CN108455869B

CN108455869B - Glass substrate for display, and method for producing glass substrate for display

Info

Publication number: CN108455869B
Application number: CN201810153967.1A
Authority: CN
Inventors: 安田兴平; 井川信彰; 林泰夫
Original assignee: Asahi Glass Co Ltd
Current assignee: AGC Inc
Priority date: 2017-02-21
Filing date: 2018-02-22
Publication date: 2022-02-18
Anticipated expiration: 2038-02-22
Also published as: KR102452960B1; TWI741148B; KR20180096518A; TW201833635A; JP6801499B2; CN108455869A; JP2018135226A

Abstract

The present invention relates to a glass substrate for a display and a method for manufacturing the glass substrate for a display. The invention provides a glass substrate for a display, which is not easy to generate stripping electrification when being stripped from an adsorption table, and a manufacturing method thereof. A glass substrate for display, characterized in that F is the average value of fluorine concentration (mol%) in the range of 0nm to 10nm in depth from the glass surface of the glass substrate opposite to the semiconductor element forming surface_0‑10nmAnd F is the average fluorine concentration (mol%) in the range of 100nm to 400nm in depth from the glass surface_100‑400nmWhen F is present_0‑10nm/F_100‑400nmNot less than 3, and the surface roughness Ra of the glass surface on the side opposite to the semiconductor element formation surface is not less than 0.3 nm.

Description

Glass substrate for display, and method for producing glass substrate for display

Technical Field

The present invention relates to a glass substrate for a display and a method for manufacturing the glass substrate for a display.

Background

In a Flat Panel Display (FPD), a material obtained by forming a transparent electrode, a semiconductor element, or the like on a glass substrate is used as a substrate. For example, in a Liquid Crystal Display (LCD), a material obtained by forming a transparent electrode, a TFT (Thin Film Transistor), or the like on a glass substrate is used as a substrate.

The formation of the transparent electrode, the semiconductor element, and the like on the glass substrate is performed in a state where the glass surface of the glass substrate opposite to the semiconductor element formation surface is fixed on the adsorption stage by vacuum adsorption. However, when a glass substrate on which a transparent electrode, a semiconductor element, and the like are formed is peeled off from the suction table, the glass substrate is charged, and electrostatic breakdown of the semiconductor element such as a TFT occurs.

In order to suppress occurrence of peeling electrification, the following operations are performed: the surface of the glass substrate on the side contacting with the adsorption table is roughened, so that the contact area between the glass substrate and the adsorption table is reduced. As a method of roughening treatment, for example, a method of chemically treating the surface of a glass substrate by atmospheric pressure plasma treatment is known (patent document 1).

Documents of the prior art

Patent document

Patent document 1: international publication No. 2010/128673

Disclosure of Invention

Problems to be solved by the invention

However, in the conventional method, the difference in work function between the glass substrate and the adsorption stage is not taken into consideration, and therefore, the occurrence of peeling electrification cannot be sufficiently suppressed, and electrostatic breakdown of the semiconductor element may occur.

The present invention has been made in view of the above problems, and provides a glass substrate for a display, which is less likely to be electrically charged when peeled off from an adsorption stage, and a method for manufacturing the same.

Means for solving the problems

The invention provides a glass substrate for display, characterized in that F is the average value of fluorine concentration (mol%) in the range of 0 nm-10 nm of depth from the glass surface of the glass substrate opposite to the semiconductor element forming surface_0-10nmAnd F is the average fluorine concentration (mol%) in the range of 100nm to 400nm in depth from the glass surface_100-400nmWhen F is present_0-10nm/F_100-400nmNot less than 3, and the surface roughness Ra of the glass surface on the side opposite to the semiconductor element formation surface is not less than 0.3 nm.

Further, the present invention provides a method for manufacturing a glass substrate for a display, comprising the step of supplying a gas containing Hydrogen Fluoride (HF) to one surface of a plate-like glass conveyed in a heat treatment apparatus,

one surface of the plate-like glass is a glass surface of the glass substrate on the side opposite to the semiconductor element formation surface,

the HF concentration in the HF-containing gas is 0.5 to 30 vol%,

the glass surface temperature when the HF-containing gas is supplied is 500 to 900 ℃.

Effects of the invention

The glass substrate for display device of the present invention is less likely to be electrically charged when peeled off from the suction table.

Drawings

Fig. 1 is an explanatory view of a method for manufacturing a glass substrate for a display according to an embodiment of the present invention, and is a schematic view showing one configuration example of a heat treatment apparatus.

Fig. 2 is an explanatory view of the method for manufacturing a glass substrate for a display according to the embodiment of the present invention, and is a schematic view showing another configuration example of the heat treatment apparatus.

Fig. 3 is an explanatory view of the method for manufacturing a glass substrate for display according to the embodiment of the present invention, and is a cross-sectional view showing an overview of a float glass manufacturing apparatus.

Fig. 4 is a graph showing the relationship of the slit width (a), the process length (b), and the process width (c) of the ejector in the embodiment.

FIG. 5 is a graph showing the relationship between the depth from the surface of the glass sheet and the fluorine concentration in the glass sheet in examples (examples 4 and 11).

Fig. 6(a) is a graph showing the relationship of irradiation light energy X to the square root Y of the number of photoelectron emissions in the embodiment. FIG. 6(b) is an enlarged view of FIG. 6(a) in which the irradiation light energy X is in the range of 5.5eV to 6.0 eV.

Reference numerals

10 glass raw material

12 molten glass

14 glass ribbon

20 plate glass

22 lower surface

24 upper surface

60. 62 Heat treatment device

70. 80 ejector

71. 81 supply port

74. 84 flow path

75. 85 exhaust port

100 float glass manufacturing device

200 melting device

210 melting tank

220 burner

300 forming device

310 molten tin

320 bath

400 slow cooling device

410 slow cooling furnace

420 transport roller

440 heater

510 Lift roller

Detailed Description

[ glass substrate for display ]

Hereinafter, a glass substrate for a display according to an embodiment of the present invention will be described.

The glass composition of the glass substrate for display of the present embodiment is not particularly limited, and may be a wide range of glass compositions such as soda-lime-silicate glass, aluminosilicate glass, borosilicate glass, and alkali-free glass.

Generally, when the difference in work function between substances is large, contact electrification is likely to occur. The work function means: in order to extract electrons from the solid, precisely the minimum amount of energy necessary to extract them into a vacuum. Electrons move from a substance having a small work function to a substance having a large work function, thereby generating charge. The glass substrate is charged due to the difference in work function between the glass substrate and the adsorption stage.

Therefore, the present inventors focused attention on the work function of the glass substrate in order to reduce the charge amount of the glass substrate. However, a method for measuring the work function of a glass substrate has not been established.

The present inventors have conducted intensive studies and found that: the difference in the fluorine atom concentration between the vicinity of the surface of the glass substrate and the inside thereof is related to the difference in the work function between the glass substrate and the adsorption stage.

That is, the energy level changes by increasing the concentration of fluorine atoms having high electronegativity in the vicinity of the surface of the glass substrate, and the work function of the glass substrate changes.

The charge amount of the glass substrate is generally determined based on the difference between the work functions of the glass substrate and the adsorption stage (the contact charge characteristic of high resistance insulating glass (high resistance) ガラス), beilin macro, takraw theory, theory a, No. 125 coil 2, 179-.

In the glass substrate for display of the present embodiment, F is the average value of the fluorine concentration (mol%) in the range of 0nm to 10nm in depth from the glass surface of the glass substrate on the side opposite to the semiconductor element formation surface_0-10nmAnd F is the average fluorine concentration (mol%) in the range of 100nm to 400nm in depth from the glass surface_100-400nmWhen F is present_0-10nm/F_100-400nm≥3。

Thus, the difference in work function between the glass substrate and the suction table is reduced, and peeling electrification of the glass substrate can be suppressed.

Here, the fluorine concentration in the vicinity of the surface of the glass substrate is represented by F_0-10nmThe fluorine concentration inside the glass substrate is set to F_100-400nmThe reason for (c) is as follows.

The movement of electrons in contact charging mainly occurs in a region of 0 to 10nm in depth from the surface of the glass substrate, and is governed by the interaction between this region and a region of 100 to 400nm in depth.

In addition, F is_0-10nmAnd F_100-400nmMeasured by X-ray photoelectron spectroscopy (XPS).

In the glass substrate for display of the present embodiment, F is preferable_0-10nm/F_100-400nmNot less than 5, more preferably F_0-10nm/F_100-400nm≥10。

When the difference in fluorine atom concentration between the vicinity of the surface of the glass substrate and the inside of the glass substrate is too large, haze is undesirably reduced.

F_0-10nm/F_100-400nmAt 150 ℃ or less, the haze is preferably reduced, and F is more preferably_0-10nm/F_100-400nm≤100。

Further, as the surface roughness of the glass surface increases, the contact area between the glass substrate and the adsorption stage becomes smaller, and the movement of electrons becomes more difficult to occur, so that peeling electrification of the glass substrate (contact electrification characteristic of high resistance insulating glass (contact belt characteristic of property ガラス), north forest macro, rattan well clamp, theory a, theory 125 coil 2, 179-.

In the glass substrate for display according to the present embodiment, the surface roughness Ra of the glass surface of the glass substrate on the side opposite to the semiconductor element formation surface is 0.3nm or more.

The surface roughness Ra was measured by an Atomic Force Microscope (AFM).

The surface roughness Ra is preferably 0.7nm or more.

However, if the surface roughness Ra is too large, large defects may be generated on the glass surface, and the strength of the glass substrate may be reduced. The surface roughness Ra of 5nm or less is preferable because large defects are not generated on the glass surface at this time, and there is no fear of a decrease in the strength of the glass substrate. The surface roughness Ra is more preferably 2nm or less.

The glass substrate for display of the present embodiment preferably has a peeling electrification amount of-10 kV or more, which is measured by the procedure described in the examples described later.

This can prevent electrostatic breakdown of the semiconductor element formed on the glass substrate for display.

The peeling electrification amount is more preferably-7 kV or more, and still more preferably-5 kV or more.

When the irradiation light energy obtained by measurement of a photoelectron emission yield spectrum (PYS) is plotted against the square root of the photoelectron emission number, the square root of the photoelectron emission number sharply increases at a point in time when the irradiation light energy reaches a certain value. The irradiation light energy which becomes the threshold value at this time is the work function. When the irradiation energy is further increased, the square root of the emission number of photoelectrons linearly increases.

The inventors of the present application have conducted intensive studies and, as a result, have found that: the slope of the linear increase has a correlation with the peeling electrification amount of the glass substrate.

In the glass substrate for display of the present embodiment, when the irradiation light energy is X (eV) and the square root of the number of photoelectrons emitted is Y, the slope Δ Y/Δ X of Y in the range of X5.5 eV to 6.0eV, which is obtained by measurement of photoelectron emission yield spectroscopy (PYS), is preferably 10 or more. The work function of the glass substrate is less than 5.5 eV. The region where X is 5.5eV to 6.0eV is a region where Y linearly increases.

The slope Δ Y/Δ X approximately represents the state density of electrons in the range of 5.5eV to 6.0 eV. It is considered that the larger the slope Δ Y/Δ X is, the less likely the glass substrate receives electrons and the less likely the glass substrate is charged.

The glass substrate for display of the present embodiment is more preferably Δ Y/Δ X.gtoreq.20, and still more preferably Δ Y/Δ X.gtoreq.50.

The glass substrate for display of the present embodiment is not particularly limited in size, but is suitable for a large glass substrate in order to suppress peeling electrification of the glass substrate. Specifically, it is preferably 2500mm × 2200mm or more, and more preferably 3130mm × 2880mm or more.

The thickness is also not particularly limited, but is suitable for a thin glass substrate in order to suppress peeling electrification of the glass substrate. Specifically, it is preferably 1.0mm or less, more preferably 0.75mm or less, and still more preferably 0.45mm or less.

The glass substrate for a display of the present embodiment is preferably alkali-free glass.

The alkali-free glass preferably contains 50 to 73% of SiO in terms of mass percentage based on the following oxides₂10.5 to 24 percent of Al₂O₃0.1 to 12 percent of B₂O₃0 to 8% of MgO, 0 to 14.5% of CaO, 0 to 24% of SrO, 0 to 13.5% of BaO, and 0 to 5% of ZrO₂And the total amount of MgO, CaO, SrO and BaO (MgO + CaO + SrO + BaO) is preferably 8% to 29.5%.

The alkali-free glass preferably contains 58% by mass based on the oxide described below% to 66% SiO₂15 to 22 percent of Al₂O₃5 to 12 percent of B₂O₃0 to 8% of MgO, 0 to 9% of CaO, 3 to 12.5% of SrO, and 0 to 2% of BaO, and the total amount of MgO, CaO, SrO, and BaO (MgO + CaO + SrO + BaO) is preferably 9 to 18%.

The alkali-free glass preferably contains 54 to 73% of SiO in terms of mass percentage based on the oxide described below₂10.5 to 22.5 percent of Al₂O₃0.1 to 5.5 percent of B₂O₃0 to 8% of MgO, 0 to 9% of CaO, 0 to 16% of SrO, and 0 to 2.5% of BaO, and the total amount of MgO, CaO, SrO, and BaO (MgO + CaO + SrO + BaO) is preferably 8 to 26%.

[ method for producing glass substrate for display ]

Next, a configuration example of the method for manufacturing a glass substrate for a display according to the present invention will be described.

In the heat treatment apparatus 60 shown in fig. 1, the plate glass 20 is conveyed in the direction of the arrow. The conveyance means is not particularly limited, and is, for example, a conveyance roller not shown. The heat treatment apparatus 60 and a heat treatment apparatus 62 described later have heaters, not shown.

Here, the lower surface 22 of the plate glass 20 is a semiconductor element forming surface of the glass substrate for display, and the upper surface 24 of the plate glass 20 is a glass surface on the opposite side of the semiconductor element forming surface.

The heat treatment apparatus 60 shown in fig. 1 has an injector 70. The gas blown from the supply port 71 of the injector 70 onto the upper surface 24 of the plate glass 20 moves in the flow path 74 in the forward or reverse direction with respect to the moving direction of the plate glass 20, and flows out to the exhaust port 75.

The injector 70 shown in fig. 1 is a two-way flow type injector in which the flow of gas from the supply port 71 to the exhaust port 75 is equally divided between the forward direction and the reverse direction with respect to the moving direction of the plate glass 20.

Fig. 2 is a schematic diagram showing another configuration example of the heat treatment apparatus. The heat treatment apparatus 62 shown in fig. 2 has an injector 80. The ejector 80 is a unidirectional flow type ejector. The unidirectional flow type injector is an injector in which the flow of gas from the supply port 81 to the exhaust port 85 is fixed in either a forward direction or a reverse direction with respect to the moving direction of the plate glass 20. With the injector 80 shown in fig. 2, the flow 84 of the gas from the supply port 81 to the exhaust port 85 is in the positive direction with respect to the moving direction of the plate glass 20. However, the flow of the gas from the supply port 81 to the exhaust port 85 may be reversed with respect to the moving direction of the plate glass 20, without being limited thereto.

In the method for manufacturing a glass substrate for a display of the present invention, a gas containing Hydrogen Fluoride (HF) is supplied to the upper surface 24 of the plate-like glass 20 from the

supply ports

71, 81 of the

injectors

70, 80.

Thus, the fluorine concentration near the glass surface on the opposite side of the semiconductor element formation surface is higher than the fluorine concentration inside the glass substrate, the difference in work function between the glass substrate and the adsorption stage is small, and peeling electrification of the glass substrate can be suppressed.

In the method for manufacturing a glass substrate for a display according to the present invention, the glass surface temperature when supplying the HF-containing gas, that is, the temperature of the upper surface 24 of the plate glass 20 is set to 500 to 900 ℃. The following effects are achieved by setting the glass surface temperature to 500 ℃ or higher.

Fluorine intrudes into the vicinity of the glass surface, and the fluorine concentration in the vicinity of the glass surface becomes higher than the fluorine concentration in the glass substrate. The glass surface temperature is more preferably 550 ℃ or higher, and still more preferably 600 ℃ or higher.

In addition, the following effects are achieved by setting the glass surface temperature to 900 ℃ or lower.

The surface roughness Ra of the glass surface is inhibited from excessively increasing, and a uniform surface shape is formed.

The glass surface temperature is more preferably 850 ℃ or lower, and still more preferably 800 ℃ or lower.

In the method for producing a glass substrate for a display according to the present invention, nitrogen (N) is used as the HF-containing gas from the viewpoint of corrosion prevention of the equipment such as the

injectors

70 and 80 of the heat treatment apparatuses 60 and 62₂) Or an inert gas such as a rare gas, is supplied as a carrier gas to the upper surface 24 of the plate glass 20 as a mixed gas with the carrier gas.

The HF concentration of the HF-containing gas supplied from the

supply ports

71, 81 of the

injectors

70, 80 is set to 0.5 vol% to 30 vol%. The following effects are achieved by setting the HF concentration to 0.5 vol% or more.

Fluorine intrudes into the vicinity of the glass surface, and the fluorine concentration in the vicinity of the glass surface becomes higher than the fluorine concentration in the glass substrate.

The HF concentration is more preferably 2 vol% or more, and still more preferably 4 vol% or more.

In addition, the following effects are achieved by setting the HF concentration to 30 vol% or less.

The generation of defects on the glass surface formed by the reaction of the glass surface with HF can be suppressed, and the decrease in strength of the glass substrate can be suppressed. The HF concentration is more preferably 26 vol% or less, and still more preferably 22 vol% or less.

The distance D between the

supply ports

71 and 81 of the

injectors

70 and 80 and the upper surface 24 of the plate glass 20 is preferably 5mm to 50 mm. The distance D is more preferably 8mm or more. The distance D is more preferably 30mm or less, and still more preferably 20mm or less. By setting the distance D to 5mm or more, even if the plate glass 20 vibrates due to, for example, an earthquake, contact between the upper surface 24 of the plate glass 20 and the

injectors

70 and 80 can be avoided. On the other hand, by setting the distance D to 50mm or less, diffusion of gas inside the apparatus can be suppressed, and a sufficient amount of gas can be made to reach the upper surface 24 of the plate glass 20 with respect to a desired amount of gas.

The distance L of the

injectors

70, 80 in the moving direction of the plate glass 20 is preferably 100mm to 500 mm. The distance L is more preferably 150mm or more, and still more preferably 200mm or more. The distance L is more preferably 450mm or less, and still more preferably 400mm or less. By setting the distance L to 100mm or more, the

supply ports

71, 81 and the

exhaust ports

75, 85 can be provided. In particular, the distance L of the ejector 70 is preferably 150mm or more, and the distance L of the ejector 80 is preferably 100mm or more. On the other hand, by setting the distance L to 500mm or less, the thermal loss (thermal breakdown) of the plate glass 20 by the

injectors

70, 80 can be suppressed, and therefore the output of the plurality of heaters can be suppressed.

The distance of the

injectors

70 and 80 in the width direction of the plate glass 20 is preferably equal to or greater than the product area of the plate glass 20 in the width direction. When the method for producing a glass substrate for a display according to the present invention is carried out as an in-line process, it is preferably 3000mm or more, and more preferably 4000mm or more.

The flow rate (linear velocity) of the HF-containing gas is preferably 20cm/s to 300 cm/s. By setting the flow rate (linear velocity) to 20cm/s or more, the flow of the HF-containing gas is stabilized, and the glass surface can be uniformly treated. The flow rate (linear velocity) is more preferably 50cm/s or more, and still more preferably 80cm/s or more.

As will be described later, when the method for producing a glass substrate for a display according to the present invention is carried out as an in-line process, by setting the flow rate (linear velocity) to 300cm/s or less, a sufficient amount of gas can be allowed to reach the top surface of the glass ribbon while suppressing the diffusion of the gas in the slow cooling device. The flow rate (linear velocity) is more preferably 250cm/s or less, and still more preferably 200cm/s or less.

The method for manufacturing a glass substrate for a display according to the present invention may be performed as an in-line process or an off-line process. The "in-line treatment" in the present specification means a case where the method of the present invention is applied to a slow cooling process of slowly cooling a glass ribbon formed by a float process, a down-draw process, or the like. On the other hand, "off-line processing" refers to a case where the method of the present invention is applied to a sheet-like glass that is shaped and cut into a desired size. Therefore, the plate glass in the present specification includes a glass ribbon formed by a float method, a down-draw method, or the like, in addition to a plate glass formed and cut into a desired size.

The method for producing a glass substrate for a display of the present invention is preferably performed as an in-line process for the following reasons.

In the case of off-line treatment, an additional process is required, whereas in the case of on-line treatment, no additional process is required, and therefore treatment can be performed at low cost. In the off-line processing, the HF-containing gas is circulated between the glass substrates to the semiconductor element formation surface of the glass substrates, whereas in the on-line processing of the glass ribbon, the circulation of the HF-containing gas can be suppressed.

A process for producing a plate-like glass such as a glass substrate for a display, comprising the steps of: the method for manufacturing the glass ribbon includes a melting step of melting glass raw materials to obtain molten glass, a forming step of forming the molten glass obtained in the melting step into a ribbon shape to obtain a glass ribbon, and a slow cooling step of slowly cooling the glass ribbon obtained in the forming step. Examples of the forming step include a float forming step by a float method and a pull-down forming step by a pull-down method.

In the case where the method for producing a glass substrate for a display according to the present invention is carried out as an in-line process, in the slow cooling step, a gas containing HF is supplied to the top surface of the glass ribbon.

The float glass manufacturing apparatus 100 shown in fig. 3 has: the glass melting apparatus includes a melting apparatus 200 that melts glass raw materials 10 to obtain molten glass 12, a forming apparatus 300 that forms the molten glass 12 supplied from the melting apparatus 200 into a ribbon shape to obtain a glass ribbon 14, and a slow cooling apparatus 400 that slowly cools the glass ribbon 14 formed by the forming apparatus 300.

The melting apparatus 200 has: a melting tank 210 that contains molten glass 12, and a burner 220 that forms a flame above the molten glass 12 contained in the melting tank 210. The glass raw material 10 fed into the melting tank 210 is slowly melted into molten glass 12 by radiant heat from the flame formed by the burner 220. The molten glass 12 is continuously supplied from the melting tank 210 to the forming device 300.

The forming apparatus 300 has a bath 320 containing molten tin 310. In the forming apparatus 300, the molten glass 12 continuously supplied onto the molten tin 310 is formed into a ribbon shape by flowing the molten glass over the molten tin 310 in a predetermined direction, thereby obtaining the glass ribbon 14. The temperature of the atmosphere in the molding apparatus 300 decreases as the temperature of the atmosphere increases from the inlet of the molding apparatus 300 toward the outlet. The atmospheric temperature in the molding apparatus 300 can be adjusted by a heater (not shown) or the like provided in the molding apparatus 300. The glass ribbon 14 is cooled while flowing in a predetermined direction, and is pulled up from the molten tin 310 in a downstream area of the bath 320. The glass ribbon 14 pulled from the molten tin 310 is conveyed to the slow cooling device 400 by the lift roller 510.

The slow cooling device 400 slowly cools the glass ribbon 14 formed by the forming device 300. The slow cooling device 400 includes a slow cooling furnace (lehr) 410 of, for example, a heat insulating structure, and a plurality of conveyance rollers 420 provided in the slow cooling furnace 410 and conveying the glass ribbon 14 in a predetermined direction. The temperature of the atmosphere in the slow cooling furnace 410 is lower as it is closer to the outlet from the inlet of the slow cooling furnace 410. The temperature of the atmosphere in the slow cooling furnace 410 can be adjusted by a heater 440 or the like provided in the slow cooling furnace 410. The glass ribbon 14 conveyed out from the outlet of the slow cooling furnace 410 is cut into a predetermined size by a cutter, and is shipped as a product.

Before shipping as a product, at least one of both surfaces of the glass substrate may be polished as necessary, and the glass substrate may be cleaned. When the method for manufacturing a glass substrate for a display according to the present invention is performed as an in-line process, the glass surface of the glass substrate on the side opposite to the semiconductor element formation surface corresponds to the top surface of the glass ribbon 14, and the semiconductor element formation surface corresponds to the bottom surface of the glass ribbon 14.

In the method for manufacturing a glass substrate for a display according to the present invention, the fluorine concentration in the vicinity of the glass surface on the opposite side of the semiconductor element formation surface is made higher than the fluorine concentration in the glass substrate, so that the difference in work function between the glass substrate and the adsorption stage is reduced, and peeling electrification of the glass substrate is suppressed, and therefore, when polishing is performed, it is preferable to polish only the bottom surface of the glass ribbon 14. The semiconductor element-formed surface of the glass substrate was polished with a polishing tool while supplying an aqueous cerium oxide solution. During polishing, a part of the aqueous cerium oxide solution surrounds the glass surface of the glass substrate opposite to the semiconductor element formation surface, and becomes a slurry residue.

The glass substrate can be cleaned by, for example, spray cleaning, slurry cleaning using a disk brush, or spray rinsing. In the slurry cleaning, slurry (for example, an aqueous cerium oxide solution or an aqueous calcium carbonate solution) is supplied to the glass surface of the glass substrate on the side opposite to the semiconductor element formation surface, and the glass surface is polished with a disk brush, thereby removing the slurry residue remaining on the glass surface on the side opposite to the semiconductor element formation surface.

In the float glass manufacturing apparatus 100 shown in fig. 3, since the method for manufacturing a glass substrate for display according to the present invention is performed as an in-line process, the

injectors

70 and 80 are provided above the glass ribbon 14 in the slow cooling apparatus 400, and a gas containing Hydrogen Fluoride (HF) is supplied to the top surface of the glass ribbon 14 using the

injectors

70 and 80. When the method for manufacturing a glass substrate for display of the present invention is performed as an in-line process, the

heat treatment apparatuses

60 and 62 shown in fig. 1 and 2 correspond to the slow cooling apparatus 400 shown in fig. 3.

In fig. 3, the

injectors

70 and 80 are provided in the slow cooling device 400, but in the float glass manufacturing apparatus according to another embodiment of the present invention, if the glass surface temperature when supplying the HF-containing gas is 500 to 900 ℃.

Examples

Hereinafter, examples of the present invention and comparative examples will be specifically described. The present invention is not limited to these descriptions.

(Experimental example 1)

In experimental example 1, the method for manufacturing a glass substrate for a display according to the present invention was performed as an off-line process.

In Experimental example 1, an alkali-free glass plate (520 mm. times.410 mm. times.0.5 mm in thickness) containing 59.5% of SiO was prepared₂17% of Al₂O₃8% of B₂O₃3.3% of MgO, 4% of CaO, 7.6% of SrO, 0.1% of BaO, 0.1% of ZrO₂The total content of MgO + CaO + SrO + BaO is 15%, the balance is inevitable impurities, and the total content of alkali metal oxides is 0.1% or less. An HF-containing gas is supplied to the upper surface of the alkali-free glass sheet from the injector 70 of the heat treatment apparatus shown in fig. 1. Fig. 4 is a graph showing the relationship among the slit width (a), the treatment length (b), and the treatment width (c) of the injector in experimental example 1.

In experimental example 1, the flow rate (L/min), treatment time (sec), and linear velocity (mm/sec) of the gases a (mm), b (mm), and c (mm), which were described above, and HF-containing gas were set to the conditions shown in table 1 below.

Further, the distance D between the supply port 71 of the injector 70 and the upper surface of the plate glass 20 was set to 10 mm.

The glass surface temperature (temperature in table 2) and the HF concentration (volume%) when the HF-containing gas was supplied were set to the conditions shown in table 2 below. In table 2, examples 1 and 2 are comparative examples, and examples 3 and 4 are examples.

After supplying the HF-containing gas, the glass surface temperature was maintained at the same temperature for 5 minutes, and then cooled to room temperature over 30 minutes.

Then, the following evaluations were carried out.

[ F concentration (F) in the vicinity of the surface and inside of the glass substrate_0-10nm、F_100-400nm)]

F is measured by the following procedure_0-10nmAnd F_100-400nm。

The glass substrate obtained by the above-described steps was cut into a width of 10mm × a length of 10mm, and subjected to an X-ray photoelectron spectrometer (ULVAC-PHI Co., Ltd.)ESCA5500) measured the F concentration (mol%) at 0nm, 2nm, 5nm, 7nm, and 10nm in depth from the glass surface of the glass substrate. Averaging the measured F concentrations at depths of 0nm, 2nm, 5nm, 7nm, and 10nm, and calculating the average F concentration in the range of 0nm to 10nm_0-10nm. Grinding to a depth of 10nm from the surface of the glass substrate was performed by C₆₀The ion beam performs sputter etching.

Further, F concentrations (mol%) at 100nm, 101nm, 112nm, 123nm, 134nm, 145nm, 156nm, 167nm, 178nm, 189nm, 200nm, 211nm, 222nm, 266nm, 310nm, 354nm, 398nm and 400nm of the glass substrate from the glass surface were measured by an X-ray photoelectron spectrometer (ESCA 5500, manufactured by ULVAC-PHI Co., Ltd.). Averaging the measured values of F concentration in the depth range of 100nm to 400nm, and calculating the average value F of F concentration in the depth range of 100nm to 400nm_100-400nm。

Fig. 5 shows the relationship between the depth from the surface of the glass plate in example 4 and the fluorine concentration in the glass plate.

[ average surface roughness Ra of glass surface ]

The glass substrate obtained by the above-described steps was cut into a width of 5mm × a length of 5mm, and the average surface roughness Ra (arithmetic average surface roughness Ra (JIS B0601-2013)) of the glass surface of the glass substrate was measured by the following method. The glass surface of the glass substrate was observed using an atomic force microscope (product name: SPI-3800N, manufactured by Seiko Instruments Co., Ltd.). The cantilever used SI-DF40P 2. Using the dynamic force mode (ダイナミック · フォース · モード), a scanning area of 5 μm × 5 μm was observed at a scanning speed of 1Hz (number of data in area: 256 × 256). Based on this observation, the average surface roughness Ra at each measurement point was calculated. The software attached to the atomic force microscope (software name: SPA-400) was used as the calculation software.

[ peeling electrification amount of glass substrate ]

The amount of peeling electrification of the glass substrate obtained by the above procedure was measured by the following method. A glass substrate having a width of 410mm, a length of 520mm and a thickness of 0.5mm was brought into contact with a vacuum suction table made of SUS304, and suction and release of the glass substrate were repeated for 110 cycles. Then, the glass substrate was peeled off from the vacuum suction table by using a lift pin (リフトピン). The change in surface potential until the glass substrate departed from the vacuum adsorption stage and risen by 5cm was measured by a surface potentiometer (product name: MODEL 341B, TREK Japan). The peak value of the measurement result was taken as the amount of peeling charge.

[ PYS measurement (. DELTA.Y/. DELTA.X) ]

In example 4, photoelectron emission yield spectroscopy (PYS) was performed by the following procedure, and the slope (Δ Y/Δ X) of the irradiation light energy X and the square root Y of the number of photoelectron emissions was obtained.

A glass substrate having a width of 20mm, a length of 20mm and a thickness of 0.5mm was prepared. The ultraviolet irradiation surface is a glass surface opposite to the semiconductor element formation surface of the glass substrate. The number of photoelectrons emitted from the irradiated surface was measured by using a photoelectron spectrometer AC-5 (manufactured by Riemann Seikagaku Co., Ltd.) in the atmosphere. The intensity of the ultraviolet light was set to 2000 nW. The ultraviolet light is irradiated with an irradiation energy X in an increment of 0.1eV within a range of 4.2 to 6.2 eV. The counting time of photoelectrons was set to 5 seconds per 0.1 eV.

Fig. 6(a) shows a graph showing the relationship between the irradiation light energy X and the square root Y of the number of photoelectron emissions in example 4. FIG. 6(b) is an enlarged view of FIG. 6(a) in which the irradiation light energy X is in the range of 5.5eV to 6.0 eV. The slope Δ Y/Δ X is calculated by linear approximation of a plot in which X is in the range of 5.5eV to 6.0eV by the least square method.

(Experimental example 2)

In experimental example 2, the method for manufacturing a glass substrate for a display according to the present invention was carried out as an in-line process.

In Experimental example 2, an alkali-free glass plate having a thickness of 0.5mm, which contained 59.5% SiO, was manufactured using the float glass manufacturing apparatus 100 shown in FIG. 3₂17% of Al₂O₃8% of B₂O₃3.3% of MgO, 4% of CaO, 7.6% of SrO, 0.1% of BaO, 0.1% of ZrO₂MgO + CaO + SrO + BaO is 15%, and the balance isIs an inevitable impurity, and the total content of alkali metal oxides is 0.1% or less.

The glass raw material 10 is melted by the melting device 200 to obtain molten glass 12, and then the molten glass 12 is supplied to the forming device 300, and the molten glass 12 is formed into a ribbon shape to obtain a glass ribbon 14. Ribbon 14 is drawn from the exit of forming device 300 and then slowly cooled in slow cooling device 400.

At a position where the temperature of the glass ribbon 14 in the slow cooling device 400 is 500 ℃, the ejector 70 having a distance L of 300mm in the moving direction of the glass ribbon 14 is provided.

Fig. 4 is a graph showing the relationship among the slit width (a), the treatment length (b), and the treatment width (c) of the injector in experimental example 2.

In experimental example 2, the flow rates (L/min), treatment times (sec), and linear velocities (mm/sec) of the gases a (mm), b (mm), and c (mm) and HF were set to the conditions shown in table 1 below.

The glass surface temperature (temperature in table 3) and the HF concentration (volume%) when the HF-containing gas was supplied were set to the conditions shown in table 3 below. In Table 3, example 11 is a comparative example, and examples 12 and 13 are examples.

The obtained glass plate was evaluated by the same procedure as in experimental example 1. FIG. 5 shows the relationship between the depth from the surface of the glass plate in example 11 and the fluorine concentration in the glass plate.

Fig. 6(a) and 6(b) show graphs showing the relationship between the irradiation light energy X and the square root Y of the number of photoelectrons emitted in examples 11 and 13.

TABLE 1

TABLE 2

TABLE 3

At F_0-10nm/F_100-400nmExamples 1, 2 and 11 in which Ra was less than 0.3nm were less than 3, and the peeling electrification amount was less than-10 kV. In contrast, in F_0-10nm/F_100-400nmIn examples 3, 4, 12 and 13 in which Ra was not less than 3 and Ra was not less than 0.3nm, the amount of peeling electrification was suppressed and the amount of peeling electrification was not less than-10 kV. In example 11,. DELTA.Y/. DELTA.X < 10, whereas in examples 4, 12 and 13,. DELTA.Y/. DELTA.X.gtoreq.10.

The present invention has been described in detail and with reference to specific embodiments thereof, but it will be apparent to one skilled in the art that various changes or modifications can be made therein without departing from the spirit and scope thereof.

The present application is based on japanese patent application 2017-029636, filed on 21/2/2017, the contents of which are incorporated herein by reference.

Claims

1. A glass substrate for a display, characterized in that,

f is the average value of fluorine concentration (mol%) in the range of 0nm to 10nm in depth from the glass surface of the glass substrate opposite to the semiconductor element forming surface_0-10nmAnd F is the average fluorine concentration (mol%) in the range of 100nm to 400nm in depth from the glass surface_100-400nmWhen the temperature of the water is higher than the set temperature,

F_0-10nm/F_100-400nm≥3，

the surface roughness Ra of the glass surface on the side opposite to the semiconductor element forming surface is 0.3nm to 5nm,

the glass substrate has a peeling electrification amount of-10 kV or more, and

the glass substrate is alkali-free glass.

2. A glass substrate for a display, characterized in that,

F_0-10nm/F_100-400nm≥3，

when the irradiation light energy in the measurement of photoelectron emission yield spectrum (PYS) is X (eV), and the square root of the photoelectron emission number is Y, the slope DeltaY/DeltaX of Y is 10 or more, wherein X is in the range of 5.5eV to 6.0eV, and

the glass substrate is alkali-free glass.

3. A method for manufacturing a glass substrate for display use according to claim 1 or 2, comprising a step of supplying a gas containing Hydrogen Fluoride (HF) to one surface of a plate-like glass transported in a heat treatment apparatus,

the concentration of HF in the HF-containing gas is 0.5 to 30 vol%,

4. The method for manufacturing a glass substrate for a display device according to claim 3, comprising the steps of:

a melting step of melting a glass raw material to obtain a molten glass,

a forming step of forming the molten glass obtained in the melting step into a ribbon shape to obtain a glass ribbon, an

A slow cooling step of slowly cooling the glass ribbon obtained in the forming step; and is

In the slow cooling step, a gas containing HF is supplied to the top surface of the glass ribbon.

5. The method for manufacturing a glass substrate for a display according to claim 4, wherein the forming step is a float forming step.