TW202220936A - Glass substrate for display - Google Patents

Abstract

In the present invention, when a sheet thickness distribution TD for a first main surface GS1 is measured in a direction Y perpendicular to a sheet drawing direction X, and where H1 is the difference in height between a first high point A01 and a second high point B01 in the sheet thickness distribution TD for the first main surface GS1, H2 is the difference in height between the second high point B01 and a third high point A02, D1 is the distance between the first high point A01 and the second high point B01 in the direction Y perpendicular to the sheet drawing direction X, and D2 is the distance between the second high point B01 and the third high point A02 in the direction Y perpendicular to the sheet drawing direction X, the height differences (H1, H2) are less than or equal to 0.005 mm, or the slopes (H1/D1, H2/D2) are less than or equal to 1*10<SP>-4</SP> if the height differences (H1, H2) exceed 0.005 mm.

Description

Glass substrate for display

The present invention relates to a glass substrate used in displays such as organic electroluminescence (Electroluminescence, EL) displays.

As is well known, in displays such as organic EL displays and liquid crystal displays, glass substrates are used in order to form elements or structures such as fine electrodes and partition walls. After uniformly coating various films on the surface of the glass substrate, a thin film transistor (TFT; Thin Film Transistor) is formed using an optical process method (exposure step, development step, etc.).

For example, Patent Document 1 discloses a glass substrate for a TFT which is formed in a rectangular shape, includes a first main surface, a second main surface facing the first main surface, and has first adjacent to each other. The length of the side and the second side, and the length of the first side and the second side shall be at least 1200 mm.

In this glass substrate, in the cross section in the plate thickness direction, in the first cross section along the straight line parallel to the first side, the difference between the maximum value of the plate thickness and the minimum value of the plate thickness, that is, the plate thickness tolerance It is set to be smaller than 6.26 μm (refer to claim 1 of this document, paragraph 0006). [Prior Art Literature] [Patent Literature]

Patent Document 1: Japanese Patent Laid-Open No. 2019-34878

[The problem to be solved by the invention] When the glass substrate for liquid crystal displays has a portion where the thickness becomes non-uniform (thickness uneven portion), it is difficult to form a TFT with high accuracy. Therefore, like the glass substrate of Patent Document 1, it is effective to limit the thickness tolerance in order to form the TFT with high accuracy.

In the manufacturing process of an organic EL display, the external appearance inspection (macro inspection) which detects the unevenness of the thin film formed on the glass substrate was implemented. In this appearance inspection, for example, light is irradiated to a glass substrate from a light source, and the reflected light is detected. When unevenness occurs, for example, the direction of the reflected light at that portion changes locally, so that the gradation changes. In such a macro-inspection, even if it is a glass substrate for which the plate|board thickness tolerance is limited like patent document 1, the state which detects abnormal external appearance arises. When unevenness of the thin film occurs, the glass substrate is discarded as poor quality.

This invention was made in view of the said situation, and it aims at providing the glass substrate for displays which can suppress the unevenness of the thin film formed on the glass substrate. [Means of Solving Problems]

The present invention was made in order to solve the above-mentioned problems, and is a glass substrate for a display having a first side along a direction in which the plate is stretched and a direction perpendicular to the direction in which the plate is stretched The second side in the direction, the first main surface, and the second main surface located on the opposite side of the first main surface in the thickness direction, and the glass substrate for a display is characterized in that it is drawn along the When the thickness distribution is measured in a direction orthogonal to the extending direction, the thickness distribution includes a first vertex, a second vertex adjacent to the first vertex, and a third vertex adjacent to the second vertex , where the height difference between the first vertex and the second vertex is set as H1 (mm), the height difference between the second vertex and the third vertex is set as H2 (mm), and the height difference between the second vertex and the third vertex is set as H2 (mm). The distance between the first vertex and the second vertex in the direction orthogonal to the board stretching direction is set to D1 (mm), and the second vertex in the direction orthogonal to the board stretching direction is set as D1 (mm). When the distance from the third vertex is D2 (mm), the H1 and the D1 fully satisfy the following formula (1) and the following formula (3), or the following formula (4), so The above H2 and the above D2 sufficiently satisfy the following formula (2) and the following formula (5), or sufficiently satisfy the following formula (6). (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)

The inventors of the present invention have repeatedly studied and found that when a thin film is formed on the first main surface of a glass substrate, the inconsistency of the thin film is likely to occur at a portion with a high mountain portion and a large inclination included in the plate thickness distribution. all. In addition, it was found that the unevenness of the thin film is likely to occur in the portion where the valley portion included in the plate thickness distribution is deep and the inclination is large. That is, it was found that the unevenness of the thin film is likely to occur at the site where the height difference (H1, H2) and the inclination (H1/D1, H2/D2) are large. In the present invention, by reducing the height difference (H1, H2) in the plate thickness distribution, or reducing the inclination (H1/D1, H2/D2) when the height difference (H1, H2) is large, It is possible to prevent the occurrence of unevenness of the film and the occurrence of poor quality associated therewith.

The present invention was made in order to solve the above-mentioned problems, and is a glass substrate for a display having a first side along a direction in which the plate is stretched and a direction perpendicular to the direction in which the plate is stretched The second side in the direction, the first main surface, and the second main surface located on the opposite side of the first main surface in the thickness direction, and the glass substrate for a display is characterized in that it is drawn along the When the plate thickness distribution is measured in a direction orthogonal to the extending direction, the plate thickness distribution includes a hypotenuse portion having a height difference and a width, and the height difference of the hypotenuse portion is set to H (mm) and the When the width of the hypotenuse portion is D (mm), the H and the D sufficiently satisfy the following formula (7) and the following formula (8), or sufficiently satisfy the following formula (9). (H/D)≦1× ^10-4・・(7) H＞0.005・・(8) H≦0.005・・(9)

The inventors of the present invention found that, as described above, by reducing the height difference (H) of the hypotenuse part included in the plate thickness distribution, or by reducing the inclination (H/D) when the height difference (H) is large ), which can prevent the occurrence of film unevenness and the accompanying quality defect.

The glass substrate for displays of this invention may be a glass substrate for organic EL displays.

The difference between the maximum value and the minimum value of the thickness of the glass substrate for a display of the present invention may be 6 μm or more. By reducing the thickness tolerance, the degree of thickness variation in the glass substrate can be reduced, and the degree of height difference or inclination of the mountain portion and the hypotenuse 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 production cost of the glass substrate can be suppressed, and the occurrence of the unevenness of the thin film and the occurrence of the quality defect accompanying it can be prevented.

The said 1st main surface and the said 2nd main surface in the glass substrate for a display may be a forging surface. Alternatively, the first major surface may be a forged surface, and the second major surface may be an etched surface.

Regarding the glass substrate for a display of 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 thickness may be 0.2 mm to 1.3 mm. [Effect of invention]

According to the present invention, the unevenness of the thin film formed on the glass substrate can be suppressed.

Hereinafter, the form for implementing this invention is demonstrated, referring drawings. 1 to 6 show one embodiment of the glass substrate for a display and its manufacturing method of the present invention. In this embodiment, although the glass substrate for organic electroluminescent displays was illustrated as a glass substrate, it is not limited to this, You may apply this invention to the glass substrate for liquid crystal displays and other various displays.

As shown in FIG. 1, the glass substrate G is comprised, for example in a rectangular shape (rectangular shape). The glass substrate G has a first side Ga along the sheet stretching direction X, a second side Gb along the direction Y orthogonal to the sheet stretching 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 this 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.

In addition, the "plate stretching direction" refers to the direction in which the plate stretching is performed when the glass substrate G is formed. Regarding the plate stretching direction X of the glass substrate G, for example, by adjusting the angle of the glass substrate G in a dark room, irradiating light from a light source (for example, a xenon lamp), and projecting the transmitted light on a screen, it can be used as a striped stripe Observed with patterns. Therefore, even if it is the state of the glass substrate G after shaping|molding, the board stretching direction X at the time of shaping|molding can be determined.

In addition, "along the plate stretching direction" means not only a case where the plate stretching direction X is geometrically parallel, but also a direction considered to be substantially parallel. In addition, "along the direction orthogonal to the board stretching direction" means not only a direction that is geometrically orthogonal to the board stretching direction X, but also a direction considered to be substantially orthogonal.

The glass substrate G has a first main surface GS1 and a second main surface GS2 located on the opposite side of the first main surface GS1 in the thickness direction. In this embodiment, the first main surface GS1 is a guaranteed surface, and the second main surface GS2 is a non-guaranteed surface. Here, the "guarantee surface" refers to, for example, the surface on the side where the thin film is formed in the manufacturing process of the display.

The first main surface GS1 and the second main surface GS2 in the glass substrate G are preferably forged surfaces. Here, the "forged surface" refers to a surface formed in a non-contact state without being in contact with a forming device or the like. Although this forged surface is not ground, it has excellent surface properties.

Not limited to this structure, regarding the glass substrate G, the first main surface GS1 may be the forging surface, and the second main surface GS2 may be the etching surface. Here, the "etched surface" refers to a surface to which a roughening process has been performed. The method of the roughening treatment is not particularly limited, and examples thereof include chemical polishing such as etching, mechanical polishing such as tape polishing, brush polishing, and abrasive grain polishing, chemical mechanical polishing (CMP), and the like. Such an etched surface reduces the generation of static electricity. Therefore, for example, when the glass substrate placed on the support table is lifted, the glass substrate can be prevented from being damaged by sticking to the support table due to static electricity.

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 still more 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 the manufacturing cost, the preferable lower limits of the difference between the maximum value and the minimum thickness of the glass substrate G (plate thickness tolerance) are 3 μm or more, 4 μm or more, 5 μm or more, 6 μm or more, 7 μm or more, especially 7.5 μm or more. On the other hand, from the viewpoint of uniformly maintaining the cell gap of the liquid crystal display, the plate thickness tolerance is preferably 20 μm or less, and more preferably 15 μm or less.

As the glass substrate G, for example, silicate glass and silica glass are used, and borosilicate glass, soda lime glass, aluminosilicate glass, chemically strengthened glass, and alkali-free glass are preferably used. Here, the so-called alkali-free glass is a glass that does not substantially contain an alkali component (alkali metal oxide), specifically, a glass whose weight ratio of the alkali component is 3000 ppm or less. The weight ratio of the alkali component in the present invention is preferably 1000 ppm or less, more preferably 500 ppm or less, and most preferably 300 ppm or less.

As shown in FIG. 1 , the thickness distribution (plate thickness) of the first main surface GS1 of the glass substrate G is measured along a planned measurement line ML set substantially parallel to the direction Y perpendicular to the plate stretching direction X. distribution curve). The measurement of the plate thickness distribution was performed along the measurement planned line ML at a pitch of 10 mm by a laser displacement meter. The laser displacement meter measures the distance (plate thickness) of the 1st main surface GS1 and the 2nd main surface GS2 in the thickness direction of the glass substrate G. The measured plate thickness distribution includes valley parts and/or mountain parts.

FIG. 2 shows valleys included in the thickness distribution of the first main surface GS1 of the glass substrate G. FIG. 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 inclinations of the first vertex A01 , the second vertex B01 , and the third vertex A02 are all 0 (zero), and constitute a valley.

Furthermore, the plate thickness distribution TD includes a first hypotenuse portion C01 between the first vertex A01 and the second vertex B01, and a second hypotenuse portion C02 between the second vertex B01 and the third vertex A02.

The first hypotenuse portion C01 has a first height difference H1 and a first width D1. The first height difference H1 of the first hypotenuse portion C01 is the difference between the heights of the first vertex A01 and the second vertex B01. The first width D1 of the first hypotenuse portion C01 is the distance between the first vertex A01 and the second vertex B01 in the direction Y orthogonal to the board stretching direction X.

The second hypotenuse portion C02 has a second height difference H2 and a second width D2. The second height difference H2 of the second hypotenuse portion C02 is the height difference between the second vertex B01 and the third vertex A02. The second width D2 of the second hypotenuse portion C02 is the distance between the second vertex B01 and the third vertex A02 in the direction Y orthogonal to the board stretching direction X.

FIG. 3 shows a mountain portion included in the plate thickness distribution of the first main surface GS1 of the glass substrate G. As shown in FIG. 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 inclinations of the first vertex B11 , the second vertex A11 , and the third vertex B12 are all 0 (zero), and constitute a mountain portion.

Furthermore, the plate thickness distribution TD includes a first hypotenuse portion C11 located between the first vertex B11 and the second vertex A11, and a second hypotenuse portion C12 located between the second vertex A11 and the third vertex B12.

The first hypotenuse portion C11 has a first height difference H1 and a first width D1. The first height difference H1 of the first hypotenuse portion C11 is the difference between the heights of the first vertex B11 and the second vertex A11. The first width D1 of the first hypotenuse portion C11 is the distance between the first vertex B11 and the second vertex A11 in the direction Y orthogonal to the board stretching direction X.

The second hypotenuse portion C12 has a second height difference H2 and a second width D2. The second height difference H2 of the second hypotenuse portion C12 is the height difference between the second vertex A11 and the third vertex B12. The second width D2 of the second hypotenuse portion C12 is the distance between the second vertex A11 and the third vertex B12 in the direction Y orthogonal to the board stretching direction X.

When there are peaks and/or valleys in the plate thickness distribution TD, the first height difference H1 (mm) and the first width D1 (mm) fully satisfy the following formula (1) and the following formula (3) , or fully satisfy the following formula (4). In addition, the second height difference H2 (mm) and the second width D2 (mm) sufficiently satisfy the following formula (2) and the following formula (5), or sufficiently satisfy the following formula (6).

(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)

When there are a plurality of peaks or valleys in the plate thickness distribution TD, all the peaks and valleys fully satisfy the conditions based on the above-mentioned expressions (1) to (6). In other words, in the case where the height difference (H1, H2) in the plate thickness distribution TD is greater than 0.005 mm, there is no mountain portion having a hypotenuse portion with an inclination (H1/D1, H2/D2) greater than 1×10 ⁻⁴ and Valley.

The inventors of the present invention have repeatedly made intensive studies, and as a result, found that when a thin film is formed on the first main surface GS1 of the glass substrate G, a thin film is likely to be generated in a portion with a high mountain portion and a large slope included in the plate thickness distribution. of unevenness. In addition, it was found that the unevenness of the thin film is likely to occur in the portion where the valley portion included in the plate thickness distribution is deep and the inclination is large. That is, it was found that the unevenness of the thin film is likely to occur at the site where the height difference (H1, H2) and the inclination (H1/D1, H2/D2) are large. That is, by reducing the height difference (H1, H2) in the plate thickness distribution TD, or reducing the inclination (H1/D1, H2/D2) when the height difference (H1, H2) is large, it is possible to The occurrence of film unevenness and the accompanying quality defect are prevented.

FIG. 4 shows another example of the plate thickness distribution of the first main surface GS1 of the glass substrate G. As shown in FIG. As shown in FIG. 3 , the plate thickness distribution TD has a hypotenuse portion C inclined with respect to the measurement direction (direction orthogonal to the plate stretching direction) Y. The hypotenuse portion C has a height difference H and a width D.

When there is a hypotenuse portion C in the plate thickness distribution TD, the height difference H (mm) and the width D (mm) of the hypotenuse portion C fully satisfy the following formula (7) and the following formula (8), or The following formula (9) is sufficiently satisfied.

(H/D)≦1× ^10-4・・(7) H＞0.005・・(8) H≦0.005・・(9)

When there are a plurality of hypotenuse portions C in the plate thickness distribution TD, all the hypotenuse portions C fully satisfy the conditions based on the above-mentioned formulae (7) to (9). In other words, when the height difference H in the plate thickness distribution TD is larger than 0.005 mm, there is no oblique side portion with an inclination H/D larger than 1×10 ⁻⁴ .

The present inventors found that when a thin film is formed on the first main surface GS1 of the glass substrate G, when the height difference and inclination of the hypotenuse portion C existing in the plate thickness distribution TD are large, the unevenness of the thin film is likely to occur. That is, by reducing the height difference H of the hypotenuse portion C, or by reducing the inclination (H/D) when the height difference H is large, it is possible to prevent the occurrence of unevenness of the film and the accompanying quality defect. produce.

Here, the following Table 1 shows the inclination and the level difference of the oblique side part included in the plate thickness distribution, and the occurrence situation of the unevenness of the thin film in this part.

[Table 1] mark The inclination of the hypotenuse Height difference of the hypotenuse (mm) film unevenness No.1 0.8× ^10-4 0.006 none No.2 1.2× ^10-4 0.006 Have No.3 1.2× ^10-4 0.004 none

In both No. 1 and No. 2, the height difference (H) of the hypotenuse portion exceeded 0.005 mm. In No. 1, the inclination (H/D) was 1×10 ⁻⁴ or less, and as a result, no unevenness of the film occurred, whereas in No. 2, the inclination (H/D) exceeded 1×10 ^{− 4} , resulting in unevenness of the film. That is, it was confirmed that the unevenness of the film can be suppressed if the inclination (H/D) is 1×10 ⁻⁴ or less even if there is a level difference in the oblique side portion.

In both No. 2 and No. 3, the inclination of the hypotenuse portion exceeded 1×10 ^-4 . In No. 3, the height difference (H) was 0.005 mm or less, and as a result, film unevenness did not occur, whereas in No. 2, the height difference (H) exceeded 0.005 mm, and film unevenness occurred. That is, it was confirmed that even if the oblique portion has an inclination, if the height difference (H) is 0.005 mm or less, the unevenness of the film can be suppressed.

From the viewpoint of further reducing the unevenness of the film and forming a uniform film, the inclination (H1/D1, H2/D2, H/D) when the height difference (H1, H2, H) is larger than 0.005 mm is preferably 0.5 ×10 ^-4 or less. In addition, when the height difference (H1, H2, H) is larger than 0.005 mm, the height difference (H1, H2, H) is preferably 0.02 mm or less. On the other hand, the inclination (H1/D1, H2/D2, H/D) is preferably 0.05×10 ⁻⁴ or more from the viewpoint of suppressing an increase in manufacturing cost associated with decreasing the inclination.

The glass substrate G is manufactured by a well-known molding method, such as a down-draw method, such as an overflow down-draw method, a slot down-draw method, or a float method. In this embodiment, the case where the glass substrate G is manufactured by the overflow down-draw method is illustrated.

Hereinafter, the method of manufacturing the glass substrate G of the said structure is demonstrated. As shown in FIG. 5 , the method mainly includes forming step S1 , slow cooling step S2 , cooling step S3 , cutting step S4 , end face processing step S5 , cleaning step S6 , and inspection step S7 .

FIG. 6 : has shown the manufacturing apparatus of the glass substrate G performed from the shaping|molding process S1 to the cutting process S4. The manufacturing apparatus 1 mainly includes the forming furnace 2 that performs the forming step S1 , the slow cooling furnace 3 that performs the slow cooling step S2 , the cooling zone 4 that performs the cooling step S3 , and the cutting device 5 that performs the cutting step S4 . In this manufacturing apparatus 1, the roll pair 6 of the upper and lower multistages is arrange|positioned in the shaping|molding furnace 2, the slow cooling furnace 3, and the cooling zone 4, respectively.

In the inner space of the forming furnace 2, a forming body 7 is arranged, and the forming body 7 forms the glass ribbon Gr from the molten glass Gm by the overflow down-draw method. In the molding step S1, the molten glass Gm supplied to the molded body 7 is made to overflow from the groove portion formed in the top portion 7a of the molded body 7, and the molten glass Gm is caused to flow along the both side surfaces 7b of the molded body 7, and the molten glass Gm flows in the molded body 7. The lower end of the molten glass Gm joins. Thereby, the plate-shaped glass ribbon Gr is continuously formed. Then, the glass ribbon Gr is conveyed downward in a vertical posture (preferably a vertical posture) by the roller pair 6 . In this case, the X direction shown in FIG. 6 becomes the plate stretching direction.

In the side wall portion of the forming furnace 2, the portion facing the molten glass Gm and the glass ribbon Gr flowing along the both side surfaces 7b of the forming body 7 (hereinafter referred to as "opposing portion") is preferably in the width direction of the glass ribbon Gr. It does not have a joint, but is composed of a single refractory. When the opposing portion is constituted by 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 poor due to the junction where the refractories are joined to each other. evenly. As a result, the plate thickness of the glass ribbon Gr changes at the place where the temperature drop of the molten glass Gm occurs, and in the plate thickness distribution TD of the glass substrate G formed by this, the height (difference in height) of the mountain portion or the oblique portion is and the inclination increases. On the other hand, if the opposing portion does not have a junction in the width direction of the glass ribbon Gr, but is formed of a single refractory material, in the thickness distribution TD of the glass substrate G, the heights (height and low) of the mountain portion and the oblique portion will be poor) and the inclination becomes smaller.

The inner space of the slow cooling furnace 3 has a predetermined temperature gradient downward. The temperature gradient of the inner space of the slow cooling furnace 3 can be adjusted by a temperature adjusting device, such as a heating apparatus provided in the inner surface of the slow cooling furnace 3, for example. In the slow cooling step S2, the glass ribbon Gr of the vertical orientation is conveyed by the roll pair 6, and is slow-cooled so that the temperature may become lower as it moves downward in the inner space of the slow-cooling furnace 3. By this slow cooling step S2, the internal strain of the glass ribbon Gr is reduced.

In cooling process S3, the glass ribbon Gr which passed through the slow cooling furnace 3 is conveyed downward by the roll pair 6, and it is made to pass through the cooling zone 4. Thereby, the glass ribbon Gr was cooled to room temperature.

As shown in FIG. 6 , the cutting device 5 is located below the cooling zone 4 . In the cutting step S4, the glass ribbon Gr passing through the vertical orientation of the cooling zone 4 is cut in the width direction at every predetermined length by the cutting device 5. As shown in FIG. Thereby, the glass substrate G can be cut out sequentially from the glass ribbon Gr. Here, the width direction of the glass ribbon Gr is a direction orthogonal to the longitudinal direction (plate stretching direction X) of the glass ribbon Gr, and in this embodiment, it substantially corresponds to the horizontal direction.

The cutting device 5 includes: a wheel cutter (not shown), which forms a scribe line along the width direction of the glass ribbon Gr by traveling on one of the main surfaces of the glass ribbon Gr descended from the cooling zone 4 S; the contact part 8 is supported from the other main surface side in the region where the scribe line S is formed; An operation for applying a bending stress to the scribe line S and its vicinity (operation in the direction A in FIG. 6 ) is performed.

In the cutting step S4, the wheel cutter descends following the glass ribbon Gr in the descending process, and forms a scribe line S in the entire area or a part of the area in the width direction of the glass ribbon Gr. In addition, the scribe line S may be formed by irradiation of a laser or the like.

The contact portion 8 includes a plate-shaped body (platen) having a flat surface that descends following the glass ribbon Gr in the process of descending and is in contact with the entire area or a part of the area in the width direction of the glass ribbon Gr. The contact surface of the contact portion 8 may be a curved surface curved in the width direction. The holding portion 9 includes a chuck that sandwiches side end portions on both sides in the width direction of the glass ribbon Gr from both sides of the front and back. A plurality of holding parts 9 are provided at intervals in the longitudinal direction of the glass ribbon Gr at each side end of the glass ribbon Gr. All of the plurality of holding portions 9 provided at one of the side end portions are held by the same arm (not shown). Moreover, similarly, the some holding part 9 provided in the other side edge part is also hold|maintained by the same arm (illustration omitted).

When the scribe line S is formed on the glass ribbon Gr, the plurality of holding parts 9 follow the glass ribbon Gr in the process of descending and descend by the operation of each arm, and perform a bending process for bending the glass ribbon Gr with the contact part 8 as a fulcrum. Action (action in direction A). Thereby, bending stress is given to the scribe line S and its vicinity, and the glass ribbon Gr is cut|disconnected in the width direction along the scribe line S. As a result of this cutting, the glass substrate G is cut out from the glass ribbon Gr. Then, the edge part of the glass substrate G corresponding to the edge part (ear part) in the width direction of the glass ribbon Gr is cut off. Thereby, the rectangular glass substrate G which has four sides Ga-Gd, 1st main surface GS1, and 2nd main surface GS2 is manufactured.

In the end surface processing step S5 , the end surfaces corresponding to the respective sides Ga to Gd of the glass substrate G are ground and polished. Then, in cleaning step S6, wiping cleaning of each main surface GS1 and GS2 is performed on the glass substrate G with a cleaning tool. Next, the glass substrate G is rinsed and washed. Then, the rinsing liquid adhering to the glass substrate G is removed by a drying apparatus including an air knife or the like. A roughening step of roughening the second main surface GS2 may be performed as needed.

In inspection step S7, the measurement of the plate thickness of the glass substrate G is performed. The plate thickness of the glass substrate G is measured by, for example, a laser displacement meter. The plate thickness distribution was measured at a plurality of locations along the direction Y orthogonal to the plate stretching direction X of the glass substrate G at a pitch of 10 mm. In addition, in inspection step S7, the presence or absence of a defect etc. in the glass substrate G is inspected by a well-known inspection apparatus.

In the inspection step S7, the thickness variation in the thickness distribution of the glass substrate G is determined according to whether the conditions based on the above-mentioned formulae (1) to (6) or the conditions based on the above-mentioned formulae (7) to (9) are sufficiently satisfied. The degree and the degree of defect, etc., judge the quality of the glass substrate G as a product.

In addition, this invention is not limited to the structure of the said embodiment, nor is it limited to the said effect. In the present invention, various modifications can be made without departing from the gist of the present invention.

1: Manufacturing device 2: Forming furnace 3: Slow cooling furnace 4: Cooling zone 5: cutting device 6: Roll pair 7: Formed body 7a: Top 7b: Both sides 8: Contact part 9: Keeping Department A: Direction A01, B11: The first vertex A02, A11: The second vertex B01, B12: The third vertex C: hypotenuse C01, C11: the first hypotenuse C02, C12: The second hypotenuse D: width/width of the hypotenuse D1: the distance between the first vertex and the second vertex/the first width D2: the distance between the second vertex and the third vertex/the second width G: glass substrate Ga: first side/first side/side of glass substrate Gb: second side/second side/side of glass substrate Gc: third side/third side/side of glass substrate Gd: Fourth side/fourth side/side of glass substrate Gr: Glass Ribbon Gm: molten glass GS1: First main surface of glass substrate/first main surface/main surface GS2: Second Main Surface of Glass Substrate/Second Main Surface/Main Surface H: The height difference/height difference of the hypotenuse H1: The height difference between the first vertex and the second vertex/height difference/first height difference H2: The height difference between the second vertex and the third vertex/height difference/second height difference ML: Determination of predetermined line TD: Plate Thickness Distribution X: Board stretch direction/direction Y: direction/direction orthogonal to the direction of sheet stretching S: dash S1: Forming step S2: Slow cooling step S3: Cooling step S4: Cut off step S5: end face processing steps S6: Cleaning step S7: Check Steps

FIG. 1 is a perspective view of a glass substrate for a display. FIG. 2 is a graph showing the thickness distribution of the glass substrate for a display. FIG. 3 is a graph showing the thickness distribution of the glass substrate for a display. FIG. 4 is a graph showing the thickness distribution of the glass substrate for a display. It is a flowchart which shows the manufacturing method of the glass substrate for displays. It is a side view which shows the manufacturing apparatus of the glass substrate for displays.

G: glass substrate

Ga: first side/first side/side of glass substrate

Gb: second side/second side/side of glass substrate

Gc: third side/third side/side of glass substrate

Gd: Fourth side/fourth side/side of glass substrate

GS1: First main surface of glass substrate/first main surface/main surface

GS2: Second Main Surface of Glass Substrate/Second Main Surface/Main Surface

ML: Determination of predetermined line

X: Board stretch direction/direction

Y: direction/direction orthogonal to the direction of sheet stretching

Claims (7)

A glass substrate for a display comprising: a first side along a sheet stretching direction, a second side along a direction orthogonal to the sheet stretching direction, a first main surface, and a The second main surface on the opposite side of the first main surface, the glass substrate for a display, when the plate thickness distribution is measured in a direction orthogonal to the plate stretching direction, the plate thickness distribution It includes a first vertex, a second vertex adjacent to the first vertex, and a third vertex adjacent to the second vertex, where the height difference between the first vertex and the second vertex is set as H1 (mm), the height difference between the second vertex and the third vertex is H2 (mm), and the first vertex and the When the distance between the two vertices is D1 (mm), and the distance between the second vertex and the third vertex in the direction orthogonal to the plate stretching direction is D2 (mm), the H1 And the said D1 fully satisfies the following formula (1) and the following formula (3), or fully satisfies the following formula (4), the said H2 and the said D2 fully satisfy the following formula (2) and the following formula ( 5), or fully satisfy the following formula (6): (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). A glass substrate for a display comprising: a first side along a sheet stretching direction, a second side along a direction orthogonal to the sheet stretching direction, a first main surface, and a The second main surface on the opposite side of the first main surface, the glass substrate for a display, when the plate thickness distribution is measured in a direction orthogonal to the plate stretching direction, the plate thickness distribution A hypotenuse portion having a height difference and a width is included, and when the height difference of the hypotenuse portion is H (mm) and the width of the hypotenuse portion is D (mm), the H and the above-mentioned D sufficiently satisfy the following formula (7) and the following formula (8), or sufficiently satisfy the following formula (9): (H/D)≦1×10 ⁻⁴ (7) H> 0.005...(8) H≦0.005...(9). The glass substrate for a display according to claim 1 or claim 2, which is a glass substrate for an organic electroluminescence display. The glass substrate for a display according to any one of Claims 1 to 3, wherein the difference between the maximum value and the minimum value of the plate thickness is 6 μm or more. The glass substrate for a display according to any one of Claims 1 to 4, wherein the first main surface and the second main surface are forged surfaces. The glass substrate for a display according to any one of Claims 1 to 4, wherein the first main surface is a forged surface, and the second main surface is an etched surface. The glass substrate for a display according to any one of claim 1 to claim 6, wherein 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 mm ~1.3 mm.

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