CN107129137A - The cutting-off method of glass substrate and the manufacture method of glass substrate - Google Patents

Abstract

The invention provides a method for cutting a glass substrate and a method for manufacturing the glass substrate. The glass substrate cutting method irradiates laser light to cut the glass substrate along the planned cutting line, wherein the glass substrate and the planned cutting line including the irradiation area of the laser beam irradiated to one surface of the glass substrate are set Part of the region in the orthogonal width direction is curved in the width direction of the glass substrate, and in the laser irradiation region, the laser irradiation part from one surface of the glass substrate to the other surface is heated to a temperature above the vaporization temperature, The irradiated area of the laser beam is moved relative to the glass substrate along the planned cutting line of the glass substrate.

Description

Cutting method of glass substrate and manufacturing method of glass substrate

This application is a divisional application of the international application PCT/JP2014/061849, which entered the Chinese national phase on October 28, 2015, with the application number 201480024048.4 and the title of the invention "Method for Cutting Glass Substrate and Method for Manufacturing Glass Substrate".

technical field

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

Background technique

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

For example, Patent Document 1 discloses a method of cutting a glass substrate by forcibly cooling with compressed gas or the like immediately after forming a notch concave portion of a predetermined depth by irradiation with laser light.

In addition, Patent Document 2 discloses a glass substrate cutting method in which a glass substrate is scanned and irradiated with laser light, the glass is melted at the irradiated part of the laser light, and the molten glass is blown away by an assist gas.

【Prior technical literature】

【Patent Literature】

[Patent Document 1] Japanese Patent Laid-Open No. 2004-059328

[Patent Document 2] Japanese Patent Laid-Open No. 60-251138

Contents of the invention

【Problems to be solved by the invention】

However, according to the method of cutting a glass substrate described in Patent Document 1, the part corresponding to the notch recess formed by irradiating the cut surface with laser light and the part formed under the notch recess during forced cooling thereafter are included. The surface properties are different.

In this way, when there are parts with different surface properties due to the cutting method in the cut surface, the cut surface needs to be polished to form a product with uniform surface properties. Therefore, it takes time to polish the cut surface.

Moreover, since it is necessary to blow compressed gas (assist gas) to the glass substrate immediately after irradiation of the laser beam, the position of the glass substrate tends to shift and cutting accuracy may decrease.

According to the cutting method of the glass substrate described in Patent Document 2, the position of the glass substrate is displaced by the pressure of the assist gas, and there is a problem that accuracy at the time of cutting may decrease. In addition, depending on the energy density of the laser light, the amount of thermal deformation of the glass may locally increase to cause cracks in the glass substrate. In addition, since the molten glass removed by the assist gas adheres to and solidifies on the cut surface or its periphery, time is required for a polishing process to remove it.

In view of the problems of the prior art described above, an object of the present invention is to provide a method for cutting a glass substrate with high precision, and to suppress the glass substrate from being cut, compared with the above-mentioned conventional method of cutting a glass substrate in which assist gas is blown to the glass substrate. The occurrence of cracks and the cutting method of the glass substrate to obtain a uniform cut surface.

【Proposal to solve the problem】

In order to solve the above-mentioned problems, the present invention provides a method for cutting a glass substrate, which cuts the glass substrate along a planned cutting line by irradiating laser light, wherein the method includes irradiating the laser light to one surface of the glass substrate. A part of the glass substrate in the width direction perpendicular to the line to cut is curved in the width direction of the glass substrate in the irradiated area of the laser beam, and in the laser irradiated area, from the The laser beam irradiating part from one surface to the other surface is heated to a gasification temperature or higher, and the laser beam irradiated area is relatively moved relative to the glass substrate along a line to cut of the glass substrate.

【Invention effect】

According to the cutting method of the glass substrate of this invention, compared with the cutting method of the conventional glass substrate using an assist gas, it is possible to cut and process a glass substrate with high precision. Furthermore, the occurrence of cracks to the glass substrate can be suppressed during cutting, and a uniform cut surface can be formed.

Description of drawings

FIG. 1 : is explanatory drawing of the cutting method of the glass substrate concerning embodiment of this invention.

2A is an explanatory diagram of the distance between a laser oscillator and one surface of a glass substrate when a glass substrate having an uneven surface is irradiated with laser light.

2B is an explanatory diagram of the distance between the laser oscillator and one surface of the glass substrate when irradiating laser light to the glass substrate including unevenness on the surface.

FIG. 3 is an explanatory diagram of a configuration example of a conveyance roller provided with a support member.

It is explanatory drawing of the structural example which arrange|positions the conveyance roller provided with a support member on the conveyance path of a glass substrate.

It is explanatory drawing of the structural example which arrange|positions the conveyance roller provided with a support member on the conveyance path of a glass substrate.

It is explanatory drawing of the structural example of the conveyance roller which bends some regions of the width direction of a glass substrate.

7 is an explanatory diagram of a heating step in the method of cutting a glass substrate according to the embodiment of the present invention.

8 is an explanatory diagram of a cooling step in the method of cutting a glass substrate according to the embodiment of the present invention.

FIG. 9 is an explanatory diagram of precipitates in a cooling step in the method for cutting a glass substrate according to the embodiment of the present invention.

10 is an explanatory diagram of the relationship between the conveyance speed of the glass substrate, the energy density of the laser beam, and the evaluation of the cut surface in Experimental Example 1 of the present invention.

11 is an explanatory diagram of the relationship between the conveyance speed of the glass substrate, the energy density of the laser beam, and the evaluation of the cut surface in Experimental Example 2 of the present invention.

12 is an explanatory diagram of the relationship between the conveyance speed of the glass substrate, the energy density of the laser beam, and the evaluation of the cut surface in Experimental Example 3 of the present invention.

13 is an explanatory diagram of the relationship between the conveyance speed of the glass substrate, the energy density of the laser beam, and the evaluation of the cut surface in Experimental Example 4 of the present invention.

14 is an explanatory diagram of another method of bending a part of the widthwise region of the glass substrate.

【Description of labels】

11 Glass substrate

12 lasers

33 Support member

40 holding member

71 Laser Irradiation Department

72 Peripheral part of laser irradiation part

81, 82 Precipitates

detailed description

Hereinafter, modes for implementing the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments, and various modifications and substitutions can be added to the following embodiments without departing from the scope of the present invention.

In this embodiment, the structural example of the cutting method of the glass substrate of this invention is demonstrated.

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

A part of the glass substrate in the width direction (hereinafter also referred to as "the width direction of the glass substrate") perpendicular to the planned cutting line (hereinafter also referred to as "the width direction of the glass substrate") that includes the irradiation region of the laser that irradiates laser light to one surface of the glass substrate is placed on the glass substrate. The substrate is bent in the width direction.

In addition, in the irradiation region of the laser beam, the laser irradiation portion from one surface to the other surface of the glass substrate is heated to a temperature equal to or higher than the gasification temperature.

Moreover, it is the cutting method of the glass substrate which moves the irradiation area of a laser beam relatively with respect to a glass substrate along the line to cut of a glass substrate.

It demonstrates concretely using FIGS. 1-8.

FIG. 1 schematically shows a structure where a glass substrate cut by the glass substrate cutting method of the present invention is viewed from the upper surface of the glass substrate on the laser irradiation side (one surface side).

The glass substrate 11 is transported in the direction indicated by the arrow A in FIG. 1, and the portion irradiated with the laser light 12 oscillated from a laser oscillator not shown (laser irradiation area) can be along the planned cutting line 13 on the glass substrate. move.

In addition, in the method for cutting a glass substrate according to the present embodiment, a part of the region in the width direction of the glass substrate including the irradiated region of the laser beam in the width direction perpendicular to the line to cut is bent in the width direction of the glass substrate. This point will be described below.

When the thickness of the glass substrate is thin, especially when the glass substrate is conveyed, wrinkles may be generated in the glass substrate. When wrinkles are generated on the glass substrate, the surface of the glass substrate includes unevenness. And, when irradiating a laser beam to a glass substrate having irregularities on the surface, as shown in FIG. The distance D1 is between the surfaces of one side. On the other hand, as shown in FIG. 2B , when laser light is irradiated to the concave portion 24 of the glass substrate 11 conveyed on the conveying roller 21, the position of the laser oscillator 23 does not change, so the distance between the laser oscillator 23 and the glass substrate 11 The distance between one surface is longer than the distance D1, and becomes the distance D2. As described above, the distance between the laser oscillator and one surface of the glass substrate changes due to irregularities on the surface of the glass substrate, and the glass substrate may not be properly heated by laser light.

On the other hand, by bending a part of the glass substrate in the width direction perpendicular to the line to cut including the irradiation region of the laser beam, it is possible to suppress wrinkles in the glass substrate at least in the curved portion of the glass substrate. Therefore, in the laser irradiation area, the distance between one surface of the glass substrate 11 and the laser oscillator as the light source of the laser can be stabilized, and heating can be appropriately performed along the planned cutting line of the glass substrate. In addition, the glass substrate can be cut and processed with high precision, and can be formed as a uniform cut surface.

There is no particular limitation on the method of bending a part of the glass substrate in the width direction perpendicular to the line to cut, including the irradiation region of the laser beam 12 irradiated to one surface of the glass substrate 11 in the width direction of the glass substrate. In addition, bending in the width direction of a glass substrate can also be said to bend the cross section of the glass substrate perpendicular|vertical to a conveyance direction upwards or downwards.

Here, a configuration example of a method of bending a part of the glass substrate in the width direction of the glass substrate will be described with reference to FIGS. 3 to 6 and 14 . FIG. 3 shows a configuration example of the conveyance roller 32 provided with the support member 33 . 4 and 5 schematically show the arrangement of the conveyance roller 32 provided with the support member 33 shown in FIG. Make up the structure of the example.

As a method of bending a part of the region of the glass substrate in the width direction of the glass substrate, a method in which a part of the region in the width direction of the glass substrate including the irradiation region of the laser beam protrudes from other regions of the glass substrate . A method of supporting a glass substrate from the other surface side of the glass substrate by a supporting member.

As shown in FIG. 3 , when a support member 33 is arranged in a part of the width direction of the conveying roller 32, the support member 33 can be used to make the surface of a part of the region 31 of the glass substrate smaller than the surface of the region 34 of other parts of the glass substrate. In a raised form, the glass substrate is supported from the lower surface side (the other surface side).

And, as shown in FIG. 4, at least a part of the conveying rollers 32 of the plurality of conveying rollers 32 arranged on the conveying path of the glass substrate conveyed in the direction shown by the block arrow A in the figure can be set as above. The conveyance roller 32 provided with the support member 33 is mentioned above. By configuring the conveyance roller in this way, it is possible to bend a part of the width direction of the glass substrate within the range shown by the region 41 in FIG. 4 . That is, the cross section of the glass substrate perpendicular|vertical to a conveyance direction can be curved upward. In this case, it is possible to select and arrange the position of the conveyance roller provided with the support member 33 so that the irradiation area of the laser beam 12 is at least within the area 41 .

In FIG. 4 , an example in which the support member 33 is provided only on one end side in the width direction of the conveyance roller 32 is shown, but it is not limited to the above-mentioned form. Depending on the number of planned cutting lines 13 of the glass substrate, the support member 33 may be provided at a plurality of locations in the width direction of the glass substrate. For example, when cutting the both ends of the width direction of a glass substrate, you may provide the support member 33 with respect to the other end part side of the width direction of the conveyance roller 32.

In addition, the structure of the support member 33 formed in the conveyance roller 32 is not specifically limited. As shown in FIG. 4 , when the supporting member 33 is formed for each conveying roller 32 , for example, an O-ring or the like is disposed on the conveying roller 32 as the supporting member 33 , thereby a part of the width direction of the conveying roller 32 surface is The region can form an annular protrusion. Furthermore, instead of being provided for each conveyance roller 32, the support member 33 may be constituted by a conveyor belt which is a belt-shaped guide member wound between a plurality of conveyance rollers as shown in FIG. 5 . Even in this case, within the range indicated by the region 41 in FIG. 5 , a part of the region of the glass substrate 11 in the width direction perpendicular to the line to cut can be bent. That is, the cross section of the glass substrate perpendicular|vertical to a conveyance direction can be curved upward.

The structure of the support member is not particularly limited as described above, but it is preferable that the support member is constituted by a belt-shaped guide member wound between a plurality of conveyance rollers as shown in FIG. 5 . This is because, when the support member is constituted by a belt-shaped guide member wound between the conveyance rollers, the glass substrate can be supported from the other surface side by the support member between the conveyance rollers, and the glass substrate can be uniformly held. The shape of the curved portion of the substrate can further suppress the occurrence of wrinkles.

The height H of the supporting member 33 shown in FIG. 3 is not particularly limited, and can be arbitrarily selected according to the plate thickness of the glass substrate to be cut, and the like.

Furthermore, 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 may be a curved shape in the width direction of the conveyance roller.

As another method of bending a part of the region in the width direction perpendicular to the planned cutting line of the glass substrate, for example, the method shown in FIG. The conveying roller 32 constitutes the thin portion 61 of the portion.

Thus, by providing the conveyance roller 32 with the portion 61 whose diameter is smaller than other portions, a concave portion (concave) is formed on the surface of the conveyance roller 32 . Therefore, the glass substrate bends in this concave portion, and as shown in FIG. 6 , the glass substrate 11 can also be bent in the vicinity of the boundary between the portion 61 having a smaller diameter than other portions and other portions. That is, the cross section of the glass substrate perpendicular to the conveyance direction can be bent downward.

As a method of bending a part of the region of the glass substrate in the width direction perpendicular to the line to cut regardless of the shape of the conveyance roller, for example, the method shown in FIG. The part of the held glass substrate 11 is exposed from the holding member 40 , and the part of the region is bent by its own weight. It should be noted that, when the holding member 40 is a table, at least one of the glass substrate 11 and the laser oscillator is moved to perform cutting processing on the glass substrate 11 .

When bending a part of the glass substrate in the width direction including the irradiation region of the laser beam 12 as described above, the irradiation region of the laser beam 12 is preferably arranged on a slope in the curved portion of the glass substrate. In this way, in the slope portion of the curved glass substrate as shown in FIGS. A gap is generated between the glass substrates 11 . Therefore, when the laser beam is irradiated, it is possible to suppress the conveyance roller 32, the support member 33, and the like from being heated, and it is possible to suppress damage to the conveyance roller 32 and the like.

The incident angle of the laser beam 12 with respect to the glass substrate is not specifically limited. For example, as shown in FIG. 3 , FIG. 6 , and FIG. 14 , the laser light 12 can be substantially perpendicular to the glass substrate surface of the unbent region of the glass substrate, that is, for example, the region 34 of other parts of the glass substrate in FIG. 3 . Irradiate. Furthermore, the angle at which the laser beam 12 is irradiated may be adjusted according to the inclination angle of the glass substrate in the irradiation area of the laser beam 12 . That is, the glass substrate 11 may be irradiated with the laser light 12 so that the surface of the glass substrate 11 is substantially perpendicular to the laser light 12 in the irradiation area of the laser light.

In addition, in the case of FIG. 3 , since the glass substrate is curved in a parabolic shape, slopes in the curved portion are generated on the right side and the left side in the figure. Therefore, it is also possible to irradiate the laser beam to the slope on the left side in the figure as shown by the arrow 12'.

However, when the curved portion of the glass substrate has a plurality of slopes, it is preferable that the support member 33 supports the glass substrate in a region of a part of the width direction of the glass substrate protruding from other regions of the glass substrate. Among them, the irradiation area of the laser beam is arranged on the slope on the side of the end portion in the width direction of the glass substrate. That is, it is preferable that the irradiation area|region of a laser beam exists in the slope of the end part side of the width direction of a glass substrate.

As described above, only a part of the width direction of the glass substrate including at least the irradiation region of the laser beam is bent in the width direction of the glass substrate, and the range of bending the glass substrate in the longitudinal direction of the glass substrate is not particularly limited. That is, a part of the glass substrate in the width direction perpendicular to the line to cut can be bent in the width direction of the glass substrate only in the range of the laser irradiation region in the longitudinal direction of the glass substrate. In addition, the longitudinal direction of the glass substrate mentioned here shows the direction parallel to the conveyance direction of a glass substrate.

However, it is preferable to make a part of the width direction of the glass substrate including the planned cutting line of the glass substrate in the range from the irradiation region of the laser beam of the glass substrate to the part separated by a predetermined distance along the planned cutting line of the glass substrate on the glass substrate. The substrate is bent in the width direction.

As mentioned above, if the glass substrate is bent in a part of the width direction of the glass substrate including at least the irradiation area of the laser beam, which is perpendicular to the line to cut, the laser irradiation area can Suppresses wrinkles. However, for example, in the case of conveying a glass substrate, if the glass substrate is bent as described above immediately before the irradiation area of the laser beam, the generation of wrinkles may not be sufficiently suppressed. Therefore, it is preferable to make the planned cutting of the glass substrate a part of the width direction of the glass substrate including the planned cutting line of the glass substrate in a predetermined range on the upstream side of the conveyance direction of the glass substrate, for example, from the irradiation area of the laser light. The glass substrate is bent in such a way that the lines are arranged on the slope.

For example, when the conveyance roller 32 equipped with the supporting member 33 is arranged as shown in FIG. located on the downstream side. That is, in the case of FIG. 4, it is preferable to arrange|position the irradiation area|region of a laser beam in the conveyance direction downstream side of a glass substrate rather than X-X' line. Moreover, in order to prevent damage to the conveyance roller 32 etc. especially when irradiating laser light, it is preferable to arrange the irradiation area of the laser beam 12 between the conveyance rollers 32 .

As described above, in the method for cutting a glass substrate according to the present embodiment, a part of the region in the width direction of the glass substrate including the irradiated region of the laser beam in the width direction perpendicular to the line to cut is bent in the width direction of the glass substrate. And in the part irradiated with the laser beam 12 (irradiation area|region of a laser beam), the laser irradiation part from one surface of a glass substrate to the other surface is heated (heating process). In addition, the region 14 that has been irradiated with laser light is separated from the irradiated region of laser light due to the glass substrate 11 being transported, and the peripheral portion of the laser irradiated portion (the portion where the glass is vaporized by irradiating laser light) 15 after laser irradiation is cooled ( cooling process). This point will be described below using FIG. 1 , FIG. 7 , and FIG. 8 . In addition, in FIG. 1, FIG. 7, and FIG. 8, for convenience of description, the periphery of the laser irradiation area is also described as a flat shape. Moreover, although the planned cutting line 13 of a glass substrate is shown in a drawing, it is not a line provided on the actual glass substrate.

The composition of the glass substrate to which the cutting method of the glass substrate of this embodiment can be applied is not specifically limited, It can apply to various glass substrates. Examples thereof include alkali-free borosilicate glass, borosilicate glass, soda lime glass, high silica glass, and other oxide-based glasses mainly composed of silicon oxide.

Also, the thickness of the glass substrate is not particularly limited, and can be arbitrarily selected, for example, according to the output of the laser oscillator to be used.

However, when the thickness of the glass substrate is thin, especially the glass substrate tends to be wrinkled. And in the cutting method of the glass substrate of this embodiment, in the irradiation area of laser, with respect to the laser irradiation part from one surface of glass substrate to the other surface, namely the whole board thickness direction of glass substrate, heat to glass substrate. above the gasification temperature. From the reasons of the above two points, the effect is exhibited particularly when the plate thickness of the glass substrate is thin. Therefore, for example, the plate thickness of the glass substrate is preferably 3.0 mm or less, more preferably 1.0 mm or less, still more preferably 0.5 mm or less, particularly preferably 0.2 mm or less. There is no particular limitation on the lower limit.

Moreover, although the shape of the glass substrate shown in FIG. 1 is rectangular, the shape of a glass substrate is not specifically limited, either. For example, it may be a ribbon-shaped glass substrate formed by a glass substrate forming apparatus such as a float method or a down-draw method.

Next, the heating process performed in the irradiation area|region of a laser beam (the part where a laser beam is irradiated to a glass substrate) is demonstrated. FIG. 7 is an enlarged view showing the periphery of the irradiated area of the laser light 12 in the cross section on the line B-B' in FIG. 1 .

In the cutting method of the glass substrate of this invention, a heating process is performed in the irradiation area|region of a laser beam by irradiating the laser beam 12 to a glass substrate as mentioned above.

Regarding the irradiation area of the laser beam of the glass substrate, the laser irradiation part 71 from one surface of the glass substrate to the other surface of the glass substrate is heated to a temperature equal to or higher than the glass vaporization temperature. Here, the one surface of a glass substrate means the surface on the laser incident side, and the other surface means the opposing surface. Therefore, in the irradiation part 71 of a laser beam, glass vaporizes, and a through-hole is formed along the irradiation direction of a laser beam (thickness direction of a glass substrate) in a short time.

In addition, the peripheral portion 72 of the laser irradiation portion 71 is also heated by heat transfer from the laser irradiation portion.

In this way, during the heating process or immediately after the heating process, that is, at the time of laser irradiation (at the time of glass vaporization) or immediately after laser irradiation, the assist gas is not blown to the laser irradiation part (the assist gas is not used), It is possible to vaporize glass in a laser irradiation part in a short time. Therefore, it is possible to perform processing with high precision without occurrence of positional displacement of the glass substrate, and to suppress the occurrence of cracks in the glass substrate.

The irradiation conditions of the laser light in the heating process are not limited, as long as they are selected in the following manner: in the laser irradiation region of the glass substrate, from one surface (the surface on which the laser light is incident) of the glass substrate to the other The laser irradiation part on one surface side can be heated to more than the gasification temperature of glass.

Specifically, for example, as long as the plate thickness of the glass substrate as the object to be cut, the glass composition, the conveyance speed of the glass substrate (the relative moving speed of the laser irradiation area with respect to the glass substrate), etc., the laser irradiation part can be selected. The energy density of the laser light and the like may be selected for the method of heating as described above. For example, it can be calculated by performing a preliminary test in advance.

In particular, the relative moving speed of the irradiation region of the laser light with respect to the glass substrate is v (m/hour), the energy density of the laser light is E (W/mm ² ), and the thickness of the glass substrate is t (mm ), it is preferable to adjust the energy density of the irradiated laser light so as to satisfy the relationship of E≧50×t×v.

Cutting of the glass substrate including the heating step is carried out in a state satisfying the above-mentioned requirements, whereby in the laser irradiation region, the laser irradiation portion from one surface of the glass substrate to the other surface of the glass substrate can be reliably heated. Above the temperature of glass vaporization.

The spot diameter of the laser beam irradiated to the glass substrate (beam diameter of the laser beam on one surface of the glass substrate) is also not limited, and can be selected according to required processing accuracy and the like.

In addition, the kind of laser beam used is not specifically limited, What is necessary is just to heat a glass substrate about the part irradiated by irradiating the laser beam which oscillates to a glass substrate. Specifically, CO ₂ laser, excimer laser, copper vapor deposition laser, YAG laser, etc. can be used, for example.

In a heating process, glass is vaporized with respect to a laser irradiation part by irradiating a laser beam to a glass substrate as mentioned above. Therefore, vaporized glass components (gas) are generated in the laser irradiation portion and its surroundings. When the above-mentioned components are precipitated or adhered to the surface of an optical system such as a lens or a mirror of a laser oscillation device disposed on the optical path of the laser light, it may not be possible to irradiate the glass substrate with laser light of sufficient energy, and it may not be possible to irradiate the laser light to the desired position. conditions, etc., may affect the processing accuracy of the glass substrate. Therefore, it is preferable to remove vaporized glass components by irradiating laser light to the glass substrate. That is, in the heating step, it is preferable to remove the vaporized glass component of the laser irradiation portion. The device for removing the vaporized glass component is not particularly limited, and a mechanism for sucking the vaporized glass component, a mechanism for blowing the vaporized glass component away with gas, or the like can be used. As for its arrangement, it only needs to be selected according to the device used, as long as it is arranged in such a way that the heating process is not hindered and the vaporized glass component can be attached to the lens, reflector, etc. arranged on the optical path of the laser. remove. For example, in FIG. 7 , it is conceivable that the laser beams are arranged near the part where the laser beam is irradiated as indicated by 73 .

In addition, in the case of using a mechanism that blows off vaporized glass components using gas, the type of gas used is not particularly limited, but it is preferably used because it is used around the portion of the glass substrate heated by laser. Non-flammable gas. Specifically, inert gases such as nitrogen and argon, air, and the like can be used, for example. Moreover, in this case, in order to prevent the displacement of the position of a glass substrate, it is preferable to supply gas so that it may not contact a glass substrate.

Next, the cooling step will be described.

In the cooling step, after laser irradiation, the glass substrate is conveyed, and the laser irradiation part after laser irradiation (the part that has been irradiated with laser light) is separated from the laser irradiation area to cool the peripheral part of the laser irradiation part.

In the cooling step, as shown in FIG. 7 , the peripheral portion 72 of the laser irradiation portion (part irradiated with laser light and vaporized in the heating step) 71 is cooled. During cooling, as shown in FIG. 8 , at least a part of the peripheral portion 72 is deposited on the surface of the glass substrate (one surface and/or the other surface of the glass substrate) as substantially linear precipitates 81 and 82. Condition. This is because the thermal conductivity of glass is low, so after the heating process, a temperature gradient occurs in the peripheral portion 72 in the cooling process, so it is presumed that at least a part of the peripheral portion 72 is heated due to the stress generated in the peripheral portion 72. Precipitation on the glass substrate was excluded. In the figure, the precipitates 81 and 82 precipitate on the upper surface (one surface) of the glass substrate, but may also precipitate on the lower surface (the other surface) side. In addition, in the cooling step, the site where the precipitates are deposited varies depending on the cooling conditions and the like, so it is not particularly limited. The position where the irradiation area of the laser beam 12 deviates is deposited.

In this way, at least a part of the peripheral portion 72 of the laser irradiated portion is excluded from the cut surface irradiated with laser light, so that a uniform cut surface can be finally obtained.

The above-mentioned precipitates are generated in the cooling step, and in order to obtain a uniform cut surface, it is preferable to cool the peripheral portion of the laser irradiation portion at an appropriate cooling rate. This cooling rate can be changed according to the relative movement speed of the irradiation area of a laser beam with respect to a glass substrate. Therefore, it is preferable to select the relative movement speed of the irradiation area|region of a laser beam with respect to a glass substrate so that the said precipitate may generate|occur|produce in a cooling process etc. by carrying out a preliminary experiment.

The relative movement speed of the irradiation area of the laser beam with respect to the glass substrate can be selected based on the preliminary experiment etc. as mentioned above, although it is not a specific value, For example, it can set it as 144 (m/hour) or more.

In the cooling step, when the precipitates 81 and 82 are generated, the precipitates 81 and the precipitates 82 may be bonded depending on the temperature of the precipitates 81 and 82 or the distance therebetween. Furthermore, depending on the situation, when the precipitates 81 and precipitates 82 are bonded, it may be difficult to discharge a part of the peripheral portion 72 from the peripheral portion 72 of the laser irradiation portion 71, and the cut surface of the glass substrate may not be a uniform cut surface. . However, in the method for cutting a glass substrate according to the present embodiment, a part of the region in the width direction of the glass substrate perpendicular to the line to cut, including the irradiated region of the laser beam, is bent in the width direction of the glass substrate. Therefore, as shown in FIG. 9, for example, in the periphery of the laser irradiation portion (the portion that is irradiated with laser light and vaporized in the heating process) 71 where the temperature of the precipitates 81 and 82 is particularly high, the cut glass substrate 91 and the The glass substrate 92 on the other side has different heights. Therefore, in the periphery of the laser irradiation part 71, the adhesion of the precipitates 81 and 82 can be suppressed, and as a result, the cut surface can be more reliably formed as a uniform cut surface.

In addition, the deposit 81 deposits between conveyance rollers, and deposits to the upper surface side or the lower surface side of the glass substrate 92 of the other side. In FIG. 9, in order to facilitate the description of the drawings, it seems that the precipitate 81 is screwed into the lower end side of the conveying roller, but even if the precipitate 81 is precipitated to the lower surface side of the glass substrate 92 on the other side, it is also located For example, between the glass substrate 92 and the conveyance roller, the behavior of the conveyance roller will not be hindered.

The precipitates 81 and 82 generated in the cooling step may also hinder cooling, so it is preferable to remove the precipitates generated in the peripheral portion of the laser irradiation portion. The method for removing the precipitate is not particularly limited, and it can be easily removed by, for example, blowing with gas, removing by suction, removing with a brush or an interference plate, or the like.

In addition, when the precipitate is blown off with gas, vibration etc. are given to a glass substrate, and it is preferable to use low pressure gas in order not to affect the cutting precision of a glass substrate.

The cooling step cools the peripheral portion 72 of the laser irradiation portion after laser irradiation as described above, and the cooling temperature is not limited. For example, the peripheral portion of the laser irradiation part is preferably cooled to a glass transition temperature or lower after heating of the laser irradiation part.

At this time, when cooling is performed by the temperature of the surrounding atmosphere after the heating step, the surrounding temperature is preferably at least the glass transition temperature or lower, preferably 100°C or lower, particularly preferably 40°C or lower. In addition, the peripheral temperature mentioned here is the temperature of the periphery of the part which performs a cooling process at least, but it is preferable that it is the temperature of the periphery including the whole glass substrate which cut|disconnects.

The cutting method of the glass substrate of this embodiment demonstrated so far is especially suitable when cutting a glass substrate along the cutting line along the conveyance direction of a glass substrate.

In addition, when manufacturing a glass substrate, in order to make the glass substrate into a desired size, both ends in the width direction of the glass substrate are cut along the cutting line along the conveying direction of the glass substrate. The cutting method of the glass substrate of embodiment. In this case, after the both ends of the width direction of the glass substrate are cut, only the central part of the width direction is used as a product. The handling path is separated.

Specifically, for example, an ear separation unit is provided on the downstream side in the conveyance direction of the glass substrate relative to the heating step, and the ear part of the cut glass substrate can be changed to a direction away from the conveyance direction of the glass substrate by the ear separation unit. and separate.

The specific structure of the ear separation unit is not particularly limited, but may be constituted by, for example, a conveying roller that becomes a fulcrum for changing the direction of the ear of the glass substrate and an ear stabilizing unit that serves as a fulcrum. The opposite side of the conveyance roller contacts the ear part of a glass substrate, and presses an ear part together with a conveyance roller.

The ear portion of the separated glass substrate is introduced into a sub-conveyance path different from the conveyance 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 of this embodiment, the glass substrate horizontally conveyed on the conveyance roller 32 was taken as an example and the cutting method of the glass substrate of this embodiment was demonstrated. However, the cutting method of the glass substrate of this embodiment is not limited to the cutting of the glass substrate conveyed horizontally, For example, it is applicable also to the glass substrate formed by the down-down method etc. and conveyed vertically. In this case, for example, from one side of the glass substrate, by pressing the member, a part of the region in the width direction of the glass substrate that includes the irradiation region of the laser irradiated with laser light and perpendicular to the planned cutting line can be placed on the side of the glass substrate. Curved across the width. Moreover, by performing a heating process and a cooling process as mentioned above, it can cut|disconnect similarly also about the glass substrate conveyed vertically.

Moreover, when vertically conveying a glass substrate, the cutting method of the glass substrate of this embodiment can also be used preferably when cutting the width direction both ends of a glass substrate. Also in this case, it is preferable to separate the both ends of the width direction of the glass substrate after cutting from the conveyance path of a glass substrate.

As above, the glass substrate cutting method of the present invention has been described, but in the glass substrate cutting method described above, the auxiliary gas is not blown to the glass substrate, so the displacement of the position of the glass substrate can be suppressed, and the glass substrate can be cut with high precision. Carry out cutting processing. Furthermore, generation of cracks in the glass substrate can be suppressed during cutting, and a cut surface with uniform surface properties can be formed.

The cutting method of the glass substrate of this embodiment demonstrated above can be applied to the manufacturing process of a glass substrate, and it can be set as the manufacturing method of a glass substrate using this cutting method of a glass substrate.

In the method for manufacturing a glass substrate as described above, the glass substrate can be cut and processed with high precision, the generation of cracks in the glass substrate can be suppressed during cutting, and a uniform cut surface can be formed, so the manufacturing yield of the glass substrate can be obtained. Improvement, shortening of the grinding time of the cut surface in the grinding process, or the effect of omitting the grinding process.

【Example】

Specific examples are listed and described below, but the present invention is not limited to these examples.

[Experimental example 1]

In this experimental example, the glass substrate was cut while changing the energy density of the laser light and the relative movement speed of the laser irradiation region with respect to the glass substrate, and the cut surface of the cut glass substrate was evaluated.

When cutting the glass substrate, according to the structure shown in FIG. While conveying the glass substrate at a predetermined conveying speed, laser light using a CO ₂ laser was irradiated along the line to cut so that the spot diameter was approximately 0.3 mm and a predetermined energy density was obtained. When cutting, the peripheral temperature (environmental temperature) of the glass substrate was room temperature (25° C.).

And at this time, as shown in FIG. 3 and FIG. 4 , a support member 33 is provided on the conveying roller 32 so that a part of the width direction of the glass substrate including the irradiation region of the laser irradiated laser is positioned in the width direction of the glass substrate. We bend and perform irradiation of laser light. At this time, the laser light 12 is irradiated to the slope of the edge part side of the width direction of a glass substrate as shown by the arrow 12 in FIG. Moreover, as shown in FIG. 4, the support member 33 is provided in the two conveyance rollers 32, and the irradiation area|region of the laser beam 12 is arrange|positioned between the conveyance roller 32 provided with the support member 33.

For the glass substrate after cutting, the glass substrate that could not be cut was evaluated as C, and although it could be cut, no precipitate was observed in the part irradiated with laser light, and the cut surface did not become uniform when visually confirmed, or The evaluation of the glass substrate which cracked in the glass substrate was B. The glass substrate which can cut|disconnect a glass substrate and can visually confirm the uniform cut surface was evaluated as A. The results are shown in Table 1 and Figure 10. FIG. 10 is a graph in which some of the results in Table 1 are graphed.

[Table 1]

In the graph shown in FIG. 10 , the relative moving speed (here, the conveying speed of the glass substrate) in the irradiation area of the laser light with respect to the glass substrate is set as v (m/hour), and the energy density of the laser light is set as When it is E (W/mm ² ), and the plate thickness of the glass substrate is t (mm), the straight line X is a straight line of E=50×t×v.

And, the straight line Y represents the minimum value of the relative moving speed (here, the conveying speed of the glass substrate) of the irradiated region of the laser light with respect to the glass substrate in which precipitates have occurred in the cooling process, and in this case, it is 144 (m /Hour).

According to FIG. 10 , the A evaluation is distributed within the range surrounded by the straight line X and the straight line Y. When the energy density is lower than the straight line X, it becomes the C evaluation, and when the transport speed is slower than the straight line Y, it becomes the B evaluation.

This is because, first, in the relative movement speed (transportation speed of the glass substrate) of each laser irradiation area with respect to the glass substrate, in the case of irradiating the laser beam with an energy density equal to or higher than the straight line X, the irradiation of the laser beam Among the regions, the laser-irradiated region from one surface of the glass substrate to the other surface can be reliably heated to a temperature equal to or higher than the glass vaporization temperature.

In addition, it is considered that by further setting the conveying speed higher than that of the straight line Y, the peripheral portion of the laser irradiation region after laser irradiation can be sufficiently cooled, and precipitates can be removed from the cut surface, so that a cut with uniform surface properties can be formed. noodle.

That is, in the glass substrate which became C evaluation, the energy of the laser light sufficient for the relative movement speed (transportation speed of the glass substrate) with respect to the glass substrate of the irradiation area of a laser beam cannot be given, and the irradiation area of a laser beam is not enough. It is possible to heat up to the other surface of the glass substrate to a temperature equal to or higher than the vaporization temperature of the glass (the temperature cannot be raised sufficiently over the entire thickness direction of the glass substrate). Therefore, it is presumed that the glass substrate cannot be cut.

Furthermore, the glass substrate having B evaluation can be irradiated with laser light having sufficient energy density for the relative movement speed of the laser irradiation area with respect to the glass substrate (transportation speed of the glass substrate), so the glass substrate can be cut.

However, the relative movement speed (transportation speed of the glass substrate) of the laser irradiation area with respect to the glass substrate is insufficient, and the cooling rate of the peripheral portion of the laser irradiation area after laser irradiation becomes slow, and the peripheral portion cannot be excluded as precipitates. Remains, it is presumed that the cut surface did not become uniform. Alternatively, when the temperature of the peripheral portion of the laser irradiation region after laser irradiation is cooled by conveyance of the glass substrate, since the cooling rate is not desired, cracks are presumed to have occurred on the cut surface and its periphery.

On the other hand, it is considered that the energy density of the laser beam can be appropriately selected with respect to the relative movement speed (transportation speed of the glass substrate) of the glass substrate of the A evaluation relative to the glass substrate corresponding to the irradiated area of the laser beam. Therefore, it is considered that the irradiated region of the laser beam is heated from one surface of the glass substrate to the other surface to a temperature equal to or higher than the gasification temperature of the glass. In addition, since the conveyance speed of the glass substrate is appropriate, it is considered that the peripheral portion of the laser irradiation region after laser irradiation is cooled at an appropriate cooling rate, and the peripheral portion of the laser irradiation region after laser irradiation is excluded as precipitates, and it is possible to obtain Uniform cut surface.

[Experimental example 2]

In this experimental example, except that the plate thickness of the glass substrate to be cut was 0.2 mm, the energy density of the laser light and the relative moving speed of the irradiation area of the laser light with respect to the glass substrate were changed in the same manner as in Experimental Example 1, and the glass substrate was cut. Cutting evaluated the cut surface of the glass substrate after cutting.

The results are shown in Table 2 and Figure 11. FIG. 11 is a graph obtained by graphing the results of Table 2. FIG.

【Table 2】

In the graph shown in FIG. 11 , the straight line X is also a straight line of E=50×t×v (t=0.2 mm) described above.

And, the straight line Y represents the minimum value of the relative moving speed (here, the conveying speed of the glass substrate) of the irradiated region of the laser light relative to the glass substrate in which precipitates have occurred in the cooling process, and in this case, it is 144 (m /Hour).

From this, it can be confirmed that the A evaluations are distributed within the range surrounded by the straight line X and the straight line Y.

[Experimental example 3]

In this experimental example, except that the plate thickness of the glass substrate to be cut was 0.3 mm, the energy density of the laser light and the relative moving speed of the irradiation area of the laser light with respect to the glass substrate were changed in the same manner as in Experimental Example 1, and the glass substrate was cut. Cutting evaluated the cut surface of the glass substrate after cutting.

The results are shown in Table 3 and Figure 12. FIG. 12 is a graph obtained by graphing the results of Table 3. FIG.

【table 3】

In the graph shown in FIG. 12 , the straight line X is also a straight line of E=50×t×v (t=0.3 mm) described above.

And, the straight line Y represents the minimum value of the relative moving speed (here, the conveying speed of the glass substrate) of the irradiated region of the laser light relative to the glass substrate in which precipitates have occurred in the cooling process, and in this case, it is 144 (m /Hour).

In this experimental example, the glass substrate was cut without changing the conveyance speed of the glass substrate and changing the energy density of the irradiated laser light. In this case, when the energy density of the laser beam is increased to have an energy density greater than that of the straight line X, the laser irradiated area can be heated from one surface of the glass substrate to the other surface of the laser irradiated area. It can be confirmed that it becomes A evaluation when it reaches the glass vaporization temperature or more.

[Experimental example 4]

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

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

【Table 4】

In the graph shown in FIG. 13 , the straight line X is also a straight line of E=50×t×v (t=0.6 mm) described above.

And, the straight line Y represents the minimum value of the relative moving speed (here, the conveying speed of the glass substrate) of the irradiated region of the laser light relative to the glass substrate in which precipitates have occurred in the cooling process, and in this case, it is 144 (m /Hour).

In this experimental example, the energy density of the irradiated laser light was lower than that of the straight line X. Therefore, it is considered that sufficient laser energy cannot be given to the relative moving speed (transportation speed of the glass substrate) of the laser irradiation area with respect to the glass substrate, and the irradiation part of the laser cannot reach the other surface of the glass substrate. until it is heated to a temperature above the vaporization temperature of the glass substrate. Therefore, it is considered that the glass substrate cannot be cut and it becomes C evaluation.

As mentioned above, although the cutting method of a glass substrate and the manufacturing method of a glass substrate were demonstrated using embodiment etc., this invention is not limited to said embodiment etc.. Various modifications and changes are possible within the scope of the gist of the present invention described in the claims.

Claims (12)

1. A method for cutting a glass substrate, wherein the glass substrate is cut along a planned cutting line by irradiating laser light, the method for cutting the glass substrate is characterized in that A region in the width direction of the glass substrate perpendicular to the line to cut, including an irradiation region of the laser beam irradiated to one surface of the glass substrate, is temporarily positioned in the width direction of the glass substrate. bent sexually, In the laser irradiation region, while bending the glass substrate, the laser irradiation part from one surface of the glass substrate to the other surface is heated to a temperature equal to or higher than the gasification temperature, The irradiated area of the laser beam is moved relative to the glass substrate along the line to cut of the glass substrate. 2. The method for cutting a glass substrate according to claim 1, wherein: The glass substrate is bent in a range separated by a predetermined distance along a line to cut of the glass substrate including an irradiation range of the laser light. 3. The method for cutting a glass substrate according to claim 1 or 2, wherein: Supporting the glass substrate from the other surface side of the glass substrate by a supporting member so that the region in the width direction of the glass substrate including the irradiation region of the laser protrudes from other regions of the glass substrate. the glass substrate so that the area in the width direction of the glass substrate including the irradiated area of the laser beam is curved in the width direction of the glass substrate. 4. The method for cutting a glass substrate according to claim 3, wherein: The support member supports the glass substrate such that the width of the glass substrate is in a region of the glass substrate in the width direction protruding from the region of the other portion of the glass substrate. The irradiation area of the laser light is arranged on the slope at the end side of the direction. 5. The cutting method of a glass substrate according to claim 1 or 2, wherein, In such a way that the region in the width direction of the glass substrate including the irradiation region of the laser beam is deflected by its own weight from the region of the other part of the glass substrate, the other surface of the glass substrate is held by a holding member. The glass substrate is held sideways so that the region in the width direction of the glass substrate including the irradiated region of the laser beam is curved in the width direction of the glass substrate. 6. The cutting method of a glass substrate according to any one of claims 1 to 5, wherein: The peripheral portion of the laser irradiated portion is cooled to a glass transition temperature or lower after heating of the laser irradiated portion. 7. The cutting method of a glass substrate according to any one of claims 1 to 6, wherein: The relative movement speed with respect to the glass substrate in the irradiated area of the laser is set as v (m/hour), the energy density of the laser light is set as E (W/mm ² ), and the plate thickness of the glass substrate is set as t (mm ), the relationship of E≥50×t×v is satisfied. 8. The cutting method of a glass substrate according to any one of claims 1 to 7, wherein: The relative movement speed of the irradiated area of the laser beam with respect to the glass substrate is 144 (m/hour) or more. 9. The cutting method of a glass substrate according to any one of claims 1 to 8, wherein: The vaporized glass component of the laser irradiation portion is removed. 10. The cutting method of a glass substrate according to any one of claims 1 to 9, wherein: The precipitates generated in the peripheral portion of the laser irradiation portion are removed. 11. The cutting method of a glass substrate according to any one of claims 1 to 10, wherein: The plate thickness of the said glass substrate is 3.0 mm or less. The manufacturing method of a glass substrate using the cutting method of the glass substrate in any one of Claims 1-11.