JP2019034878A - TFT glass substrate - Google Patents

Abstract

To provide a TFT glass substrate capable of highly accurately and/or quickly forming an element or a structure.SOLUTION: A TFT glass substrate 1 is formed of a rectangular glass plate 10 including a first main surface 11 and a second main surface 12 opposite to the first main surface 11. In visual field from the thickness direction of the glass plate 10, the large-sized glass plate 10 includes the first main surface 11, the second main surface 12 opposite to the first main surface 11, a first side 13 connecting the first main surface 11 and the second main surface 12 and a second side 14 adjacent to the first side 13, and the first side 13 and the second side 14 have a length of at least 1200 mm or more. A plate thickness tolerance being a difference between the maximum Wmax of thickness W of the glass plate 10 and the minimum Wmin of thickness W in a first cross section 15 is less than 6.26 μm.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a glass substrate for TFT.

  2. Description of the Related Art Conventionally, a flat display panel such as a liquid crystal display is manufactured by opposing two glass substrates having elements or structures such as fine electrodes and partition walls formed on the surface thereof. For glass substrates for flat display panels, elements and structures are formed on the glass substrate by uniformly applying various films on the surface, then exposing and developing using a photo process technique. It is customary to apply a manufacturing process of a thin film transistor (TFT). As a glass substrate for that purpose, for example, in Patent Document 1, a difference in plate thickness between a reference point and a position 20 mm away from the reference point in the X and / or Y direction is a glass plate of 300 mm × 300 mm or more. A glass substrate having an absolute value of 3 μm or less is disclosed.

JP 2009-155136 A

  At present, there is a demand for forming elements and structures on a glass substrate with higher accuracy and / or speed, but it has not yet reached a sufficient area.

  The present invention provides a TFT glass substrate capable of forming elements and structures with higher accuracy and / or speed.

  The glass substrate for TFT of the present invention is composed of a rectangular glass plate having a first main surface and a second main surface facing the first main surface, and in a field of view from the thickness direction of the glass plate The first side and the second side that are adjacent to each other, and the length of the first side and the second side is at least 1200 mm or more, of the cross section in the plate thickness direction of the glass plate, In the first cross section along the straight line parallel to the first side, the thickness tolerance which is the difference between the maximum thickness value and the minimum thickness value of the glass plate is less than 6.26 μm.

  ADVANTAGE OF THE INVENTION According to this invention, the glass substrate for TFT which has a large board | plate with a small board | plate thickness tolerance and suitable for TFT manufacture which is easy to focus on the exposure process in a TFT manufacturing line, for example can be provided.

FIG. 1 shows an example of a first embodiment of a glass substrate for TFT according to the present invention. FIG. 1 (a) is a front perspective view, FIG. 1 (b) is an AA cross-sectional view of FIG. The B section enlarged schematic diagram of (b) is shown. FIG. 2 is a schematic view showing an example of a float glass manufacturing apparatus for a TFT glass substrate according to the present invention. FIG. 3 is a schematic view showing convex portions generated during the manufacture of the TFT glass substrate according to the present invention. 4 specifically shows the convex portion of FIG. 3, FIG. 4A is a front perspective view of the glass plate, and FIG. 4B is an explanatory view showing an etching state of the convex portion. FIG. 5 is a schematic view showing an injector installed in a float glass manufacturing apparatus for a TFT glass substrate according to the present invention. FIG. 6 is a schematic diagram of a beam which is an injector that is long in the width direction of the glass plate. FIG. 6A is an overall configuration diagram of the beam, and FIGS. 6B to 6D are HF in three gas systems. It is a schematic diagram which shows the flow of gas. FIG. 7 is a graph obtained by actually plotting the thickness tolerance in the first cross section between the glass substrate for TFT according to the present invention and the comparative example. FIG. 8 is a graph obtained by actually measuring and plotting the thickness tolerances in all cross sections between the TFT glass substrate according to the present invention and the comparative example. FIG. 9 is a graph comparing average values of absolute values of first-order differential values of the thickness of the first cross section of the TFT glass substrate according to 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 according to the present invention. FIG. 11 is a table showing the ratio of roughness at each processing temperature in the TFT glass substrate according to the present invention. FIG. 12 is a front perspective view showing an example of the third embodiment of the glass substrate for TFT according to the present invention. FIG. 13 is a graph obtained by measuring and plotting the fluorine content in the first region and the second region at each processing temperature in the TFT glass substrate according to the present invention. FIG. 14 is a table showing calculation results based on FIG. FIG. 15 is a graph obtained by measuring and plotting the β-OH amounts of the first main surface and the second main surface of the glass substrate for TFT according to the present invention.

  Hereinafter, an example of a specific embodiment of a glass substrate for TFT according to the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1, the glass substrate 1 for TFT of this embodiment is comprised from the rectangular glass plate 10 provided with the 1st main surface 11 and the 2nd main surface 12 facing the 1st main surface 11. As shown in FIG. Furthermore, a first side 13 connecting the first main surface 11 and the second main surface 12 and a second side 14 adjacent to the first side 13 are provided. In the field of view of the glass plate 10 from the thickness direction, the first side 13 and the second side 14 are adjacent to each other. The glass substrate 1 for TFT of this embodiment is comprised with the large sized glass plate 10 whose length of the 1st edge | side 13 and the 2nd edge | side 14 is at least 1200 mm or more. The visual field from the thickness direction of the glass plate 10 refers to a plan view. In the present specification, a rectangle is not intended to be a strict rectangle only, but a shape in which any two adjacent sides intersect within a range of 10 to 170 °, and four corners are chamfered into a curved shape or a polygonal shape. The shape may be different. When the rectangle is a strict rectangle, the first side 13 and the second side 14 intersect each other vertically.

  In recent years, from the viewpoint of high efficiency, such a large glass plate 10 is divided into small portions in the future to obtain a plurality of glass substrates. In this process, necessary TFTs are formed on each glass substrate in the state of the large glass plate 10 while assuming future dividing lines. However, in the large glass plate 10, even if the glass surface is slightly inclined, there is a large difference in plate thickness between the one end surface side and the corresponding other end surface side. Moreover, the larger the glass plate 10, the more swell of the glass plate due to various factors in the manufacturing process, and the thickness of the glass plate 10 varies in various places. Moreover, even if the glass surface is polished, it is extremely difficult to eliminate these differences and variations in plate thickness.

  On the other hand, in the TFT formation process, it is necessary to focus on the glass surface and the like with an exposure machine. However, the large glass plate 10 having the above-described problems has the following problems. That is, the exposure machine has to frequently and finely adjust the unevenness on the surface of the glass plate 10 and cannot be processed at a high speed. In addition, when the unevenness change was too steep, the focus could not be adjusted sufficiently on the exposure machine side, and the accuracy of TFT formation was lowered.

  In Patent Document 1, there is a possibility that there are irregularities of 3 μm or more within a range of 20 mm or less, and in that case, there are problems such as a decrease in speed and a decrease in accuracy as described above. In addition, with respect to the TFT formation process in which exposure is performed over the entire main surface of the glass plate, it is possible that the local definition of the plate thickness only at the reference point and a position 20 mm away from the reference point is not sufficient.

  In the present embodiment, the second main surface 12 of the glass plate 10 is a semiconductor element forming surface in the TFT glass substrate 1, the first main surface 11 is a glass surface opposite to the semiconductor element forming surface, and the semiconductor element At the time of formation, it is fixed on the suction stage by vacuum suction.

  Further, the glass plate 10 has a first cross section 15 along the straight line parallel to the first side 13 with respect to the direction of the thickness W of the glass plate 10 (see FIG. 1B). When the first main surface 11 of the first cross section 15 is schematically enlarged, the first main surface 11 is a continuous surface with irregularities, and the maximum value Wmax of the plate thickness W and the minimum value Wmin of the plate thickness W are (See FIG. 1C). The plate thickness W was measured with a laser displacement meter (manufactured by KEYENCE, SI-F80). The measurement pitch was 20 mm for both the minor axis and the major axis. The plate thickness W of the glass plate 10 is, for example, 1.0 mm or less, and the TFT glass substrate 1 has a large and thin glass plate 10. The plate thickness W is, for example, 0.01 mm or more. The first cross section 15 is not a specified cross section, but can be arbitrarily selected along a straight line parallel to the first side 13. Further, in FIG. 1C, the second main surface 12 side is smooth for convenience, but may be uneven as in the first main surface 11. When the 1st main surface 11 and the 2nd main surface 12 have an unevenness | corrugation, the average height of the range of 20 micrometers which is an analysis diameter of a displacement meter was made into plate | board thickness.

The glass substrate 1 for TFT of this embodiment is preferably non-alkali glass. Alkali-free glass, by mass percentage based on the following oxides, the SiO ₂ fifty to seventy-three% of _{Al 2 O 3 10.5~24%, B} 2 O 3 and from 0.1 to 12%, the MgO 0 -8%, CaO 0-14.5%, SrO 0-24%, BaO 0-13.5%, ZrO ₂ 0-5%, and a combination of MgO, CaO, SrO and BaO. The amount (MgO + CaO + SrO + BaO) is preferably 8 to 29.5%.

Further, alkali-free glass, by mass percentage based on the following oxides, the SiO ₂ 58 to 66% of _{Al 2 O 3 15~22%, B} 2 O 3 5 to 12% of MgO 0 to 8 %, CaO 0 to 9%, SrO 3 to 12.5%, BaO 0 to 2%, and the total amount of MgO, CaO, SrO and BaO (MgO + CaO + SrO + BaO) is 9 to 18% Is preferred.

The alkali-free glass, by mass percentage based on the following oxides, the SiO ₂ from 54 to 73%, the _{Al 2 O 3 10.5~22.5%, B} 2 O 3 0.1 to 5. 5%, MgO 0-8%, CaO 0-9%, SrO 0-16%, BaO 0-2.5%, and the total amount of MgO, CaO, SrO and BaO (MgO + CaO + SrO + BaO) Is preferably 8 to 26%.
By being non-alkali glass, the alkaline component contained in the glass plate 10 is eluted by a change over time and does not adversely affect TFTs formed on the glass surface. In the present specification, “non-alkali” does not completely include an alkali component in a strict sense, but refers to a concept that allows a degree of inclusion as an impurity. Specifically, for example, about 0.01% by mass is allowed.

  FIG. 2 is a schematic view showing an example of a manufacturing method of the TFT glass substrate 1 according to the present embodiment. The TFT glass substrate 1 according to the present embodiment is prepared by preparing appropriate amounts of various raw materials constituting the glass, heating and melting, and then homogenizing by defoaming or stirring, and then using a well-known float method or down draw method (for example, fusion). Method) or a press method, etc., and after slow cooling, cut into a desired size to produce a product. In the present embodiment, a manufacturing method of the glass substrate 1 for TFT will be described taking a float method as an example.

  A float glass manufacturing apparatus 100 shown in FIG. 2 is a melting apparatus 110 that melts a glass raw material 2 to form a molten glass 3 and a molding apparatus that forms the molten glass 3 supplied from the melting apparatus 110 into a strip shape to form a glass ribbon 4. 120 and a slow cooling device 130 that slowly cools the glass ribbon 4 molded by the molding device 120.

  The melting apparatus 110 includes a melting tank 111 that stores the molten glass 3 and a burner 112 that forms a flame above the molten glass 3 stored in the melting tank 111. The glass raw material 2 put into the melting tank 111 is gradually melted into the molten glass 3 by the radiant heat from the flame formed by the burner 112. The molten glass 3 is continuously supplied from the melting tank 111 to the molding apparatus 120.

  The molding apparatus 120 includes a bathtub 122 that accommodates molten tin 121. The forming apparatus 120 forms the strip-shaped glass ribbon 4 by causing the molten glass 3 continuously supplied on the molten tin 121 to flow on the molten tin 121 in a predetermined direction. The ambient temperature in the molding apparatus 120 becomes lower as it goes from the inlet to the outlet of the molding apparatus 120. The atmospheric temperature in the molding apparatus 120 is adjusted by a heater (not shown) provided in the molding apparatus 120. The glass ribbon 4 is cooled while flowing in a predetermined direction, and is pulled up from the molten tin 121 in the downstream area of the bathtub 122. The glass ribbon 4 pulled up from the molten tin 121 is conveyed to the slow cooling device 130 by the lift-out roll 140.

  The slow cooling device 130 gradually cools the glass ribbon 4 formed by the forming device 120. The slow cooling device 130 includes, for example, a slow cooling furnace (rare) 131 having a heat insulating structure and a plurality of transport rolls 132 that are disposed in the slow cooling furnace 131 and transport the glass ribbon 4 in a predetermined direction. The atmospheric temperature in the slow cooling furnace 131 becomes lower as it goes from the inlet to the outlet of the slow cooling furnace 131. The ambient temperature in the slow cooling furnace 131 is adjusted by a plurality of heaters 133 provided in the slow cooling furnace 131. In addition, in the slow cooling device 130, an injector 200 for blowing an etching gas, which will be described later, onto the glass ribbon 4 is provided.

  The glass ribbon 4 carried out from the outlet 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 composed of the glass plate 10. Before shipping, at least one of both surfaces of the TFT glass substrate 1 may be polished and cleaned as necessary.

  In the manufacturing process of the glass plate 10 including the float glass manufacturing apparatus 100 described above as an example, unevenness may occur on the surface of the glass plate 10 due to a habit unique to the manufacturing apparatus. In particular, as shown in FIG. 3, there may be a phenomenon in which the convex portions 16 on the line are generated at a plurality of locations in the width direction of the glass plate 10 from the forming device 120 to the slow cooling device 130. Further, as shown in FIG. 4, the convex portion 16 is often formed on a line in a direction parallel to the first side 13 of the glass plate 10. In FIGS. 3 and 4, the convex portion 16 is illustrated in parallel with the first side 13, but is not limited thereto. That is, the line shape does not have to be parallel to the first side 13, and there may be a part that is divided or partially missing in the middle, or a part that is continuously or discontinuously displaced in the middle.

  In order to make the surface irregularities and convex portions 16 smooth by etching (see FIG. 4B), the concave and convex portions formed on the glass ribbon 4 with the etching gas in the slow cooling device 130 of the float glass manufacturing apparatus 100. And an injector 200 for spraying the convex portion 16 and the like.

  In addition, although the example in which the convex part 16 was formed only in the 1st main surface 11 side was shown in FIG. 4, it is not limited to this. That is, a convex portion may be formed only on the second main surface 12 side, and may be formed on both the first main surface 11 and the second main surface 12. When there is a convex portion 16 on the first main surface 11 side, the convex portion 16 is on the second main surface 12 side when the convex portion 16 is on the first main surface 11 side so that it can cope with how the convex portions are formed. In some cases, it is preferable to provide the injector 200 on the second main surface 12 side.

  In addition, when the convex part 16 is formed in the 1st main surface 11, when the 1st main surface 11 is adsorbed and fixed in a TFT formation process, the new convex part derived from the convex part 16 will be the 2nd main surface 12 side. Can be formed. Therefore, it is preferable that the unevenness present on the surface of the glass plate is extremely small regardless of whether the semiconductor element formation surface is present. Even when the convex portion 16 on the first main surface 11 side is removed, the second main surface 12 is removed. Elements and structures can be formed on the side with higher accuracy and / or speed.

  The injector 200 will be described in detail with reference to FIG. FIG. 5 shows an embodiment of the injector 200.

  The injector 200 includes a supply port 201 for blowing an etching gas such as hydrogen fluoride (HF) gas onto the glass ribbon 4 and an exhaust port 202 for exhausting the etching gas. The embodiment has exhaust ports 202 on both sides with respect to one supply port 201.

  The gas (etching gas) blown from the supply port 201 of the injector 200 onto the surface of the glass ribbon 4 is a gas in the forward direction (arrow A direction) or in the reverse direction with respect to the moving direction of the glass ribbon 4 (see arrow A). It moves through the flow path 203 indicating the flow, flows out to the exhaust port 202, and is exhausted. That is, in the double flow type, the flow path 203 from the supply port 201 to the exhaust port 202 is equally divided in the forward direction and the 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 to 50 mm or less, it is possible to suppress the gas from diffusing into the atmosphere, and a sufficient amount of gas can reach the surface of the glass ribbon 4 with respect to the desired gas amount. On the other hand, 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 process is processed online, the glass ribbon 4 changes due to the fluctuation of the position of the glass ribbon 4. And the injector 200 may come into contact with each other.

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

  When the surface treatment is performed by supplying an etching gas such as hydrogen fluoride (HF) gas to the glass ribbon 4 being transported in the float glass manufacturing apparatus 100, the glass ribbon 4 is transported as shown in FIG. In the case of flowing over 132, it may be supplied from the side not touching the transport roll 132, or may be supplied from between adjacent transport rolls 132 on the side touching the transport roll 132.

  Further, by arranging two or more conveyors in series and installing the injector 200 between adjacent conveyors, the surface of the glass ribbon 4 may be processed by supplying the gas from the side in contact with the conveyor. Moreover, when the glass ribbon 4 is flowing on the conveyor, you may supply from the side which is not touching the conveyor. Moreover, you may supply from the side which touches a conveyor by using the mesh raw material which is not covered with some glass ribbons 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 to 50 mm. The distance D is more preferably 8 mm or more. The distance D is more preferably 30 mm or less, and still more preferably 20 mm or less. By setting the distance D to be 5 mm or more, contact between the surface of the glass ribbon 4 and the injector 200 can be avoided even if the glass ribbon 4 vibrates due to, for example, an earthquake. On the other hand, by setting the distance D to 50 mm or less, the gas can be prevented from diffusing inside the apparatus, and a sufficient amount of gas can reach the upper surface of the glass ribbon 4 with respect to the desired gas amount.

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

  And as shown in FIG. 2, when implementing the manufacturing method of the glass substrate 1 for TFT of this embodiment as an on-line process, gas is made into a slow cooling apparatus by making a flow rate (linear velocity) into 300 cm / s or less. A sufficient amount of gas can reach the upper surface of the glass ribbon 4 in a state in which it is prevented from diffusing inside. The flow velocity (linear velocity) is more preferably 250 cm / s or less, and further preferably 200 cm / s or less.

  The injector 200 is desirably arranged with respect to a predetermined surface to be processed (for example, the concavo-convex portion or the convex portion 16). For example, as shown in FIG. 3, the convex portions 16 are generated at three locations. In this case, it is desirable that the injectors 200 (three places in total) are arranged on the convex portion 16 respectively.

  Further, a long injector may be provided in the width direction of the glass plate, and the location to be sprayed may be appropriately adjusted according to the convex portion 16. For example, FIG. 6A shows a cross-sectional view of a beam 302 that adjusts the amount of HF gas by dividing it into three regions indicated by I, II, and III in the width direction X of the glass ribbon 4. The beam 302 is an injector that is long in the width direction of the glass plate, and is configured by extending the injector 200 in FIG. 5 in a direction perpendicular to the paper surface. The gas systems 311 to 313 are divided by partition walls 314 and 315, and HF gas is caused to flow out from the gas blowing holes (supply ports) 316 and blown to the glass. The arrow in (a) of Drawing 6 shows the flow of HF gas. The arrow in (b) of FIG. 6 shows the flow of HF gas in the gas system 311. The arrow in (c) of FIG. 6 shows the flow of HF gas in the gas system 312. The arrows in FIG. 6D indicate the flow of HF gas in the gas system 313.

  In addition, the structure of an injector is not limited to embodiment shown to (a)-(d) of FIG. For example, a plurality of partition walls may be provided and divided into three or more parts. The more the gas is divided, the more the local gas can be sprayed, and the pin point can be sprayed onto the convex portion 16.

  Moreover, you may provide the convex part detection sensor which detects the position of the convex part 16, and a partition moving apparatus in that case. By providing these, the partition wall can be adjusted in the width direction so that the 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 may be provided in the number of spaces provided by being divided by the partition walls.

  Further, as another embodiment, in order to prevent HF gas from being sprayed to a location other than the convex portion 16 in one gas spraying space, an unnecessary gas blow hole 316 (directly above the location other than the convex portion is used. A gas blowing hole closing device for closing the gas blowing holes located may be provided. Also in this case, it is possible to determine which gas blowing holes 316 are unnecessary based on the position information of the protruding portions 16 from the protruding portion detection sensor, and to control the gas blowing hole closing device. In this case, a plurality of gas systems and partition walls need not be provided.

  Further, as another embodiment, in order to prevent HF gas from being sprayed to a location other than the convex portion 16 in one gas spraying space, an unnecessary gas blow hole 316 (directly above the location other than the convex portion is used. You may provide the suction device which suck | inhales HF gas spouted from the gas blowing hole located. Also in this case, based on the positional information of the convex part 16 from the convex part detection sensor, which gas blowing hole 316 is unnecessary may be determined, and the suction device may be controlled. In this case, a plurality of gas systems and partition walls need not be provided.

  The manufacturing method of the glass substrate 1 for TFT of this embodiment may be implemented as online processing, and may be implemented as offline processing. “Online processing” in the present specification refers to the case where the method of the present embodiment is applied in the slow cooling process of slowly cooling the glass ribbon 4 formed by the float method, the downdraw method, or the like. On the other hand, “offline processing” refers to a case where the method of the present embodiment is applied to the glass plate 10 that has been molded and cut into a desired size. Therefore, the glass plate 10 in the present specification includes a glass ribbon 4 formed by a float method, a downdraw method, or the like, in addition to the glass plate 10 that has been formed and cut to a desired size.

  The manufacturing method of the TFT glass substrate 1 of the present embodiment is preferably performed as online processing for the following reason. In the case of offline processing, it is necessary to increase the number of processes, whereas in the case of online processing, it is not necessary to increase the number of processes, so that processing can be performed at low cost. Moreover, in the case of off-line processing, the gas containing HF wraps around the semiconductor element formation surface, which is the second main surface 12 of the glass plate 10, whereas in the case of on-line processing of the glass ribbon 4, the gas containing HF The wraparound can be suppressed.

  The float glass manufacturing apparatus 100 shown in FIG. 2 has an injector 200 installed above the glass ribbon 4 in the slow cooling apparatus 130 in order to implement the manufacturing method of the TFT glass substrate 1 of the present embodiment as an online process. Using this injector 200, a gas containing hydrogen fluoride (HF) is supplied to the top surface of the glass ribbon 4. In FIG. 2, the injector 200 is installed in the slow cooling device 130, but if the glass surface temperature for supplying the gas containing HF is 500 to 900 ° C., the injector 200 is placed in the molding device 120. May be installed.

  In the manufacturing method of the glass substrate 1 for TFT of this embodiment, the surface treatment is performed by spraying a gas (gas) containing hydrogen fluoride (HF) on at least one surface of the glass ribbon 4. Instead of hydrogen fluoride gas, a gas (gas) or liquid containing molecules having fluorine atoms in the structure may be used.

Etching gas includes hydrogen fluoride (HF), chlorofluorocarbon (CFC), fluorocarbon (FC), hydrochlorofluorocarbon (HCFC), hydrofluorocarbon (HFC)), halon, hydrogen fluoride (HF), fluorine Simple substance (F ₂ ) trifluoroacetic acid (CF ₃ COOH), carbon tetrafluoride (CF ₄ ), silicon tetrafluoride (SiF ₄ ), phosphorus pentafluoride (PF ₅ ), phosphorus trifluoride (PF ₃ ), Boron trifluoride (BF ₃ ), nitrogen trifluoride (NF ₃ ), chlorine trifluoride (ClF ₃ ), or the like can be used, but it is not limited to these gases and liquids. Among these, hydrogen fluoride (HF) gas is preferable because of cost and handling methods are well known.

  FIG. 7 is a graph obtained by actually measuring the thickness tolerance (μm) of the first cross section 15 in the comparative example (A to C) using the TFT glass substrate 1 of the present embodiment as an example. In the embodiment, the positional information of the convex portion is obtained from a glass ribbon having a width of 3500 mm, and the convex portion is removed by blowing HF gas to the position of the convex portion. Here, the gas flow rate was 0.5 m / SEC, the glass temperature was 625 to 575 ° C., the gas concentration was 20% HF, 80% N2, and the treatment time was about 10 sec. Since the removal amount has a linear relationship with the HF concentration in the gas and the processing time, the removal amount can also be adjusted by adjusting the two parameters shown on the left. Then, the glass ribbon was cut | disconnected and the glass plate of 1200 mm x 1200 mm was obtained, and this was made into the Example. Each of Comparative Examples A to C is a large TFT glass plate having a size of 1200 mm × 1200 mm or more, and can be obtained through a general distribution route.

  In FIG. 7, each plot shows a tolerance obtained by measuring the plate thickness at a pitch of 20 mm in the first cross section 15 and based on those data. Note that the number of a plurality of plots in the same sample indicates the N number (number of times of measurement), which is a value obtained from each of the different first cross sections 15.

  From this graph, the TFT glass substrate 1 of the present embodiment has the maximum value Wmax and the minimum value of the plate thickness W of the glass plate 10 in the first cross section 15 along a straight line parallel to the first side 13. It can be understood that the thickness tolerance, which is the difference in Wmin, is less than 6.26 μm. Moreover, Preferably, they are 6.0 micrometers, 5.8 micrometers, 5.5 micrometers, 5.3 micrometers, and 5.0 micrometers or less. Although a minimum is not limited, For example, it is 1.0 micrometer or more.

  As described above, in the exposure process in the TFT production line, the glass plate 10 having a small thickness tolerance is required so that the exposure machine can be easily focused. The glass substrate 1 for TFT of this embodiment is a glass plate. The first side 13 and the second side 14 have a length of at least 1200 mm, and there is no glass plate 10 having such a large size with a thickness tolerance of less than 6.26 μm. With the TFT glass substrate 1 in the form, elements and structures can be formed with higher accuracy and / or speed.

  In addition, the fact that the thickness tolerance in the first cross section 15 is extremely small is the effect that the convex portions 16 and the like generated due to the habit inherent to the glass plate manufacturing apparatus are smoothed by the etching gas, and the change in the thickness W Mean small.

  FIG. 8 shows the thickness tolerance (μm) of all cross sections with respect to the entire surface of the glass plate 10 in the comparative examples (A to C) using the TFT glass substrate 1 of the present embodiment as an example. This is a plotted graph.

  In FIG. 8, each plot shows a tolerance obtained by measuring a plurality of plate thicknesses at a pitch of 20 mm in a section in the plate thickness direction of an arbitrarily extracted glass plate and obtaining the data. Note that the number of plots in the same sample indicates the N number, and is a value obtained from another section selected at random.

  From this graph, it can be understood that the thickness tolerance of the glass substrate 1 for TFT of this embodiment is less than 7.12 μm in every cross section in the thickness direction of the glass plate. And in every cross section, the effect that sheet thickness tolerance becomes small is seen. Therefore, in the present embodiment, a TFT glass substrate 1 having a large glass plate 10 having a small thickness tolerance in every cross section and capable of forming elements and structures more accurately and / or quickly at the time of TFT manufacture is provided. Can be provided.

  The 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. Although a minimum is not limited, For example, it is 1.0 micrometer or more.

  FIG. 9 shows the average value of the absolute value of the first derivative of the thickness W of the first cross section 15 of the glass plate 10 in the comparative examples (A to C) using the TFT glass substrate 1 of the present embodiment as an example. It is the graph which compared.

  In FIG. 9, each plot is obtained on the basis of the data obtained by measuring a plurality of plate thicknesses at a pitch of 20 mm in the first cross section 15. That is, the primary differential value indicates the inclination of the change in the plate thickness between the pitches. Note that the number of the plurality of plots in the same sample indicates the N number, which is a value obtained from a different first cross section 15.

  From this graph, it can be understood that the average value of the absolute value of the first derivative value of the plate thickness W is less than 1.72E-02 in the first cross section 15 of the TFT glass substrate 1 of the present embodiment. The absolute value of the first derivative value of the plate thickness W indicates the degree of change (inclination) of the plate thickness W along the first cross section 15, and the smaller the average value of the absolute values over the first cross section 15, the smaller the change. (Slope is small), that is, there are few irregularities existing on the glass surface and it is smooth. If the average value of the absolute value of the first derivative of the plate thickness W is 1.72E-02 or more, the unevenness on the surface of the glass plate is too steep, so it takes a lot of time to focus the exposure machine. In addition, since the focus cannot be adjusted sufficiently, the accuracy of TFT formation tends to decrease. Therefore, according to this embodiment, the glass substrate 1 for TFT which can form an element and a structure with higher precision and / or quickness at the time of TFT manufacture can be provided.

  Moreover, the average value of the absolute value of the first derivative value of the plate thickness W is preferably 1.7E-02 or less, more preferably 1.65E-02 or less, and further preferably 1.6E-02 or less. Although a minimum is not limited, For example, it is 5.0E-03 or more.

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

  Further, the standard deviation of the absolute value of the first derivative value of the plate thickness W is preferably 1.4E-03 or less, more preferably 1.3E-03 or less. Although a minimum is not specifically limited, For example, it is 1.0E-04 or more.

  And the glass substrate 1 for TFT of this embodiment WHEREIN: In the 1st cross section 15, the maximum value of the absolute value of the secondary differential value of plate | board thickness W is 6.0E-03 or less. Preferably it is 5.8E-03 or less, More preferably, it is 5.5E-03 or less. Although a minimum is not specifically limited, For example, it is 1.0E-03 or more. The fact that the maximum value of the absolute value of the secondary differential value of the plate thickness W is small indicates that the inflection point of the plate thickness is dull. That is, it means that a smoothed surface is formed by the etching gas spraying effect. This makes it easy to focus with a plurality of divided exposure machines. Therefore, according to this embodiment, the glass substrate 1 for TFT which can form an element and a structure with higher precision and / or quickness at the time of TFT manufacture can be provided.

  Further, in the TFT glass substrate 1 of the present embodiment, the standard deviation of the absolute value of the second derivative of the plate thickness W is 1.5E-04 or less in the first cross section 15. 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. Although a minimum is not specifically limited, For example, it is 5.0E-06 or more. The fact that the standard deviation of the absolute value of the second derivative value of the plate thickness W is extremely small means that there is no particularly large protrusion, the change in the plate thickness W of the glass plate 10 is small, and the surface smoothed by the etching gas blowing effect. Is formed.

  In the first cross section 15, the standard deviation of the absolute value of the first derivative value, the maximum value of the absolute value of the second derivative value, and the standard deviation of the absolute value of the second derivative value are extremely small. This means that the entire surface of is smoothed. By smoothing the entire surface of the glass plate 10, it becomes easy to focus, for example, in an exposure process in a TFT production line, and a large TFT glass substrate 1 excellent in productivity and quality can be provided.

  FIG. 10 is a front perspective view showing a second embodiment of the glass substrate 1 for TFT of the present embodiment. The second embodiment will be described based on FIG.

  In the TFT glass substrate 1 of the second embodiment, a roughened region 20 and a non-roughened region 21 are formed on the first main surface 11 of the glass plate 10 with a predetermined width. The roughened region 20 is a region to which an etching gas having a width L parallel to the second side 14 is sprayed, and may be a region in which the convex portion 16 is smoothed, for example. The non-roughened region 21 is a region where no etching gas is blown. The roughened region 20 does not necessarily have to be accompanied by the removal of the convex portion 16. For example, by adjusting the amount of etching gas to be sprayed and the glass temperature, the surface of the glass plate can be roughened with little reduction in the plate thickness. The glass plate 10 does not necessarily need to be smoothed.

  During the manufacture of the TFT, the first main surface 11 of the glass plate 10 is suction-fixed. However, since static electricity tends to accumulate on the first main surface 11, the glass plate 10 sticks when the suction fixing is released, and the glass plate 10 breaks. There's a problem. In addition, there is a problem that the formed TFT element malfunctions due to static electricity accumulated on the glass plate 10. With respect to these problems, the roughened region 20 is formed on the first main surface 11 to form a region with a partially rough surface, making it difficult to accumulate static electricity and preventing charging. .

  Further, in the roughened region 20 to which the etching gas is blown, for example, when the convex portion 16 or the like is smoothed by etching, a predetermined roughness Ra is given while extremely reducing the thickness tolerance in the thickness W direction. can do. Thereby, it is possible to provide a TFT glass substrate 1 having a large glass plate 10 that can form elements and structures more accurately and / or quickly in TFT manufacturing and that can prevent charging. The roughness Ra was measured under the conditions of Scan Asist mode, scan size: 5 μm × 5 μm, and scan rate: 0.977 Hz using an Atomic Force Microscope (manufactured by Bruker, Dimension Icon). Thereafter, the arithmetic average roughness (Ra) within the above range was calculated after correcting the secondary inclination.

  In the second embodiment, the roughened region 20 is formed in a line shape having a predetermined width L in a direction parallel to the first side 13 of the glass plate 10. The roughened region 20 can be arbitrarily increased, and a plurality of roughened regions 20 may be formed in a line shape in a direction parallel to the first side 13.

11, the processing temperature (℃) and roughness Ra ₁ of roughened region 20 in a roughness Ra ₂ of the non-roughened regions 21, the ratio of the roughness Ra (ratio of Ra ₁ and Ra ₂₎ It is the table | surface which showed. The processing temperature (° C.) is the ambient temperature around the glass when the etching gas is blown in the manufacturing process. Roughness Ra ₁ and Ra ₂ roughening region and non-roughened regions obtained by each measuring 10 points, which is the average value.

  From this table, it can be understood that the ratio of the roughness Ra between the roughened region 20 and the non-roughened region 21 is larger than 1 in the TFT glass substrate 1 of the present embodiment. Preferably it is 3 or more, More preferably, it is 10 or more, More preferably, it is 20 or more. Although an upper limit is not specifically limited, For example, it is 100 or less. When the ratio of the roughness Ra is set to the above range, static electricity is difficult to be accumulated in the roughened region, and thus the entire glass plate, and charging can be prevented.

The arithmetic average roughness Ra ₁ of the roughened region 20 of the TFT glass substrate 1 of the present embodiment is Ra ₁ > 0.5 nm, and the arithmetic average roughness Ra ₂ of the non-roughened region 21 is It can be understood that Ra ₂ ≦ 0.5 nm. Ra ₁ is preferably 1.0 nm or more, more preferably 3.0 nm or more, and further preferably 5.0 nm or more. Although an upper limit is not specifically limited, For example, it is 50 nm or less, Preferably it is 30 nm or less, More preferably, it is 20 nm or less. Moreover, the lower limit of Ra ₂ is not particularly limited, but is, for example, 0.2 nm or more. When the arithmetic mean roughness Ra ₂ of the arithmetic average roughness Ra ₁ and the non-roughened area 21 of the roughened region 20 is within the above range, roughened areas, and difficult reservoir static throughout thus the glass plate, Charging can be prevented, and elements and structures can be formed with higher accuracy and / or speed in TFT manufacturing.

  Further, in the TFT glass substrate 1 of the present embodiment, the area of the roughened region 20 is smaller than the area of the non-roughened region 21, and the area of the roughened region 20 and the non-roughened region 21. The ratio with the area is 3 or more and 300 or less. By spraying the etching gas only on necessary portions, efficient surface treatment of the glass plate 10 can be performed, charging can be prevented, and elements and structures can be formed with higher accuracy and / or speed in TFT manufacturing.

  For example, when the gas is blown to the glass plate 10 having the first side 13 of 1200 mm with a width of 400 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. For example, when gas is blown to the glass plate 10 having the first side 13 of 3000 mm with a width of 10 mm, the ratio is preferably 280 or less, more preferably 250 or less, and further preferably 230 or less. Efficient surface treatment of the glass plate 10 can be performed by performing treatment only on necessary portions. Moreover, when accompanying the removal of the convex part 16, a glass plate can be smoothed.

  The roughened region 20 has a width L in a direction parallel to the second side 14 of 10 mm to 1000 mm. The width L is preferably 20 mm or more, more preferably 30 mm or more, further preferably 50 mm or more, and preferably 900 mm or less, more preferably 800 mm or less, and still more preferably 700 mm or less. Efficient surface treatment of the glass plate 10 can be performed by performing treatment only on necessary portions. Moreover, when accompanying the removal of the convex part 16, a glass plate can be smoothed. When there are a plurality of roughened regions 20, the width L indicates the width of one roughened region 20 rather than the total of all.

  FIG. 12 is a front perspective view showing a third embodiment of the glass substrate 1 for TFT of the present embodiment. A third embodiment will be described with reference to FIG.

  In the TFT glass substrate 1 of the third embodiment, the first region 30 and the second region 31 are formed on the first main surface 11 of the glass plate 10 with a predetermined width. The first region 30 is a region in which a fluorine-containing gas (HF or the like) that is an etching gas having a width L parallel to the second side 14 is sprayed. For example, the convex portion 16 is smoothed to reduce the thickness tolerance. It is also a region having a predetermined roughness Ra. The second region 31 is a region where a gas containing fluorine is not sprayed. In addition, the 1st area | region 30 does not necessarily need to be accompanied by removal of the convex part 16. FIG. For example, by adjusting the amount of HF gas to be sprayed and the glass temperature, fluorine can be imparted to the surface of the glass plate with almost no reduction in plate thickness. The glass plate 10 does not necessarily need to be smoothed.

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

  FIG. 13 is a graph obtained by measuring and plotting the fluorine content (wt%) in the first region 30 and the second region 31 at each processing temperature (° C.). The horizontal axis indicates the sample number. 1 and No. 12 is the second region 31, and the other (No. 2 to 11) is the first region 30. The interval between each sample is 25 mm. The processing temperature (° C.) is the ambient temperature around the glass when the fluorine-containing gas is blown in the manufacturing process. The content of fluorine was measured using X-ray Fluorescence (manufactured by Rigaku Corporation, ZSX Primus II). The analysis diameter was φ20 mm, and the intensity of F-Kα rays on the glass surface was measured. Thereafter, the F concentration of the sample was calculated based on a calibration curve taken with a glass having the same composition with a known F concentration.

  FIG. 14 is a table showing values calculated based on the measured values of FIG. The fluorine content F (wt%) of the first region 30 and the second region 31 is an average value of each sample at each processing temperature, and the F concentration ratio is the F value of the first region 30 and the F value of the second region 31. The F slope (wt% / mm) is the sample No. 1 and No. It is the value which calculated the inclination (value of No. 2 / value of No. 1) with 2.

  From the graph of FIG. 13 and the table of FIG. 14, it can be understood that the ratio of the fluorine content (wt%) between the first region 30 and the second region 31 is greater than 1. The ratio is preferably 3 or more, more preferably 5 or more, and still more preferably 8 or more. Although an upper limit is not specifically limited, For example, it is 40 or less, Preferably it is 35 or less, More preferably, it is 30 or less, More preferably, it is 25 or less. If the glass composition originally has no fluorine, the fluorine content in the second region 31 is 0, and the ratio value is infinite.

  By spraying a gas containing fluorine on 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 the area | region where the element for TFT is easy to peel. For example, when the first region 30 is formed in a line shape on the second main surface 12 which is a TFT formation surface and coincides with a future planned dividing line, an element is mistakenly formed in the region of the planned dividing line. Even if it is, it can peel easily.

  For example, when the convex portion 16 or the like is smoothed with an etching gas containing fluorine, fluorine can be applied to the first region while extremely reducing the thickness tolerance in the thickness W direction. The TFT glass substrate 1 having a large glass plate 10 that can be formed with higher accuracy and / or speed and can impart water and oil repellency to the first region can be provided. Furthermore, since a region roughened by fluorine can be formed, it is possible to provide a TFT glass substrate 1 that prevents static electricity from being accumulated during TFT manufacturing and prevents charging.

  Further, from the graph of FIG. 13 and the table of FIG. 14, 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 ≦ It can be understood that F2 ≦ 0.15 wt%. In addition, the lower limit of F1 is preferably 0.8 wt% or more, more preferably 1.0 wt% or more, and the upper limit of F1 is preferably 4.0 wt% or less, more preferably 3.0 wt% or less.

  By setting the fluorine content F of the first region 30 and the second region 31 in the above range, it is possible to adjust the water / oil repellency. In addition, for example, when the convex part 16 or the like is accompanied by smoothing or roughening, it is possible to provide the glass plate 10 having a small thickness tolerance so that the focus in the exposure process in the TFT production line can be easily adjusted, and it is difficult to accumulate static electricity. The glass substrate 1 for TFT which prevents charging can be provided.

  In the TFT glass substrate 1 of the present embodiment, the area of the first region 30 is smaller than the area of the second region 31, and the ratio of the area of the first region 30 to the area of the second region 31 is 3 or more and 300 or less. By spraying a gas containing fluorine only on a necessary portion, efficient surface treatment of the glass plate 10 becomes possible. Moreover, when the removal of the convex part 16 is accompanied, the glass plate 10 can be smoothed.

  Further, from the table of FIG. 14, in the first region 30 of the TFT glass substrate 1 of the present embodiment, the inclination of the fluorine content F in the direction parallel to the second side 14 is 0.001 wt% / mm or more. It can be understood that it is 0.15 wt% / mm or less. And preferably it is 0.13 wt% / mm or less, More preferably, it is 0.12 wt% / mm or less, More preferably, it is 0.10 wt% / mm or less. By spraying a fluorine-containing gas only on necessary portions, efficient surface treatment of the glass plate 10 becomes possible. Moreover, when accompanying the removal of the convex part 16, a glass plate can be smoothed.

  As for the glass plate 10 of the glass substrate 1 for TFT of this embodiment, it is desirable that at least one of the first main surface 11 and the second main surface 12 does not have a polishing flaw. More preferably, it is desirable that none have polishing scratches. The presence or absence of a polishing flaw can be determined by surface observation with an AFM (Atomic Force Microscope). In the present specification, when one or more scratches having a length of 5 μm or more exist in a 100 μm × 5 μm region, the surface is called “having polishing flaws”, and the opposite is “no polishing flaws”. It is called a state. Since the first main surface 11 and the second main surface 12 do not have polishing scratches, elements and structures can be formed with higher accuracy and / or speed in TFT manufacturing. Further, the surface strength of the glass plate 10 can be increased.

  FIG. 15 is a graph obtained by measuring the β-OH amounts of the first main surface 11 and the second main surface 12 in the present embodiment.

  From the graph of FIG. 15, the glass plate 10 of the TFT glass substrate 1 of the present embodiment is bulky on both the first main surface 11 that is not in contact with molten tin and the second main surface 12 that is in contact with molten tin. It can be understood that the layer having a water content of 80% or less with respect to the water content (center position in the plate thickness W direction) has 10 μm or more.

  If at least one of the first principal surface 11 and the second principal surface 12 has a layer having a moisture content of 80% or less with respect to the moisture content of the bulk, the glass plate is It can be understood that the glass plate 10 is manufactured by the float process. The float method is an excellent method for obtaining a glass plate having a larger area, and it is easy to obtain a glass plate of 1200 mm × 1200 mm or more. The size of the glass plate is preferably 1500 mm × 1500 mm or more, more preferably 2000 mm × 2000 mm or more, and further preferably 2500 mm × 2500 mm or more. The length of at least one side is 1200 mm to 7000 mm. A glass substrate on which a plurality of TFTs are formed can be taken out from one glass plate. Note that the β-OH value, which is the amount of water, is measured by transmittance using an infrared spectrophotometer or secondary ion mass spectrometry (SIMS).

  In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably. In addition, the material, shape, dimension, numerical value, form, number, arrangement location, and the like of each component in the above-described embodiment are arbitrary and are not limited as long as the present invention can be achieved.

  Moreover, a highly flat glass substrate is not limited to a glass substrate for TFT, and is required in various fields. For example, when a resin pattern is formed on the surface of glass by imprinting, the mold may not be pressed properly at the portion corresponding to the concave area of the glass swell, and a desired pattern may not be obtained. In this case, a higher flat glass is desirable because the pressing force of the mold is uniformly transmitted to the glass surface. 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 the invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit and scope of the invention. This application is based on Japanese Patent Application No. 2017-155468 filed on Aug. 10, 2017, the contents of which are incorporated herein by reference.

  The glass substrate for TFT of the present invention is suitably used in the field of demanding a large glass plate having a small thickness tolerance in order to improve productivity in the TFT production line, prevent charging, and the like.

DESCRIPTION OF SYMBOLS 1 Glass substrate for TFT 10 Glass plate 11 1st main surface 12 2nd main surface 13 1st edge 14 2nd edge 15 1st cross section 16 Convex part 20 Roughening area | region 21 Non-roughening area | region 30 1st area | region 31 1st 2 areas 100 Float glass manufacturing equipment 200 Injector

Claims (22)

It is composed of a rectangular glass plate having a first main surface and a second main surface facing the first main surface,
In the visual field from the thickness direction of the glass plate, the first side and the second side that are adjacent to each other,
The length of the first side and the second side is at least 1200 mm or more,
The thickness tolerance which is the difference between the maximum value of the thickness of the glass plate and the minimum value of the thickness in the first cross section along the straight line parallel to the first side among the cross sections in the thickness direction of the glass plate. A glass substrate for TFTs having a thickness of less than 6.26 μm.   2. The glass substrate for TFT according to claim 1, wherein the thickness tolerance is less than 7.12 μm in every cross section in the thickness direction of the glass plate.   3. The glass substrate for TFT according to claim 1, wherein an average value of absolute values of first-order differential values of the plate thickness is less than 1.72E-02 in the first cross section.   The glass substrate for TFT according to claim 1 or 2, wherein in the first cross section, the standard deviation of the absolute value of the first derivative of the plate thickness is 1.5E-03 or less.   The glass substrate for TFT according to any one of claims 1 to 4, wherein in the first cross section, the maximum absolute value of the second derivative of the plate thickness is 6.0E-03 or less.   The glass substrate for TFT according to any one of claims 1 to 5, wherein in the first cross section, a standard deviation of an absolute value of a second derivative value of the plate thickness is 1.5E-04 or less. The first main surface has a roughened region and a non-roughened region,
The glass substrate for TFT according to any one of claims 1 to 6, wherein a roughness ratio between the roughened region and the non-roughened region is greater than 1. The arithmetic average roughness Ra ₁ of the roughened region is Ra ₁ > 0.5 nm, and the arithmetic average roughness Ra ₂ of the non-roughened region is Ra ₂ ≦ 0.5 nm. TFT glass substrate. The area of the roughened region is smaller than the area of the non-roughened region,
The glass substrate for TFT according to claim 7 or 8, wherein a ratio of an area of the roughened region to an area of the non-roughened region is 3 or more and 300 or less.   10. The TFT glass substrate according to claim 7, wherein the roughened region is formed in a line shape in a direction parallel to the first side. 11.   11. The glass substrate for TFT according to claim 7, wherein a plurality of the roughened regions are formed in a line shape in a direction parallel to the first side.   The glass substrate for TFT according to claim 10 or 11, wherein the roughened region has a width in a direction parallel to the second side of 10 mm or more and 1000 mm or less. The first main surface has a first region and a second region,
The glass substrate for TFT according to any one of claims 1 to 6, wherein a ratio of fluorine content between the first region and the second region is larger than one.   14. The fluorine content F1 in the first region is 0.5 wt% ≦ F1 ≦ 5 wt%, and the fluorine content F2 in the second region is 0 ≦ F2 ≦ 0.15 wt%. TFT glass substrate. The area of the first region is smaller than the area of the second region,
The glass substrate for TFT according to claim 13 or 14, wherein 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 TFT glass substrate according to claim 13, wherein the first region is formed in a line shape in a direction parallel to the first side.   The glass substrate for TFT according to any one of claims 13 to 16, wherein a plurality of the first regions are formed in a line shape in a direction parallel to the first side.   18. The TFT glass according to claim 16, wherein, in the first region, an inclination of a fluorine content in a direction parallel to the second side is 0.001 wt% / mm or more and 0.15 wt% / mm or less. substrate.   19. The glass substrate for TFT according to claim 1, wherein the glass composition of the glass plate is alkali-free glass.   20. The glass substrate for TFT according to claim 1, wherein the glass plate has no polishing scratches 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 to 20, wherein the glass plate has a thickness of 1.0 mm or less.   The glass plate has at least one of the first main surface and the second main surface having a layer having a moisture content of 80% or less with respect to a bulk moisture content of 10 μm or more. The glass substrate for TFTs according to any one of the above items.

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