WO2007094160A1 - Method and apparatus for chamfering glass substrate - Google Patents

Abstract

Novel method and apparatus for chamfering a glass substrate are provided for improving productivity by improving bending strength and shock strength of an end plane of the glass substrate and by preventing breakage and chipping of the glass substrate in a glass substrate manufacturing process. In the method and apparatus for chamfering the glass substrate by using laser beams, the end plane of the glass substrate is irradiated with the laser beams, and a cooling gas is blown to the laser beam irradiation area on the glass substrate.

Description

 Specification

 Method and apparatus for chamfering glass substrate

 Technical field

 TECHNICAL FIELD [0001] The present invention relates to a glass substrate and a glass substrate for display, and more particularly to a chamfering method and apparatus for a glass substrate used as a glass substrate for a flat panel display or a photomask.

 Background art

 [0002] At present, glass substrates for displays, particularly glass substrates for flat panel displays such as liquid crystal displays, plasma displays, organic EL displays, field emission displays, window glass for buildings such as houses and buildings, Glass substrates are used as opening members in many fields, such as window glass for vehicles such as automobiles, railways, aircraft, ships, and transportation vehicles. Such a glass substrate is formed from molten glass using a float method, a fusion method or a downdraw method. Further, it can be obtained by redrawing a primary-formed glass plate.

[0003] In particular, in the flat panel display manufacturing process, when these glass substrates are transported or positioned, cracking or chipping from the end surface of the glass substrate due to impact or mechanical external force becomes a problem. Yes. For example, when placing a glass substrate in the manufacturing apparatus, the impact is chipped to Rukoto force ^s crack the glass substrate when pressed against the pin for alignment.

 [0004] In order to solve the above problems, the end face of a glass substrate has been chamfered to improve bending strength and impact strength. The chamfering of the glass substrate is generally performed by grinding the end surface itself with a grindstone, and the edge surface itself. In these cases, in order to further improve the bending strength and impact strength of the end face of the glass substrate, it is desirable to polish it in a state close to a mirror surface. ) Chamfering is finished.

[0005] Further, in this method, since the glass substrate is firmly fixed and chamfering is performed with a grindstone, there is a problem that the chamfering takes a very long time. Furthermore, the glass powder removed by polishing Since the glass substrate was contaminated by the polishing slurry and polishing slurry, cleaning was necessary.

 [0006] As another chamfering method, a chamfering method using a carbon dioxide (CO 2) laser has been proposed.

 2

 (Patent Literature:! ~ 5). In this method, the edge of the cut glass substrate is melted and rounded with a carbon dioxide laser so that it can be chamfered at high speed without contact, but strong stress remains around the edge of the glass substrate that is not described in the patent literature. There was a serious problem.

 [0007] The stress is usually a tensile stress generated in the longitudinal direction of the edge of the glass substrate. In many cases, the chamfered glass substrate is cut again only by reducing the edge strength of the glass substrate. In this case, the cracks were disturbed by this stress, and there was a problem that the cracks could not be cut along the cutting line.

 [0008] Japanese Patent No. 2612322 proposes a method of chamfering a glass substrate heated to just below the softening temperature by laser beam irradiation. However, in this method, the entire glass substrate needs to be heated and held. In the chamfering of large glass substrates, it is difficult to make a device, and it takes too much time from heating to slow cooling. Further, in chamfering a glass substrate covered with a display panel, heating the whole may cause a member having low heat resistance to be damaged, which is not preferable.

 [0009] JP-A-2-48423 discloses a chamfering method by irradiating a glass substrate with a laser beam, but there is no description about the problem of residual stress, and there is no description about a solution method.

 [0010] In WO2003 / 015976, a force S for preheating and chamfering a glass substrate with an elliptical laser beam and further annealing with an elliptical laser beam to reduce residual stress is described. The However, there is no description as to whether the residual stress of the glass substrate was actually reduced by this method.

[0011] In Japanese Patent No. 3387645, a carbon dioxide laser beam is focused and irradiated on an electrode forming surface side edge of a glass substrate end of a liquid crystal panel to remove a short-circuit electrode, and a corner of the glass substrate is melted to form a yarn. A method of simultaneously performing chamfering processing is disclosed. However, this method does not describe a method for processing the entire edge of the glass substrate into a curved shape. In addition, the problem of residual stress is not taken into consideration at all, and a solution is not developed. Not shown.

 [0012] Japanese Patent No. 3129153 discloses a method of chamfering a glass substrate after thermal cleaving. However, in this method, a laser beam is irradiated from above the substrate surface to perform thermal cleaving and immediately chamfering. However, in this thermal cleaving, the glass substrate is not separated until the crack tip reaches the substrate end surface. ,. Therefore, even if the carbon dioxide laser beam for chamfering is irradiated before substrate separation, only the top surface can be chamfered, and if the glass at the cleaved portion is brought close to the melting temperature, the cut surface is fused again. There is concern about being done. Therefore, this method cannot be used for round chamfering of glass substrates. In this method, the residual stress problem is not taken into consideration at all, and the solution is not disclosed.

 [0013] Patent Document 1: Japanese Patent No. 2612322

 Patent Document 2: JP-A-2-48423

 Patent Document 3: W2003 / 015976

 Patent Document 4: Japanese Patent No. 3387645

 Patent Document 5: Japanese Patent No. 3129153

 Disclosure of the invention

 Problems to be solved by the invention

[0014] The present invention has been made in view of the above circumstances, and is a bending strength of an end face of a glass substrate and a glass substrate for a display, in particular, a glass substrate for a flat panel display or a glass substrate used as a photomask. The purpose of the present invention is to provide a novel glass substrate chamfering method and apparatus capable of improving the productivity by improving the impact strength and preventing the breakage and chipping of the glass substrate in the flat panel display manufacturing process. .

 Means for solving the problem

[0015] In order to achieve the above object, the present invention provides a method for chamfering a glass substrate by irradiating a laser beam, wherein the glass substrate is irradiated with at least one laser beam and the glass substrate is irradiated with the laser beam. Provided is a glass substrate chamfering method, wherein a cooling gas is blown to a laser beam irradiation portion of a substrate. In the present invention, the irradiation angle of the laser beam is preferably within 70 ° in the longitudinal direction of the end surface and within 70 ° in the thickness direction with respect to the vertical direction of the end surface of the glass substrate. Yes.

 In the present invention, the cooling gas blowing direction is preferably within 70 ° in the longitudinal direction of the end surface and within 45 ° in the plate thickness direction with respect to the vertical direction of the end surface of the glass substrate. Ms.

 In the present invention, the cooling gas preferably has a wind speed of lmZ seconds to 200 m / second in the laser beam irradiation section.

The present invention also connects the portions of the end face of the glass substrate where l / e ² (e is the base of natural logarithm, the same applies below) where the energy density distribution in the cross section of the laser beam irradiated portion is the maximum. When the width in the longitudinal direction of the end face of the glass substrate on the surface surrounded by the curve is W (mm) and the relative speed of the laser beam and the glass substrate is U (mm / s), W≤ 0. 15 XU + 2 is more preferable 0.02≤W≤0. 15 XU + 2 is more preferable

[0020] Further, in the present invention, when the average power density defined by the total wattage / irradiation area of the cross section of the laser beam irradiation portion at the end face of the glass substrate is P (W / mm ² ), (0. 5X U + 0. 2) / 0. 7X (0. 15XU + 2) ≤P≤ (10XU + 10) /0.005XUX0.7 It is more preferable that (4XU) /0.7/ (0 More preferably, 15XU + 2) ≤P≤ (10XU + 10) /0.005XUX0.7.

 [0021] In the present invention, it is preferable to preheat the end face of the glass substrate before irradiating the end face of the glass substrate with the laser beam.

 [0022] In addition, it is preferable that a speed at which the laser beam strikes is 0.1 to 200 mmZ seconds relative to the glass substrate.

 [0023] Further, the wavelength of the laser beam is preferably 3 to: 11 μm.

 [0024] Further, it is preferable that the laser beam converges in the thickness direction of the end surface of the glass substrate with respect to the glass substrate.

[0025] The present invention is suitable for continuous chamfering of a glass substrate in a line in which molten glass is continuously supplied to produce a glass substrate by a float process. [0026] Further, the present invention is a glass substrate chamfering apparatus for performing the above-described glass substrate chamfering method for irradiating a laser beam, and a mechanism for irradiating at least one laser beam on an end surface of the glass; A chamfering device for a glass substrate, comprising: a mechanism for blowing cooling gas to a laser beam irradiation part of the glass substrate;

 The invention's effect

 [0027] According to the method and apparatus of the present invention, a glass substrate and a glass substrate for display, in particular, a glass substrate for flat panel display and a chamfered glass substrate used as a photomask are provided, and a flat panel display manufacturing process is provided. The glass substrate can be prevented from cracking and chipping, and productivity can be improved.

 Brief Description of Drawings

 FIG. 1 is a schematic perspective view illustrating a chamfering method according to the present invention.

 FIG. 2 is a schematic plan view for explaining a chamfering method according to the present invention.

 FIG. 3 is a schematic side view for explaining a chamfering method according to the present invention.

 FIG. 4 is a conceptual diagram of an example of a glass substrate chamfering apparatus according to the present invention.

 Explanation of symbols

 [0029] 1: Glass substrate, 2: End face, 3: Laser beam, 3C: Laser beam center line, 4: Irradiation part

 5: Air blowing nozzle, 5C: Air blowing nozzle center line, 6: Cooling gas, 7: Laser beam irradiation device, 11: Test glass substrate

 A: Irradiation angle in the longitudinal direction of the end face of the laser beam center line with respect to the vertical direction of the end face of the glass substrate

 B: Irradiation angle in the thickness direction of the end face of the laser beam center line with respect to the vertical direction of the end face of the glass substrate

 C: Air blowing angle in the longitudinal direction of the end surface of the cooling gas center line with respect to the vertical direction of the end surface of the glass substrate

 D: Air blowing angle in the thickness direction of the end surface of the cooling gas center line with respect to the vertical direction of the end surface of the glass substrate

W: Longitudinal direction of the end surface of the glass substrate on the end surface of the glass substrate surrounded by a curve connecting the portions where the energy density distribution in the cross section of the laser beam irradiated part is the maximum lZe ² Width of

 u: Relative scanning speed between laser beam and glass substrate

 BEST MODE FOR CARRYING OUT THE INVENTION

 [0030] Preferred embodiments of a glass substrate chamfering method and apparatus according to the present invention will be described below in detail with reference to the accompanying drawings.

 [0031] The glass substrate to be chamfered in the present invention is a glass substrate and a glass substrate for display, particularly a glass substrate having a thickness of 0 · 0 5 to 7 mm used as a glass substrate for a flat panel display or a photomask. preferable. Particularly preferred is a glass substrate for liquid crystal having a strain point of 610 ° C to 690 ° C, a softening point of 930 ° C to 1000 ° C, and a thickness of 0.05 to lmm. In the method of the present invention, the glass material constituting the glass substrate is not particularly limited as long as the surface can be made smooth by irradiating with a laser beam. Therefore, the method of the present invention can be applied to almost all glass materials.

 [0032] In many cases, the end surface of the glass substrate to be chamfered is cracked by a wheel or diamond glass force tatter and then cleaved using bending stress, or cracked in a part of the plate. The glass is broken by extending cracks using the thermal stress generated when a glass substrate is heated with a carbon dioxide laser, YAG laser, or burner. Also, those cut with a disk-shaped blade with diamond or other abrasive grains fixed, those obtained by grinding the various cut glass end faces with a grindstone, and the end faces of glass plates being manufactured by the float method or fusion method As such, it may be an end face of glass processed by a pressing method.

 FIG. 1 is a schematic perspective view illustrating a chamfering method according to the present invention, FIG. 2 is a schematic plan view illustrating a chamfering method according to the present invention, and FIG. 3 is a schematic side view illustrating a chamfering method according to the present invention. FIG.

 As shown in FIGS .:! To 3, while the laser beam 3 is irradiated at a predetermined angle with respect to the vertical direction of the end surface 2 of the glass substrate 1, the cooling gas 6 is supplied from the cooling nozzle 5 to the irradiation portion. The end surface 2 of the glass substrate 1 is chamfered by blowing air. The principle of chamfering by this method is as follows.

The glass near the end surface 2 of the glass substrate 1 that has been melted by the irradiation of the laser beam 3 is cooled. The heat is immediately cooled by the blowing of the gas 6 and the heat removal from the end surface 2 of the glass substrate 1 that has been melted to the outside air increases, and the amount of heat conducted to the inside of the glass substrate 1 is relatively greatly reduced. Further, the heat transferred from the end surface 2 of the glass substrate 1 to the inside by heat transfer also cools the surface of the glass substrate 1 other than the end surface 2 in the vicinity of the laser beam irradiating section 4, so that the glass substrate 1 itself Becomes difficult to be heated. Therefore, the thickness of the melted part near the end surface 2 of the glass substrate 1 can be kept thin, and the residual stress can be kept low, so that when the glass substrate 1 is re-cut without causing the glass substrate 1 to break down. Does not adversely affect.

 The laser beam 3 is irradiated in a direction in which the angle A of the longitudinal direction of the end surface 2 of the laser beam center line 3C is within ± 70 ° with respect to the vertical direction of the end surface 2 of the glass substrate 1 and the thickness direction The angle B is preferably within ± 70 °. If the angle A is larger than 70 ° or smaller than 170 °, the width W of the cross section in the longitudinal direction of the laser beam 3 on the end surface 2 of the glass substrate 1 may become too wide, and the desired width may not be obtained. is there. If the angle B is larger than 70 ° or smaller than 70 °, the influence of the extra portion of the laser beam 3 that does not irradiate the end face 2 becomes large, and the chamfered end face 2 There can be a large difference in the curved surface between the front and back sides. More preferably, the angle A is within ± 60 °, and the angle B is within ± 50 °, more preferably the angle A is within ± 50 °, and the angle B is within ± 30 °.

 [0037] The blowing direction of the cooling gas 6 to be blown is such that the longitudinal angle C of the end face 2 of the center line 6C of the cooling gas with respect to the vertical direction of the end face 2 of the glass substrate 1 is within ± 70 °. The thickness direction angle D is preferably within ± 45 °. When the angle C is larger than 70 ° or smaller than 70 °, the amount of cooling gas 6 blown to the laser beam irradiation unit 4 decreases, so the blowing nozzle 5 must be brought close to the glass substrate 1, The degree of freedom of installation is reduced. Further, if the angle D is larger than 45 ° or smaller than 45 ° in the thickness direction, a large wind pressure is applied to the surface of the glass substrate 1 and the position of the glass substrate 1 may be shifted. More preferably, the angle C is within ± 60 °, and the angle D is within ± 35 °, more preferably, the angle C is within ± 50 °, and the angle D is within ± 20 °.

In addition, the wind speed of the cooling gas 6 is preferably lmZ seconds to 200 m / second in the laser beam irradiation unit 4. When the wind speed is less than ^ m / sec, the glass substrate 1 has an end face 2 Heat conduction to the inside of the glass substrate 1 with low heat removal to the outside air becomes easier. Therefore, the volume of the melted part and the stress generating part of the glass substrate 1 is increased, which affects the glass strength and cutting characteristics. If the wind speed is higher than 200 m / sec, the air blower becomes large and difficult to realize, and the wind pressure may cause the position of the glass substrate 1 to shift. In addition, the heat removal from the end surface 2 of the glass substrate 1 to the outside air is increased, the laser power necessary to melt the end surface 2 of the glass substrate 1 is increased, and a high-power laser device is required, which is not practical. . The wind speed of the cooling gas 6 is more preferably 2 to: 150 m / sec, and further preferably 5 to: 100 m / sec.

 Note that the cooling gas 6 is not particularly limited, but a gas that does not burn or decompose by the laser beam 3 is preferable. For example, dry air is particularly preferred from the viewpoint of environment and handling,

[0040] The laser beam 3 is a surface of the glass substrate 1 that is surrounded by a curve connecting portions where the energy density distribution of the cross section of the laser beam irradiating section 4 is 1 / e ^{2 at the} maximum on the end surface 2 of the glass substrate 1. When the width in the longitudinal direction of the end face 2 of 1 is W (mm) and the relative scanning speed of the laser beam 3 and the glass substrate 1 is U (mm / s), W≤0.15 XU + 2 It is preferable that If the width W is larger than 0.15 XU + 2, the value of the residual stress of the glass substrate 1 is increased, and the thickness of the residual stress layer is increased, which may reduce the edge strength of the glass substrate 1. When the glass substrate 1 chamfered under the condition that the width W is larger than 0.15 XU + 2 is cut by extending a crack formed by a glass force cutter or the like, the crack is removed from the planned cutting line. I can't cut it accurately. However, the width W can be reduced only to the light wavelength due to the wave-optical diffraction limit, and it is necessary to secure a sufficient distance between the condensing lens and the glass substrate in view of workability. Therefore, from a practical viewpoint, the width W is limited to 20 zm or more. Therefore, it is preferable that 0.02≤W≤0.15 XU + 2, more preferably 0.025≤W≤0.15XU + 1.5, and more preferably 0.0.3≤W≤0. 15 XU + 1.

In addition, the laser beam 3 has an average power density defined by the total wattage Z irradiation area of the cross section of the laser beam irradiation unit 4 on the end surface 2 of the glass substrate 1 as P (W / mm ² ). When the smooth chamfering point of view and the deformation of the end surface 2 of the glass substrate 1 due to heating, the specific origin (0.5XU + 0.2) /0.7/ (0.15XU + 2) ≤P≤ (10XU + 10) /0.005XUX0. 7 power S preferred. In addition, it is more preferable to Pi, (0.5XU + 0.2) /0.7/ (0.15XU + 1.5) or more, more preferably (0.5XU + 0.2) /0.7. It is more than / (0. 15XU + 1). In particular, (4XU) /0.7/ (0.15XU + 2) or more is preferred. Further, P is more preferably (10XU + 10) /0.005XU/0.7X0.01 or less, and further preferably (10XU + 10) /0.005XU/0.7X0.002 or less.

The laser beam 3 preferably moves relative to the glass substrate 1 at a speed of 0.:! To 200 mm / sec. 0. If it is slower than 1 mm / sec, the productivity will deteriorate, and if it is faster than 200 mm / sec, a high-power laser device will be required to obtain the required power, which is not practical and the end face 2 of the glass substrate 1 is sufficient. There is a risk that the smooth end face 2 cannot be obtained without heating. The running speed is more preferably 0.5 to 180 mmZ seconds, and still more preferably 1 to 150 mm / sec.

 [0043] Before the end surface 2 of the glass substrate 1 is irradiated with the laser beam 3, the end surface 2 of the glass substrate 1 may be preheated. When preheating is performed, there is less risk of cracking of the glass substrate 1 due to abrupt temperature changes in the irradiation section 4 that irradiates the laser beam 3, and the relative scanning speed between the laser beam 3 and the glass substrate 1 is increased. Can do. Preheating may heat the entire glass substrate 1, but it is not preferable because it reduces productivity. The preheating method is not particularly limited, but preferably the surface layer portion of the end surface 2 of the glass substrate 1 is locally heated using a resistance heating element, a heater using a heating wire, a high-intensity lamp, or a carbon dioxide laser. preferable. The maximum temperature reached by preheating is such that the temperature of the glass substrate 1 does not exceed the strain point of the glass substrate.

 The laser beam 3 is preferably a laser beam 3 having a wavelength of 3 to 11 xm. If the wavelength is shorter than 3 microns, the glass may not absorb the laser beam 3 and the end face 2 of the glass substrate 1 may not be heated sufficiently. In addition, when the wavelength is longer than 11 xm, it is difficult to obtain a laser device, which is practical. More preferably, the wavelength is 4 to 10.9 xm, and still more preferably the wavelength 9 to: 10.8 xm.

[0045] The oscillation mode of the laser light source is not particularly limited, and continuous wave light (CW light) or pulse emission is not limited. Either oscillation light or modulated light of continuous wave light (which modulates continuous wave light by turning it on and off and gives a periodic intensity change) may be used. However, in the case of modulated light of pulsed oscillation light and continuous oscillation light, if the relative scanning speed U of the laser beam 3 is slow, chamfered irregularity may occur in the scanning direction. In that case, it is preferable that the product of the oscillation and modulation period and the relative running speed of the laser beam 3 and the glass substrate 1 is not more than half of the thickness of the glass substrate 1.

[0046] For example CO laser, especially a laser beam is the most common of the oscillation wavelength 10. 6 _beta m

 2

 I like it. When the laser beam 3 in this wavelength region is irradiated, most of the laser beam 3 is absorbed by the glass substrate 1, and the temperature of the portion irradiated with the laser beam 3 can be raised to a soft temperature or higher.

 [0047] In addition, the laser beam 3 may be applied to the glass substrate 1 so as to converge in the thickness direction of the end face of the glass substrate. When the laser beam 3 diverges in the thickness direction of the end face of the glass substrate, after the end face 2 portion of the glass substrate 1 is rounded by melting, the plate of the end face 2 of the glass substrate 1 in the irradiation section 4 Since the incident angle of the light beam with respect to the vicinity of the edge in the thickness direction becomes large, it becomes difficult to absorb the energy of the laser beam 3 and the heating becomes insufficient. As a result, the melting of the part becomes insufficient and scratches may remain, leading to a reduction in edge strength.

[0048] In the method of the present invention, in principle, it is difficult to prevent stress from being generated at the chamfered portion of the glass substrate 1. Since cracks on the end surface 2 of the glass substrate 1 are melted and removed by heat. In addition, the same strength as the chamfered glass substrate 1 by conventional grinding can be secured, and there is no problem with practical strength. In addition, regarding optical problems represented by birefringence, there is no problem in ordinary applications, for example, flat panel displays, because pixels do not come to the glass edge. If necessary, residual stress can be easily removed by slowly cooling the entire glass substrate 1.

[0049] As an apparatus using the present invention, for example, a laser beam emitted from at least one laser beam generator is formed into a desired cross-sectional shape by a convex lens or a cylindrical lens, and this is applied to the end surface of the glass substrate. In addition to providing a mechanism for irradiating at a desired relative speed, it is also possible to provide a mechanism for blowing cooling air to the laser beam irradiation unit at the same time. An apparatus capable of obtaining a desired chamfered glass substrate can be configured.

FIGS. 4A to 4C are conceptual diagrams of examples of a glass substrate chamfering apparatus according to the present invention. FIG. 4 (a) shows an example in which the laser beam irradiation device 7 is fixed and the glass substrate is transported in the direction H to move the two relative to each other. As shown in FIG. 4 (a), this apparatus conveys the glass substrate 1 in an accurately positioned state (not shown), a laser beam 3 generator (not shown), and a cross-sectional shape of the laser beam 3. Is configured by a laser beam irradiation device 7 that controls the laser beam irradiation to the end surface 2 of the glass substrate 1, a device (not shown) that transmits the laser beam 3 from the generator to the laser beam irradiation device 7, and a cooling gas blowing nozzle 5. Is done. Note that descriptions of the power supply, blower (compressor, etc.), the device that controls the output of the laser beam 3 and the air volume of the cooling gas 6 were omitted.

 [0051] Thus, since the number of driving units is small, the apparatus has a very simple configuration. The chamfering may be performed one end face at a time, but as shown in FIG. 4 (a), both end faces 2 parallel to the conveyance direction H of the glass substrate 1 can be simultaneously performed.

 [0052] Fig. 4 (b) is an example in which the laser beam irradiation device 7 is fixed to an apparatus for manufacturing a continuously formed glass substrate and the two are relatively moved. In this way, it is possible to continuously chamfer the glass substrate in a production line such as the float method or the fusion method by continuously supplying molten glass. If chamfering can be performed in such a production line, the process of loading a glass substrate once onto an intermediate pallet etc. in the glass substrate production line that is continuously formed as in the past and then re-entering the chamfering line in the next process. Can be reduced, and the efficiency of equipment and processes can be improved. Furthermore, since the number of steps for handling the glass substrate before chamfering is reduced, it is possible to reduce cracks and chips caused by weak end face strength. The chamfering may be performed one end face at a time, but both end faces 2 parallel to the moving direction I of the glass substrate 1 may be simultaneously performed as shown in FIG. 4 (b).

 FIG. 4 (c) is an example in which the glass substrate 1 is fixed and the laser beam irradiation device 7 and the blowing nozzle 5 are moved to move both relative to each other. The chamfering may be performed one end face at a time, but as shown in FIG. 4 (c), both end faces 2 parallel to the conveying direction J of the laser beam irradiation device 7 and the blowing nozzle 5 can be simultaneously performed. Also, the four end faces may be performed simultaneously.

[0054] As described above, the apparatus of the present invention is configured so that the relative motion between the laser beam and the glass substrate is the same as that of the glass substrate. The laser beam irradiation device 7 and the blower nozzle 5 that can carry 1 are scanned. Further, chamfering may be performed simultaneously by a plurality of laser beam irradiation devices 7 or a plurality of laser beam irradiation devices 7. For simplification of the apparatus, the blowing nozzle 5 and the laser beam irradiation apparatus 7 may be integrated.

 Example

 [0055] Hereinafter, the present invention will be described in more detail by way of examples.

 As shown in FIG. 1, a chamfering test of the glass substrate in this example was performed. As a glass substrate for testing 1, a glass substrate for a liquid crystal display that was cleaved by a wheel cutter was prepared under the following conditions.

 A: Length 12cm, width 2.5cm, thickness 0.7mm

 B: Length 12cm, width 2.5cm, thickness 0.5mm

 C: Length 12cm, width 2.5cm, thickness 0.5mm

 D: Length 12cm, width 2.5cm, thickness 0.5mm

 E: Length 12cm, width 2.5cm, thickness 0.5mm

 F: Length 12cm, width 2.5cm, thickness 0.5mm

 G: Length 5cm, width 0.5cm, thickness 0.3mm

 Here, the end surfaces of the C and F glass substrates were further chamfered with a # 500 grinding wheel so that the radius of curvature was approximately 0.25 mm. The glass substrates A to F are liquid crystal display glass substrates (trade name AN100, manufactured by Asahi Glass Co., Ltd.), and the glass substrate G is a liquid crystal display glass substrate (trade name 0A_10, Nippon Electric Glass). Made by Co., Ltd.).

[0056] As an example 1, the above glass substrate A is used, and as shown in FIG. 1, a continuous oscillation carbon dioxide laser device with a wavelength of 10.6 microns is applied to the end surface of the glass substrate 1 (the laser oscillation form is CW light). Using a spherical lens and a cylindrical lens (not shown), the end face 2 of the glass substrate 1 with the laser beam 3 having a total wattage Q of 18 W in the cross section of the laser beam irradiation section 4 at the end face 2 of the glass substrate 1 is used. The width W in the longitudinal direction of the end face of the glass substrate on the surface surrounded by the curve connecting the portions where the energy density distribution in the cross section of the laser beam irradiation part 4 becomes 1 / e ^{2 at the} maximum is 0.1 mm, the plate thickness The laser beam 3 was irradiated so that the height H in the direction was a substantially elliptical shape of 3.5 mm. Average power defined by total wattage / irradiation area at this time The density P was about 51 W / mm ² . The laser beam 3 was irradiated at an irradiation angle A in the longitudinal direction of the end surface 2 with respect to a direction perpendicular to the end surface 2 of the glass substrate 1 at 0 ° and an irradiation angle A in the plate thickness direction at 0 °.

 [0057] The cooling gas 6 is blown with dry air as the cooling gas 6, and the cooling gas 6 has a blowing angle C of 40 ° in the longitudinal direction of the end surface with respect to the vertical direction of the end surface 2 of the glass substrate 1, and the plate thickness. The position and orientation of the cooling nozzle 5 were adjusted so that the air blowing angle D in the direction was 0 °. The wind speed S of the cooling gas 6 was about 25 mZ seconds on the end surface of the glass substrate 1.

 [0058] The glass substrate 1 is irradiated with the laser beam 3 in the longitudinal direction of the end surface 2 of the glass substrate 1, and the relative running speed U between the laser beam 3 and the glass substrate 1 is set to 2 mm / second. I ran away.

 Further, chamfering of Examples 2 to 7 was carried out in the same manner as Example 1 except that the prepared B to G glass substrates were used and the following conditions were changed as shown in Table 1. In Example 6, preheating is performed by preparing another continuous-wave carbon dioxide laser device (laser oscillation type is CW light) with a wavelength of 10.6 microns from the irradiation center of the laser beam 3 in the longitudinal direction of the glass substrate. 19W output, 13mm upstream, 7mm in the direction from the edge to the upper surface of the glass substrate, cross-sectional force of the laser beam on the upper surface of the glass substrate plate, 30mm in the longitudinal direction of the plate and 10mm in the width direction The end surface 2 of the glass substrate 1 was preheated by irradiation with

 Table 1 shows the test conditions.

 [table 1]

テストの結果、例 1から 7のガラス基板 1の端面 2が溶融により平滑化し角が丸まり、 面取りされたガラス基板が得られた。また、前記ガラス基板 1を、ホイールカッター（三 星ダイヤモンド工業株式会社製 Ml 59)を用いて人手でスクライブ後手折りし、スクラ イブ痕に沿つて割断できることを確認した。

As a result of the test, the end surface 2 of the glass substrate 1 of Examples 1 to 7 was smoothed by melting and the corners were rounded, and a chamfered glass substrate was obtained. Further, the glass substrate 1 is attached to a wheel cutter (three Using Ml 59) manufactured by Hoshi Diamond Industrial Co., Ltd., it was confirmed that it could be cleaved along the scribe mark after manual scribing after manual scribing.

[0060] As a comparative example, chamfering was performed without blowing air under the same conditions as in Examples 1 to 7. As a result, in each case, the end surface 2 of the glass substrate 1 was smoothed by melting and the corners were rounded, and a chamfered glass substrate was obtained. When the glass substrate 1 was scribed in the same manner as above, the scribe was performed. Cracks were self-propelled in places other than the marks and could not be cut normally. Industrial applicability

[0061] Since the present invention undergoes many processes in production, it can be widely applied to glass substrates that require chamfering of the end face of the glass substrate where the strength of the glass is a problem. It is particularly suitable for liquid crystal displays, plasma displays, and organic EL display plates that have undergone many manufacturing processes. It should be noted that the entire contents of the Akita Book, 2006-38018 filed on February 15, 2006, and the claims, drawings, and abstract are cited herein, and the specification of the present invention is disclosed. It is included as an indication.

Claims

The scope of the claims  [1] A method for chamfering a glass substrate by irradiating a laser beam, wherein the end surface of the glass substrate is irradiated with at least one laser beam and a cooling gas is blown to the laser beam irradiation part of the glass substrate. A method for chamfering a glass substrate.  [2] The irradiation angle of the laser beam is within ± 70 ° in the longitudinal direction of the end surface and within ± 70 ° in the plate thickness direction with respect to the vertical direction of the end surface of the glass substrate. The method for chamfering a glass substrate according to claim 1. [3] The cooling gas blowing direction is within ± 70 ° in the longitudinal direction of the end surface and within ± 45 ° in the plate thickness direction with respect to the vertical direction of the end surface of the glass substrate. The method for chamfering a glass substrate according to claim 1 or 2. [4] The method for chamfering a glass substrate according to any one of claims 1 to 3, wherein a wind speed of the cooling gas is a wind speed of lm / sec to 200 m / sec in the laser beam irradiation section. . [5] The glass substrate on the end face of the glass substrate that is surrounded by a curve connecting the portions where l / e ² (e is the base of natural logarithm) where the energy density distribution of the laser beam irradiation section is the maximum When the width in the longitudinal direction of the end face is W (mm) and the relative speed of the laser beam and the glass substrate is U (mm / s),  5. The method of chamfering a glass substrate according to claim 1, wherein W≤0.15XU + 2. [6] The end face of the glass substrate on the end face of the glass substrate surrounded by a curve connecting lZe ² (e is the base of natural logarithm) where the energy density distribution in the cross section of the laser beam irradiated portion is the maximum. When the width in the longitudinal direction is W (mm) and the relative speed of the laser beam and the glass substrate is U (mm / s),  0. 02≤W≤0. 15 X U + 2  5. The method for chamfering a glass substrate according to claim 1, wherein the force is any one of claims 1 to 4. [7] When the average power density defined by the total wattage / irradiation area of the laser beam irradiated section at the end face of the glass substrate is P (W / mm ² ), (0.5XU + 0. 2) / 0. 7 / (0. 15XU + 2) ≤P≤ (10XU + 10) /0.005XUX 0.7  The method for chamfering a glass substrate according to any one of claims 1 to 6, wherein: [8] When the average power density defined by the total wattage Z irradiation area of the laser beam irradiation portion cross section at the end face of the glass substrate is P (W / mm ² ),  The glass substrate according to any one of claims 1 to 6, wherein (4XU) /0.7.7/ (0.15XU + 2) ≤P≤ (10XU + 10) /0.005XUX0.7. Chamfering method.  [9] The chamfering of the glass substrate according to any one of claims 1 to 8, wherein the end surface of the glass substrate is preheated before irradiating the end surface of the glass substrate with the laser beam. Method.  [10] The glass according to any one of [9] to [9] above, wherein a speed at which the laser beam is swept is 0.:! To 200 mm / second relative to the glass substrate. How to chamfer a board.  [11] The glass substrate chamfering method according to any one of [1] to [10], wherein the wavelength of the laser beam is 3 to 11 / m. [12] The method for chamfering a glass substrate according to any one of [1] to [11], wherein the laser beam is converged in a thickness direction of an end face of the glass substrate with respect to the glass substrate. [13] The glass substrate is continuously chamfered in a line in which molten glass is continuously supplied and a glass substrate is manufactured by a float process, and the claw of the glass substrate is continuously performed. The chamfering method of the glass substrate of description. [14] Claim: A glass substrate chamfering apparatus for performing the method of chamfering a glass substrate according to any one of! To 13, wherein the end surface of the glass is irradiated with at least one laser beam; A chamfering device for a glass substrate, comprising: a mechanism for blowing cooling gas to a laser beam irradiation part of the glass substrate.