Glass substrate for display

Abstract

When measuring the plate thickness distribution (TD) of the first main surface (GS1) in the direction (Y) orthogonal to the plate drawing direction (X), the height difference between the first vertex (A01) and the second vertex (B01) in the plate thickness distribution (TD) of the first main surface (GS1) is set as H1, the height difference between the second vertex (B01) and the third vertex (A02) is set as H2, the distance between the first vertex (A01) and the second vertex (B01) in the direction (Y) orthogonal to the plate drawing direction (X) is set as D1, and the distance between the second vertex (B01) and the third vertex (A02) in the direction (Y) orthogonal to the plate drawing direction (X) is set as D2. At this time, make the height differences (H1, H2) be 0.005 mm or less, or when the height differences (H1, H2) are higher than 0.005 mm, make the slopes (H1 / D1, H2 / D2) be 1×10 ‑4 or less.

Description

Technical Field

[0001] The present invention relates, for example, to a glass substrate used in a display such as an organic EL display. Background Art

[0002] As is well known, in displays such as organic EL displays and liquid crystal displays, a glass substrate is used to form fine electrodes, partitions, and other elements or structures. After various films are uniformly coated on the surface of the glass substrate, a thin film transistor (TFT; Thin Film Transistor) is formed using optical process techniques (exposure process, development process, etc.).

[0003] For example, in Patent Document 1, a glass substrate for a TFT is disclosed, which is configured to have a rectangular shape with a first main surface and a second main surface opposite to the first main surface, and has a first side and a second side adjacent to each other, and the lengths of the first side and the second side are set to at least 1200 mm or more.

[0004] In this glass substrate, in a first cross section along a straight line parallel to the first side in a cross section in the plate thickness direction, the difference between the maximum value and the minimum value of the plate thickness, that is, the plate thickness tolerance, is less than 6.26 μm (see Claim 1 and Paragraph 0006 of the same document).

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: JP-A-2019-34878 Summary of the Invention

[0008] -Problems to be Solved by the Invention-

[0009] If there is a portion where the thickness becomes uneven (wall thickness uneven portion) in the glass substrate for a liquid crystal display, it is difficult to accurately form a TFT. For this reason, it is effective to restrict the plate thickness tolerance as in the glass substrate described in Patent Document 1 above in order to accurately form a TFT.

[0010] In the manufacturing process of an organic EL display, an appearance inspection (macroscopic inspection) for detecting non-uniformity of a film formed on a glass substrate is performed. In this appearance inspection, for example, light is irradiated onto the glass substrate from a light source, and the reflected light is detected. When non-uniformity occurs, for example, at this portion, the direction of the reflected light locally changes, so that the shade changes. In such a macroscopic inspection, even for a glass substrate with restricted plate thickness tolerance as in Patent Document 1, a situation where an appearance abnormality is detected may occur. When non-uniformity of the film occurs, the glass substrate is regarded as defective and discarded.

[0011] The present invention is proposed in view of the above circumstances, and its object is to provide a glass substrate for a display that can suppress unevenness of a thin film formed on a glass substrate.

[0012] -Means for Solving the Problem-

[0013] To solve the above problems, a glass substrate for a display has: a first side along the plate drawing direction; a second side along a direction orthogonal to the plate drawing direction; a first main surface; and a second main surface on the opposite side of the first main surface in the thickness direction. The feature is that when measuring the plate thickness distribution along a direction orthogonal to the plate drawing direction, the plate thickness distribution includes a first vertex, a second vertex adjacent to the first vertex, and a third vertex adjacent to the second vertex. Let the height difference between the first vertex and the second vertex be H1 (mm), the height difference between the second vertex and the third vertex be H2 (mm), the distance between the first vertex and the second vertex in the direction orthogonal to the plate drawing direction be D1 (mm), and the distance between the second vertex and the third vertex in the direction orthogonal to the plate drawing direction be D2 (mm). At this time, H1 and D1 satisfy the following formula (1) and the following formula (3), or satisfy the following formula (4), and H2 and D2 satisfy the following formula (2) and the following formula (5), or satisfy the following formula (6).

[0014] (H1 / D1) ≤ 1×10 -4 …(1)

[0015] (H2 / D2) ≤ 1×10 -4 …(2)

[0016] H1 > 0.005…(3)

[0017] H1 ≤ 0.005…(4)

[0018] H2 > 0.005…(5)

[0019] H2 ≤ 0.005…(6)

[0020] As a result of repeated intensive research by the present inventors, it has been found that when forming a thin film on the first main surface of a glass substrate, unevenness of the thin film is likely to occur at portions where the peak portions contained in the plate thickness distribution are high and have a large inclination. In addition, it has been found that unevenness of the thin film is likely to occur at portions where the valley portions contained in the plate thickness distribution are deep and have a large inclination. That is, it has been found that unevenness of the thin film is likely to occur at portions where the above-mentioned height differences (H1, H2) and inclinations (H1 / D1, H2 / D2) are large. In the present invention, by reducing the above-mentioned height differences (H1, H2) in the plate thickness distribution, or by reducing the inclination (H1 / D1, H2 / D2) when the height differences (H1, H2) are large, generation of unevenness of the thin film and generation of associated quality defects can be prevented.

[0021] The present invention is for solving the above-mentioned problems, and a glass substrate for a display includes: a first side along the plate drawing direction; a second side along a direction orthogonal to the plate drawing direction; a first main surface; and a second main surface on the opposite side of the first main surface in the thickness direction, and is characterized in that when measuring the plate thickness distribution along a direction orthogonal to the plate drawing direction, the plate thickness distribution includes a bevel portion having a height difference and a width, the height difference of the bevel portion is set to H (mm), the width of the bevel portion is set to D (mm), and at this time, the H and the D satisfy the following formula (7) and the following formula (8), or satisfy the following formula (9).

[0022] (H / D) ≤ 1×10 -4 …(7)

[0023] H > 0.005 …(8)

[0024] H ≤ 0.005 …(9)

[0025] The present inventors have found that by reducing the height difference (H) of the bevel portion contained in the plate thickness distribution as described above, or by reducing the inclination (H / D) when the height difference (H) is large, generation of unevenness of the thin film and generation of associated quality defects can be prevented.

[0026] The glass substrate for a display according to the present invention may also be a glass substrate for an organic EL display.

[0027] The glass substrate for a display according to the present invention may also have a difference between the maximum value and the minimum value of the plate thickness of 6 μm or more. By reducing the plate thickness tolerance, the degree of wall thickness unevenness in the glass substrate can be reduced, and the degree of the height difference and inclination of the peak portion and the bevel portion can be reduced, but the manufacturing cost of the glass substrate increases. In the present invention, by setting the plate thickness tolerance within the above-mentioned range, the manufacturing cost of the glass substrate can be suppressed, and generation of unevenness of the thin film and generation of associated quality defects can be prevented.

[0028] The first major surface and the second major surface of the glass substrate for a display may be fire-polished surfaces. Alternatively, the first major surface may be a fire-polished surface and the second major surface may be an etched surface.

[0029] In the glass substrate for a display according to the present invention, the size of the first side may be 1200 mm or more, the size of the second side may be 1200 mm or more, and the plate thickness may be 0.2 to 1.3 mm.

[0030] -Advantages of the Invention-

[0031] According to the present invention, non-uniformity of a thin film formed on the glass substrate can be suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a perspective view of the glass substrate for a display.

[0033] Figure 2 is a graph showing the plate thickness distribution of the glass substrate for a display.

[0034] Figure 3 is a graph showing the plate thickness distribution of the glass substrate for a display.

[0035] Figure 4 is a graph showing the plate thickness distribution of the glass substrate for a display.

[0036] Figure 5 is a flowchart showing a method for manufacturing the glass substrate for a display.

[0037] Figure 6 is a side view of a manufacturing apparatus for the glass substrate for a display. DETAILED DESCRIPTION OF THE INVENTION

[0038] Hereinafter, modes for carrying out the present invention will be described with reference to the drawings. Figures 1 to 6 This shows an embodiment of the glass substrate for a display and a method for manufacturing the same according to the present invention. In this embodiment, an organic EL display glass substrate is exemplified as the glass substrate, but the present invention is not limited thereto and can also be applied to glass substrates for liquid crystal displays and various other displays.

[0039] As shown in Figure 1As shown, the glass substrate G is configured, for example, in a rectangular shape (a rectangular shape). The glass substrate G has: a first side Ga along the plate drawing direction X; a second side Gb along the direction Y orthogonal to the plate drawing direction X; a third side Gc substantially parallel to the second side Gb; and a fourth side Gd substantially parallel to the first side Ga. In the present embodiment, the lengths of the first side Ga and the fourth side Gd are preferably 1200 mm or more, more preferably 1800 mm or more, and still more preferably 2100 mm or more. The lengths of the second side Gb and the third side Gc are preferably 1200 mm or more, more preferably 2150 mm or more, and still more preferably 2400 mm or more. On the other hand, the lengths of the first side Ga, the second side Gb, the third side Gc, and the fourth side Gd are all preferably 4000 mm or less.

[0040] In addition, the so-called "plate drawing direction" refers to the direction in which the plate is drawn when forming the glass substrate G. For example, while adjusting the angle of the glass substrate G in a dark room, light is irradiated from a light source (e.g., a xenon lamp), and the transmitted light is projected onto a screen, whereby the plate drawing direction X of the glass substrate G can be observed as a linear stripe pattern. Therefore, even in the state of the formed glass substrate G, the plate drawing direction X at the time of forming can be determined.

[0041] In addition, the so-called "along the plate drawing direction" not only refers to the case of being geometrically parallel to the plate drawing direction X, but also includes a direction that can be regarded as substantially parallel. In addition, the so-called "along the direction orthogonal to the plate drawing direction" not only refers to the direction that is geometrically orthogonal to the plate drawing direction X, but also includes a direction that can be regarded as substantially orthogonal.

[0042] The glass substrate G has: a first main surface GS1; and a second main surface GS2 on the opposite side of the first main surface GS1 in the thickness direction. In the present embodiment, the first main surface GS1 is set as the guaranteed surface, and the second main surface GS2 is set as the non-guaranteed surface. Here, the so-called "guaranteed surface" is, for example, the surface on the side where a thin film is formed during the manufacturing process of the display.

[0043] The first main surface GS1 and the second main surface GS2 of the glass substrate G are preferably fire-polished surfaces. Here, the so-called "fire-polished surface" is a surface formed in a non-contact state in contact with a forming device or the like. Such a fire-polished surface, although not polished, has excellent surface properties.

[0044] It is not limited to this structure. The glass substrate G may also have the first main surface GS1 as a fire-polished surface and the second main surface GS2 as an etched surface. Herein, the so-called "etched surface" refers to a surface on which a roughening treatment has been performed. The method of the roughening treatment is not particularly limited, and examples include chemical polishing such as etching, mechanical polishing such as tape polishing, brush polishing, and abrasive polishing, and chemical mechanical polishing (CMP). Such an etched surface reduces the generation of static electricity. Therefore, for example, when the glass substrate placed on the support table is lifted, it can prevent the glass substrate from adhering to the support table due to static electricity and being damaged.

[0045] The plate thickness (thickness dimension) of the glass substrate G is preferably 1.0 mm or less, more preferably 0.7 mm or less, and further preferably 0.5 mm or less. On the other hand, the plate thickness of the glass substrate G is preferably 0.2 mm or more, more preferably 0.3 mm or more. From the viewpoint of suppressing an increase in manufacturing cost, the lower limit of the preferred difference between the maximum value and the minimum value of the plate thickness (plate thickness tolerance) in the glass substrate G is 3 μm or more, 4 μm or more, 5 μm or more, 6 μm or more, 7 μm or more, particularly 7.5 μm or more. On the other hand, from the viewpoint of keeping the liquid crystal gap layer of the liquid crystal display uniform, the plate thickness tolerance is preferably 20 μm or less, more preferably 15 μm or less.

[0046] The glass substrate G is, for example, made of silicate glass or silica glass, and is preferably composed of borosilicate glass, soda-lime glass, aluminosilicate glass, chemically strengthened glass, or non-alkali glass. Herein, the so-called non-alkali glass refers to a glass that substantially does not contain an aluminum component (aluminum metal oxide). Specifically, it is a glass in which the weight ratio of the aluminum component is 3000 ppm or less. In the present invention, the weight ratio of the aluminum component is preferably 1000 ppm or less, more preferably 500 ppm or less, and most preferably 300 ppm or less.

[0047] As Figure 1 shown, the first main surface GS1 of the glass substrate G measures the plate thickness distribution (plate thickness distribution curve) along a measurement predetermined line ML that is set to be substantially parallel to the direction Y orthogonal to the plate drawing direction X. The measurement of the plate thickness distribution is performed along the measurement predetermined line ML at 10 mm intervals by a laser displacement meter. The laser displacement meter measures the distance (plate thickness) between the first main surface GS1 and the second main surface GS2 in the thickness direction of the glass substrate G. The measured plate thickness distribution includes valleys and / or peaks.

[0048] Figure 2Represents a valley portion contained in the plate thickness distribution in the first main surface GS1 of the glass substrate G. The plate thickness distribution TD includes: a first vertex A01; a second vertex B01 adjacent to the first vertex A01; and a third vertex A02 adjacent to the second vertex B01. The first vertex A01, the second vertex B01, and the third vertex A02 all have an inclination of 0 (zero), forming a valley portion.

[0049] Furthermore, the plate thickness distribution TD includes: a first inclined edge portion C01 located between the first vertex A01 and the second vertex B01; and a second inclined edge portion C02 located between the second vertex B01 and the third vertex A02.

[0050] The first inclined edge portion C01 has a first height difference H1 and a first width D1. The first height difference H1 of the first inclined edge portion C01 is the height difference between the first vertex A01 and the second vertex B01. The first width D1 of the first inclined edge portion C01 is the distance between the first vertex A01 and the second vertex B01 in the direction Y orthogonal to the plate drawing direction X.

[0051] The second inclined edge portion C02 has a second height difference H2 and a second width D2. The second height difference H2 of the second inclined edge portion C02 is the height difference between the second vertex B01 and the third vertex A02. The second width D2 of the second inclined edge portion C02 is the distance between the second vertex B01 and the third vertex A02 in the direction Y orthogonal to the plate drawing direction X.

[0052] Figure 3 Represents a peak portion contained in the plate thickness distribution in the first main surface GS1 of the glass substrate G. The plate thickness distribution TD includes: a first vertex B11; a second vertex A11 adjacent to the first vertex B11; and a third vertex B12 adjacent to the second vertex A11. The first vertex B11, the second vertex A11, and the third vertex B12 all have an inclination of 0 (zero), forming a peak portion.

[0053] Furthermore, the plate thickness distribution TD includes: a first inclined edge portion C11 located between the first vertex B11 and the second vertex A11; and a second inclined edge portion C12 located between the second vertex A11 and the third vertex B12.

[0054] The first inclined edge portion C11 has a first height difference H1 and a first width D1. The first height difference H1 of the first inclined edge portion C11 is the height difference between the first vertex B11 and the second vertex A11. The first width D1 of the first inclined edge portion C11 is the distance between the first vertex B11 and the second vertex A11 in the direction Y orthogonal to the plate drawing direction X.

[0055] The second bevel portion C12 has a second height difference H2 and a second width D2. The second height difference H2 of the second bevel portion C12 is the height difference between the second vertex A11 and the third vertex B12. The second width D2 of the second bevel portion C12 is the distance between the second vertex A11 and the third vertex B12 in the direction Y orthogonal to the sheet pulling direction X.

[0056] When there are peak portions and / or valley portions in the sheet thickness distribution TD, the first height difference H1 (mm) and the first width D1 (mm) satisfy the following formula (1) and the following formula (3), or satisfy the following formula (4). In addition, the second height difference H2 (mm) and the second width D2 (mm) satisfy the following formula (2) and the following formula (5), or satisfy the following formula (6).

[0057] (H1 / D1) ≤ 1×10 -4 …(1)

[0058] (H2 / D2) ≤ 1×10 -4 …(2)

[0059] H1 > 0.005 …(3)

[0060] H1 ≤ 0.005 …(4)

[0061] H2 > 0.005 …(5)

[0062] H2 ≤ 0.005 …(6)

[0063] When there are multiple peak portions or valley portions in the sheet thickness distribution TD, all the peak portions and valley portions satisfy the conditions based on the above formulas (1) to (6). In other words, when the height differences (H1, H2) in the sheet thickness distribution TD are larger than 0.005 mm, there are no peak portions and valley portions of the bevel portion having an inclination (H1 / Dl, H2 / D2) larger than 1×10 -4 large.

[0064] As a result of repeated intensive studies by the present inventors, it has been found that when forming a thin film on the first main surface GS1 of the glass substrate G, in a portion where the peak portion in the sheet thickness distribution is high and has a large inclination, non-uniformity of the thin film is likely to occur. In addition, it has been found that in a portion where the valley portion in the sheet thickness distribution is deep and has a large inclination, non-uniformity of the thin film is likely to occur. That is, it has been found that non-uniformity of the thin film is likely to occur in portions where the above height differences (H1, H2) and inclinations (H1 / D1, H2 / D2) are large. That is, by reducing the above height differences (H1, H2) in the sheet thickness distribution TD, or reducing the inclinations (H1 / D1, H2 / D2) when the height differences (H1, H2) reach a certain level, generation of non-uniformity of the thin film and accompanying quality defects can be prevented.

[0065] Figure 4 Another example of the plate thickness distribution in the first major surface GS1 of the glass substrate G. As Figure 3 shown, the plate thickness distribution TD has a slanted edge portion C that is inclined with respect to the measurement direction Y (a direction orthogonal to the plate drawing direction). The slanted edge portion C has a height difference H and a width D.

[0066] When there is a slanted edge portion C in the plate thickness distribution TD, the height difference H (mm) and the width D (mm) of the slanted edge portion C satisfy the following formula (7) and the following formula (8), or satisfy the following formula (9).

[0067] (H / D) ≤ 1×10 -4 …(7)

[0068] H > 0.005…(8)

[0069] H ≤ 0.005…(9)

[0070] When there are multiple slanted edge portions C in the plate thickness distribution TD, all the slanted edge portions C satisfy the conditions of the above formulas (7) to (9). In other words, in the plate thickness distribution TD, when the height difference H is greater than 0.005 mm, there is no slanted edge portion with an inclination H / D greater than 1×10 -4 greater.

[0071] The inventors found that when forming a thin film on the first major surface GS1 of the glass substrate G, if the height difference and the inclination of the slanted edge portion C in the plate thickness distribution TD are large, unevenness of the thin film is likely to occur. That is, it was found that by reducing the height difference H of the slanted edge portion C, or by reducing the inclination (H / D) when the height difference H is large, the occurrence of unevenness of the thin film and the accompanying quality defects can be prevented.

[0072] Here, Table 1 below shows the inclination and the height difference of the slanted edge portion contained in the plate thickness distribution, and the occurrence status of the unevenness of the thin film at that portion.

[0073] [Table 1]

[0074] Notation Inclination of the bevel portion Height difference of the bevel portion (mm) Non-uniformity of the film No.1 <![CDATA[0.8×10 -4 > 0.006 None No.2 <![CDATA[1.2×10 -4 > 0.006 Yes No.3 <![CDATA[1.2×10 -4 > 0.004 None

[0075] In No. 1 and 2, the height difference (H) of the slanted edge portion is higher than 0.005 mm. In No. 1, the inclination (H / D) is 1×10 -4 or less, and as a result, unevenness of the thin film did not occur. In contrast, in No. 2, the inclination (H / D) is higher than 1×10 -4 , and unevenness of the thin film occurred. That is, it was confirmed that even if there is a height difference in the slanted edge portion, as long as the inclination (H / D) is 1×10 -4 or less, the unevenness of the thin film can be suppressed.

[0076] In No. 2 and 3, the inclination of the bevel portion is higher than 1×10 -4 . In No. 3, the height difference (H) is 0.005 mm or less. As a result, non-uniformity of the thin film is not generated. In No. 2, the height difference (H) is higher than 0.005 mm, and non-uniformity of the thin film is generated. That is, it is confirmed that even if there is an inclination in the bevel portion, as long as the height difference (H) is 0.005 mm or less, non-uniformity of the thin film can be suppressed.

[0077] From the viewpoint of forming a more uniform thin film by further reducing non-uniformity of the thin film, the inclination (H1 / D1, H2 / D2, H / D) in the case where the height differences (H1, H2, H) are larger than 0.005 mm is preferably 0.5×10 -4 or less. In addition, in the case where the height differences (H1, H2, H) are larger than 0.005 mm, the height differences (H1, H2, H) are preferably 0.02 mm or less. On the other hand, from the viewpoint of suppressing an increase in manufacturing cost accompanying a decrease in inclination, the inclination (H1 / D1, H2 / D2, H / D) is preferably 0.05×10 -4 or more.

[0078] The glass substrate G is manufactured by a known forming method such as a down-draw method (e.g., an overflow down-draw method, a slot down-draw method) or a float method. In the present embodiment, a case where the glass substrate G is manufactured by the overflow down-draw method is illustrated.

[0079] Hereinafter, a method for manufacturing the glass substrate G having the above structure will be described. As Figure 5 shown, this method mainly includes a forming step S1, a slow cooling step S2, a cooling step S3, a cutting step S4, an end face processing step S5, a cleaning step S6, and an inspection step S7.

[0080] Figure 6 FIG. shows a manufacturing apparatus for the glass substrate G that performs the forming step S1 to the cutting step S4. The manufacturing apparatus 1 mainly includes: a forming furnace 2 that performs the forming step S1; a slow cooling furnace 3 that performs the slow cooling step S2; a cooling zone 4 that performs the cooling step S3; and a cutting device 5 that performs the cutting step S4. In this manufacturing apparatus 1, upper and lower multi-stage roller pairs 6 are respectively arranged in the forming furnace 2, the slow cooling furnace 3, and the cooling zone 4.

[0081] In the internal space of the forming furnace 2, a forming body 7 for forming a glass ribbon Gr from molten glass Gm by the overflow down-draw method is arranged. In the forming step S1, the molten glass Gm supplied to the forming body 7 overflows from a trough portion formed at the top 7a of the forming body 7, and the molten glass Gm flows along both side surfaces 7b of the forming body 7, and these molten glass Gm merge at the lower end of the forming body 7. Thereby, a plate-shaped glass ribbon Gr is continuously formed. Thereafter, the glass ribbon Gr is transported downward by the roller pair 6 in a longitudinal posture (preferably a vertical posture). In this case,Figure 6 The X direction shown in [Figure] becomes the sheet pulling direction.

[0082] Among the side wall portions of the forming furnace 2, the portion facing the molten glass Gm and the glass ribbon Gr flowing along both side surfaces 7b of the formed body 7 (hereinafter referred to as the "opposing portion") is preferably free of joints in the width direction of the glass ribbon Gr and is composed of a single refractory. When the opposing portion is composed of a plurality of refractories divided in the width direction of the glass ribbon Gr, the temperature distribution of the glass ribbon Gr (molten glass Gm) tends to become non-uniform through the joints where the refractories are joined to each other. As a result, at the site where the temperature of the molten glass Gm decreases, a change occurs in the sheet thickness of the glass ribbon Gr, and in the sheet thickness distribution TD of the glass sheet G based thereon, the height (level difference) and inclination of the peak portion or the bevel portion become larger. In contrast, if the opposing portion is free of joints in the width direction of the glass ribbon Gr and is composed of a single refractory, the height (level difference) and inclination of the peak portion and the bevel portion become smaller in the sheet thickness distribution TD of the glass sheet G.

[0083] The internal space of the annealing furnace 3 has a given temperature gradient downward. The temperature gradient of the internal space of the annealing furnace 3 can be adjusted, for example, by a temperature adjusting device such as a heating device provided on the inner surface of the annealing furnace 3. In the annealing step S2, the vertically oriented glass ribbon Gr is conveyed by the roller pair 6 and annealed as it moves downward in the internal space of the annealing furnace 3 so that the temperature becomes lower. Through this annealing step S2, the internal strain of the glass ribbon Gr is reduced.

[0084] In the cooling step S3, the glass ribbon Gr that has passed through the annealing furnace 3 is conveyed downward by the roller pair 6 and passed through the cooling zone 4. Thereby, the glass ribbon Gr is cooled to room temperature.

[0085] As Figure 6 shown, the cutting device 5 is located below the cooling zone 4. In the cutting step S4, the vertically oriented glass ribbon Gr that has passed through the cooling zone 4 is cut in the width direction at every given length by this cutting device 5. Thereby, the glass substrates G can be sequentially cut out from the glass ribbon Gr. Here, the width direction of the glass ribbon Gr is the direction orthogonal to the long side direction (sheet pulling direction X) of the glass ribbon Gr, and is substantially in the horizontal direction in the present embodiment.

[0086] The cutting device 5 includes: a wheel cutter (not shown), which forms a score line S along the width direction of the glass ribbon Gr by traveling on one main surface of the glass ribbon Gr descending from the cooling zone 4; a contact portion 8, which supports from the other main surface side in the region where the score line S is formed; and a holding portion 9, which performs an operation for applying bending stress to the score line S and its vicinity while holding the glass ribbon Gr corresponding to the glass substrate G to be cut out. Figure 6The movement in the A direction in

[0087] In the cutting process S4, the wheel cutter follows the descending glass ribbon Gr and forms a scoring line S over the entire width or a part of the width direction of the glass ribbon Gr. In addition, the scoring line S can also be formed by laser irradiation or the like.

[0088] The contact portion 8 is composed of a plate-like body (flat plate) that follows the descending glass ribbon Gr and has a plane that contacts the entire width or a part of the width direction of the glass ribbon Gr. The contact surface of the contact portion 8 can be a curved surface that is curved in the width direction. The holding portion 9 is composed of chucks that sandwich the side end portions on both sides in the width direction of the glass ribbon Gr from both the front and back. A plurality of holding portions 9 are provided at intervals in the longitudinal direction of the glass ribbon Gr at the side end portions of the glass ribbon Gr. The plurality of holding portions 9 provided at one side end portion are held by all these identical arms (not shown). In addition, similarly, the plurality of holding portions 9 provided at the other side end portion are also held by all these identical arms (not shown).

[0089] If a scoring line S is formed in the glass ribbon Gr, through the movement of each arm, the plurality of holding portions 9 follow the descending glass ribbon Gr and perform an action (action in the A direction) for bending the glass ribbon Gr with the contact portion 8 as a fulcrum. Thereby, bending stress is imparted to the scoring line S and its vicinity, and the glass ribbon Gr is cut in the width direction along the scoring line S. As a result of this cutting, the glass substrate G is cut out from the glass ribbon Gr. After that, the end portions of the glass substrate G corresponding to the end portions (ears) in the width direction of the glass ribbon Gr are cut off. Thereby, a rectangular glass substrate G having four sides Ga to Gd, a first main surface GS1, and a second main surface GS2 is manufactured.

[0090] In the end face processing process S5, grinding and polishing processes are performed on the end faces corresponding to the respective sides Ga to Gd of the glass substrate G. After that, in the cleaning process S6, wiping and cleaning of the respective main surfaces GS1 and GS2 of the glass substrate G are performed using a cleaning tool. Next, rinsing and cleaning of the glass substrate G are performed. After that, the rinsing liquid attached to the glass substrate G is removed by a drying device equipped with an air knife or the like. A roughening process for performing a roughening process on the second main surface GS2 can also be performed as needed.

[0091] In the inspection process S7, the thickness of the glass substrate G is measured. The thickness of the glass substrate G is measured by a laser displacement meter, for example. The thickness distribution is measured at a plurality of positions at 10 mm intervals in the direction Y orthogonal to the plate drawing direction X of the glass substrate G. In addition to this, in the inspection process S7, the presence or absence of defects in the glass substrate G is inspected by a known inspection device.

[0092] In the inspection process S7, based on whether the conditions based on the above formulas (1) to (6) or the conditions based on the above formulas (7) to (9) are satisfied, the degree of wall thickness non-uniformity in the thickness distribution of the glass substrate G, the degree of defects, etc., it is determined whether the glass substrate G as a product is good or not.

[0093] In addition, the present invention is not limited to the structure of the above-described embodiments and is not limited to the above-described effects. The present invention can be variously modified without departing from the gist of the present invention.

[0094] -Symbol Explanation-

[0095] A01, B11 First vertex

[0096] A02, A11 Second vertex

[0097] B01, B12 Third vertex

[0098] C Hypotenuse part

[0099] D Width of the hypotenuse part

[0100] D1 Distance between the first vertex and the second vertex

[0101] D2 Distance between the second vertex and the third vertex

[0102] G Glass substrate

[0103] Ga First side of the glass substrate

[0104] Gb Second side of the glass substrate

[0105] GS1 First main surface of the glass substrate

[0106] GS2 Second main surface of the glass substrate

[0107] H Level difference of the hypotenuse part

[0108] H1 Level difference between the first vertex and the second vertex

[0109] H Two Level difference between the second vertex and the third vertex

[0110] TD Plate thickness distribution

[0111] X Plate drawing direction

[0112] Y Direction orthogonal to the plate drawing direction.

Claims

1. A glass substrate for a display, having: A first side along the plate drawing direction; A second side along a direction orthogonal to the plate drawing direction; A first main surface; and A second main surface located on the opposite side of the first main surface in the thickness direction, The glass substrate for a display is characterized in that When measuring the plate thickness distribution along a direction orthogonal to the plate drawing direction, the plate thickness distribution includes a first vertex, a second vertex adjacent to the first vertex, and a third vertex adjacent to the second vertex, Let the height difference between the first vertex and the second vertex be H1, the height difference between the second vertex and the third vertex be H2, the distance between the first vertex and the second vertex in the direction orthogonal to the plate drawing direction be D1, and the distance between the second vertex and the third vertex in the direction orthogonal to the plate drawing direction be D2, where the units of H1, H2, D1, and D2 are mm. At this time, The H1 and the D1 satisfy the following formula (1) and the following formula (3) and the H2 and the D2 satisfy the following formula (2) and the following formula (5), or The H1 and the D1 satisfy the following formula (1) and the following formula (3) and the H2 satisfies the following formula (6), or The H1 satisfies the following formula (4) and the H2 and the D2 satisfy the following formula (2) and the following formula (5), (H1 / D1) ≤ 1×10 -4 ··· (1) (H2 / D2) ≤ 1×10 -4 ··· (2) H1>0.005 ···（3） H1≤0.005 ···（4） H2>0.005 ···（5） H2≤0.005 ···（6）。 2. A glass substrate for a display, having: A first side along the plate drawing direction; A second side along a direction orthogonal to the plate drawing direction; A first main surface; and A second main surface located on the opposite side of the first main surface in the thickness direction, The glass substrate for a display is characterized in that When measuring the plate thickness distribution along a direction orthogonal to the plate drawing direction, the plate thickness distribution includes a beveled edge portion having a height difference and a width, Let the height difference of the beveled edge portion be H and the width of the beveled edge portion be D, where the units of H and D are mm. At this time, The H and the D satisfy the following formula (7) and the following formula (8), (H / D) ≤ 1×10 -4 ··· (7) H>0.005 ···（8）。 3. The glass substrate for a display according to claim 1 or 2, characterized in that The glass substrate for a display is a glass substrate for an organic EL display.

4. The glass substrate for a display according to claim 1 or 2, characterized in that The difference between the maximum value and the minimum value of the plate thickness is 6 μm or more.

5. The glass substrate for a display according to claim 1 or 2, characterized in that The first main surface and the second main surface are flame-polished surfaces.

6. The glass substrate for a display according to claim 1 or 2, characterized in that The first main surface is a flame-polished surface and the second main surface is an etched surface.

7. The glass substrate for a display according to claim 1 or 2, characterized in that The size of the first side is 1200 mm or more, the size of the second side is 1200 mm or more, and the plate thickness is 0.2 - 1.3 mm.

Images