KR20160013841A - Glass substrate cutting method and glass substrate manufacturing method - Google Patents

Abstract

A method for cutting a glass substrate along a line along which a piece is intended to be cut by irradiating a laser beam on the glass substrate, the method comprising: A part of the width direction is curved in the width direction of the glass substrate and heated at a temperature not lower than a temperature at which the laser light irradiating portion from one surface to the other surface of the glass substrate is vaporized in the irradiation region of the laser light, Is moved relative to the glass substrate along a line along which the glass substrate is to be cut.

Description

TECHNICAL FIELD [0001] The present invention relates to a glass substrate cutting method and a glass substrate manufacturing method,

The present invention relates to a method of cutting a glass substrate and a method of manufacturing a glass substrate.

As a method of cutting a glass substrate, a cutting method using laser light has been studied.

For example, Patent Document 1 discloses a method of cutting a glass substrate forcibly cooled with a compressed gas or the like immediately after forming a notched portion having a predetermined depth by irradiating a laser beam.

Patent Document 2 discloses a glass substrate cutting method in which a glass substrate is irradiated with a laser beam while scanning with laser light to melt the glass with respect to an irradiated portion of the laser beam, and the molten glass is blown off by the assist gas.

Japanese Patent Application Laid-Open No. 2004-059328 Japanese Patent Laid-Open No. 60-251138

However, according to the cutting method of the glass substrate described in Patent Document 1, the cut surface has a portion corresponding to the notched concave portion formed by irradiating the laser beam, and a portion formed at the lower portion of the notched concave portion when forced cooling is performed thereafter And the surface characteristics of both are different.

In the case where there is a part of the cut surface which is different in surface characteristics due to the cutting method, it is necessary to cut the cut surface to obtain a cut surface with uniform surface characteristics. Therefore, it takes time to perform the polishing process on the cut surface.

In addition, since it is necessary to inject a compressed gas (assist gas) to the glass substrate immediately after irradiating the laser beam, the position of the glass substrate is liable to be displaced, so that the cutting precision is sometimes lowered.

According to the cutting method of the glass substrate described in Patent Document 2, there is a problem that the position of the glass substrate is displaced by the pressure of the assist gas and the precision at the time of cutting is lowered. In addition, depending on the energy density of the laser light, the amount of thermal deformation of the localized glass is increased, and cracks are sometimes generated in the glass substrate. Further, since the molten glass removed by the assist gas adheres to and solidifies on the cut surface or the periphery thereof, it takes time for the polishing process to remove it.

SUMMARY OF THE INVENTION In view of the above problems of the prior art, the present invention is capable of cutting a glass substrate with high precision compared to a conventional method of cutting a glass substrate by spraying an assist gas onto the glass substrate, And to provide a method of cutting a glass substrate which can obtain a uniform cut surface.

According to an aspect of the present invention, there is provided a method of cutting a glass substrate by cutting a glass substrate along a line along which a piece is to be cut by irradiating a laser beam, the method including irradiating a laser beam onto the one surface of the glass substrate A portion of the glass substrate in the width direction orthogonal to the line along which the glass substrate is intended to be cut is curved in the width direction of the glass substrate so that the area from one surface of the glass substrate to the other surface And irradiating the laser light onto the glass substrate along a line along which the glass substrate is to be cut, wherein the laser light irradiating portion is heated to a temperature higher than a vaporization temperature, and the region irradiated with the laser light is moved relatively to the glass substrate.

According to the cutting method of the glass substrate of the present invention, it is possible to cut the glass substrate with high accuracy as compared with the conventional method of cutting the glass substrate by using the assist gas. Further, it is possible to suppress the occurrence of cracks on the glass substrate at the time of cutting, and to provide a uniform cut surface.

1 is an explanatory diagram illustrating a cutting method of a glass substrate according to an embodiment of the present invention;
FIG. 2A is an explanatory diagram of a distance between one surface of a glass substrate and a laser oscillating device when laser light is irradiated onto a glass substrate including irregularities on its surface; FIG.
Fig. 2B is an explanatory diagram of a distance between one surface of a glass substrate and a laser oscillation device when laser light is irradiated onto a glass substrate including irregularities on its surface; Fig.
3 is an explanatory diagram of a configuration example of a conveying roller provided with a support member;
4 is an explanatory diagram of a configuration example in which a conveying roller having a support member is disposed on a conveying path of a glass substrate;
Fig. 5 is an explanatory diagram of a configuration example in which a conveying roller having a support member is disposed on a conveying path of a glass substrate; Fig.
6 is an explanatory diagram of a configuration example of a conveying roller for bending a part of the width direction of the glass substrate.
7 is an explanatory diagram of a heating step in a cutting method of a glass substrate according to an embodiment of the present invention.
8 is an explanatory diagram of a cooling step in a glass substrate cutting method according to an embodiment of the present invention.
9 is an explanatory diagram of a precipitate in a cooling step in a glass substrate cutting method according to an embodiment of the present invention.
10 is an explanatory diagram of the relationship between the glass substrate transport speed and the energy density of the laser light of Experimental Example 1 of the present invention and the evaluation of the cut surface.
11 is an explanatory diagram of the relationship between the glass substrate transport speed and the energy density of the laser light of Experimental Example 2 of the present invention and the evaluation of the cut surface.
12 is an explanatory diagram of the relationship between the glass substrate conveying speed and the energy density of the laser beam in Experimental Example 3 of the present invention and the evaluation of the cut surface.
Fig. 13 is an explanatory diagram of the relationship between the glass substrate transport speed and the energy density of the laser light of Experimental Example 4 of the present invention and the evaluation of the cut surface. Fig.
14 is an explanatory diagram of another method of bending a part of the area in the width direction of the glass substrate;

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiments, and various modifications and substitutions may be made without departing from the scope of the present invention. .

In this embodiment, a structural example of the glass substrate cutting method of the present invention is described.

The method for cutting a glass substrate according to the present embodiment is a method for cutting a glass substrate along a line along which a piece is intended to be cut by irradiating a laser beam, and has the following configuration.

(Hereinafter also referred to as " the width direction of the glass substrate ") perpendicular to the line along which the object is intended to be cut in the glass substrate including the region irradiated with laser light for irradiating the laser light onto one surface of the glass substrate, And curved in the width direction of the glass substrate.

Then, in the irradiation area of the laser beam, the laser beam is irradiated at a temperature higher than the vaporization temperature of the laser beam irradiation part from one surface to the other surface of the glass substrate.

Further, the present invention is a method for cutting a glass substrate, characterized in that the irradiated region of the laser beam is moved relative to the glass substrate along a line along which the glass substrate is to be cut.

Will be described in detail with reference to Figs. 1 to 8. Fig.

Fig. 1 schematically shows a configuration in which a portion of a glass substrate cut by a cutting method of the present invention is viewed from the top surface of a glass substrate on one side (one surface side) of a laser beam irradiation side.

The glass substrate 11 is transported in a direction indicated by an arrow A in Fig. 1, and a portion irradiated with a laser beam 12 (laser beam irradiation region) emitted from a laser oscillation device (not shown) So that it can move along the line 13.

In the method of cutting the glass substrate according to the present embodiment, a part of the width direction orthogonal to the line along which the object is intended to be cut in the glass substrate including the region irradiated with laser light is curved in the width direction of the glass substrate. This point will be described below.

The thickness of the glass substrate is thin, and in particular, when the glass substrate is being conveyed, wrinkles may occur on the glass substrate. When wrinkles are generated on the glass substrate, the surface of the glass substrate includes irregularities. When irradiating the glass substrate including the concavo-convex surface with laser light, laser light is irradiated onto the convex portion 22 of the glass substrate 11, which is being conveyed on the conveying roller 21 as shown in Fig. 2A The distance between one surface of the laser oscillator 23 and one surface of the glass substrate 11 becomes a distance D1. 2B, when the laser beam is irradiated to the concave portion 24 of the glass substrate 11 being conveyed on the conveying roller 21, the position of the laser oscillator 23 does not change , The distance between one surface of the laser oscillator 23 and one surface of the glass substrate 11 becomes longer than the distance D1 and becomes the distance D2. As described above, the distance between one surface of the laser oscillator and one surface of the glass substrate changes due to the unevenness of the surface of the glass substrate, so that the glass substrate can not be appropriately heated by the laser light.

In contrast, by bending a part of the width direction perpendicular to the planned line of the glass substrate including the irradiation area of laser light, it is possible to suppress at least the occurrence of wrinkles on the glass substrate with respect to the curved part of the glass substrate have. This makes it possible to stabilize the distance between one surface of the glass substrate 11 and the laser oscillator, which is the light source of the laser light, in the irradiation area of the laser light, and appropriately perform heating along the line along which the glass substrate is to be cut. Further, the glass substrate can be cut with high accuracy, and a uniform cut surface can be obtained.

A part of the width direction orthogonal to the planned line of the glass substrate including the area irradiated with the laser beam for irradiating the laser beam 12 on one surface of the glass substrate 11 is curved in the width direction of the glass substrate The method is not particularly limited. The curving of the glass substrate in the width direction can be also referred to as curving the end face of the glass substrate perpendicular to the carrying direction upward or downward.

Here, a structural example of a method of bending a portion of the glass substrate in the width direction of the glass substrate will be described with reference to Figs. 3 to 6 and Fig. 14. Fig. 3 shows a configuration example of the conveying roller 32 provided with the support member 33. As shown in Fig. Fig. 4 and Fig. 5 show an example in which the conveying roller 32 having the support member 33 shown in Fig. 3 is arranged on the conveying path of the glass substrate, Of the present invention is schematically shown from the upper surface of the glass substrate.

There is provided a method for curving a part of a region of a glass substrate in a width direction of the glass substrate so that a part of the region in the width direction of the glass substrate including the region irradiated with the laser beam protrudes from the region of another portion of the glass substrate, And a method of supporting the glass substrate from the other surface side of the substrate.

3, when the supporting member 33 is disposed in a part of the conveying roller 32 in the width direction, the surface of the partial region 31 of the glass substrate is held by the supporting member 33, (The other surface side) of the glass substrate so as to be higher than the area 34 of the other portion of the substrate.

4, at least a part of the conveying rollers 32 of the plurality of conveying rollers 32 disposed on the conveying path of the glass substrate conveyed in the direction indicated by the block arrow A The conveying roller 32 having the support member 33 as shown in Fig. By constituting the conveying roller in this way, a part of the width direction of the glass substrate in the range indicated by the area 41 in Fig. 4 can be curved. That is, the end face of the glass substrate perpendicular to the carrying direction can be bent upward. At this time, it is possible to select a place where the conveying rollers provided with the support member 33 are arranged such that the irradiation area of the laser beam 12 is at least in the region 41. [

4 shows an example in which the supporting member 33 is provided only on one end side in the width direction of the conveying roller 32, but the present invention is not limited to this. The support members 33 can be provided at a plurality of locations in the width direction of the glass substrate in accordance with the number of the lines 13 to be cut of the glass substrate. For example, in the case of cutting both ends in the width direction of the glass substrate, the supporting member 33 can be provided also on the other end side in the width direction of the conveying roller 32. [

The configuration of the support member 33 formed on the conveying roller 32 is not particularly limited. 4, when the support member 33 is formed for each of the conveying rollers 32, for example, by placing an O-ring on the conveying roller 32 as the support member 33, An annular convex portion can be formed with respect to a part of the surface in the width direction. 5, the support member 33 may be constituted by a tape-like guide member, that is, a belt, which is wound around a plurality of conveying rollers, as shown in Fig. In this case also, it is possible to bend a part of the area in the width direction perpendicular to the line along which the glass substrate 11 is to be cut in the range shown by the area 41 in Fig. That is, the end face of the glass substrate perpendicular to the carrying direction can be bent upward.

As described above, the supporting member is not particularly limited in its constitution, but it is preferable that the supporting member is constituted by a tape-shaped guide member which is wound around a plurality of conveying rollers as shown in Fig. When the support member is constituted by the tape-shaped guide member which is wound around the conveying rollers, even between the conveying rollers, the glass substrate can be supported by the support member on the other surface side, and the shape of the curved portion of the glass substrate can be uniformly So that occurrence of wrinkles can be further suppressed.

The height H of the support member 33 shown in Fig. 3 is not particularly limited and can be arbitrarily selected depending on the thickness of the glass substrate to be cut.

The shape of the surface of the support member 33 in contact with the glass substrate is not particularly limited, and may be a flat shape as shown in Fig. 3, or a curved shape in the width direction of the conveying roller.

As another method for curving a part of the width direction orthogonal to the line along which the glass substrate is intended to be cut, for example, as shown in Fig. 6, in some conveying rollers 32 around the area irradiated with laser light, And a conveying roller 32 having a portion 61 whose diameter is smaller than that of the portion.

A concave portion is formed on the surface of the conveying roller 32 by providing the conveying roller 32 with a portion 61 whose diameter is smaller than that of the other portion. As a result, the glass substrate may bend in the concave portion, and the glass substrate 11 may be bent in the vicinity of the boundary between the portion 61 whose diameter is smaller than that of the other portion and the other portion as shown in Fig. That is, the end face of the glass substrate perpendicular to the carrying direction can be bent downward.

As a method of bending a part of the width direction orthogonal to the line along which the object is intended to be cut on the glass substrate without depending on the shape of the conveying roller, for example, as shown in Fig. 14, The part of the glass substrate 11 held by the member 40 is released from the holding member 40 and the area of the part is curved by bending it with its own weight . When the holding member 40 is a table, at least one of the glass substrate 11 and the laser oscillator is moved to cut the glass substrate 11.

As described above, when a part of the area in the width direction of the glass substrate including the irradiated area of the laser light 12 is curved, the irradiated area of the laser light 12 is shifted from the curved part of the glass substrate to the inclined surface part Or the like. This is because, in the inclined surface portion of the curved glass substrate as shown in Figs. 3, 6 and 14, the conveying roller 32 and the supporting member 33 for supporting the glass substrate on the other surface (lower surface) The gap between the holding member 40 and the glass substrate 11 is generated. This is because it is possible to suppress heating of the conveying roller 32, the support member 33, and the like when the laser beam is irradiated, and damage to the conveying roller 32 and the like can be suppressed.

The incident angle of the laser beam 12 to the glass substrate is not particularly limited. 3, 6 and 14, the laser beam 12 is incident on the unbent area of the glass substrate, that is, the area of another part of the glass substrate in FIG. 3 (for example, 34 so as to be substantially perpendicular to the surface of the glass substrate. The angle at which the laser light 12 is irradiated may be adjusted in accordance with the inclination angle of the glass substrate in the irradiation area of the laser light 12. [ That is, the laser beam 12 may be irradiated on the glass substrate 11 so that the surface of the glass substrate 11 and the laser beam 12 are substantially perpendicular to each other in the irradiation region of the laser beam.

In the case of Fig. 3, since the glass substrate is curved in a parabolic shape, the inclined surface of the curved portion occurs on the right side of the figure and on the left side of the figure. As a result, as shown by the arrow 12 ', laser light may be irradiated on the sloped surface on the left side in the figure.

However, in the case where the curved portion of the glass substrate has a plurality of inclined surfaces, the support member 33 is provided on a portion of the glass substrate in the width direction, which protrudes from the region of another portion of the glass substrate, It is preferable that the glass substrate be supported so that the irradiation region of the laser beam is disposed on the inclined surface on the end side. That is, it is preferable that the irradiation area of the laser beam is on an inclined surface on the end side in the width direction of the glass substrate.

As described above, at least a region in the width direction of the glass substrate including at least the region irradiated with the laser beam may be curved in the width direction of the glass substrate, and the range of curving the glass substrate with respect to the length direction of the glass substrate is particularly limited It is not. That is, only a part of the width direction orthogonal to the line along which the glass substrate is intended to be cut may be curved in the width direction of the glass substrate only for the range of the laser light irradiation area in the longitudinal direction of the glass substrate. Here, the longitudinal direction of the glass substrate means a direction parallel to the transport direction of the glass substrate.

However, a part of the width direction of the glass substrate including the line along which the glass substrate is intended to be cut, from the area irradiated with laser light of the glass substrate to the area spaced apart from the glass substrate by a predetermined distance along the line along which the glass substrate is to be cut, It is preferable to bend in the width direction of the substrate.

As described above, when the glass substrate is curved with respect to a part of the width direction orthogonal to the line along which the object is intended to be cut in the glass substrate including at least the laser light irradiation area, The occurrence of wrinkles can be suppressed. However, for example, in the case of transporting a glass substrate, when the glass substrate is bent as described above immediately before the region irradiated with the laser beam, the degree of suppression of the occurrence of wrinkles may not be sufficient enough. This makes it possible to cut the glass substrate with respect to a part of the width direction of the glass substrate including the line along which the glass substrate is to be cut, for example, over a predetermined range on the upstream side in the transport direction of the glass substrate, It is preferable to bend the glass substrate so that the predetermined line is disposed on the inclined plane.

For example, as shown in Fig. 4, in the case of disposing the conveying roller 32 having the support member 33, the support member 33 having the support member 33 disposed at the most upstream side in the conveying direction of the glass substrate It is preferable that the irradiation area of the laser beam 12 is located on the downstream side of the vertex position of the conveying roller 32. In other words, in the case of FIG. 4, it is preferable to arrange such that the irradiation region of the laser beam is arranged on the downstream side in the transport direction of the glass substrate than the X-X 'line. In particular, in order to prevent the conveying roller 32 and the like from being damaged when the laser beam is irradiated, it is preferable to arrange the irradiation area of the laser beam 12 between the conveying rollers 32. [

As described above, in the glass substrate cutting method of this embodiment, a part of the width direction orthogonal to the line along which the object is intended to be cut of the glass substrate including the area irradiated with laser light is curved in the width direction of the glass substrate . In the portion irradiated with the laser light 12 (laser light irradiation region), the laser light irradiation portion from one surface to the other surface of the glass substrate is heated (heating process). The region 14 already irradiated with the laser beam is separated from the region irradiated with the laser beam by being conveyed by the glass substrate 11 and is irradiated with the laser beam irradiated portion irradiated with the laser beam 15 are cooled (cooling process). This point will be described below with reference to Figs. 1, 7, and 8. Fig. 1, 7, and 8, the periphery of the irradiation area of the laser beam is also described as a flat shape for convenience of the substrate. Although the lines 13 to be cut of the glass substrate are shown in the figure, these lines are not provided on an actual glass substrate.

The composition of the glass substrate to which the method of cutting the glass substrate of the present embodiment can be applied is not particularly limited and can be applied to various glass substrates. Examples thereof include alkali-free borosilicate glass, borosilicate glass, soda lime glass, high silica glass, and other oxide-based glass containing silicon oxide as a main component.

The thickness of the glass substrate is not particularly limited, and can be arbitrarily selected depending on, for example, the output of the laser oscillation apparatus to be used.

However, when the thickness of the glass substrate is small, wrinkles tend to occur particularly on the glass substrate. In the method of cutting the glass substrate according to the present embodiment, the glass is vaporized in the region irradiated with the laser beam, with respect to the laser beam irradiating portion from one surface to the other surface of the glass substrate, Heating above the temperature. From the above two reasons, it is particularly effective when the thickness of the glass substrate is thin. For this reason, for example, the thickness of the glass substrate is preferably 3.0 mm or less, more preferably 1.0 mm or less, more preferably 0.5 mm or less, particularly preferably 0.2 mm or less. The lower limit value is not particularly limited.

In addition, although the shape of the glass substrate shown in Fig. 1 is rectangular, the shape of the glass substrate is not particularly limited. For example, a strip-shaped glass substrate molded by a glass substrate forming apparatus such as a float method or a down-draw method may be used.

Next, a heating step performed in an irradiation area of a laser beam (a part irradiated with a laser beam on the glass substrate) will be described. FIG. 7 is an enlarged view of the vicinity of the irradiation area of the laser beam 12 in the section taken along line B-B 'in FIG.

In the cutting method of the glass substrate of the present invention, the heating process is performed in the irradiation region of the laser beam by irradiating the laser beam 12 onto the glass substrate as described above.

The laser beam irradiating portion 71 from one surface of the glass substrate to the other surface of the glass substrate is heated to a temperature above the vaporization temperature of the glass with respect to the irradiation region of the laser beam of the glass substrate. Here, one surface of the glass substrate refers to the side on which the laser beam is incident, and the other surface means the opposite surface. As a result, with respect to the laser beam irradiating portion 71, the glass is vaporized and a through hole is formed in a short time in the irradiation direction of the laser beam (the thickness direction of the glass substrate).

The peripheral portion 72 of the laser light irradiating portion 71 is also heated by the heat from the laser light irradiating portion.

As described above, without supplying the assist gas to the laser beam irradiating portion (without using the assist gas) at the time of the heating process or immediately after that, that is, at the time of laser light irradiation (during the glass vaporization) , The glass can be vaporized with respect to the laser beam irradiating section in a short time. Thus, the glass substrate can be processed with high accuracy without causing positional deviation or the like, and the occurrence of cracks in the glass substrate can be suppressed.

The irradiation condition of the laser beam in the heating process is not limited. The irradiation condition of the laser beam from the side of the one surface of the glass substrate (the side from which the laser beam enters) to the other side of the surface of the glass substrate It may be selected so as to be heated to a temperature higher than the vaporization temperature of the glass.

Concretely, for the laser light irradiating part, for example, from the plate thickness of the glass substrate to be cut, the glass composition, the transporting speed of the glass substrate (the relative moving speed of the irradiated area of the laser light to the glass substrate) The energy density of the laser light or the like may be selected so as to be heated. For example, by performing a preliminary test in advance.

Especially when the relative moving speed of the laser beam to the glass substrate is v (m / hour), the energy density of the laser beam is E (W / mm 2) and the thickness of the glass substrate is t (mm)

E? 50 × t × v

It is preferable to adjust the energy density of the laser light to be irradiated so as to satisfy the relationship

By performing cutting of the glass substrate including the heating process while satisfying these requirements, the laser light irradiating portion from one surface of the glass substrate to the other surface of the glass substrate in the irradiation region of the laser light is heated to a temperature As shown in Fig.

But is not limited to the spot diameter of the laser beam irradiated on the glass substrate (the beam diameter of the laser beam on one surface of the glass substrate), and can be selected in accordance with the required processing accuracy or the like.

The kind of the laser to be used is not particularly limited, and any laser may be used as long as it can heat the glass substrate with respect to the irradiated portion by irradiating laser light oscillated on the glass substrate. Specifically, for example, a CO ₂ laser, an excimer laser, a copper deposition laser, a YAG laser, or the like can be used.

In the heating process, the glass substrate is vaporized with respect to the laser beam irradiating unit by irradiating the glass substrate with laser light as described above. As a result, a vaporized glass component (gas) is generated in the laser light irradiating portion and its periphery. When such a component is deposited and adhered to the surface of an optical system such as a lens or a mirror of a laser oscillator disposed on the optical path of the laser beam, the laser beam can not be irradiated to the glass substrate, There is a possibility that the laser beam can not be irradiated, and there is a possibility that the processing accuracy of the glass substrate is affected. Therefore, it is preferable to remove the vaporized glass component by irradiating the glass substrate with laser light. That is, in the heating step, it is preferable to remove the glass component of the vaporized laser light irradiating portion. The means for removing the vaporized glass component is not particularly limited and a mechanism for sucking the vaporized glass component and a mechanism for blowing off the glass component vaporized by the gas can be used. The arrangement may be selected in accordance with the means to be used, and the vaporized glass component may be disposed so as to be removed before adhered to a lens, a mirror, or the like disposed on the optical path of the laser beam without hindering the heating process. For example, as shown in Fig. 7, as shown by (73), it is considered to be disposed in the vicinity of the portion irradiated with laser light.

When a mechanism for blowing off a glass component vaporized by a gas is used, the type of the gas to be used is not particularly limited. However, from the viewpoint that the glass substrate is used in the vicinity of a portion heated by laser light, It is preferable to use gas. Specifically, for example, an inert gas such as nitrogen or argon, or air may be used. In this case, in order to prevent the positional displacement of the glass substrate, it is preferable to supply the glass substrate such that the gas does not touch the glass substrate.

Next, the cooling process will be described.

In the cooling step, after the laser beam is irradiated, the glass substrate is conveyed so that the laser beam irradiating portion (already irradiated with the laser beam) after the laser beam irradiation is away from the irradiated region of the laser beam and the peripheral portion of the laser beam irradiating portion is cooled will be.

In the cooling step, as shown in Fig. 7, the peripheral portion 72 of the laser light irradiating portion (the portion vaporized by laser light irradiation in the heating step) 71 is cooled. At least a part of the peripheral portion 72 is precipitated on the glass substrate surface (one surface and / or the other surface of the glass substrate) as the filament precipitates 81 and 82 as shown in Fig. 8 There is a case. This is because the glass has a low thermal conductivity and a temperature gradient is generated in the peripheral portion 72 in the cooling process after the heating process so that the stress generated in the peripheral portion 72 causes a temperature gradient of the peripheral portion 72 At least a part thereof is excluded and is reported to be precipitated. Although the precipitates 81 and 82 are deposited on the upper surface (one surface) of the glass substrate in the drawing, they may precipitate on the lower surface (the other surface). For example, the precipitates 81 and 82 are more likely to be scattered in the conveying direction of the glass substrate than the area irradiated with the laser beam 12, And is deposited from a position deviated from the irradiation area of the laser beam 12. [

As described above, since at least a part of the peripheral portion 72 of the laser light irradiating portion is excluded from the cut surface irradiated with laser light, it is possible to finally obtain a uniform cut surface.

In order to generate the precipitate in the cooling step and obtain a uniform cut surface, it is preferable that the peripheral portion of the laser light irradiated portion is cooled at an appropriate cooling rate. The cooling rate can be changed by the relative moving speed of the irradiation area of the laser beam with respect to the glass substrate. Therefore, it is preferable to select the relative moving speed of the laser beam irradiated region with respect to the glass substrate so as to generate the precipitates in the cooling step by carrying out a preliminary experiment or the like.

The relative moving speed of the irradiated region of the laser beam with respect to the glass substrate can be selected by a preliminary experiment or the like as described above and is not specified, but can be set to, for example, 144 m / hour or more.

When the precipitates 81 and 82 are generated in the cooling step, the precipitates 81 and the precipitates 82 may be adhered to each other depending on the temperature of the precipitates 81 and 82, the distance between them, and the like. In some cases, when the precipitate 81 and the precipitate 82 are adhered to each other, a part of the peripheral portion 72 of the laser light irradiating portion 71 is difficult to be discharged from the peripheral portion 72, The cut surface may not be formed. However, in the method for cutting a glass substrate according to the present embodiment, a part of the width direction orthogonal to the line along which the object is intended to be cut in the glass substrate including the region irradiated with laser light is curved in the width direction of the glass substrate. Thus, as shown in Fig. 9, for example, in the vicinity of the laser light irradiating portion (portion vaporized by laser light irradiation in the heating process) 71 in which the temperature of the precipitates 81 and 82 is particularly high, The height of the glass substrate 91 on one side and the height of the glass substrate 92 on the other side are different. Therefore, it is possible to suppress adhesion of the precipitates 81 and 82 to each other around the laser beam irradiating portion 71, and as a result, it is possible to more reliably make the cut surface uniform.

The precipitate 81 is precipitated between the conveying rollers and is deposited on the upper surface side or the lower surface side of the glass substrate 92 on the other side. 9 shows that the precipitate 81 appears to be turned to the lower end side of the conveying roller for the sake of description of the figure but even if the precipitate 81 is deposited on the lower surface side of the other glass substrate 92, It is located between the glass substrate 92 and the conveying roller and does not hinder the behavior of the conveying roller.

The precipitates 81 and 82 generated in the cooling process sometimes interfere with the cooling, so it is preferable to remove precipitates formed in the peripheral portion of the laser light irradiated portion. The means for removing the precipitate is not particularly limited and can be easily removed by, for example, blowing off with a gas, removing by suction, removing by a brush, an obstruction plate, or the like.

Further, when the precipitate is blown away by the gas, it is preferable to use a low-pressure gas so as to give a vibration to the glass substrate so as not to affect the cutting accuracy of the glass substrate.

The cooling step is to cool the peripheral portion 72 of the laser light irradiating portion after the laser light irradiation as described above, and the cooling temperature is not limited thereto. For example, it is preferable that the peripheral portion of the laser light irradiation portion is cooled to the glass transition temperature or lower after heating the laser light irradiation portion.

At this time, when cooling is carried out at a temperature of the surrounding atmosphere after the heating step, the ambient temperature is preferably at least the glass transition temperature, more preferably not more than 100 캜, and particularly preferably not more than 40 캜. The ambient temperature referred to herein is at least the ambient temperature of the part undergoing the cooling step, preferably the ambient temperature including the entire glass substrate being cut.

The method of cutting a glass substrate of the present embodiment described so far can be preferably used particularly when cutting a glass substrate at a cutting line along the transport direction of the glass substrate.

In general, when manufacturing a glass substrate, both ends in the width direction of the glass substrate are cut at a cutting line along the carrying direction of the glass substrate in order to obtain a desired size of the glass substrate. At this time, Method can be preferably used. In this case, since both ends in the width direction of the glass substrate are cut and only the center portion in the width direction is used as a product, both end portions in the width direction of the glass substrate, that is, the ear portions are preferably separated from the conveying path of the glass substrate after cutting .

Specifically, for example, ear separation means is provided on the downstream side of the heating process in the conveying direction of the glass substrate, and the ear separating means separates the ear portion of the cut glass substrate from the conveying direction of the glass substrate Can be changed and separated.

The ear separating means is not particularly limited. For example, the ear separating means may include a conveying roller serving as a supporting point for changing the direction of the ear portion of the glass substrate, a conveying roller contacting the ear portion of the glass substrate on the opposite side of the conveying roller, And the ear stable holding means for pressing the ear portion together.

The ear portion of the separated glass substrate can be introduced into the sub-transport path different from the transport path and can be collected separately from the central portion of the glass substrate.

In the above description of the cutting method of the glass substrate according to the present embodiment, the cutting method of the glass substrate of the present embodiment has been described taking the glass substrate being horizontally transported on the transporting roller 32 as an example. However, the cutting method of the glass substrate according to the present embodiment is not limited to the cutting of the glass substrate being horizontally transported, but can also be applied to a glass substrate formed by, for example, a down-draw method or the like and vertically transported. In this case, for example, a part of the width direction orthogonal to the line along which the object is intended to be cut, of the glass substrate including the irradiation area of the laser light for irradiating the laser light by the pressing member from one side of the glass substrate, Direction. As described above, the glass substrate that is vertically transported by performing the heating process and the cooling process can be similarly cut.

Even when the glass substrate is vertically conveyed, the method of cutting the glass substrate of the present embodiment can be preferably used when cutting both ends in the width direction of the glass substrate. Even in this case, both end portions in the width direction of the cut glass substrate are preferably separated from the conveying path of the glass substrate.

The method of cutting the glass substrate of the present invention has been described above. However, in the method of cutting the glass substrate, since the assist gas is not jetted onto the glass substrate, the positional displacement of the glass substrate is suppressed, It can be cut and processed. In addition, the occurrence of cracks in the glass substrate at the time of cutting can be suppressed, and a cut surface with uniform surface characteristics can be obtained.

The above-described method for cutting a glass substrate according to the present embodiment can be applied to a manufacturing process for a glass substrate, and a glass substrate manufacturing method using the cutting method for the glass substrate can be employed.

In the method of manufacturing such a glass substrate, it is possible to cut the glass substrate with high precision, thereby suppressing the occurrence of cracks on the glass substrate at the time of cutting, and making the glass substrate a uniform cut surface. The effect of shortening the polishing time of the cutting face in the polishing step or omitting the polishing step can be obtained.

Example

Hereinafter, the present invention will be described with reference to specific examples, but the present invention is not limited to these examples.

[Experimental Example 1]

In this Experimental Example, the glass substrate was cut by changing the energy density of the laser light and the relative moving speed of the irradiated region of the laser light to the glass substrate, and the cut surface of the glass substrate after the cutting was evaluated.

When the glass substrate was cut, a glass substrate (trade name: AN100, manufactured by Asahi Glass Co., Ltd.) containing 100 mm in length, 100 mm in width, and 0.1 mm in thickness of the alkali-free borosilicate glass ) Was irradiated with a laser beam using a CO ₂ laser along a line along which the material was to be cut, with a spot diameter of about 0.3 mm so as to have a predetermined energy density while the glass substrate was transported at a predetermined transporting speed. The ambient temperature (environmental temperature) of the glass substrate at the time of cutting was room temperature (25 DEG C).

3 and 4, a supporting member 33 is provided on the conveying roller 32, and a part of the glass substrate including the irradiation area of the laser beam irradiated with laser light in the width direction Was irradiated with a laser beam while bending the region in the width direction of the glass substrate. At this time, the laser beam 12 was irradiated to the inclined surface on the end side in the width direction of the glass substrate as indicated by the arrow 12 in Fig. 4, the supporting member 33 is provided on the two conveying rollers 32, and the conveying rollers 32 provided with the supporting members 33 are provided between the irradiation regions of the laser light 12 .

As for the glass substrate after the cutting, C for the uncut portion was cut, but it was found that no precipitate was observed in the portion irradiated with the laser, and the cut surface was not uniformized by visual inspection, B was evaluated as the occurrence of cracks. When the glass substrate was cut and it was confirmed that the glass substrate was a uniform cut surface, it was evaluated as A. The results are shown in Table 1 and FIG. FIG. 10 is a graph showing a part of the results of Table 1. FIG.

In the graph shown in Fig. 10, the straight line X represents v (m / hour), the energy density of the laser light is E (W / Mm < 2 >) and the plate thickness of the glass substrate is t (mm), E = 50 x t x v.

The straight line Y represents the minimum value of the relative moving speed (in this case, the conveying speed of the glass substrate) of the irradiated region of the laser beam generated in the cooling step with respect to the glass substrate, and in this case, 144 (m / hour).

According to Fig. 10, when the A evaluation is distributed in the range surrounded by the straight line X and the straight line Y, the C evaluation is performed when the energy density is smaller than the straight line X, and the B evaluation is performed when the conveying speed is slower than the straight line Y.

This is because when laser light having an energy density equal to or higher than a straight line X is irradiated at a relative moving speed (conveying speed of the glass substrate) of the irradiation area of each laser beam to the glass substrate, It can be surely heated to a temperature above the vaporization temperature of the glass with respect to the irradiation region of the laser light from the surface to the other surface.

Further, by making the conveying speed equal to or higher than the straight line Y, it is considered that the peripheral portion of the irradiated region of the laser beam after irradiation with the laser beam can be sufficiently cooled and removed from the cut surface portion as the precipitate, .

That is, in the glass substrate subjected to the C evaluation, sufficient energy of laser light is not applied to the relative moving speed of the irradiated region of the laser beam to the glass substrate (the transporting speed of the glass substrate) (The temperature of the glass substrate was not sufficiently raised over the entire range of the thickness direction of the glass substrate). As a result, it can be concluded that the glass substrate can not be cut.

Further, the glass substrate subjected to the B evaluation was irradiated with laser light having a sufficient energy density with respect to the relative moving speed of the laser light irradiated region with respect to the glass substrate (conveying speed of the glass substrate), so that the glass substrate could be cut .

However, the relative moving speed of the irradiated region of the laser beam to the glass substrate (conveying speed of the glass substrate) is insufficient, the cooling rate at the periphery of the irradiated region of the laser beam after irradiation of the laser beam is slowed and its periphery is not excluded as a precipitate And that the cut surface was not uniform. Or when the temperature of the peripheral portion of the irradiated region of the laser beam after the laser beam irradiation is cooled by the conveyance of the glass substrate is not a desired cooling rate, it is confirmed that a crack has occurred in the cut surface and its periphery.

On the contrary, it is considered that the glass substrate for evaluation A was able to appropriately select the energy density of the laser beam in accordance with the relative moving speed of the irradiation region of the laser beam to the glass substrate (the transporting speed of the glass substrate). Therefore, it is considered that the glass substrate is heated to a temperature higher than the vaporization temperature of the glass from one surface of the glass substrate to the other surface with respect to the irradiation region of the laser beam. In addition, since the conveying speed of the glass substrate is appropriate, the peripheral portion of the irradiated region of the laser beam irradiated with the laser beam is cooled at an appropriate cooling rate, the peripheral portion of the irradiated region of the laser beam irradiated with the laser beam is excluded as a precipitate, Is thought to have been obtained.

[Experimental Example 2]

In this experimental example, the energy density of the laser beam and the relative moving speed of the irradiated region of the laser beam to the glass substrate were changed in the same manner as in Experimental Example 1, except that the thickness of the glass substrate to be cut was changed to 0.2 mm, The substrate was cut, and the cut surface of the glass substrate after the cutting was evaluated.

The results are shown in Table 2 and Fig. 11 is a graph showing the results of Table 2.

Also in the graph shown in Fig. 11, the straight line X is a straight line having the above-mentioned E = 50 x t x v (t = 0.2 mm).

The straight line Y represents the minimum value of the relative moving speed (in this case, the conveying speed of the glass substrate) of the irradiated area of the laser beam generated in the cooling step with respect to the glass substrate, in this case, 144 (m / h).

According to this, it was confirmed that the A evaluation was distributed in the range surrounded by the straight line X and the straight line Y.

[Experimental Example 3]

In this experimental example, the energy density of the laser beam and the relative moving speed of the irradiated region of the laser beam to the glass substrate were changed in the same manner as in Experimental Example 1, except that the thickness of the glass substrate to be cut was 0.3 mm, The substrate was cut, and the cut surface of the glass substrate after the cutting was evaluated.

The results are shown in Table 3 and Fig. 12 is a graph showing the results of Table 3.

In the graph shown in Fig. 12, the straight line X is a straight line having the above-mentioned E = 50 x t x v (t = 0.3 mm).

The straight line Y represents the minimum value of the relative moving speed (in this case, the conveying speed of the glass substrate) of the irradiated area of the laser beam generated in the cooling step with respect to the glass substrate, in this case, 144 (m / h).

In the present experimental example, the glass substrate is cut by changing the energy density of the laser light to be irradiated without changing the conveying speed of the glass substrate. According to this, when the energy density of the laser beam is increased to have an energy density higher than that of the straight line X, the temperature of the laser beam irradiated region from the one surface of the glass substrate to the other surface , And it was confirmed that the A evaluation was made.

[Experimental Example 4]

In this experimental example, the energy density of the laser beam and the relative moving speed of the laser beam irradiated area with respect to the glass substrate were changed in the same manner as in Experimental Example 1, except that the thickness of the glass substrate to be cut was changed to 0.6 mm, The substrate was cut, and the cut surface of the glass substrate after the cutting was evaluated.

The results are shown in Table 4 and Fig. FIG. 13 is a graph showing the results of Table 4. FIG.

In the graph shown in Fig. 13, the straight line X is a straight line having the above-mentioned E = 50 x t x v (t = 0.6 mm).

The straight line Y represents the minimum value of the relative moving speed (in this case, the conveying speed of the glass substrate) of the irradiated area of the laser beam generated in the cooling step with respect to the glass substrate, in this case, 144 (m / h).

In this experimental example, the energy density of the laser light irradiated from the straight line X was lower. As a result, sufficient energy of laser light can not be applied to the relative moving speed of the irradiation area of the laser beam with respect to the glass substrate (conveying speed of the glass substrate) It is considered that the temperature was not higher than the vaporization temperature. Therefore, the glass substrate could not be cut and it was considered that the C evaluation was made.

As described above, the method of cutting the glass substrate and the method of manufacturing the glass substrate have been described with the embodiments and the like, but the present invention is not limited to the above-described embodiments and the like. Various modifications and variations are possible within the scope of the present invention described in the claims.

The present application claims priority based on Japanese Patent Application No. 2013-112182 filed on May 28, 2013, and claims the entire contents of Japanese Patent Application No. 2013-112182 in the present international application .

11: glass substrate
12: Laser light
33: support member
40: holding member
71: Laser light irradiation part
72: peripheral portion of the laser light irradiating portion
81, 82: precipitate

Claims (12)

A method of cutting a glass substrate by irradiating a laser beam to cut the glass substrate along a line along which a line is to be cut,
A part of the width direction orthogonal to the line along which the glass substrate is intended to be cut, including the area irradiated with laser light for irradiating the laser beam, is curved on one surface of the glass substrate in the width direction of the glass substrate,
The laser light irradiating portion from one surface to the other surface of the glass substrate is heated to a temperature higher than a vaporization temperature in the irradiation region of the laser light,
Wherein the irradiation region of the laser beam is moved relative to the glass substrate along a line along which the glass substrate is to be cut. 2. The glass substrate according to claim 1, further comprising: a light source for emitting a laser beam,
Wherein a part of the glass substrate in the width direction including the line along which the glass substrate is to be cut is curved in the width direction of the glass substrate. The glass substrate according to any one of claims 1 to 3, wherein a part of the width direction of the glass substrate including the irradiation area of the laser beam is projected from a region of another part of the glass substrate, By supporting the glass substrate from the surface side of the side,
Wherein a portion of the glass substrate including the irradiation region of the laser beam in the width direction is curved in the width direction of the glass substrate. The image forming apparatus according to claim 3,
The glass substrate is arranged so that an area irradiated with the laser beam is disposed on an inclined surface on an end side of the glass substrate in the width direction among a region of a portion of the glass substrate in the width direction, Of the glass substrate. The glass substrate according to any one of claims 1 to 3, wherein a part of the width direction of the glass substrate including the irradiated region of the laser beam is bent from a region of another portion of the glass substrate by its own weight, By holding the glass substrate from the other surface side of the glass substrate,
Wherein a portion of the glass substrate including the irradiation region of the laser beam in the width direction is curved in the width direction of the glass substrate. The method of cutting a glass substrate according to any one of claims 1 to 5, wherein a peripheral portion of the laser light irradiation portion is cooled to a temperature not higher than a glass transition temperature after heating the laser light irradiation portion. The laser processing method according to any one of claims 1 to 6, wherein the relative moving speed of the laser light irradiated area with respect to the glass substrate is v (m / hour), the energy density of the laser light is E (W / In the case where the thickness of the plate is t (mm)
E? 50 × t × v
Of the glass substrate. The method of cutting a glass substrate according to any one of claims 1 to 7, wherein the relative moving speed of the laser light irradiated region with respect to the glass substrate is 144 m / hour or more. 9. The method of cutting a glass substrate according to any one of claims 1 to 8, wherein the glass component of the vaporized laser light irradiating portion is removed. 10. The method of cutting a glass substrate according to any one of claims 1 to 9, wherein a precipitate generated in a peripheral portion of the laser light irradiating portion is removed. 11. The method of cutting a glass substrate according to any one of claims 1 to 10, wherein the thickness of the glass substrate is 3.0 mm or less. A method of manufacturing a glass substrate, using the method for cutting a glass substrate according to any one of claims 1 to 11.

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