JP2018109239A - Device manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device manufacturing method capable of applying uniform film deposition treatment to plural glass substrates by restraining variation of flexion of the plural glass substrates.SOLUTION: In a step, plural rectangular glass substrates 3 is made to a reference posture at which they are arranged almost in parallel to a vertical plane and at equal intervals, and reactive gas flows between the respective glass substrates 3 to apply film deposition treatment. Variation of the flexion of the plural glass substrates 3 at an inclined posture at which the glass substrate is inclined on the basis of the reference posture is a numerical value found by normalizing a standard deviation of the flexion of the plural glass substrates 3 at the inclined posture. A standard deviation σ is normalized by Nσ=σ×K and K=t/L, and the normalized standard deviation Nσ is 0.08×10or more and 0.2×10or less. Here, t is a thickness of the glass substrate 3, and L is a length of one side of the glass substrate 3.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a glass substrate group including a plurality of glass substrates and a glass substrate manufacturing method.

  Conventionally, a technique for efficiently processing a plurality of glass substrates simultaneously has been developed. In Patent Document 1, a plurality of glass substrates can be simultaneously formed on a plurality of glass substrates by arranging and storing them in a heating furnace in a substantially upright posture. Moreover, in patent document 1, the amount of reactive gas can be changed by changing the space | interval between glass substrates.

JP 2012-244032 A

  In the heating furnace, each glass substrate includes, for example, gravity due to slight inclination of the glass substrate, thermal stress due to temperature distribution in the glass substrate, and a film generated in the film formed on the glass substrate. External force such as stress acts. As a result, bending occurs in each glass substrate. That is, when the main surface of the glass substrate receives an external force, the glass substrate is deformed into a bow shape. As a result, in the heating furnace, each glass substrate is subjected to heat treatment while the main surfaces of each glass substrate are exposed to the reactive gas in a state where each glass substrate is bent.

  Therefore, during the heat treatment of each glass substrate, if there is a large variation in deflection among a plurality of glass substrates, the spacing between adjacent glass substrates may vary, and the amount of reactive gas flowing between the glass substrates may become uneven. It was. As a result, the film quality becomes inhomogeneous between the plurality of glass substrates, and the quality of the glass substrate after film formation may vary. In addition, the film quality may be inhomogeneous within the main surface of each glass substrate.

  As described above, if the variation in the deflection of the plurality of glass substrates is large, uniform processing becomes difficult even between the plurality of glass substrates and within each glass substrate. As a result, a large variation in the deflection of the plurality of glass substrates causes a reduction in quality of the final product using each glass substrate. In addition, as a final product, a display device and other electric and electronic devices are assumed.

  The present invention has been made in view of the above problems, and an object of the present invention is to make it possible to perform uniform processing on a plurality of glass substrates by suppressing variations in the deflection of the plurality of glass substrates. It is providing the board | substrate group and the glass substrate manufacturing method.

  The glass substrate group according to the first aspect of the present invention includes a plurality of glass substrates that are processed in a state of being arranged in a reference posture. The variation in the bending of the plurality of glass substrates in the tilted posture tilted based on the reference posture is within a predetermined range.

  In the glass substrate group, the variation in the deflection of the plurality of glass substrates is preferably a numerical value obtained by normalizing the standard deviation of the deflection of the plurality of glass substrates in the inclined posture.

  In this glass substrate group, the glass substrate is preferably rectangular, and the standard deviation is preferably normalized by equations (1) and (2).

Nσ = σ × K (1)
K = t ² / L ⁴ (2)

  Nσ is a normalized standard deviation. σ is the standard deviation of the amount of deflection of the plurality of glass substrates. t is the thickness of the glass substrate. L is the length of one side of the glass substrate.

  In this glass substrate group, it is preferable that the normalized standard deviation Nσ is 0.2 × 10 −12 or less.

  The said glass substrate group WHEREIN: It is preferable that the said inclination attitude | position is an attitude | position from which the angle which the main surface of the said glass substrate and a perpendicular line form becomes larger than 0 degree | times and below 10 degree | times.

  In the glass substrate group, the main surface of the glass substrate preferably includes a first main surface and a second main surface facing each other. It is preferable that the variation of the deflection of the plurality of glass substrates in a posture in which the first main surface is directed obliquely upward is within the predetermined range. The plurality of glass substrates are preferably arranged or laminated such that the first main surface of the glass substrate and the second main surface of the glass substrate arranged next to the glass substrate are opposed to each other. .

  In the glass substrate group, it is preferable that the plurality of glass substrates be arranged or laminated so that an action direction of an external force acting on the glass substrate in the processing is opposed to the first main surface.

  In the glass substrate group, the main surface of the glass substrate preferably includes a first main surface and a second main surface facing each other. The variation of the bending of the plurality of glass substrates in a posture in which the first main surface faces obliquely upward, and the variation of the bending of the plurality of glass substrates in a posture in which the second main surface faces obliquely upward. Is preferably within the predetermined range.

  In the glass substrate group, the reference posture is preferably a posture in which the plurality of glass substrates are arranged so as to be substantially parallel to the vertical plane and equidistant from each other.

  The glass substrate manufacturing method by the 2nd viewpoint of this invention manufactures a glass substrate from a glass ribbon. The glass substrate manufacturing method includes a step of forming molten glass into the glass ribbon with a float bath and a direction perpendicular to both side surfaces of the glass ribbon between the downstream side of the float bath and the inside of the slow cooling furnace. And a control step of controlling the temperature of the glass ribbon so that the temperature increases from the central part of the glass ribbon toward the both side surfaces.

  In this glass substrate manufacturing method, the control step is performed from the downstream side of the float bath outlet to the inside of the slow cooling furnace, and the average temperature of the central portion of the glass ribbon is determined by the central portion of the glass ribbon. The process of controlling the temperature of the said center part of the said glass ribbon, the said one end part, and the said other end part so that it may become lower than each of the average temperature of one end part and the other end part among the both ends which pinch | interpose It is preferable to contain.

  In this glass substrate manufacturing method, it is preferable that the one end portion of the glass ribbon includes a first end portion and a second end portion that is farther from the center portion than the first end portion. It is preferable that the other end portion of the glass ribbon includes a third end portion and a fourth end portion separated from the center portion by the third end portion. In the control step, the average temperature of the second end portion is higher than the average temperature of the first end portion and the second end portion between the downstream side of the float bath outlet and the inside of the slow cooling furnace. As described above, between the step of controlling the temperature of the first end and the second end, and between the downstream of the float bath and the inside of the slow cooling furnace, the average temperature of the fourth end is And a step of controlling the temperature of the third end and the fourth end so as to be higher than the average temperature of the third end and the fourth end.

  According to the present invention, it is possible to suppress the variation in the bending of the plurality of glass substrates in the inclined posture close to the reference posture within a predetermined range. Therefore, even when a plurality of glass substrates are arranged in the reference posture and the process is performed, the deflection is uniform, so that the variation in the interval between the adjacent glass substrates can be suppressed, and the plurality of glass substrates arranged in the reference posture can be homogenized. Can be processed. As a result, quality degradation of the final product using each glass substrate can be suppressed. The reference posture is the posture of the glass substrate when processing is performed on a plurality of glass substrates. The tilted posture is a posture in which the glass substrate is tilted based on the reference posture.

It is a perspective view which shows typically the glass substrate group in Embodiment 1 of this invention. (A) It is the perspective view which showed typically the bending measuring apparatus which measures the bending of the glass substrate in Embodiment 1. FIG. (B) It is the side view which showed typically the bending measuring apparatus in Embodiment 1. FIG. It is a flowchart which shows the evaluation method of the bending characteristic in Embodiment 2 of this invention. (A) It is a vertical side view which shows schematic structure of the manufacturing apparatus of the glass substrate group in Embodiment 3 of this invention. (B) It is a top view which shows typically the glass ribbon and heater group of Fig.4 (a). (A) It is a figure which shows typically the temperature distribution along the width direction of the glass ribbon of FIG.4 (b). (B) It is sectional drawing by the Vb-Vb line | wire of FIG.4 (b). 10 is a flowchart illustrating a method for manufacturing a glass substrate group by a manufacturing apparatus according to Embodiment 3. It is explanatory drawing of the temperature control along the width direction of the glass ribbon by the Example of this invention. (A) It is a figure which shows the bending characteristic of the glass substrate group manufactured by the manufacturing method by the Example of this invention. (B) It is a figure which shows the bending characteristic of the glass substrate group manufactured with the general manufacturing method.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof is not repeated.

(Embodiment 1)
[Basic principle]
FIG. 1 is a perspective view schematically showing a glass substrate group 1 in Embodiment 1 of the present invention. The glass substrate group 1 includes a plurality of glass substrates 3. The plurality of glass substrates 3 are processed in a state where they are arranged in a reference posture. The variation in the bending of the plurality of glass substrates 3 in the tilted posture tilted based on the reference posture is within a predetermined range. The reference posture is the posture of the glass substrate 3 when performing processing such as film formation on the plurality of glass substrates 3. The tilted posture is a posture in which the glass substrate 3 is tilted based on the reference posture.

  In the first embodiment, it is possible to suppress the variation in the bending of the plurality of glass substrates 3 in the inclined posture close to the reference posture within a predetermined range. Therefore, even when the plurality of glass substrates 3 are arranged in the reference posture and the processing is performed, the deflection is uniform, so that the variation in the interval between the adjacent glass substrates 3 can be suppressed, and the plurality of glass substrates arranged in the reference posture. 3 can be processed homogeneously. As a result, quality degradation of the final product using each glass substrate 3 can be suppressed.

  The predetermined range is, for example, the usage mode of the glass substrate 3 (for example, the standard posture, the content of processing performed in the standard posture), the application (for example, the type and specification of the final product), and / or the specification (for example, the characteristics). , Material, and size) are set experimentally and / or empirically.

  Hereinafter, in the first embodiment, the variation in the bending of the plurality of glass substrates 3 is indicated by a numerical value obtained by normalizing the standard deviation of the bending of the plurality of glass substrates 3 in the inclined posture. By making the numerical value obtained by normalizing the standard deviation equal to or less than the specified value, the plurality of glass substrates 3 are aligned and are adjacent when the plurality of glass substrates 3 are arranged in the reference posture and processed. The dispersion | variation in the space | interval of the glass substrate 3 is suppressed. The specified value is set experimentally and / or empirically in consideration of the usage mode, application, and / or specifications of the glass substrate 3 as in the predetermined range, for example.

  In the following description, unless otherwise specified, the reference posture is a posture in which the plurality of glass substrates 3 are arranged so as to be substantially parallel to the vertical plane and equidistant from each other. The glass substrate 3 has a rectangular shape. The glass substrate 3 has two long sides LS and two short sides SS.

[Measure deflection]
FIGS. 2A and 2B are a perspective view and a side view, respectively, schematically showing the deflection measuring device 8. The deflection measuring device 8 measures the deflection of the glass substrate 3. The length of the long side LS and the length of the short side SS of the glass substrate 3 are a length L and a length W, respectively. The thickness of the glass substrate 3 is the thickness t.

  The deflection measuring device 8 includes two support members 5 and a laser positioning meter 7. The positional relationship between the two support members 5 and the laser positioning meter 7 is fixed. The two support members 5 are arranged in parallel along the horizontal direction. The length of the support member 5 along the horizontal direction is the same as the length W of the short side SS of the glass substrate 3 or slightly longer than the length W of the short side SS.

  The glass substrate 3 is arranged such that two short sides SS are supported by two support members and are in an inclined posture. The short side SS of the glass substrate 3 is horizontal. In FIG. 2B, as an example of the inclined posture, the posture in which the glass substrate 3 stands upright with respect to the vertical line 6 is given. Specifically, the tilted posture is a posture in which the glass substrate 3 is tilted so that the main surface of the glass substrate 3 and the vertical line 6 form a predetermined angle θ in a side view. When the glass substrate 3 is not bent, the two support members 5 support the glass substrate 3 in an inclined manner so that the main surface of the glass substrate 3 and the vertical line 6 form a predetermined angle θ. In the first embodiment, the predetermined angle θ is 5 degrees. The main surface is the front surface or the back surface of the glass substrate 3 and is a concept for distinguishing from the end surface.

  The 1st attitude | position and 2nd attitude | position of the glass substrate 3 are demonstrated. The main surface of the glass substrate 3 includes a first main surface F1 and a second main surface F2 facing each other. In the first embodiment, the main surface that is processed in the reference posture is defined as a first main surface F1. In addition, in the state in which the glass substrate 3 is supported by the support member 5, the main surface that faces obliquely upward is defined as the designated surface among the first principal surface F <b> 1 and the second principal surface F <b> 2 and Define a face as a non-designated face. The inclined posture of the glass substrate 3 when the first main surface F1 is the designated surface is defined as the first posture. The inclination posture of the glass substrate 3 when the second main surface F2 is the designated surface is defined as the second posture.

  Hereinafter, the measurement method and result of bending will be described. In the first posture, the deflection of the glass substrate 3 is measured by the laser positioning meter 7. Thereafter, in the second posture, the deflection of the glass substrate 3 is measured by the laser positioning meter 7. In the example of FIG. 2B, since the first main surface F1 faces obliquely upward, the first main surface F1 is a designated surface and the second main surface F2 is a non-designated surface. Accordingly, the posture of the glass substrate 3 is the first posture.

  The laser positioning meter 7 irradiates the center of the surface of the glass substrate 3 with laser light, and measures the distance a between the center of the surface and the laser positioning meter 7. The center of the surface is a position of length W / 2 perpendicular to the long side LS and a position of length L / 2 perpendicular to the short side SS on the non-designated surface. The measured distance a is the amount of bending of the glass substrate 3. The amount of deflection is indicated by direction and magnitude. Further, the amount of bending that becomes concave in the direction in which the external force acts is shown as positive, and the amount of bending that becomes convex in the direction in which the external force acts is shown as negative.

  The laser positioning meter 7 measures a distance a (amount of deflection a) for each of the plurality of glass substrates 3 in the first posture. Then, a personal computer (PC) (not shown) calculates a standard deviation σ of absolute values of a plurality of distances a (amounts of deflection a of the plurality of glass substrates 3) with respect to the plurality of glass substrates 3. Further, the PC normalizes the standard deviation σ based on the equations (1) and (2). The constant K is calculated from the thickness t of the glass substrate 3 and the length L of the long side LS based on the formula (2). Hereinafter, the normalized standard deviation σ is defined as a normalized standard deviation Nσ.

Nσ = σ × K (1)
K = t ² / L ⁴ (2)

It is preferable that the normalized standard deviation Nσ of the degree of bending (the absolute value of the distance a) of the plurality of glass substrates 3 measured in the first posture is 0.2 × 10 ⁻¹² (specified value) or less.

Similarly, the laser positioning meter 7 measures the distance a for each of the plurality of glass substrates 3 in the second posture. And PC calculates the normalization standard deviation N (sigma) of the absolute value of several distance a with respect to several glass substrate 3 based on Formula (1). It is also preferable that the normalized standard deviation Nσ of the magnitude of deflection of the plurality of glass substrates 3 measured in the second posture is 0.2 × 10 ⁻¹² (specified value) or less. In the above, the measurement method and result of a bending were demonstrated.

Next, the variation in deflection will be described. When the variation in the direction of the deflection is large, when the variation in the size of the deflection is large, or when the variation in the direction and the size of the deflection is large, the normalized standard deviation Nσ exceeds 0.2 × 10 ⁻¹² .

On the other hand, in the plurality of glass substrates 3 of the first embodiment, the normalized standard deviation Nσ is 0.2 × 10 ⁻¹² or less, and the variation in the direction and size of the plurality of glass substrates 3 is small. . Therefore, when the plurality of glass substrates 3 are arranged in the reference posture and processed, the variation in the interval between the adjacent glass substrates 3 can be reduced. As a result, it becomes possible to perform a uniform process with respect to the plurality of glass substrates 3, and it is possible to suppress deterioration in quality of the final product using each glass substrate 3.

Furthermore, in both the first posture and the second posture, the normalized standard deviation Nσ is 0.2 × 10 ⁻¹² or less. Therefore, the dispersion | variation in the space | interval of the glass substrate 3 can be made small, without depending on the direction of an unavoidable external force at the time of processing to the several glass substrate 3. FIG. As a result, it is possible to perform a uniform process on the plurality of glass substrates 3 without depending on the direction of the inevitable external force. Here, the inevitable external force will be described. Several glass substrate 3 is arrange | positioned with a reference | standard attitude | position in a processing apparatus (not shown), and a process is performed. The unavoidable external force is always generated in a certain direction in the processing apparatus, and is an external force unique to each processing apparatus.

  As described above, the variation in the bending of the plurality of glass substrates 3 in the first posture is within the predetermined range, and the variation in the bending of the plurality of glass substrates 3 in the second posture is within the predetermined range. However, the variation in the bending of the plurality of glass substrates 3 in the first posture may be either within a predetermined range, or the variation in the bending of the plurality of glass substrates 3 in the second posture may be in the predetermined range.

  For example, when the variation in the deflection of the plurality of glass substrates 3 in the first posture is within a predetermined range, the plurality of glass substrates 3 are arranged next to the first main surface F1 of the glass substrate 3 and the glass substrate 3. The glass substrate 3 is arranged or laminated so as to face the second main surface F2 of the glass substrate 3 and packed. As a result, the variation in the deflection of the plurality of glass substrates 3 in the first posture (the variation in the deflection when the deflection is measured using only the first main surface F1 (one main surface) as the designated surface) is within a predetermined range. It becomes possible to ship the glass substrate group 1 which guaranteed this. The glass substrate group 1 that guarantees the variation in bending is shipped to, for example, a business operator that performs processing on the glass substrate group 1 in a reference posture. In addition, in both the first posture and the second posture, the plurality of glass substrates 3 can be arranged or stacked in the same manner when the variation in deflection of the plurality of glass substrates 3 is within a predetermined range. preferable.

For example, the normalized standard deviation Nσ may be 0.2 × 10 ⁻¹² or less in either the first posture or the second posture. In this case, it is preferable to know in advance that an inevitable external force during processing is generated in a specific direction. The glass substrate 3 is processed in such a way that the surface of the normalized standard deviation Nσ corresponding to the inevitable external force is 0.2 × 10 ⁻¹² or less. For example, when the normalized standard deviation Nσ in the first posture is 0.2 × 10 ⁻¹² or less, a plurality of glasses are set such that an inevitable external force is directed from the first main surface F1 side to the second main surface F2 side. The substrate 3 is arranged in a standard posture. That is, the plurality of glass substrates 3 are arranged or stacked so that the direction of the external force acting on the glass substrate 3 in the process and the first main surface F1 face each other. The deflection variation has been described above.

  As shown in FIG. 2 (b), the glass substrate 3 is arranged in an inclined posture at the time of measurement. Hereinafter, the reason why the glass substrate 3 is arranged in an inclined posture will be described.

  First, the bending of the glass substrate with respect to an external force will be described. The external force is, for example, gravity, wind force, thermal stress (in-substrate temporary strain), film stress, and the like. When an external force is applied to the main surface of the glass substrate, the glass substrate is deformed into a convex shape in a direction opposite to the direction of the external force. This deformation is bending. The total amount of deflection St of the glass substrate with respect to the external force is the sum of the first deflection SP1, the second deflection SP2, and the third deflection SP3.

  The first deflection SP1 is a true warp of the glass substrate itself in the state of zero gravity and no external force. The first deflection SP1 can be pseudo-quantified by measuring the deflection difference between the front surface and the back surface even under gravity. The first deflection SP1 has a sign. The second deflection SP2 is a deformation according to a physical property value (such as Young's modulus) determined by the material of the glass substrate with respect to an external force. The second deflection SP2 is a physical constant and can be calculated. When the material of the glass substrate has a high Young's modulus, the second deflection SP2 can be reduced. The second deflection SP2 has a sign. The third bend SP3 is another bend. The third bend SP3 is a bend that greatly deforms in the direction of the external force even with a slight external force. There is no sign for the third deflection SP3.

  The first bend SP1 and the second bend SP2 can cancel each other, but the third bend SP3 cannot be canceled. Further, the second deflection SP2 is constant under the determined use conditions. Therefore, in order to observe the influence of the first deflection SP1 and the third deflection SP3 on the total deflection St, the second deflection SP2 is made as small as possible and the total deflection St is measured. Therefore, by arranging the glass substrate 3 in an inclined posture, the second deflection SP2 due to gravity is made as small as possible, and the first deflection SP1 and the third deflection SP3 are measured. Therefore, the amount of deflection a measured by the laser positioning meter 7 mainly includes the first deflection SP1 and the third deflection SP3.

  In order to measure the bending mainly including the first bending SP1 and the third bending SP3 by making the second bending SP2 as small as possible, for example, the predetermined angle θ in FIG. 2B is larger than 0 degree and not larger than 10 degrees. Set to. When the predetermined angle θ is set to 5 degrees, a more suitable measurement environment can be constructed. The reason why the glass substrate 3 is arranged in an inclined posture has been described above.

(Embodiment 2)
[Evaluation of deflection characteristics]
The above-mentioned normalized standard deviation Nσ can be applied to the evaluation of the bending characteristics of a plurality of glass substrates. The plurality of manufactured glass substrates are stored in a package (not shown). For each package, the normalized standard deviation Nσ is calculated by measuring the deflection of the plurality of glass substrates stored. And a bending characteristic is evaluated for every package. When the normalized standard deviation Nσ of a plurality of glass substrates housed in a certain package is 0.2 × 10 ⁻¹² or less, the glass substrate of the package is evaluated as having good deflection characteristics, for example, shipped. The On the other hand, when the normalized standard deviation Nσ of a plurality of glass substrates housed in a certain package exceeds 0.2 × 10 ⁻¹² , it is evaluated that the glass substrate of the package does not have good deflection characteristics, For example, it is discarded.

  Hereinafter, with reference to FIG.2 and FIG.3, the evaluation method of the bending characteristic in Embodiment 2 of this invention is demonstrated. FIG. 3 is a flowchart showing a method for evaluating a deflection characteristic according to the second embodiment of the present invention. In step S1 (collecting step), the operator collects one glass substrate (a glass substrate to be measured) from a plurality of glass substrates accommodated in the package. In step S3 (arrangement step), the worker arranges the glass substrate collected in step S3 so as to be in an inclined posture. Specifically, the collected glass substrate is supported by the support member 5 in the first posture. In step S5 (measurement step), the laser positioning meter 7 measures the deflection of the glass substrate placed in step S3. Specifically, the laser positioning meter 7 measures the distance a, that is, the amount of deflection a of the glass substrate supported by the support member 5.

  In step S7, the operator determines whether or not step S1 to step S5 have been completed for n (n is an integer of 2 or more) glass substrates. When it is determined that the process is completed (“Yes” in step S7), the process proceeds to step S9. On the other hand, when it is determined that the process has not been completed (“No” in step S7), the process returns to step S1. Step S1, step S3, and step S5 are repeated until “Yes” is determined in step S7 (repetition step). For example, the number n is the total number of the plurality of glass substrates stored in the package. For example, the number n is the number arbitrarily extracted from a plurality of glass substrates stored in the package. However, even when arbitrarily extracting, the number n of glass substrates to be extracted is predetermined.

In step S9, the PC calculates the variation in the measured deflection of the n glass substrates. Specifically, the PC calculates the normalized standard deviation Nσ of the deflection of the n glass substrates based on the formula (1). In step S11, the PC or the operator determines whether or not the variation in deflection is within a predetermined range. Specifically, the PC or the operator determines whether the normalized standard deviation Nσ is within 0.2 × 10 ⁻¹² . When the normalized standard deviation Nσ is 0.2 × 10 ⁻¹² or less, the glass substrate of the package is evaluated to have good deflection characteristics, and otherwise, the glass substrate of the package has good deflection characteristics. Not evaluated.

  As described above, Steps S1 to S11 are performed on the plurality of glass substrates in the first posture. And after completion | finish of process S1-process S11 with respect to a 1st attitude | position, process S1-process S11 are performed with respect to the several glass substrate of a 2nd attitude | position. In the steps S1 to S11 for the first posture and the steps S1 to S11 for the second posture, the packaging body is common, and the n glass substrates collected from the packaging body are the same.

  As described above, according to the evaluation method described with reference to FIGS. 2 and 3, it is possible to ship a plurality of glass substrates 3 in which variation in interval is suppressed during processing to a customer. As a result, it becomes possible to perform a uniform process on each glass substrate 3, and the quality degradation of the final product using each glass substrate 3 can be suppressed.

(Embodiment 3)
[Glass substrate group manufacturing apparatus and glass substrate group manufacturing method]
Fig.4 (a) is a vertical side view which shows schematic structure of the manufacturing apparatus 10 of the glass substrate group 1 in Embodiment 3 of this invention. FIG. 4B is a plan view schematically showing the glass ribbon 9 and the heater group 19 (19a) of FIG. Hereinafter, the manufacturing apparatus 10 will be described with reference to FIG.

  The manufacturing apparatus 10 manufactures the glass substrate group 1 using a float method. The manufacturing apparatus 10 includes a float bath 11, a lift-out unit 15, and a slow cooling furnace (rare) 21. The lift-out unit 15 is provided between the float bath 11 and the slow cooling furnace 21.

  Molten tin 13 is stored in the float bath 11. On the molten tin 13 of the float bath 11, molten glass is continuously supplied from the upstream side of the float bath 11. Then, the molten glass is formed into a glass ribbon 9 (band glass) on the molten tin 13. After passing through the lift-out part 15, the glass ribbon 9 is continuously conveyed to the slow cooling furnace 21 arranged on the downstream side of the lift-out part 15.

  In the lift-out unit 15 and the slow cooling furnace 21, a plurality of rollers 17 that form the transport path 20 are arranged. Accordingly, the glass ribbon 9 is continuously conveyed by the plurality of rollers 17 and gradually cooled. The glass ribbon 9 is unloaded from the downstream end (not shown) of the slow cooling furnace 21 and then cut into a predetermined length. As a result, the glass substrate 3 is obtained from the glass ribbon 9.

  A heater group 19 (heating means) is arranged below the plurality of rollers 17. The heater group 19 includes a plurality of heaters (not shown). Each of the plurality of heaters can be controlled independently. The heater group 19 controls the temperature distribution along the width direction (direction 14) of the glass ribbon 9 and the temperature gradient along the transport direction 12. The direction 14 is a direction perpendicular to both side surfaces 31 of the glass ribbon 9.

  Hereinafter, with reference to FIG. 4, the manufacturing method of the glass substrate group 1 is demonstrated in detail. In the third embodiment, the heater group 19 controls the temperature distribution along the direction 14 in the section V, so that the glass substrate group 1 is manufactured by the manufacturing apparatus 10. The section V is a section from the downstream side of the outlet of the float bath 11 to the middle of the conveyance path 20 in the slow cooling furnace 21.

The section V is defined by the viscosity of the glass ribbon 9. The viscosity of the glass can correspond to the temperature of the glass. Therefore, the definition of the section V by viscosity corresponds to the definition of the section V by temperature. For example, the section V is a section in which the viscosity of the glass ribbon 9 corresponds to 10 ^11.5 dPa · s or more and 10 ^14.5 dPa · s or less. The upstream end of the section V coincides with the upstream end of the liftout portion 15. The temperature of the glass ribbon 9 at the upstream end of the section V is a temperature corresponding to a viscosity of 10 ^11.5 dPa · s. The downstream end of the section V is located in the middle of the conveyance path 20 in the slow cooling furnace 21. The temperature of the glass ribbon 9 at the downstream end of the section V is a temperature corresponding to a viscosity of 10 ^14.5 dPa · s.

  The heater group 19 includes a heater group 19a arranged in the section V. The transport path 20 includes a transport path 20a in the section V. In the present specification, the left and right are the left and right when the line of sight is directed in the conveyance direction 12 of the glass ribbon 9.

  As shown in FIG. 4B, the glass ribbon 9 positioned in the section V includes a center portion 27 (center portion), a right end portion 29R (one end portion), and a left end portion 29L (the other end portion). The right end portion 29R and the left end portion 29L sandwich the central portion 27. The right end 29R includes an inner right end 25R (first end) and an outer right end 23R (second end). The outer right end portion 23R is farther from the central portion 27 than the inner right end portion 25R. The left end 29L includes an inner left end 25L (third end) and an outer left end 23L (fourth end). The outer left end 23L is farther from the central portion 27 than the inner left end 25L.

  The heater group 19 a controls the temperature of the glass ribbon 9 along the direction 14 so that the temperature increases from the central portion 27 of the glass ribbon toward both side surfaces 31. Hereinafter, the temperature control in the direction 14 will be specifically described with reference to FIGS. 4 and 5.

  FIG. 5A is a diagram schematically showing a temperature distribution along the direction 14 in FIG. FIG. 5B is a cross-sectional view taken along the line Vb-Vb in FIG. By performing temperature control described later, the temperature distribution shown in FIG. 5A is realized along the direction 14. Details will be described below.

A position P _R , a position P _R1 , a position P _R2 , a position P _C , a position P _L , a position P _L1 , and a position P _L2 along the direction 14 are defined. Position P _R is distant end from the center position P _C of the glass ribbon 10, of both ends of the right end 29R. That is, the position _{P R,} in cross section, to match the right side 31. Position _{P R2} is an end closer to the center position _{P C} of the both ends of the right end 29R. Position _{P R1} is a position between the position _{P R2} and the position _{P R.} Position _{P L} is the end furthest from the center position _{P C} of the both ends of the left end 29L. That is, the position _{P L,} in cross section, match the side face 31 of the left side. Position _{P L2} is an end closer to the center position _{P C} of the both ends of the left end 29L. The position P _L1 is a position between the position P _L and the position P _L2 .

Define a distance P _R P _R2 , a distance P _L P _L2 , a distance P _R P _L , a distance P _R P _R1 , and a distance P _L P _L1 along the direction 14. Distance _P R _{P R2} is the distance between the position _{P R} and the position _{P R2.} The distance P _L P _L2 is a distance between the position P _L and the position P _L2 . Distance _P R _{P L} is the distance between the position _{P L} and the position _{P R.} Distance _P R _{P R1} is a distance between the position _{P R} and the position _{P R1.} The distance P _L P _L1 is a distance between the position P _L and the position P _L1 .

The temperature T _L , the temperature T _L1 , the temperature T _L2 , the temperature T _R , the temperature T _R1 , and the temperature T _R2 along the direction 14 are respectively the temperature at the position P _L , the temperature at the position P _L1 , and the temperature at the position P _L2 . , the temperature of the position _{P R,} the temperature of the position _{P R1,} and the temperature of the position _{P R2.} For example, 6 corresponding to the position P _L , the position P _L1 , the position P _L2 , the position P _R , the position P _R1 , and the position PR ₂ on the surface of the glass ribbon 9 (the surface opposite to the surface facing the roller 17). By arranging two thermocouples (not shown), temperature T _L , temperature T _L1 , temperature T _L2 , temperature T _R , temperature T _R1 , and temperature T _R2 are measured. When six thermocouples along the direction 14 are set as one set, a plurality of sets of thermocouples are arranged at regular intervals along the conveyance direction 12 in the section V. As a result, the temperature T _L , the temperature T _L1 , the temperature T _L2 , the temperature T _R , the temperature T _R1 , and the temperature TR ₂ along the direction 14 can be measured at each position along the conveyance direction 12 of the glass ribbon 9.

Average temperature _{T R-R2} is the average temperature between the position _{P R} along the direction 14 and the position _{P R2,} for example, an average value between the temperature _{T R} and the temperature _{T R2.} Average temperature _{T R2-L2} is the average temperature between the position _{P R2} along the direction 14 and the position _{P L2,} for example, an average value between the temperature _{T R2} and the temperature _{T L2.} The average temperature T _L-L2 is an average temperature between the position P _L and the position P _L2 along the direction 14, and is, for example, an average value of the temperature T _L and the temperature T _L2 . Average temperature _{T R-R1} is the average temperature between the positions _{P R} and the position _{P R1} along the direction 14, for example, an average value between the temperature _{T R} and the temperature _{T R1.} The average temperature T _L-L1 is an average temperature between the position P _L and the position P _L1 along the direction 14, and is, for example, an average value of the temperature T _L and the temperature T _L1 .

  In the section V, the heater group 19a controls the temperature along the direction 14 so as to satisfy the expressions (3), (4), (5), and (6) ("first temperature control"). Defined.)

0.7 ≦ P _R PR ₂ / P _L P _L2 ≦ 1.3 (3)
(P _L P _L2 + P _R P _R2 ) / P _R P _L > 0.2 (4)
T _R-R2 > T _R2-L2 (5)
T _L-L2 > T _R2-L2 (6)

In the manufacturing process of the glass substrate group 1, by performing the first temperature control along the direction 14, the glass substrate group 1 having a small normalized standard deviation Nσ of deflection can be manufactured. That is, the glass substrate group 1 having a normalized standard deviation Nσ of 0.2 × 10 ⁻¹² or less can be manufactured.

  More preferably, the heater group 19a controls the temperature along the direction 14 so as to satisfy Expression (7) instead of Expression (4). That is, in the section V, the heater group 19a controls the temperature along the direction 14 so as to satisfy the expressions (3), (5), (6), and (7) (“second temperature”). Defined as "control").

(P _L P _L2 + P _R P _R2 ) / P _R P _L > 0.4 (7)

  In the manufacturing process of the glass substrate group 1, by performing the second temperature control along the direction 14, the glass substrate group 1 having a smaller normalized standard deviation Nσ of the deflection is compared with the case where the first temperature control is performed. Can be manufactured.

  Further, in addition to the first temperature control or in addition to the second temperature control, the heater group 19a extends along the direction 14 so as to satisfy the expressions (8), (9), and (10). The temperature is controlled (defined as “third temperature control”).

0.7 ≦ P _{R PR 1} / P _L P _L1 ≦ 1.3 (8)
T _R-R1 > T _R-R2 (9)
T _L-L1 > T _L-L2 (10)

  In the manufacturing process of the glass substrate group 1, by performing the first temperature control and the third temperature control along the direction 14, or by performing the second temperature control and the third temperature control along the direction 14, Compared with the case where only the first temperature control is performed and the case where only the second temperature control is performed, the glass substrate group 1 having a smaller normalized standard deviation Nσ of the deflection can be manufactured. By performing the first temperature control and the third temperature control or the second temperature control and the third temperature control, the temperature distribution shown in FIG.

  As described above, in the section V shown in FIG. 4B, the heater group 19 a performs the first temperature control and the third temperature control or the second temperature control and the third temperature control along the direction 14. At the same time, the heater group 19 a controls the temperature gradient of the glass ribbon 9 along the transport direction 12 so that the temperature gradually decreases from the upstream side toward the downstream side over the entire transport path 20. Therefore, in the glass ribbon 9, even if the position along the direction 14 is the same, if the position along the transport direction 12 is different, the temperature varies depending on the temperature gradient along the transport direction 12. However, in the section V, the first temperature control and the third temperature control or the second temperature control and the third temperature control are performed along the direction 14 at any position along the transport direction 12. As a result, the temperature distribution in the direction 14 at any position along the transport direction 12 is expressed by the equations (3) to (6) and (8) to (10), or (3) and (3). The temperature distribution is defined by (5) to (10) (see FIG. 5A).

  Next, with reference to FIGS. 4-6, the manufacturing method of the glass substrate group 1 using 2nd temperature control and 3rd temperature control is demonstrated. FIG. 6 is a flowchart illustrating a method for manufacturing the glass substrate group 1 by the manufacturing apparatus 10 according to the third embodiment. The glass ribbon 9 formed by the float bath 11 is gradually cooled in the slow cooling furnace 21, and the glass substrate group 1 is manufactured from the glass ribbon 9.

  In step S <b> 21, the molten glass is formed into the glass ribbon 9 with the float bath 11. In step S <b> 23, the heater group 19 a controls the temperature of the glass ribbon 9 in the section V so that the temperature increases from the central portion 27 of the glass ribbon 9 toward the both side surfaces 31 along the direction 14.

Step S23 includes step S231, step S233, and step S235. At step S231, the heater group 19a, in section V, the average temperature _{T R2-L2} of the central portion 27 of the glass ribbon 9, the average temperature _{T R-R2} and the left end 29L of the right end portion 29R (one end portion) ( The temperatures of the central portion 27, the right end portion 29R, and the left end portion 29L of the glass ribbon are controlled so as to be lower than each of the average temperatures _TL-L2 of the other end portion. Specifically, in step S231, the heater group 19a controls the temperature along the direction 14 so as to satisfy the expressions (3), (5), (6), and (7).

In step S233, the heater group 19a is configured such that in the section V, the average temperature TR _-R1 of the outer right end 23R is higher than the average temperature TR _{-R2 of} the outer right end 23R and the inner right end 25R. The temperatures of the outer right end 23R and the inner right end 25R are controlled. Specifically, the heater group 19a controls the temperature along the direction 14 so as to satisfy the expressions (8) and (9).

In step S235, the heater group 19a is configured such that, in the section V, the average temperature T _L-L1 of the outer left end 23L is higher than the average temperature T _{L-L2 of} the outer left end 23L and the inner left end 25L. The temperatures of the outer left end 23L and the inner left end 25L are controlled. Specifically, the heater group 19a controls the temperature along the direction 14 so as to satisfy the expressions (8) and (10).

  Here, in practice, step S21, step S231, step S233, and step S235 are executed simultaneously, and control of each step is continued until the manufacture of the glass substrate group 1 is completed.

  Moreover, the flow of control when manufacturing the glass substrate group 1 of FIG. 1 by performing the first temperature control and the third temperature control is the same as the control flow shown in the flowchart of FIG. However, in step S231, the heater group 19a controls the temperature along the direction 14 so as to satisfy the expressions (3) to (6).

  As described above, according to the manufacturing method shown in FIG. 6, the temperature of the glass ribbon 9 is controlled so that the temperature increases from the central portion 27 of the glass ribbon 9 toward the both side surfaces 31 along the direction 14. A plurality of glass substrates 3 in which the variation of the above is suppressed can be manufactured.

  Next, the present invention will be specifically described based on examples, but the present invention is not limited to the following examples.

In this embodiment, for explaining the conditions for producing a plurality of glass substrates 3 which normalized standard deviation Nσ is under 0.2 × 10 ^{-12 or less.}

  In the present embodiment, the reference posture is the glass used when performing the process of forming a film on the plurality of glass substrates 3 in a state where the plurality of glass substrates 3 are arranged substantially parallel to the vertical plane and equidistant from each other. This is the posture of the substrate 3.

Next, an example of temperature control for manufacturing a plurality of glass substrates 3 having a normalized standard deviation Nσ of 0.2 × 10 ⁻¹² or less will be described with reference to FIG. 4, FIG. 5, and FIG. . The temperature control is the second temperature control and the third temperature control described with reference to FIG. 5 (temperature control satisfying all of Expression (3) and Expressions (5) to (10)).

FIG. 7 is an explanatory diagram of the temperature control along the direction 14 according to the embodiment of the present invention. The average temperature is shown along direction 14 at a position within interval V. In the manufacturing method according to the present embodiment, temperature control that satisfies all of the above-described equations (5), (6), (9), and (10) is executed. The average temperature T _R-R2 of the right end portion 29R is 696 ° C., and the average temperature T _R2-L2 of the central portion 27 is 695 ° C. Therefore, Formula (5) is satisfy | filled. The average temperature T _L-L2 of the left end portion 29L is 698 ° C., and the average temperature T _R2-L2 of the central portion 27 is 695 ° C. Therefore, Formula (6) is satisfy | filled. Moreover, the average temperature TR _-R1 of the outer right end 23R is 697 ° C. Therefore, Expression (9) is satisfied. The average temperature T _L-L1 of the outer left end 23L is 700 ° C. Therefore, Formula (10) is satisfy | filled.

  On the other hand, temperature control by a general manufacturing method does not satisfy all of the formulas (5), (6), (9), and (10).

  Next, with reference to FIG. 8, the measured value and the normalized standard deviation Nσ of the deflection of the plurality of glass substrates 3 manufactured by the second temperature control and the third temperature control will be described.

Fig.8 (a) shows the bending characteristic of the several glass substrate 3 manufactured by the manufacturing method by the Example of this invention. In the package A, a plurality of glass substrates 3 (n (= 20) glass substrates A-1 to A-20) are stored. FIG. 8A shows the absolute value of the deflection amount a (distance a) of the glass substrates A-1 to A-20 in the first posture and the second posture. The normalized standard deviations Nσ of the deflection with respect to the first posture and the second posture are 0.10 × 10 ⁻¹² and 0.08 × 10 ⁻¹² , respectively, and are equal to or less than the specified value 0.2 × 10 ⁻¹² .

On the other hand, as shown in FIG. 8B, the packaging B contains n (= 15) glass substrates B-1 to B-15 manufactured by a general manufacturing method. FIG. 8B shows the absolute value of the amount of deflection a of the glass substrates B-1 to B-15 in the first posture and the second posture. The normalized standard deviations Nσ of the deflection with respect to the first posture and the second posture are 0.39 × 10 ⁻¹² and 0.37 × 10 ⁻¹² , respectively, which exceed the specified value 0.2 × 10 ⁻¹² . .

In this example, the length W of the short side SS of each glass substrate A-1 to A-20 is 900 mm, the length L of the long side LS is 1200 mm, and the thickness t is 1.8 mm. The size of each glass substrate B1-B-15 is the same as the size of each glass substrate A-1 to A-20. Therefore, in the glass substrates A-1 to A-20 and the glass substrates B1 to B-15, the constant K of the formula (2) included in the formula (1) is 1.56 × 10 ⁻¹² .

  The glass substrates A-1 to A-20 are arranged substantially parallel to the vertical plane and equidistant from each other so that the short side SS is horizontal in the heating furnace during the film formation process (during heat treatment). The Therefore, even when measuring the deflection, the short sides SS of the glass substrates A-1 to A-20 are supported so as to be horizontal.

As described above with reference to FIG. 8, for the glass substrates A-1 to A-20 of the package A manufactured by the manufacturing method in the present example, the normalized standard deviation Nσ of the deflection is a specified value of 0.2. Since it is × 10 ⁻¹² or less, variation in the direction and size of bending is small. Therefore, even when various inevitable external forces are applied to the glass substrates A-1 to A-20 when the glass substrates A-1 to A-20 are subjected to film formation (heat treatment), The direction and the magnitude of the bending of the glass substrates A-1 to A-20, which are arranged substantially equidistantly in parallel with each other, are kept within a certain range.

  Therefore, during the film forming process (at the time of heat treatment), the variation in the distance between the adjacent glass substrates A-1 to A-20 can be reduced. As a result, in the film forming process, the film modification by the reactive gas is within the design range at any position of any glass substrate A-1 to A-20. Can be manufactured. Various inevitable external forces include, for example, gravity due to slight inclination of the glass substrate, thermal stress due to temperature distribution in the glass substrate, and film stress generated in the film formed on the glass substrate. is there.

On the other hand, for the glass substrates B-1 to B-15 of the packaging B manufactured by a general manufacturing method, the normalized standard deviation Nσ of the deflection exceeds the specified value 0.2 × 10 ⁻¹² , so that the desired design It becomes difficult to manufacture a film-forming glass substrate that satisfies the specifications.

Further, the glass substrate A-1 to A-20 in the present embodiment, in both the first orientation and the second orientation, the normalized standard deviation Nσ deflection is 0.2 × ^{10 -12} or less. Therefore, variations in the distance between the glass substrates A-1 to A-20 can be reduced without depending on the direction of the inevitable external force when the film forming process is performed on the glass substrates A-1 to A-20. As a result, a high-quality film-formed glass substrate can be manufactured. The inevitable external force in this case is an external force unique to each heating furnace, and tends to always occur in a certain direction in the heating furnace, and is caused by the property of temperature unevenness in the heating furnace during the film forming process. .

  In the present example, the first main surface F1 of each glass substrate A-1 to A-20 was used as a use surface (film formation surface). The use surface is the main surface of the glass substrate on which a film subjected to modification is formed during film formation (gas phase reaction heat treatment). Usually, the top surface is often set as the use surface because the top surface and the bottom surface of the float forming have fewer defects in the top surface. However, which of the top surface and the bottom surface is set as the use surface is arbitrary. The top surface is a main surface that is not in contact with the molten tin 13 in the float bath 11, and the bottom surface is a main surface that is in contact with the molten tin 13 (see FIG. 4A).

In this example, the normalized standard deviation Nσ of deflection was 0.2 × 10 ⁻¹² or less in both the first posture and the second posture. However, the normalized standard deviation Nσ may be 0.2 × 10 ⁻¹² or less in either the first posture or the second posture. In this case, it is preferable that it is known in advance that an inevitable external force during film formation (heat treatment) is generated in a specific direction. The glass substrate A-1 to A-20 is subjected to a film forming process in such a way that the surface where the normalized standard deviation Nσ is 0.2 × 10 ⁻¹² or less corresponds to the inevitable external force direction. For example, when the normalized standard deviation Nσ in the first posture is 0.2 × 10 ⁻¹² or less, the inevitable external force (external force unique to each heating furnace) is the first main surface F1 side (use surface side). ) To the second main surface F2 side (non-use surface side), a plurality of glass substrates A-1 to A-20 are arranged.

  In addition, you may provide the mark for discriminating a 1st main surface and a 2nd main surface in glass substrate A-1-A-20, respectively. For example, the main surface may be discriminable by chamfering any one or more of the corners of the glass substrates A-1 to A-20 to have a different shape from the other corners. Alternatively, the first main surface and the second main surface may be discriminated based on the reflected light when the one main surface is partially processed or formed into a film and a predetermined light source is applied to each main surface.

  In this embodiment, the glass substrates A-1 to A-20 are aluminosilicate glass (aluminosilicate glass) which is formed by a float process, has a strain point of 570 ° C. or higher, and contains an alkali metal. Each glass substrate A-1 to A-20 has a rectangular shape with a short side SS of 700 mm or more. The thickness t of each glass substrate A-1 to A-20 is 0.5 mm or more and 3.0 mm or less.

In this embodiment, the glass substrates A-1 to A-20 are subjected to a slow cooling process that is continuous with the process of forming molten glass into the glass ribbon 9 in the float bath 11. However, each glass substrate A-1 to A-20 is subjected to reheating and gradual cooling treatment in a state where each glass substrate A-1 to A-20 is cut out from the glass ribbon 9 into a rectangular surface shape. Not received. Therefore, the normalized standard deviation Nσ of the deflection of the glass substrates A-1 to A-20 is maintained at 0.2 × 10 ⁻¹² or less.

  The present invention is not limited to the above-described embodiment, and can be implemented in various modes without departing from the gist thereof. For example, the following modifications are possible.

(1) In Embodiments 1 to 3 and Examples, the example in which the specified value when determining that the variation in deflection is small is 0.2 × 10 ⁻¹² has been given. However, the specified value is not limited to this example, and can be determined experimentally and / or empirically.

  (2) In the first to third embodiments and examples, the normalized standard deviation Nσ is taken as an example as an index for determining the variation in deflection. However, the index is not limited to the normalized standard deviation Nσ, and may be, for example, the standard deviation σ.

  (3) In Expression (1), the normalized standard deviation Nσ includes the standard deviation σ. The standard deviation σ is, for example, standard deviation σn−1 or standard deviation σn. The standard deviation σn is obtained as a positive square root of a value obtained by dividing the sum of the squares of the deviations by the number n of the population. The standard deviation σn-1 is obtained as a positive square root of a value obtained by dividing the sum of squares of deviations by (n-1). In the example (FIG. 8), the normalized standard deviation Nσ was calculated based on the standard deviation σn.

  (4) In FIG. 2, the short side SS is supported by the support member 5, and the glass substrate 3 is disposed so that the short side SS is horizontal. However, the long side LS of the glass substrate 3 may be supported by the support member 5, and the glass substrate 3 may be disposed so that the long side LS is horizontal. In this case, in the formula (2), the length W of the short side SS is used instead of the length L of the long side LS. For example, when the plurality of glass substrates 3 are processed in the reference posture and the short side SS is supported horizontally, the short side SS is supported horizontally even when measuring the deflection. For example, when the plurality of glass substrates 3 are processed in the reference posture and the long side LS is supported horizontally, the long side LS is supported horizontally even when measuring the deflection.

  (5) In the first to third embodiments and examples, the glass substrate group 1 is taken as an example.

  INDUSTRIAL APPLICABILITY The present invention can be used in the field of manufacturing and using a glass substrate in which variation in deflection affects the quality of the final product.

DESCRIPTION OF SYMBOLS 1 Glass substrate group 3 Glass substrate 5 Support member 7 Laser positioning meter 8 Deflection measuring device 9 Glass ribbon 10 Manufacturing apparatus 11 Float bath 12 Conveyance direction 13 Molten tin 14 Width direction 15 Lift-out part 17 Roller 19 (19a) Heater group 20 ( 20a) Transport route 21 Slow cooling furnace (rare)
23R outer right end portion 23L outer left end portion 25R inner right end portion 25L inner left end portion 27 central portion 29R right end portion 29L left end portion 31 side surface LS long side SS short side L long side length W short side length t thickness θ predetermined Angle a Distance (amount of deflection)
F1 1st main surface F2 2nd main surface V section

Claims (3)

A device comprising a step of performing a film forming process by flowing a reactive gas between each glass substrate after a plurality of rectangular glass substrates are arranged in parallel so as to be substantially parallel to a vertical plane and equidistant from each other. A manufacturing method comprising:
The variation of the deflection of the plurality of glass substrates in the tilted posture tilted based on the reference posture is a numerical value obtained by normalizing the standard deviation of the deflection of the plurality of glass substrates in the tilted posture,
The inclined posture is a posture in which an angle formed between the main surface of the glass substrate and a vertical line is 5 degrees,
The standard deviation is normalized by equations (1) and (2),
The normalized standard deviation Nσ is 0.08 × 10 ⁻¹² or more and 0.2 × 10 ⁻¹² or less, and the device manufacturing method.
Nσ = σ × K (1)
K = t ² / L ⁴ (2)
Nσ is a normalized standard deviation.
σ is the standard deviation of the amount of deflection of the plurality of glass substrates.
t is the thickness of the glass substrate.
L is the length of one side of the glass substrate. The main surface of the glass substrate includes a first main surface and a second main surface facing each other,
The normalized standard deviation Nσ indicating the variation of the deflection of the plurality of glass substrates in a posture in which the first main surface faces obliquely upward is 0.08 × 10 ⁻¹² or more and 0.2 × 10 ^{−. 12} or less,
The plurality of glass substrates are arranged or laminated such that the first main surface of the glass substrate and the second main surface of the glass substrate arranged adjacent to the glass substrate are opposed to each other. The method of manufacturing a device according to claim 1. The main surface of the glass substrate includes a first main surface and a second main surface facing each other,
The normalized standard deviation Nσ indicating the variation of the deflection of the plurality of glass substrates in a posture in which the first main surface faces obliquely upward is 0.08 × 10 ⁻¹² or more and 0.2 × 10 ^{−. The} normalized standard deviation Nσ indicating the variation of the deflection of the plurality of glass substrates in a posture in which the second main surface faces obliquely upward is 0.08 × 10 ⁻¹² or more and 0 or less. The device manufacturing method according to claim 2, wherein the manufacturing method is 2 × 10 ⁻¹² or less.