peripheral end face Gd of the glass substrate G and the like based on the image data captured by the imaging means 20.

[0043] The control unit 50 includes an arithmetic processing unit constituted by a CPU (Central Processing Unit), a storage unit constituted by a ROM (Read Only Memory), a RAM (Random Access Memory), an HDD (Hard Disk Drive), and the like. In addition, the storage unit stores in advance a program for controlling the operation of the entire defect inspection apparatus 1 and a program for inspecting the presence or absence of defects on the outer peripheral end face Gd of the glass substrate G based on the image data captured by the imaging means 20. Furthermore, the control unit 50 is provided with an interface connected to the imaging means 20, the first illumination means 30, the second illumination means 40, and the like.

[0044] Note that the control unit 50 may be provided with an input means such as a touch panel and an output means such as a monitor.

[0045] Then, the control unit 50 inspects the presence or absence of defects on the outer peripheral end face Gd of the glass substrate G and determines the state of the outer peripheral end face Gd according to the following procedure.

[0046] That is, when the image data including the outer peripheral end face Gd of the glass substrate G captured by the imaging means 20 is transmitted to the control unit 50, the control unit 50 performs binarization processing on the image data and extracts a contour line tracing the shape of the outer peripheral end face Gd.

[0047] Then, the control unit 50 checks for the presence of a break point on the extracted contour line. If the break point is confirmed, it determines that there are defects such as scratches, chips, or dirt on the outer peripheral end face Gd of the glass substrate. If the break point is not confirmed and the contour line is continuous, it determines that there are no defects on the outer peripheral end face Gd of the glass substrate.

[0048] [Configuration of Stage 10] Next, the configuration of stage 10 will be described in detail with reference to FIGS. 2, 3(a)(b), and 5(a)(b).

[0049] As described above, stage 10 supports the glass substrate G in an inclined vertical posture state. As shown in FIG. 2, stage 10 includes a stage substrate 11 and a plurality (two in this embodiment) of support pins 12·12.

[0050] The stage substrate 11 is, for example, in this embodiment, formed of a substantially C-shaped plate member so as to avoid contact with the effective surface (the region excluding the outer peripheral edge Gc) on the main surface of the glass substrate G. Further, the stage substrate 11 has a plurality (five in this embodiment) of protruding portions 11a·11a··· that protrude toward the outer peripheral edge Gc of the glass substrate G supported by the stage 10.

[0051] Note that the shape of the stage substrate 11 is not limited to this embodiment, and any shape may be used as long as it has the plurality of protruding portions 11a·11a···. Also, the number of the protruding portions 11a is not limited to this embodiment. For example, instead of providing a plurality of divided protruding portions 11a·11a···, a continuous single protruding portion having an annular shape may be provided.

[0052] The protruding end of each protruding portion 11a is formed in an arc shape along the outer peripheral edge Gc of the glass substrate G. On the other hand, the plane on one side (the front side in the present embodiment) of each protruding portion 11a functions as a support surface 11a1 that supports the outer peripheral edge portion Gc of the glass substrate G from the other main surface side of the glass substrate G supported by the stage 10 (the rear main surface (back surface Gb) side in the present embodiment; see FIG. 1).

[0053] Then, the stage substrate 11 supports the glass substrate G in an inclined vertical posture with the support surfaces 11a1·11a1··· of these five protruding portions 11a·11a··· (more specifically, the support surfaces 11a1 on the protruding end side) each in contact with the outer peripheral edge portion Gc on the back surface Gb of the glass substrate G.

[0054] Here, FIGS. 3(a) and 3(b) are enlarged views of the protruding portion 11a shown by the region A in FIG. 2. As shown in this figure, in a state where the glass substrate G is supported by the stage 10, on the support surface 11a1 of each protruding portion 11a, a groove portion 11b is provided at a position overlapping the outer peripheral end surface Gd of the glass substrate G as viewed from one main surface side (the front surface Ga side; see FIG. 1) of the glass substrate G and formed along the outer peripheral end surface Gd.

[0055] As a result, the support surface 11a1 of each protruding portion 11a is provided along the outer peripheral end surface Gd of the glass substrate G and contacts the glass substrate G through a region (hereinafter, appropriately referred to as the "contact region 11c") that is separated from the outer peripheral end surface Gd toward the center side of the glass substrate G. In addition, the support surface 11a1 of each protruding portion 11a is provided at a position overlapping the outer peripheral end surface Gd of the glass substrate G as viewed from one main surface side (the front surface Ga side) of the glass substrate G, is formed along the outer peripheral end surface Gd, and has a bottom surface of the groove portion 11b (hereinafter, appropriately referred to as the "separated region 11b1") that is separated from the contact region 11c toward the other main surface side (the back surface Gb side) of the glass substrate G.

[0056] By providing the groove portion 11b having such a shape in each protruding portion 11a, it is possible to more reliably avoid the contact region 11c on the support surface 11a1 of the stage 10 overlapping with the outer peripheral end surface Gd of the glass substrate G when viewed from the surface Ga side of the glass substrate G through the groove portion 11b.

[0057] Therefore, on the image data captured by the imaging means 20 (see FIG. 1), it is possible to more reliably suppress the reflected light Lc (refer to FIG. 4(a)) reflected by the defect generated in the contact region 11c from being imaged at a position overlapping with the outer peripheral end surface Gd of the glass substrate G. Using the defect inspection apparatus 1, it is possible to stably and accurately inspect the presence or absence of defects on the outer peripheral end surface Gd of the glass substrate G.

[0058] For example, FIG. 4(a) shows an example of image data obtained by imaging the vicinity of the protruding end of the protruding portion 111a in a state where the glass substrate G is supported on a conventional stage 110 without the groove portion 11b. As shown in this figure, in the conventional stage 110, the reflected light Lc reflected by the defect generated in the contact region 111c is imaged at a position overlapping with the outer peripheral end surface Gd of the glass substrate G, and there are cases where the presence or absence of defects on the outer peripheral end surface Gd of the glass substrate G cannot be accurately inspected. On the other hand, FIG. 4(b) shows an example of image data obtained by imaging the vicinity of the protruding end of the protruding portion 11a in a state where the glass substrate G is supported on the stage 10 of the present embodiment. As shown in this figure, since the groove portion 11d is provided, the reflected light Lc reflected by the defect generated in the contact region 11c does not enter a position overlapping with the outer peripheral end surface Gd of the glass substrate G, and the presence or absence of defects on the outer peripheral end surface Gd of the glass substrate G can be stably and accurately inspected.

[0059] In addition, as shown in Fig. 3(a), in the present embodiment, in a state where the glass substrate G is supported by the stage 10, the dimension d1 between the outer peripheral end face Gd of the glass substrate G and the end face on the outer peripheral end face Gd side in the contact region 11c (hereinafter, appropriately referred to as "first end face 11c1") as viewed from one main surface side (surface Ga side) of the glass substrate G is set to be 0.5 mm or more and 3 mm or less.

[0060] Here, when the dimension d1 between the outer peripheral end face Gd of the glass substrate G and the first end face 11c1 of the contact region 11c is less than 0.5 mm (d1 < 0.5 mm), even if the contact region 11c is provided at a position away from the outer peripheral end face Gd of the glass substrate G as viewed from the one main surface side (surface Ga side), it is difficult to surely suppress the reflected light Lc reflected by the defect generated in the contact region 11c from being imaged at a position overlapping the outer peripheral end face Gd of the glass substrate G on the image data captured by the imaging means 20.

[0061] On the other hand, when the dimension d1 between the outer peripheral end face Gd of the glass substrate G and the first end face 11c1 of the contact region 11c exceeds 3 mm (d1 > 0.5 mm), since the contact region 11c needs to be provided within a limited range of the outer peripheral edge portion Gc of the glass substrate G excluding the effective surface, it is impossible to sufficiently secure the contact surface of the contact region 11c (that is, the surface in contact with the outer peripheral edge portion Gc of the glass substrate G), and it is difficult to stably support the glass substrate G by the stage 10.

[0062] For these reasons, in the present embodiment, the dimension d1 between the outer peripheral end face Gd of the glass substrate G and the first end face 11c1 of the contact region 11c is set to be 0.5 mm or more and 3 mm or less (0.5 mm ≤ d1 ≤ 3 mm). While more surely suppressing the reflected light Lc reflected by the defect generated in the contact region 11c from being imaged at a position overlapping the outer peripheral end face Gd of the glass substrate G on the image data captured by the imaging means 20, the glass substrate G can be stably supported by the stage 10, and the presence or absence of defects in the outer peripheral end face Gd of the glass substrate G can be more stably and accurately inspected.

[0063] Also, in the present embodiment, on the support surface 11a1 of each protruding portion 11a, the width dimension d2 between the first end surface 11c1 on the outer peripheral end surface Gd side of the glass substrate G and the end surface on the central side of the glass substrate G (hereinafter, appropriately referred to as "second end surface 11c2") in the contact region 11c is set to be 0.5 mm or more and 3 mm or less.

[0064] Here, when the width dimension d2 between the first end surface 11c1 and the second end surface 11c2 in the contact region 11c is less than 0.5 mm (d2 < 0.5 mm), it is impossible to sufficiently secure the contact surface of the contact region 11c (the surface that contacts the outer peripheral edge portion Gc of the glass substrate G), and it is difficult to stably support the glass substrate G by the stage 10.

[0065] On the other hand, when the width dimension d2 between the first end surface 11c1 and the second end surface 11c2 in the contact region 11c exceeds 3 mm (d2 > 3 mm), since the contact region 11c needs to be provided within a limited range of the outer peripheral edge portion Gc of the glass substrate G excluding the effective surface, it is difficult to provide the contact region 11c at a position sufficiently separated from the outer peripheral end surface Gd of the glass substrate G when viewed from the surface Ga side of the glass substrate G. It is difficult to surely suppress the reflected light Lc reflected by the defect generated in the contact region 11c from being imaged at a position overlapping the outer peripheral end surface Gd of the glass substrate G in the image data captured by the imaging means 20.

[0066] For these reasons, in the present embodiment, the width dimension d2 between the first end surface 11c1 and the second end surface 11c2 in the contact region 11c is set to be 0.5 mm or more and 3 mm or less (0.5 mm ≤ d2 ≤ 3 mm). While stably supporting the glass substrate G by the stage 10, it is possible to more surely suppress the reflected light Lc reflected by the defect generated in the contact region 11c from being imaged at a position overlapping the outer peripheral end surface Gd of the glass substrate G in the image data captured by the imaging means 20, and it is possible to more stably and accurately inspect the presence or absence of defects on the outer peripheral end surface Gd of the glass substrate G.

[0067] Furthermore, as shown in FIG. 3(b), in the present embodiment, in a state where the glass substrate G is supported by the stage 10, the support surface 11a1 at each protruding portion 11a is provided at a position overlapping the outer peripheral end surface Gd of the glass substrate G when viewed from one main surface side (front surface Ga side) of the glass substrate G, and is formed along the outer peripheral end surface Gd. The support surface 11a1 has a separation region 11b1 separated from the other main surface side (back surface Gb side) of the glass substrate G with respect to the contact region 11c, and the separation dimension h between the contact region 11c and the separation region 11b1 is set to 1 mm or more (H≦1 mm).

[0068] Here, when the separation dimension h between the contact region 11c and the separation region 11b1 is less than 1 mm (h<1 mm), even if the separation region 11b1 is provided at a position separated from the back surface Gb side of the glass substrate G with respect to the outer peripheral end surface Gd of the glass substrate G, on the image data captured by the imaging means 20, it is difficult to surely suppress the reflected light Lc reflected by the defect generated in the separation region 11b1 from being imaged at a position overlapping the outer peripheral end surface Gd of the glass substrate G.

[0069] For this reason, in the present embodiment, the separation dimension h between the contact region 11c and the separation region 11b1 is set to 1 mm or more (h≦1 mm). On the image data captured by the imaging means 20, it is possible to more surely suppress the reflected light Lc reflected by the defect generated in the separation region 11b1 from being imaged at a position overlapping the outer peripheral end surface Gd of the glass substrate G, and it is possible to more stably and accurately inspect the presence or absence of defects at the outer peripheral end surface Gd of the glass substrate G.

[0070] In FIG. 2, the two support pins 12·12 are each formed of a round bar member, and are fixed to the stage substrate 11 so as to be able to contact the lower side of the outer peripheral end surface Gd of the glass substrate G supported in a vertical posture by the stage 10.

[0071] As described above, the defect inspection apparatus 1 in the present embodiment is a defect inspection apparatus for inspecting defects on the glass substrate G, and includes a stage 10 that supports the glass substrate G, an imaging unit 20 that images the glass substrate G supported by the stage 10 from one main surface (front surface Ga) side, and a control unit 50 that determines the state of the outer peripheral end surface Gd of the glass substrate G based on the image data imaged by the imaging unit 20. Further, the stage 10 has a support surface 11a1 that supports the outer peripheral edge portion Gc of the glass substrate G from the other main surface (back surface Gb) side of the glass substrate G.

[0072] The support surface 11a1 is provided along the outer peripheral end surface Gd of the glass substrate G and has a contact region 11c that contacts the glass substrate G at a position separated from the outer peripheral end surface Gd of the glass substrate G toward the center side of the glass substrate G.

[0073] According to the defect inspection apparatus 1 in the present embodiment having such a configuration, in the support surface 11a1 of the stage 10 that supports the outer peripheral edge portion Gc of the glass substrate G, the contact region 11c that contacts the glass substrate G is provided at a position separated from the outer peripheral end surface Gd of the glass substrate G toward the center side of the glass substrate G. Therefore, for example, even when defects such as peeling of the coating or fine scratches due to aging or the like occur in the contact region 11c, it is possible to suppress the reflected light Lc reflected by the defect from being reflected at a position overlapping the outer peripheral end surface Gd of the glass substrate G on the image data.

[0074] Therefore, for example, on the image data subjected to binarization processing, it is possible to prevent a breakage point caused by the reflected light Lc from occurring on the contour line of the outer peripheral end surface Gd of the extracted glass substrate G, and it is possible to accurately inspect the presence or absence of defects on the outer peripheral end surface Gd of the glass substrate G.

Example

[0075] Next, an example of the stage 10 in the defect inspection apparatus 1 described above will be described with reference to FIGS. 3(a), 3(b), and 5. Note that the shape of the groove portion in the stage 10 is not limited to this.

[0076] [Preparation of Stage 10] First, as an example of this embodiment, a stage 10 in which a groove portion 11b is provided on the support surface 11a1 of each protruding portion 11a, as shown in FIGS. 3(a) and 3(b), was prepared. In the groove portion 11b, the above-described dimension d1 was set to approximately 1.5 mm (d1 = 1.5 mm), the width dimension d2 was set to approximately 2.8 mm (d2 = 2.8 mm), and the separation dimension h was set to 6 mm (h = 6 mm).

[0077] On the other hand, as a comparative example, a conventional stage in which the groove portion 11b is not provided on the support surface 11a1 of each protruding portion 11a was prepared.

[0078] [Preparation of Object to be Inspected] Next, as objects to be inspected, a plurality of glass substrates G, G,... were prepared. For each glass substrate G, a disk-shaped glass substrate having a thickness of 0.4 mm and a diameter of 200 mm was adopted.

[0079] [Defect Inspection] Then, the prepared stage 10 of the example and the conventional stage were respectively attached to the defect inspection apparatus 1 in order, and defect inspections were performed on a plurality of glass substrates G, G,... according to the following procedures.

[0080] [Defect Inspection Using the Stage 10 of the Example] In the defect inspection apparatus 1 to which the stage 10 of the example was attached, 1790 glass substrates G, G,... were prepared as the number of samples, and the presence or absence of defects on the outer peripheral end surface Gd of each glass substrate G was inspected. Regarding the inspection of the presence or absence of the above defects, first, it was performed by image inspection using the defect inspection apparatus 1, and then, for the glass substrate G determined to have a defect by the image inspection, it was performed by visual inspection by an operator. [Defect Inspection Using the Conventional Stage] In the conventional defect inspection apparatus 1 to which a stage was attached, 2,094 glass substrates G, G,... were prepared as the number of samples, and the presence or absence of defects in the outer peripheral end surface Gd of each glass substrate G was inspected respectively. The inspection for the presence or absence of the above defects was performed in the same manner as when the stage 10 of the example was used.

[0081] [Results of Defect Inspection] The results of the defect inspection using the stage 10 of the example and the defect inspection using the conventional stage are shown in Table 1 and Table 2.

[0082]

Table 1

[0083]

Table 2

[0084] As shown in Table 1, in the defect inspection using the stage 10 of the example, in the image inspection by the defect inspection apparatus 1, 926 glass substrates G were determined to be non-defective with no significant defects found in the outer peripheral end surface Gd. The ratio (good product determination rate) of the number of good product determinations to the total number of samples was 51.7%.

[0085] Also, in the defect inspection using the conventional stage, in the image inspection by the defect inspection apparatus 1, 453 glass substrates G were determined to be non-defective with no significant defects found in the outer peripheral end surface Gd. The ratio (good product determination rate) of the number of good product determinations to the total number of samples was 21.6%.

[0086] On the other hand, as shown in Table 2, the number of glass substrates G (determination number) determined to have defects by the defect inspection using the stage 10 of the example and subjected to visual inspection was 864. In the visual inspection by the above operator, 713 glass substrates G were determined to be non-defective with no significant defects found in the outer peripheral end surface Gd. The ratio of the number of non-defective products determined by visual inspection to the total number of samples (non-defective product determination rate) was 39.8%.

[0087] In addition, the number of glass substrates G (determination quantity) for which defects were determined to be present by defect inspection using a conventional stage and for which visual inspection was performed was 1,641. In the visual inspection by the above-mentioned operator, 1,441 glass substrates G were determined to be non-defective with no significant defects found on the outer peripheral end face Gd. The ratio of the number of non-defective products determined by visual inspection to the total number of samples (non-defective product determination rate) was 68.8%.

[0088] In Tables 1 and 2, in the case of defect inspection using stage 10 of the embodiment, the non-defective product determination rate by image inspection (51.7%) is higher than the non-defective product determination rate by visual inspection (39.8%), and it can be said that the accuracy of defect inspection by the defect inspection apparatus 1 is high. On the other hand, in the case of defect inspection using a conventional stage, the non-defective product determination rate by image inspection (21.6%) is lower than the non-defective product determination rate by visual inspection (68.8%), and it can be said that the accuracy of defect inspection by the defect inspection apparatus 1 is slightly lower compared to the case of defect inspection using stage 10 of the embodiment. And in the case of defect inspection using stage 10 of the embodiment, the non-defective product determination rate by image inspection is improved by approximately 30% compared to the case of defect inspection using a conventional stage.

[0089] As described above, the embodiments of the present application have been explained. However, the present application is not limited to such embodiments at all, but is merely illustrative, and it goes without saying that the present application can be implemented in various other forms within the scope not departing from the gist of the present application. The scope of the present application is indicated by the description in the claims, and further includes the equivalent meaning described in the claims and all modifications within the scope.

Explanation of Reference Numerals

[0090] 1 Defect inspection apparatus 10 Stage 11a1 Support surface 11b Groove portion 11b1 Separation region 11c Contact region 11c1 First end face 11c2 Second end face 20 Imaging means 50 Control unit d1 Dimension d2 Width dimension G Glass substrate Ga Surface (one main surface) Gb Back surface (the other main surface) Gc Outer peripheral edge portion Gd Outer peripheral end face h Separation dimension S01 Forming process S02 Inspection process

Claims

1. A glass substrate defect inspection apparatus for inspecting defects of a glass substrate, comprising: a stage for supporting the glass substrate; imaging means for imaging the glass substrate supported by the stage from one main surface side; a control unit for determining the state of the outer peripheral edge portion of the glass substrate based on the image data imaged by the imaging means; wherein the stage has a support surface for supporting the outer peripheral edge portion of the glass substrate from the other main surface side of the glass substrate; the support surface is provided along the outer peripheral end surface of the glass substrate and has a contact region that contacts the glass substrate at a position away from the outer peripheral end surface toward the central side of the glass substrate; A glass substrate defect inspection apparatus characterized by the above.

2. The stage supports the glass substrate in an inclined vertical posture, The glass substrate defect inspection apparatus according to claim 1, characterized by the above.

3. In a state where the glass substrate is supported by the stage, the support surface is provided at a position overlapping the outer peripheral end surface of the glass substrate as viewed from the one main surface side and has a groove portion formed along the outer peripheral end surface; The glass substrate defect inspection apparatus according to claim 1 or claim 2, characterized by the above.

4. In a state where the glass substrate is supported by the stage, the dimension between the outer peripheral end surface of the glass substrate and the first end surface on the outer peripheral end surface side in the contact region as viewed from the one main surface side of the glass substrate is 0.5 mm or more and 3 mm or less; The glass substrate defect inspection apparatus according to claim 1 or claim 2, characterized by the above.

5. On the support surface, the width dimension between the first end surface on the outer peripheral end surface side of the glass substrate and the second end surface on the central side of the glass substrate in the contact region is 0.5 mm or more and 3 mm or less; The glass substrate defect inspection apparatus according to claim 1 or claim 2, characterized by the above.

6. In a state where the glass substrate is supported by the stage, the support surface is provided at a position overlapping the outer peripheral end surface of the glass substrate as viewed from the one main surface side and is formed along the outer peripheral end surface, and has a separation region separated from the other main surface side of the glass substrate with respect to the contact region, the separation dimension between the contact region and the separation region is 1 mm or more; The glass substrate defect inspection apparatus according to claim 1 or claim 2, characterized by the above.

7. A forming step of forming a glass substrate After completion of the forming step, there is provided an inspection step of inspecting a defect of the obtained glass substrate using the defect inspection apparatus according to claim 1 or claim 2, with the glass substrate as an object to be inspected. A method for manufacturing a glass substrate, characterized by the above.

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