TWI798247B - Glass substrate for TFT - Google Patents

Abstract

The present invention provides a glass substrate for TFT capable of forming elements or structures more accurately and/or rapidly. The glass substrate 1 for TFT comprises a rectangular glass plate 10 with a first main surface 11 and a second main surface 12 opposite to the first main surface 11, in the field of view from the plate thickness direction of the glass plate 10, it has The first main surface 11, the second main surface 12 opposite to the first main surface 11, the first side 13 connecting the first main surface 11 and the second main surface 12, and the first side 13 adjacent to the first side 13 Two sides 14, and the length of the first side 13 and the second side 14 is at least 1200 mm or larger glass plate 10. The difference between the maximum value Wmax of the thickness W of the glass plate 10 and the minimum value Wmin of the thickness W of the glass plate 10 in the first cross section 15, that is, the thickness tolerance is less than 6.26 μm.

Description

Glass substrate for TFT

The invention relates to a glass substrate for TFT.

Conventionally, flat-panel display panels such as liquid crystal displays are manufactured by facing two glass substrates on which elements or structures such as fine electrodes and partition walls are formed on the surface. For glass substrates for flat-panel display panels, the manufacturing process of thin film transistors (TFT; Thin Film Transistor) is usually applied, that is, after various films are uniformly coated on the surface, exposure and development are performed using photoprocess methods. Elements or structures are formed on the glass substrate. As a glass substrate for a flat-panel display panel, for example, Patent Document 1 discloses a glass plate of 300 mm × 300 mm or more, and the plate thickness of a reference point and a position 20 mm away from the reference point in the X and/or Y directions. The absolute value of the difference is 3 μm or less for glass substrates. [Prior Art Document] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open No. 2009-155136

[Problem to be solved by the invention]

Although there is currently a demand for more precise and/or rapid formation of elements or structures on glass substrates, such requirements have not yet been fully met.

The present invention provides a glass substrate for TFT capable of forming elements or structures more accurately and/or rapidly. [Technical means to solve the problem]

The glass substrate for TFT of the present invention includes a rectangular glass plate having a first main surface and a second main surface facing the first main surface, and has mutually opposite views in the field of view from the plate thickness direction of the above glass plate. Adjacent first side and second side, the length of the first side and the second side is at least 1200 mm, along a straight line parallel to the first side in the section of the glass plate in the thickness direction In the first section, the difference between the maximum thickness and the minimum thickness of the glass plate, that is, the thickness tolerance is less than 6.26 μm. [Effect of Invention]

According to the present invention, for example, it is possible to provide a glass substrate for TFT having a small thickness tolerance and a large glass plate which is easy to focus in an exposure step in a TFT production line and is suitable for TFT production.

Hereinafter, an example of a specific embodiment of the glass substrate for TFT of this invention is described in detail using drawing.

As shown in FIG. 1 , the glass substrate 1 for TFT of the present embodiment includes a rectangular glass plate 10 having a first main surface 11 and a second main surface 12 opposite to the first main surface 11, and further has a first The first side 13 connecting the main surface 11 to the second main surface 12 , and the second side 14 adjacent to the first side 13 . In the view from the plate thickness direction of the glass plate 10, the 1st side 13 and the 2nd side 14 are adjacent to each other. The glass substrate 1 for TFT of this embodiment includes the large glass plate 10 whose length of the 1st side 13 and the 2nd side 14 is at least 1200 mm or more. The view from the thickness direction of the glass plate 10 means a top view. In this specification, the so-called rectangle does not only refer to a strict rectangle, but can also be any shape in which two adjacent sides intersect in the range of 10-170°, or a shape in which four corners are chamfered into a curved or polygonal shape. When the rectangle is a strict rectangle, the first side 13 and the second side 14 intersect each other perpendicularly.

In recent years, such a large glass plate 10 is divided into small pieces in the future to obtain a plurality of glass substrates from the viewpoint of high efficiency. In this process, in the state of a large glass plate 10 , while setting the planned dividing line in the future, desired TFTs are formed on each glass substrate. However, in a large glass plate 10, even if the glass surface is slightly inclined, there will be a large difference in plate thickness between one end surface side and the corresponding other end surface side. Also, the larger the glass plate 10, the more fluctuations of the glass plate caused by various reasons in the manufacturing process, etc., resulting in uneven thickness than the glass plate 10. Also, even if the glass surface is ground, it is extremely difficult to eliminate the difference or unevenness of the plate thickness.

On the other hand, in the TFT formation process, it is necessary to use an exposure machine to focus on the glass surface, etc., but in the case of a large glass plate 10 having the above-mentioned problems, there are the following problems. That is, the exposure machine must frequently and slightly adjust the focus for the unevenness of the surface of the glass plate 10, and cannot perform processing at a high speed. Also, when the unevenness is changed too rapidly, the focus cannot be adjusted sufficiently on the exposure machine side, and the precision of TFT formation is lowered.

Furthermore, in Patent Document 1, unevenness of 3 μm or more may exist in a range of 20 mm or less, and in this case, there is a problem of a decrease in speed or a decrease in accuracy as described above. Also, for the TFT formation process in which exposure is performed over the entire main surface of the glass plate, it may not be sufficient to only perform local regulation of the plate thickness at the reference point and the position 20 mm away from the reference point.

In this embodiment, the second main surface 12 of the glass plate 10 is the semiconductor element formation surface in the glass substrate 1 for TFT, and the first main surface 11 is the glass surface on the opposite side of the semiconductor element formation surface. , fixed on the adsorption table by vacuum adsorption.

Moreover, the glass plate 10 has the 1st cross-section 15 along the straight line parallel to the 1st side 13 with respect to the direction of the thickness W of the glass plate 10 (refer FIG.1(b)). If the first main surface 11 of the first cross-section 15 is enlarged schematically, the first main surface 11 is a concavo-convex continuous surface, and has a maximum value Wmax of the thickness W of the glass plate 10 and a minimum value Wmin of the thickness W ( Refer to Figure 1(c)). The plate thickness W was measured with a laser displacement meter (manufactured by KEYENCE, SI-F80). The measurement distance is set to 20 mm for both the short diameter and the long diameter. The thickness W of the glass plate 10 is, for example, 1.0 mm or less, and the glass substrate 1 for TFT has a large and thin glass plate 10 . Also, the plate thickness W is, for example, 0.01 mm or more. Furthermore, the first cross-section 15 is not a specific cross-section, and can be arbitrarily selected along a straight line parallel to the first side 13 . Moreover, in FIG. 1( c ), the second main surface 12 side is made smooth for convenience, but it may have unevenness similar to the first main surface 11 . When the first main surface 11 and the second main surface 12 have unevenness, the average height in the range of 20 μm, which is the analysis diameter of the displacement meter, is defined as the plate thickness.

The glass substrate 1 for TFT of this embodiment is preferably an alkali-free glass. The alkali-free glass preferably contains 50-73% of SiO ₂ , 10.5-24% of Al ₂ O ₃ , 0.1-12% of B ₂ O ₃ , and 0-8% of MgO, 0-14.5% of CaO, 0-24% of SrO, 0-13.5% of BaO, 0-5% of ZrO ₂ , and the total amount of MgO, CaO, SrO and BaO (MgO+CaO+SrO+BaO) is 8-29.5% .

In addition, the alkali-free glass preferably contains 58-66% of SiO ₂ , 15-22% of Al ₂ O ₃ , 5-12% of B ₂ O ₃ , 0-8 % of MgO, 0-9% of CaO, 3-12.5% of SrO, 0-2% of BaO, and the total amount of MgO, CaO, SrO and BaO (MgO+CaO+SrO+BaO) is 9-18%.

Moreover, the alkali-free glass preferably contains 54-73% of SiO ₂ , 10.5-22.5% of Al ₂ O ₃ , 0.1-5.5% of B ₂ O ₃ , 0-8 % of MgO, 0-9% of CaO, 0-16% of SrO, 0-2.5% of BaO, and the total amount of MgO, CaO, SrO and BaO (MgO+CaO+SrO+BaO) is 8-26%. Since the alkali-free glass is used, the alkaline components contained in the glass plate 10 will not be eluted due to changes over time, and will not adversely affect the TFTs formed on the surface of the glass. Furthermore, in this specification, the so-called "alkali-free" does not mean completely excluding alkaline components in the strict sense, but refers to the concept of the degree to which it is allowed to be included as impurities. Specifically, for example, about 0.01% by mass is allowed.

FIG. 2 is a schematic diagram showing an example of a method of manufacturing the glass substrate 1 for TFT according to this embodiment. The glass substrate 1 for TFT of the present embodiment prepares various raw materials constituting the glass in appropriate amounts, and homogenizes them by defoaming or stirring after heating and melting. Or pressing method, etc., to form a plate shape, and after slow cooling, cut it into the required size and make it into a product. In this embodiment, the manufacturing method of the glass substrate 1 for TFTs is demonstrated using a float method as an example.

The float glass manufacturing apparatus 100 shown in FIG. 2 is provided with: a melting device 110, which melts the glass raw material 2 to form a molten glass 3; and a forming device 120, which forms the molten glass 3 supplied from the melting device 110 into a ribbon. forming a glass ribbon 4; and a slow cooling device 130, which slowly cools the glass ribbon 4 formed by the forming device 120.

The melting apparatus 110 is equipped with the melting tank 111 which accommodates the molten glass 3, and the burner 112 which forms a flame above the molten glass 3 accommodated in the melting tank 111. The glass raw material 2 thrown into the melting tank 111 is slowly melted into the molten glass 3 by the radiant heat from the flame formed by the burner 112 . Molten glass 3 is continuously supplied to forming device 120 from melting tank 111 .

The molding device 120 includes a bath 122 that accommodates molten tin 121 . The forming device 120 flows the molten glass 3 continuously supplied onto the molten tin 121 in a specific direction on the molten tin 121 to form a ribbon-shaped glass ribbon 4 . The ambient temperature in the forming device 120 becomes lower from the entrance of the forming device 120 toward the exit. The ambient temperature in the molding device 120 is adjusted by a heater (not shown) or the like installed in the molding device 120 . The glass ribbon 4 is cooled while flowing in a specific direction, and pulled from the molten tin 121 in the downstream area of the bath 122 . The glass ribbon 4 pulled from the molten tin 121 is conveyed to the slow cooling device 130 by the lifting roller 140 .

The slow cooling device 130 slowly cools the glass ribbon 4 formed by the forming device 120 . The slow cooling device 130 includes, for example: a slow cooling furnace (annealing furnace) 131 with a thermal insulation structure; and a plurality of transport rollers 132, which are arranged in the slow cooling furnace 131 to transport the glass ribbon 4 in a specific direction. The ambient temperature in the slow cooling furnace 131 becomes lower as it goes from the entrance of the slow cooling furnace 131 toward the exit. The ambient temperature in the slow cooling furnace 131 is adjusted by a plurality of heaters 133 etc. installed in the slow cooling furnace 131 . Moreover, the injector 200 which blows the following etching gas onto the glass ribbon 4 is installed in the slow cooling apparatus 130. As shown in FIG.

The glass ribbon 4 carried out from the exit of the slow cooling furnace 131 is cut into a predetermined size by a cutting machine, and shipped as a glass substrate 1 for TFT including a glass plate 10 . Before shipment, at least one of both surfaces of the TFT glass substrate 1 may be ground and cleaned if necessary.

In the manufacturing process of the glass plate 10 including the above-mentioned float glass manufacturing apparatus 100 mentioned as an example, the surface of the glass plate 10 may become uneven|corrugated by the characteristic etc. inherent to a manufacturing apparatus. In particular, as shown in FIG. 3 , from the forming device 120 to the slow cooling device 130 , the phenomenon that the protrusion 16 on the line is observed is observed at one to a plurality of positions in the width direction of the glass plate 10 . Also, as shown in FIG. 4 , the protrusions 16 are often formed on a line in a direction parallel to the first side 13 of the glass plate 10 . In addition, in FIG.3 and FIG.4, although the convex part 16 and the 1st side 13 were illustrated as an example, it is not limited to this. That is, the so-called linear shape does not need to be parallel to the first side 13, and may have a part that is disconnected or partially missing in the middle, or may have a continuously or discontinuously shifted part in the middle.

In order to etch the unevenness or the convexity 16 on the surface to make it smooth (refer to FIG. The injector 200 of the part or the convex part 16 and the like.

In addition, in FIG. 4, although the example which formed the convex part 16 only in the 1st main surface 11 side was shown, it is not limited to this. That is, there may be a case where the convex portion is formed only on the second main surface 12 side, or a case may be formed on both the first main surface 11 and the second main surface 12 . In order to cope regardless of how the convex portion is formed, it is preferable that when the convex portion 16 exists on the first main surface 11 side, the injector 200 is provided on the first main surface 11 side and the convex portion exists on the second main surface 12 side. In the case of 16, injector 200 is provided on the second main surface 12 side.

Furthermore, if the protrusions 16 are formed on the first main surface 11, when the first main surface 11 is adsorbed and fixed in the TFT forming step, new protrusions originating from the protrusions 16 may be formed on the second main surface. Face 12 side. Therefore, regardless of the semiconductor element formation surface, it is preferable that there are very few unevennesses on the surface of the glass plate, and when the convex portion 16 on the first main surface 11 side is removed, it is also possible to achieve higher accuracy and/or Elements or structures are rapidly formed on the second main surface 12 side.

The injector 200 will be described in detail based on FIG. 5 . FIG. 5 is an embodiment of injector 200 .

The injector 200 is equipped with the supply port 201 which blows etching gas, such as hydrogen fluoride (HF) gas, to the glass ribbon 4, and the exhaust port 202 which discharges etching gas. In the embodiment, there are exhaust ports 202 on both sides of one supply port 201 .

The gas (etching gas) blown from the supply port 201 of the injector 200 to the surface of the glass ribbon 4 has a flow of gas in the forward direction (direction of arrow A) or in the opposite direction relative to the moving direction of the glass ribbon 4 (see arrow A). The flow path 203 moves, and flows out to the exhaust port 202 to be exhausted. That is, in the two-flow type, the flow path 203 from the supply port 201 toward the exhaust port 202 is equally divided into a forward direction and a reverse direction with respect to the moving direction of the glass ribbon 4 .

The distance D between the bottom surface of the supply port 201 of the injector 200 and the glass ribbon 4 is preferably 50 mm or less. By setting it as 50 mm or less, diffusion of gas to the atmosphere can be suppressed, and a sufficient amount of gas can reach the surface of the glass ribbon 4 with respect to the required amount of gas. Conversely, if the distance between the bottom surface of the supply port 201 and the glass ribbon 4 is too short, for example, when the glass ribbon 4 produced by the float method is processed on-line, the position of the glass ribbon 4 may change and the glass ribbon 4 may be damaged. Risk of contact with injector 200.

The injector 200 can be used in any form such as double-flow or single-flow, and two or more sprayers can be arranged in series in the flow direction of glass to treat the surface of the glass ribbon 4 .

When surface treatment is performed by supplying etching gas such as hydrogen fluoride (HF) gas to the glass ribbon 4 conveyed in the float glass manufacturing apparatus 100, for example, when the glass ribbon 4 flows on the conveying roller 132 as shown in FIG. 2 , It may be supplied from the side not in contact with the conveyance roller 132, or may be supplied from between the adjacent conveyance rollers 132 on the side in contact with the conveyance roller 132.

Moreover, the surface of the glass ribbon 4 may be processed by arranging two or more conveyors in series, installing the injector 200 between adjacent conveyors, and supplying the gas from the side in contact with the conveyors. Moreover, when the glass ribbon 4 flows on a conveyor, it can also be supplied from the side which does not contact a conveyor. Moreover, it can also supply from the side which contacts a conveyor by using the mesh material which does not cover a part of glass ribbon 4, such as a mesh belt, for a conveyor belt.

The distance D between the supply port 201 of the injector 200 and the glass ribbon 4 is preferably 5-50 mm. The distance D is more preferably 8 mm or more. Also, the distance D is more preferably 30 mm or less, further preferably 20 mm or less. By making distance D 5 mm or more, even if glass ribbon 4 vibrates by an earthquake etc., contact of the surface of glass ribbon 4 and injector 200 can be avoided, for example. On the other hand, by setting the distance D to be 50 mm or less, diffusion of the gas inside the device can be suppressed, and a sufficient amount of gas can reach the upper surface of the glass ribbon 4 relative to the required amount of gas.

Also, the flow velocity (linear velocity) of the gas is preferably 20 to 300 cm/s. By setting the flow velocity (linear velocity) to 20 cm/s or more, in particular, the gas flow of the HF-containing gas is stabilized, so that the glass surface can be treated in the same manner. The flow velocity (linear velocity) is more preferably at least 50 cm/s, further preferably at least 80 cm/s.

Furthermore, when the manufacturing method of the glass substrate 1 for TFT of this embodiment is implemented as an in-line process as shown in FIG. A sufficient amount of gas reaches the upper surface of the glass ribbon 4 under the condition that the diffusion of the gas inside the slow cooling device is suppressed. The flow velocity (linear velocity) is more preferably at most 250 cm/s, further preferably at most 200 cm/s.

The injector 200 is ideally configured relative to a specific surface to be processed (such as a concave-convex portion or a convex portion 16, etc.). Injectors 200 (a total of three locations) are respectively arranged on the convex portions 16 .

In addition, a longer injector can be installed in the width direction of the glass plate, and the position of blowing can be adjusted appropriately in conjunction with the convex portion 16. For example, a cross-sectional view of a beam 302 that adjusts the amount of HF gas by dividing the glass ribbon 4 into three regions shown by I, II, and III in the width direction X is shown in FIG. 6( a ). The jet 302 is an injector that is longer in the width direction of the glass plate, and is formed by stretching the injector 200 in FIG. 5 in a direction perpendicular to the paper. The gas systems 311 to 313 are divided by partition walls 314 and 315 , and each of the gas systems 311 to 313 makes HF gas flow out from the gas blowing hole (supply port) 316 and blows it to the glass. Arrows in Fig. 6(a) indicate the flow of HF gas. Arrows in FIG. 6( b ) indicate the flow of HF gas in the gas system 311 . The arrows in FIG. 6( c ) indicate the flow of HF gas in the gas system 312 . Arrows in FIG. 6( d ) indicate the flow of HF gas in the gas system 313 .

Furthermore, the structure of the injector is not limited to the embodiment shown in Fig. 6 (a) to (d). For example, it is good also as the structure which provided the some partition and divided into 3 or more. The more it is divided into plural parts, the more locally the gas can be sprayed, and the more precisely it can be blown to the convex part 16 .

In addition, at this time, a protrusion detection sensor for detecting the position of the protrusion 16 and a partition wall moving device may be provided. By providing these, the partition walls can be adjusted in the width direction so that HF gas is blown only from directly above the convex portion 16 based on the positional information of the convex portion from the convex portion detection sensor. Here, the gas system only needs to install the number of spaces divided by the partition wall.

Also, as another embodiment, in a gas blowing space, in order to prevent the blowing of HF gas to the positions other than the convex portion 16, an unnecessary gas blowing hole 316 (located directly above the position other than the convex portion 16) may also be provided. Gas blowing hole) Clogged gas blowing hole plugging device. In this case, it is also possible to determine which gas blowing hole 316 is unnecessary based on the position information of the convex portion 16 from the convex portion detection sensor, and to control the gas blowing hole blocking device. Furthermore, in this case, a plurality of gas systems and partition walls may not be provided.

Also, as another embodiment, in a gas blowing space, in order to prevent the blowing of HF gas to the positions other than the convex portion 16, it is also possible to provide suction from the unnecessary gas blowing hole 316 (the positive hole 316 located at the position other than the convex portion). The suction device for the HF gas ejected from the upper gas blowing hole). In this case, it can be determined which gas blowing hole 316 is unnecessary based on the position information of the convex portion 16 from the convex portion detection sensor, and the suction device can be controlled. Furthermore, in this case, a plurality of gas systems and partition walls may not be provided.

The manufacturing method of the glass substrate 1 for TFTs of this embodiment can be implemented by online processing, and can also be implemented by offline processing. The "on-line processing" in this specification refers to the case where the method of this embodiment is applied to the slow cooling process of slowly cooling the glass ribbon 4 formed by the float method or the down-draw method. On the other hand, "offline processing" refers to the case where the method of this embodiment is applied to the glass plate 10 formed and cut into a desired size. Therefore, the glass plate 10 in this specification includes the glass ribbon 4 formed by the float method, the down-draw method, etc. other than the glass plate 10 formed and cut|disconnected to the required size.

It is preferable to implement the manufacturing method of the glass substrate 1 for TFTs 1 of this embodiment by in-line processing for the following reason. Off-line processing requires additional steps, but on-line processing requires no additional steps, so processing can be performed at low cost. Also, if the off-line processing is performed, the gas containing HF is transferred to the semiconductor element forming surface as the second main surface 12 of the glass plate 10, whereas the on-line processing of the glass ribbon 4 can suppress the gas containing HF. transfer into.

The float glass manufacturing device 100 shown in FIG. 2 implements the manufacturing method of the TFT glass substrate 1 of the present embodiment in an in-line processing manner. Therefore, an injector 200 is installed above the glass ribbon 4 in the slow cooling device 130. A gas containing hydrogen fluoride (HF) is supplied to the top surface of the glass ribbon 4 using the injector 200 . In addition, in FIG. 2 , the injector 200 is installed in the slow cooling device 130 , but the injector 200 may be installed in the forming device 120 as long as the glass surface temperature to which the gas containing HF is supplied is 500 to 900° C.

In the manufacturing method of the glass substrate 1 for TFTs of this embodiment, the surface treatment is performed by blowing gas (gas) containing hydrogen fluoride (HF) to at least one surface of the glass ribbon 4 . Instead of hydrogen fluoride gas, a gas (gas) or liquid containing molecules in which fluorine atoms exist in its structure can also be used.

As the etching gas, hydrogen fluoride (HF), fluorocarbons (such as chlorofluorocarbons (CFC), fluorocarbons (FC), hydrofluorocarbons (HCFC), hydrofluorocarbons (HFC)), halomethane, Hydrogen fluoride (HF), fluorine (F ₂ ), trifluoroacetic acid (CF ₃ COOH), carbon tetrafluoride (CF ₄ ), silicon tetrafluoride (SiF ₄ ), phosphorus pentafluoride (PF ₅ ), trifluoride Phosphorous trifluoride (PF ₃ ), boron trifluoride (BF ₃ ), nitrogen trifluoride (NF ₃ ), chlorine trifluoride (ClF ₃ ), etc., but not limited to these gases or liquids. In addition, among these, hydrogen fluoride (HF) gas is preferable from the viewpoint of cost and the well-known treatment method.

FIG. 7 is a graph obtained by actually measuring the plate thickness tolerance (μm) of the first section 15 in the examples and comparative examples (A to C) using the glass substrate 1 for TFT of this embodiment as an example. In the example, the position information of the convex portion was obtained from a glass ribbon having a width of 3500 mm, and HF gas was blown to the position of the convex portion to remove the convex portion. Here, the gas flow rate is set to 0.5 m/SEC, the glass temperature is set to 625-575°C, the gas concentration is set to 20% HF, 80% N2, and the processing time is set to about 10 sec. The removal amount has a linear relationship with the HF concentration in the gas and the treatment time, so by adjusting the above two parameters, the removal amount can also be adjusted. Then, the glass ribbon was cut|disconnected, and the glass plate of 1200 mm x 1200 mm was obtained, and this was made into an Example. Comparative examples A to C are all large glass plates for TFT with a size of 1200 mm×1200 mm or more, which can be obtained through common distribution channels.

In FIG. 7 , each curve represents the tolerance obtained by measuring the plate thickness at 20 mm intervals in the first section 15 and based on the data. In addition, the number of plural curves in the same sample represents the number N (the number of measurements), which are values obtained from different first cross-sections 15 respectively.

From this graph, it can be understood that the maximum value Wmax and the minimum value of the thickness W of the glass plate 10 of the glass substrate 1 for TFT according to the present embodiment are in the first section 15 along a straight line parallel to the first side 13. The difference of Wmin means that the plate thickness tolerance does not reach 6.26 μm. Also, it is preferably 6.0 μm, 5.8 μm, 5.5 μm, 5.3 μm, or 5.0 μm or less. The lower limit is not limited, and is, for example, 1.0 μm or more.

As mentioned above, in the exposure step in the TFT production line, in order to facilitate the focus of the exposure machine, a glass plate 10 with a small plate thickness tolerance is required. The first glass plate 10 of the glass substrate 1 for TFT of this embodiment is The length of the side 13 and the second side 14 is at least 1200 mm or more. In such a large-sized glass plate 10, there is no plate thickness tolerance less than 6.26 μm, which can be realized by the glass substrate 1 for TFT of this embodiment. Form elements or structures more precisely and/or more quickly.

Also, the fact that the plate thickness tolerance is very small in the first cross section 15 is due to the effect of smoothing the protrusions 16 etc. by the etching gas due to the inherent characteristics of the glass plate manufacturing apparatus, which means that the change in the plate thickness W is small.

FIG. 8 is a drawing of the glass substrate 1 for TFT of this embodiment as an example, and the plate thickness tolerances (μm) of all cross-sections are actually measured with respect to the entire surface of the glass plate 10 in the examples and comparative examples (A to C). chart.

In FIG. 8 , each curve represents the tolerance obtained by measuring the plate thickness at a plurality of points at intervals of 20 mm in the thickness direction section of a glass plate randomly extracted and based on the data. Furthermore, the number of multiple curves in the same sample represents the number N, which is the value obtained from different cross-sections selected at random.

From this graph, it can be understood that the glass substrate 1 for TFT according to this embodiment has a plate thickness tolerance of less than 7.12 μm in all cross-sections in the plate thickness direction of the glass plate. Furthermore, the effect of narrowing the plate thickness tolerance was observed in all cross-sections. Therefore, in this embodiment, it is possible to provide a large glass plate 10 having a small plate thickness tolerance in all cross-sections, and it is possible to form elements or structures more accurately and/or rapidly during TFT manufacturing. A glass substrate 1 for TFT.

Also, the plate thickness tolerance is preferably 7.0 μm or less, more preferably 6.5 μm or less, and still more preferably 6.0 μm or less. The lower limit is not limited, and is, for example, 1.0 μm or more.

9 is the absolute value of the first differential value of the first differential value of the plate thickness W of the first section 15 of the glass plate 10 in the examples and comparative examples (A to C) using the glass substrate 1 for TFT of the present embodiment as an example. The graph obtained by comparing the mean values.

In FIG. 9 , each curve is obtained by measuring the plate thickness at a plurality of points at intervals of 20 mm in the first section 15 and obtaining them based on the data. That is, the primary differential value represents the slope of the change in plate thickness between the pitches. In addition, the number of plural curves in the same sample represents the number N, which are values obtained from different first cross-sections 15 .

From this graph, it can be understood that the average value of the absolute value of the first differential value of the plate thickness W in the first cross section 15 of the glass substrate 1 for TFT of this embodiment is less than 1.72E-02. The absolute value of the first differential value of the plate thickness W indicates the degree of change (slope) of the plate thickness W along the first section 15, and the smaller the average value of the absolute value over the first section 15, the smaller the change (slope) The smaller), that is, the surface of the glass has less unevenness and is smoother. If the average value of the absolute value of the first differential value of the plate thickness W is more than 1.72E-02, the unevenness of the surface of the glass plate changes too rapidly. Therefore, it takes more time to align the focus of the exposure machine, and because Since the focus cannot be adjusted sufficiently, the precision of TFT formation tends to decrease. Therefore, according to this embodiment, the glass substrate 1 for TFT which can form an element or a structure more accurately and/or rapidly at the time of TFT manufacture can be provided.

Also, the average value of the absolute value of the first differential value of the plate thickness W is preferably at most 1.7E-02, more preferably at most 1.65E-02, and still more preferably at most 1.6E-02. The lower limit is not limited, and is, for example, 5.0E-03 or more.

In the first cross section 15 of the glass substrate 1 for TFT of this embodiment, the standard deviation of the absolute value of the first differential value of the plate thickness W is 1.5E-03 or less. The standard deviation of the absolute value of the first differential value of the sheet thickness W indicates the degree of variation (inclination) of the sheet thickness W along the first cross section 15 . The smaller the standard deviation of the absolute value over the first cross-section 15 is, the smaller the variation is (the smaller the slope is), and the unevenness is less and smoother.

Also, the standard deviation of the absolute value of the primary differential value of the plate thickness W is preferably at most 1.4E-03, more preferably at most 1.3E-03. The lower limit is not particularly limited, and is, for example, 1.0E-04 or more.

Furthermore, in the glass substrate 1 for TFT of this embodiment, the maximum value of the absolute value of the second differential value of the thickness W in the 1st cross section 15 is 6.0E-03 or less. Preferably it is 5.8E-03 or less, more preferably 5.5E-03 or less. The lower limit is not particularly limited, and is, for example, 1.0E-03 or more. A smaller maximum value of the absolute value of the second differential value of the plate thickness W indicates that the inflection point of the plate thickness is blunted. That is, it means that a surface smoothed by the blowing effect of etching gas is formed. Therefore, in particular, it is easy to focus using a multiple-divided exposure machine. Therefore, according to this embodiment, the glass substrate 1 for TFT which can form an element or a structure more accurately and/or rapidly at the time of TFT manufacture can be provided.

Furthermore, the standard deviation of the absolute value of the second differential value of the plate thickness W in the first cross section 15 of the glass substrate 1 for TFT of this embodiment is 1.5E-04 or less. Preferably it is 1.4E-04 or less, More preferably, it is 1.3E-04 or less, More preferably, it is 1.2E-04 or less. The lower limit is not particularly limited, and is, for example, 5.0E-06 or more. The standard deviation of the absolute value of the second-order differential value of the plate thickness W is extremely small, which means that there is no particularly large protrusion, and the change of the plate thickness W of the glass plate 10 is small, and it is smoothed by the blowing effect of the etching gas. noodle.

In the first section 15, the standard deviation of the absolute value of the first differential value of the plate thickness W, the maximum value of the absolute value of the second differential value, and the standard deviation of the absolute value of the second differential value are extremely small, which means that the entire thickness of the glass plate 10 is The face is smoothed. By smoothing the entire surface of the glass plate 10, for example, focusing can be easily achieved in an exposure step in a TFT production line, and a large-sized glass substrate 1 for TFT with excellent productivity and quality can be provided.

Fig. 10 is a front perspective view showing a second embodiment of the glass substrate 1 for TFT according to this embodiment. A second embodiment will be described based on FIG. 10 .

In the glass substrate 1 for TFTs of the second embodiment, the roughened region 20 and the non-roughened region 21 are formed on the first main surface 11 of the glass plate 10, and these are made to have a predetermined width. The roughened region 20 is a region where the etching gas is blown and has a width L parallel to the second side 14 , and may be, for example, a region obtained by smoothing the convex portion 16 . In addition, the non-roughening region 21 is a region where no etching gas is blown. Furthermore, the roughened region 20 does not need to be accompanied by the removal of the protrusions 16 . For example, by adjusting the amount of etching gas blown or the temperature of the glass, the surface of the glass plate can be roughened almost without decreasing the plate thickness. The glass plate 10 also does not need to be smoothed.

During TFT manufacturing, the first main surface 11 of the glass plate 10 is adsorbed and fixed, but since it is easy to accumulate static electricity on the first main surface 11, when the adsorption and fixation is released, the glass plate 10 will be closely adhered, and there is a glass plate 10. The problem of rupture. In addition, there is also a problem that the formed TFT element is defective due to static electricity accumulated in the glass plate 10 . To deal with these problems, the roughened region 20 can be formed on the first main surface 11, and a region with relatively rough surface roughness can be locally formed to prevent static electricity from accumulating, thereby preventing electrification.

In addition, in the roughened region 20 blown with etching gas, for example, when the protrusions 16 etc. are smoothed by etching, the thickness tolerance in the direction of the thickness W can be minimized and a specific roughness Ra can be given. . Thereby, the glass substrate 1 for TFT which has the large glass plate 10 which can form an element or a structure more precisely and/or rapidly in TFT manufacture, and can also prevent electrification can be provided. Roughness Ra was measured using an Atomic Force Microscope (manufactured by Bruker, Dimension Icon) in Scan Asyst mode, scan size: 5 μm×5 μm, and scan rate: 0.977 Hz. Thereafter, after performing slope correction twice, the arithmetic mean roughness (Ra) within the above-mentioned range was calculated.

In the second embodiment, the roughened region 20 has a predetermined width L in a direction parallel to the first side 13 of the glass plate 10 and is formed in a linear shape. In addition, the number of roughened regions 20 may be arbitrarily increased, and a plurality of them may be formed linearly in a direction parallel to the first side 13 .

Fig. 11 shows the roughness Ra ₁ of the roughened region 20, the roughness Ra ₂ of the non-roughened region 21, and the ratio of roughness Ra (ratio of Ra ₁ to Ra ₂ ) at each treatment temperature (°C) table. The processing temperature (° C.) is the ambient temperature around the glass when the etching gas is blown in the manufacturing steps. Roughness Ra ₁ and Ra ₂ are the average values obtained by measuring 10 points of each of the roughened area and the non-roughened area.

From this table, it can be understood that the ratio of roughness Ra of the roughened region 20 to the non-roughened region 21 is larger than 1 in the glass substrate 1 for TFT of the present embodiment. Preferably it is 3 or more, More preferably, it is 10 or more, Still more preferably, it is 20 or more. The upper limit is not particularly limited, and is, for example, 100 or less. When the ratio of the roughness Ra is within the above-mentioned range, it is possible to prevent static electricity from being easily accumulated in the roughened region and even in the entire glass plate.

In addition, it can be understood that the arithmetic average roughness _Ra1 of the roughened region 20 of the glass substrate 1 for TFT according to this embodiment is _Ra1 >0.5 nm, and the arithmetic average roughness _Ra2 of the non-roughened region 21 is Ra2 _≦ 0.5nm. Ra ₁ is preferably at least 1.0 nm, more preferably at least 3.0 nm, further preferably at least 5.0 nm. The upper limit is not particularly limited, and is, for example, 50 nm or less, preferably 30 nm or less, more preferably 20 nm or less. Also, the lower limit of Ra ₂ is not particularly limited, and is, for example, 0.2 nm or more. If the arithmetic mean roughness Ra ₁ of the roughened area 20 and the arithmetic mean roughness Ra ₂ of the non-roughened area 21 are set within the above-mentioned range, the roughened area and even the glass plate as a whole are less likely to accumulate static electricity, thereby enabling By preventing electrification, elements or structures can be formed more accurately and/or quickly in TFT manufacturing.

Also, in the glass substrate 1 for TFT of the present embodiment, the area of the roughened region 20 is smaller than the area of the non-roughened region 21, and the ratio of the area of the roughened region 20 to the area of the non-roughened region 21 is 3 or more and 300 or less. By blowing the etching gas only to necessary parts, the surface treatment of the glass plate 10 can be efficiently performed, electrification can be prevented, and elements or structures can be formed more accurately and/or rapidly in TFT production.

For example, when blowing gas with a width of 400 mm to a glass plate 10 with a first side 13 of 1200 mm, the ratio of the area of the roughened region 20 to the area of the non-roughened region 21 is preferably 5 or 10 or more. More preferably, it is 20 or more. Also, for example, when blowing gas at a width of 10 mm to a glass plate 10 having a first side 13 of 3000 mm, the ratio is preferably 280 or less, more preferably 250 or less, and still more preferably 230 or less. The surface treatment of the glass plate 10 can be efficiently performed by treating only necessary parts. In addition, the glass plate can be smoothed when accompanied by the removal of the protrusions 16 .

And the width L of the direction parallel to the 2nd side 14 of the roughened area|region 20 is 10 mm or more and 1000 mm or less. The width L is preferably at least 20 mm, more preferably at least 30 mm, further preferably at least 50 mm, further preferably at most 900 mm, more preferably at most 800 mm, further preferably at most 700 mm. The surface treatment of the glass plate 10 can be efficiently performed by treating only necessary parts. In addition, the glass plate can be smoothed when accompanied by the removal of the protrusions 16 . In addition, when there are a plurality of roughened regions 20 , the width L is not the sum of all the roughened regions 20 , but the width of one roughened region 20 .

Fig. 12 is a front perspective view showing a third embodiment of the glass substrate 1 for TFT according to this embodiment. A third embodiment will be described based on FIG. 12 .

In the glass substrate 1 for TFT of 3rd Embodiment, the 1st area|region 30 and the 2nd area|region 31 are formed in the 1st main surface 11 of the glass plate 10, and these have a predetermined width. The first region 30 is a region blown with a fluorine-containing gas (HF, etc.) as an etching gas having a width L parallel to the second side 14, for example, also for smoothing the convex portion 16 and making the plate thickness tolerance smaller. A region with a specific roughness Ra. In addition, the second area 31 is an area where no fluorine-containing gas is blown. Furthermore, the first region 30 does not need to be accompanied by the removal of the convex portion 16 . For example, by adjusting the amount of HF gas to be blown or the temperature of the glass, fluorine can be imparted to the surface of the glass plate almost without reducing the plate thickness. The glass plate 10 also does not need to be smoothed.

In the third embodiment, the first region 30 to which the fluorine-containing gas is blown is formed in a linear shape in a direction parallel to the first side 13 of the glass plate 10 . In addition, the number of first regions 30 may be arbitrarily increased, and a plurality of them may be formed linearly in a direction parallel to the first side 13 .

Fig. 13 is a graph drawn by measuring the fluorine content (wt %) in the first region 30 and the second region 31 at each treatment temperature (°C). The horizontal axis represents the sample number, No. 1 and No. 12 are the second area 31 , and the others (No. 2 to 11) are the first area 30 . The interval between each sample is 25 mm. The treatment temperature (°C) refers to the ambient temperature around the glass when blowing fluorine-containing gas during the manufacturing process. The fluorine content was measured using X-ray Fluorescence (manufactured by Rigaku, ZSX Primus II). The analysis diameter is set to f20 mm, and the intensity of the F-Kα line on the glass surface is measured. Thereafter, the F concentration of the sample was calculated based on a calibration curve obtained using a glass of the same composition whose F concentration was known.

FIG. 14 is a table showing values calculated based on the measured values in FIG. 13 . The fluorine content F (wt%) of the first area 30 and the second area 31 is the average value of each sample at each treatment temperature, and the F concentration ratio is obtained by dividing the F value of the first area 30 by the F value of the second area 31 The value of F, the slope of F (wt%/mm) is the value obtained by calculating the slope (value of No.2/value of No.1) of samples No.1 and No.2.

According to the graph in FIG. 13 and the table in FIG. 14 , it can be understood that the ratio of the fluorine content (wt %) in the first region 30 and the second region 31 is greater than 1. Moreover, the ratio is preferably 3 or more, more preferably 5 or more, and still more preferably 8 or more. The upper limit is not particularly limited, and is, for example, 40 or less, preferably 35 or less, more preferably 30 or less, and still more preferably 25 or less. Furthermore, when the original glass composition does not contain fluorine, the fluorine content in the second region 31 is 0, and the ratio becomes infinite.

By blowing the fluorine-containing gas to the first region 30 , water and oil repellency can be imparted to the surface of the first region 30 . That is, it can be set as a region where the element for TFT is easily peeled off. For example, when the first region 30 is formed in a linear shape on the second main surface 12, which is the TFT formation surface, so as to coincide with the planned division line in the future, even if elements are erroneously formed in the region of the planned division line , and can be easily peeled off.

In the case of using an etching gas containing fluorine, for example, to smooth the convex portion 16, the thickness tolerance in the direction of the thickness W can be made extremely small, and fluorine can be added to the first region, thereby providing a method that can be used more efficiently in TFT manufacturing. A glass substrate 1 for TFT having a large glass plate 10 that can form elements or structures with high precision and/or quickly, and can impart water and oil repellency to the first region. Furthermore, since a region roughened by fluorine can be formed, it is possible to provide a glass substrate 1 for TFT that prevents static electricity from accumulating at the time of TFT manufacture and prevents electrification.

Also, according to the graph in FIG. 13 and the table in FIG. 14, it can be understood that the fluorine content F1 in the first region 30 is 0.5 wt%≦F1≦5 wt%, and the fluorine content F2 in the second region is 0≦F2≦0.15 wt. %. Also, the lower limit of F1 is preferably at least 0.8 wt%, more preferably at least 1.0 wt%, and the upper limit of F1 is preferably at most 4.0 wt%, more preferably at most 3.0 wt%.

Water and oil repellency can be adjusted by setting the fluorine content F of the first region 30 and the second region 31 to the above range. Also, for example, when accompanied by smoothing or roughening of the protrusions 16, etc., it is possible to provide a glass plate 10 with a small thickness tolerance in such a way that the focus in the exposure step on the TFT production line can be easily aligned, Furthermore, it is possible to provide a glass substrate 1 for TFT that prevents static electricity from accumulating easily and prevents electrification.

Furthermore, in the glass substrate 1 for TFT of this embodiment, the area of the 1st region 30 is smaller than the area of the 2nd region 31, and the ratio of the area of the 1st region 30 to the area of the 2nd region 31 is 3 or more and 300 or less. The surface treatment of the glass plate 10 can be performed efficiently by blowing the fluorine-containing gas only to the necessary part. In addition, the glass plate 10 can be smoothed when the protrusion 16 is removed.

Also, it can be understood from the table of FIG. 14 that in the first region 30 of the TFT glass substrate 1 of the present embodiment, the slope of the fluorine content F in the direction parallel to the second side 14 is 0.001 wt %/mm or more and 0.15 wt %/mm or more. wt%/mm or less. And, it is preferably 0.13 wt%/mm or less, more preferably 0.12 wt%/mm or less, and still more preferably 0.10 wt%/mm or less. The surface treatment of the glass plate 10 can be performed efficiently by blowing the fluorine-containing gas only to the necessary part. In addition, the glass plate can be smoothed when accompanied by the removal of the protrusions 16 .

Preferably, the glass plate 10 of the glass substrate for TFT 1 of the present embodiment does not have polishing marks on at least one of the first main surface 11 and the second main surface 12 . It is more preferable that none have grinding marks. The presence or absence of grinding marks can be judged by surface observation using an AFM (Atomic Force Microscope: Atomic Force Microscope). In this specification, when there is one or more scratches with a length of 5 μm or more in the area of 100 μm×5 μm, it is called the state of “with grinding marks” on the surface, and the opposite is called “without grinding marks” state. Since the first main surface 11 and the second main surface 12 do not have grinding marks, elements or structures can be formed more accurately and/or rapidly in TFT production. Moreover, the surface strength of the glass plate 10 can be improved.

Fig. 15 is a graph obtained by measuring the amount of β-OH on the first main surface 11 and the second main surface 12 in this embodiment.

It can be understood from the graph of FIG. 15 that the glass plate 10 of the glass substrate 1 for TFT of the present embodiment has 10 on either the first main surface 11 that is not in contact with the molten tin or the second main surface 12 that is in contact with the molten tin. A layer with a moisture content of 80% or less relative to the main body (central position in the thickness W direction) of μm or more.

It can be understood that if at least one of the first main surface 11 and the second main surface 12 has a layer with a moisture content of 10 μm or more and a moisture content of 80% or less relative to the main body, the glass plate is made of a floating type. Glass plate 10 manufactured by method. The float method is an excellent method for obtaining glass plates with a larger area, and it is easy to obtain glass plates with a size of 1200 mm × 1200 mm or more. The size of the glass plate is preferably at least 1500 mm×1500 mm, more preferably at least 2000 mm×2000 mm, further preferably at least 2500 mm×2500 mm. The length of at least one side is 1200 mm to 7000 mm. A plurality of glass substrates on which TFTs are formed can be taken out from one glass plate. In addition, the β-OH value which is water content is measured by the transmittance using an infrared spectrophotometer or secondary ion mass spectrometry (SIMS).

In addition, this invention is not limited to the said embodiment, A change, improvement, etc. can be added suitably. In addition, the material, shape, size, numerical value, form, quantity, arrangement position, etc. of each component in the above-mentioned embodiment are arbitrary as long as they can reach the present invention, and are not limited.

In addition, highly flat glass substrates are not limited to glass substrates for TFTs, and are required in various fields. For example, in the case of forming a resin pattern on the surface of glass by imprinting, there are cases where the portion of the concave region corresponding to the undulations of the glass is not properly pressed against the mold and a desired pattern is not obtained. In this case, if it is a higher flat glass, the pressing force of the mold will be evenly transmitted to the glass surface, so it is ideal. For example, when the size of the glass used for imprinting is rectangular, the length of at least one side is 50 mm to 7000 mm.

Although this invention was demonstrated in detail with reference to the specific embodiment, it is clear for those skilled in the art that various corrections and changes can be added without deviating from the spirit and range of this invention. This application is based on Japanese Patent Application No. 2017-155468 filed on August 10, 2017 and Japanese Patent Application No. 2018-138799 filed on July 24, 2018, and the contents thereof are incorporated by reference. Introduced in this article. [Industrial availability]

The glass substrate for TFT of the present invention is preferably used in a field requiring a large-sized glass plate with a small thickness tolerance for improving productivity on a TFT production line, preventing static electricity, and the like.

1‧‧‧Glass substrate for TFT 2‧‧‧Glass raw material 3‧‧‧Molten glass 4‧‧‧Glass ribbon 10‧‧‧Glass plate 11‧‧‧First main surface 12‧‧‧Second main surface 13‧ ‧‧First side 14‧‧‧Second side 15‧‧First section 16‧‧‧Convex part 20‧‧‧Roughened area 21‧‧Non-roughened area 30‧‧‧First area 31 ‧‧‧The second area 100‧‧‧float glass manufacturing device 110‧‧‧melting device 111‧‧‧melting tank 112‧‧‧burner 120‧‧‧forming device 121‧‧‧melting tin 122‧‧‧bath 130‧‧‧slow cooling device 131‧‧‧slow cooling furnace 132‧‧‧conveying roller 133‧‧‧heater 140‧‧‧lifting roller 200‧‧‧ejector 201‧‧‧supply port 202‧‧‧exhaust Port 203‧‧‧flow path 302‧‧‧jet 311‧‧‧gas system 312‧‧‧gas system 313‧‧‧gas system 314‧‧‧partition wall 315‧‧‧partition wall 316‧‧‧gas blowing hole D‧‧‧distance L‧‧‧width W‧‧‧thickness Wmax‧‧‧maximum value Wmin‧‧‧minimum value X‧‧‧direction Y‧‧‧direction Z‧‧‧direction

Fig. 1 shows an example of the first embodiment of the glass substrate for TFT of the present invention, Fig. 1(a) shows a front perspective view, (b) shows a cross-sectional view of A-A of (a), and (c) shows an enlarged portion of B of (b) pattern diagram. Fig. 2 is a schematic view showing an example of a float glass manufacturing apparatus for a glass substrate for TFT according to the present invention. Fig. 3 is a schematic view showing protrusions generated during the manufacture of the glass substrate for TFT of the present invention. Fig. 4 specifically shows the convex part of Fig. 3, Fig. 4 (a) is a front perspective view of a glass plate, (b) is an explanatory diagram showing the etching state of the convex part. Fig. 5 is a schematic view showing an injector installed in a float glass manufacturing apparatus for a glass substrate for TFT according to the present invention. Fig. 6 is a schematic view of the beam of the injector which is longer in the width direction of the glass plate, Fig. 6(a) is the overall configuration diagram of the beam, and each of (b) to (d) represents three gases Schematic diagram of the flow of HF gas in the system. Fig. 7 is a graph drawn by actually measuring the thickness tolerance of the glass substrate for TFT of the present invention and the comparative example in the first section. Fig. 8 is a graph drawn by actually measuring the thickness tolerance of the glass substrate for TFT of the present invention and the comparative example in all cross-sections. 9 is a graph comparing the average value of the absolute value of the first differential value of the first cross-section of the glass substrate for TFT of the present invention and the comparative example. Fig. 10 is a front perspective view showing an example of the second embodiment of the glass substrate for TFT of the present invention. Fig. 11 is a table showing the ratio of roughness at each processing temperature in the glass substrate for TFT of the present invention. Fig. 12 is a front perspective view showing an example of a third embodiment of the glass substrate for TFT of the present invention. 13 is a graph drawn by measuring the fluorine content in the first region and the second region at each treatment temperature in the glass substrate for TFT of the present invention. FIG. 14 is a table showing the calculation results based on FIG. 13 . Fig. 15 is a graph drawn by measuring the amount of β-OH on the first main surface and the second main surface of the glass substrate for TFT of the present invention.

1‧‧‧Glass substrate for TFT

10‧‧‧glass plate

11‧‧‧The first main surface

12‧‧‧The second main surface

13‧‧‧side 1

14‧‧‧side 2

15‧‧‧The first section

W‧‧‧board thickness

Wmax‧‧‧maximum value

Wmin‧‧‧minimum value

Claims (23)

A glass substrate for TFT, which comprises a rectangular glass plate with a first main surface and a second main surface facing the first main surface, and has mutual mutual Adjacent first side and second side, the length of the first side and the second side is at least 1200 mm, and the distance between the straight line parallel to the first side in the section of the glass plate in the thickness direction In the first section, the difference between the maximum thickness and the minimum thickness of the glass plate, that is, the thickness tolerance is less than 6.26 μm, the first main surface has a roughened area and a non-roughened area, and the roughened The ratio of the roughness of the surfaced area to the aforementioned non-roughened area is greater than 1. The glass substrate for TFT according to claim 1, wherein the arithmetic mean roughness Ra ₁ of the roughened region is Ra ₁ >0.5nm, and the arithmetic mean roughness Ra ₂ of the non-roughened region is Ra ₂ ≦0.5nm. The glass substrate for TFT according to claim 1 or 2, wherein the area of the above-mentioned roughened area is smaller than the area of the above-mentioned non-roughened area, and the ratio of the area of the above-mentioned roughened area to the area of the above-mentioned non-roughened area is 3 Above and below 300. The glass substrate for TFT as claimed in claim 1 or 2, wherein the above-mentioned roughened region is in the same position as the above-mentioned first The direction in which the sides are parallel is formed in a linear shape. The glass substrate for TFT according to claim 1 or 2, wherein the plurality of roughened regions are formed linearly in a direction parallel to the first side. The glass substrate for TFT according to Claim 4, wherein the width of the roughened region in a direction parallel to the second side is 10 mm to 1000 mm. The glass substrate for TFT according to claim 5, wherein the width of the roughened region in a direction parallel to the second side is 10 mm to 1000 mm. A glass substrate for TFT, which comprises a rectangular glass plate with a first main surface and a second main surface facing the first main surface, and has mutual mutual Adjacent first side and second side, the length of the first side and the second side is at least 1200 mm, and the distance between the straight line parallel to the first side in the section of the glass plate in the thickness direction In the first section, the difference between the maximum thickness and the minimum thickness of the glass plate, that is, the thickness tolerance is less than 6.26 μm, and the first main surface has a first region and a second region, and the first region The ratio to the content of fluorine in the second region is greater than 1. The glass substrate for TFT according to claim 8, wherein the fluorine content F1 in the first region is 0.5 wt%≦F1≦5wt%, and the fluorine content F2 in the second region is 0≦F2≦0.15wt%. The glass substrate for TFT according to claim 8 or 9, wherein the area of the first region is smaller than the area of the second region, and the ratio of the area of the first region to the area of the second region is 3 or more and 300 or less. The glass substrate for TFT according to claim 8 or 9, wherein the first region is formed in a linear shape in a direction parallel to the first side. The glass substrate for TFT according to claim 8 or 9, wherein a plurality of said first regions are formed in a line in a direction parallel to said first side. The glass substrate for TFT according to claim 11, wherein in the first region, the slope of the fluorine content in the direction parallel to the second side is 0.001 wt%/mm or more and 0.15 wt%/mm or less. The glass substrate for TFT according to claim 12, wherein in the first region, the slope of the fluorine content in the direction parallel to the second side is 0.001 wt%/mm to 0.15 wt%/mm. A glass substrate for TFT, which comprises a rectangular glass plate with a first main surface and a second main surface facing the first main surface, and has mutual mutual Adjacent sides 1 and 2 The length of the above-mentioned first side and the above-mentioned second side is at least 1200 mm, and in the first cross-section along the straight line parallel to the above-mentioned first side in the cross-section of the above-mentioned glass plate in the thickness direction, the length of the glass plate The difference between the maximum value of the plate thickness and the minimum value of the plate thickness, that is, the plate thickness tolerance is less than 6.26 μm, and the above-mentioned glass plate has a relative thickness of 10 μm or more on at least one of the above-mentioned first main surface and the above-mentioned second main surface. The moisture content of the main body is a layer with a moisture content of 80% or less. The glass substrate for TFT according to any one of claims 1, 2, 8, 9, and 15, wherein the thickness tolerance of the glass plate is less than 7.12 μm in all cross-sections in the thickness direction of the glass plate. The glass substrate for TFT according to any one of Claims 1, 2, 8, 9, and 15, wherein the average value of the absolute value of the first differential value of the plate thickness is less than 1.72E-02 in the first section. The glass substrate for TFT according to any one of Claims 1, 2, 8, 9, and 15, wherein in the first section, the standard deviation of the absolute value of the first differential value of the plate thickness is 1.5E-03 or less. The glass substrate for TFT according to any one of Claims 1, 2, 8, 9, and 15, wherein in the above-mentioned first section, the maximum value of the absolute value of the second differential value of the above-mentioned plate thickness is 6.0E-03 or less . The glass substrate for TFT according to any one of Claims 1, 2, 8, 9, and 15, wherein in the above-mentioned first section, the standard deviation of the absolute value of the second-order differential value of the above-mentioned plate thickness is 1.5E-04 or less Down. The glass substrate for TFT according to any one of claims 1, 2, 8, 9, and 15, wherein the glass composition of the glass plate is alkali-free glass. The glass substrate for TFT according to any one of claims 1, 2, 8, 9, and 15, wherein the glass plate has no grinding marks on at least one of the first main surface and the second main surface. The glass substrate for TFT according to any one of claims 1, 2, 8, 9, and 15, wherein the thickness of the glass plate is 1.0 mm or less.

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