KR20150035577A

KR20150035577A - Glass-substrate-cutting method and glass-substrate production method

Info

Publication number: KR20150035577A
Application number: KR20147034251A
Authority: KR
Inventors: 도시유키 우에마츠; 히데유키 다카하시; 히데키 마스다
Original assignee: 아사히 가라스 가부시키가이샤
Priority date: 2012-06-28
Filing date: 2013-05-31
Publication date: 2015-04-06
Also published as: TW201404516A; JPWO2014002685A1; TWI603801B; WO2014002685A1; CN104364208A; JP6206406B2; CN104364208B

Abstract

1. A method for cutting a glass substrate by irradiating a laser beam onto the glass substrate, the method comprising the steps of: irradiating a laser beam from one surface of the glass substrate to the other surface of the glass substrate, And irradiating the irradiated region of the laser beam along a line along which the glass substrate is to be cut is moved relative to the glass substrate so that the irradiated region of the laser beam is moved relative to the glass substrate. .

Description

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

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 proposes a method of cutting a glass substrate forcibly cooled by a compressed gas or the like immediately after forming a notched portion with a predetermined depth by irradiating a laser beam.

Patent Document 2 proposes a method of cutting a glass substrate by irradiating the glass substrate while scanning with laser light, melting the glass with respect to the irradiated portion of the laser beam, and blowing the molten glass by the assist gas.

However, according to the cutting method of the glass substrate proposed in Patent Document 1, the cut surface has a portion corresponding to the cut-out concave portion formed by irradiating the laser beam, and a portion formed at the lower portion of the cut- And the surface characteristics of both are different.

In the case where there is a part of the cut surface having different surface characteristics due to the cutting method, it is necessary to cut the cut surface to obtain a product and to make the cut surface uniform in surface characteristics. This necessitated time for the polishing process for the cut surface.

Further, since it is necessary to inject a compressed gas (assist gas) onto the glass substrate immediately after irradiating the laser beam, the position of the glass substrate is liable to be displaced, and the cutting accuracy is sometimes lowered.

According to the method of cutting the glass substrate proposed 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 took time for the polishing process to remove it.

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

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems of the prior art and provides a method of cutting a glass substrate capable of cutting a glass substrate with high precision as compared with a conventional method of cutting a glass substrate by spraying an assist gas onto the glass substrate The purpose.

According to an aspect of the present invention, there is provided a method for cutting a glass substrate by irradiating a laser beam onto the glass substrate, the method comprising the steps of: irradiating a laser beam onto one surface of the glass substrate, Characterized in that the laser light irradiating portion from one surface to the other surface is heated to a temperature not lower than a vaporization temperature and the irradiated region of the laser light is moved relative to the glass substrate along a line along which the glass substrate is to be cut A method of cutting a substrate is provided.

According to the cutting method of the glass substrate of the present invention, the glass substrate can be cut with high accuracy as compared with the conventional method of cutting the glass substrate using the assist gas.

1 is an explanatory diagram illustrating a cutting method of a glass substrate according to an embodiment of the present invention;
2 is an explanatory diagram of a heating step in a cutting method of a glass substrate according to an embodiment of the present invention.
3 is an explanatory diagram of a cooling step in a glass substrate cutting method according to an embodiment of the present invention.
Fig. 4 is an explanatory diagram of the relationship between the transport speed of the glass substrate of Experimental Example 1 of the present invention, the energy density of the laser light, and the evaluation of the cut surface. Fig.
5 is an explanatory diagram of the relationship between the transport speed of the glass substrate of Experimental Example 2 of the present invention and the energy density of laser light and the evaluation of the cut surface.
6 is an explanatory diagram of the relationship between the transport speed of the glass substrate of Experimental Example 3 of the present invention and the energy density of the laser light and the evaluation of the cut surface.
Fig. 7 is an explanatory diagram of the relationship between the transport speed of the glass substrate of Experimental Example 4 of the present invention, the energy density of laser light, and the evaluation of the cut surface. Fig.

Hereinafter, 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 permutations may be added to the following embodiments without departing from the scope of the present invention. have.

In the present embodiment, a method of cutting a glass substrate of the present invention will be described.

A cutting method of a glass substrate of the present invention is a cutting method of a glass substrate for cutting a glass substrate by irradiating a laser beam, and has the following constitution.

The laser light irradiating portion from one surface of the glass substrate to the other surface is heated to a temperature higher than the vaporization temperature in the irradiation region of the laser light irradiated with laser light on one surface of the glass substrate.

And the region irradiated with 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 3. Fig.

Fig. 1 schematically shows the structure of the glass substrate cut by the cutting method of the present invention, viewed from the top surface of the glass substrate on one side (one surface side) of the laser light irradiation side.

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

1, the laser light irradiating portion from one surface to the other surface of the glass substrate is heated in the portion irradiated with the laser light 12 (irradiation region of the laser light) (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).

1, the portion where the laser beam 12 is irradiated on the glass substrate 11 (the region irradiated with the laser beam) is displaced by transporting the glass substrate 11, But it is not limited to this shape as long as it can be irradiated along the line to be cut. For example, by fixing the glass substrate 11 and adjusting and operating the optical system of the optical path of the laser beam between the laser oscillator and the glass substrate, the position of the portion irradiated with the laser beam 12 . The position of the portion where the glass substrate 11 is irradiated and the laser beam 12 is irradiated may also be displaced.

For convenience of explanation, the line along which the glass substrate is to be cut 13 is shown in the figure, but a line on the glass substrate is not provided. The intended line to be cut is not limited to a straight line, but may be an arbitrary line such as a curve depending on the shape of the glass substrate after the cutting as required.

The composition of the glass substrate to which the method of cutting the glass substrate of the present invention 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 oxide-based glass containing other silicon oxide as a main component.

The thickness of the glass substrate is not particularly limited either.

When the above-mentioned glass substrate is irradiated with the laser light and heated, the laser light is irradiated onto the laser light irradiating portion from one surface side to the other surface of the glass substrate in the irradiation region of the laser light, that is, The glass is heated above the vaporization temperature. Therefore, it is preferable to select the thickness of the glass substrate in accordance with the output of the laser oscillator or the like. 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, and particularly preferably 0.2 mm or less. The lower limit value of the glass substrate is not particularly limited as long as it is a value larger than zero (0).

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 process performed in an irradiation area of a laser beam (a part irradiated with a laser beam on the glass substrate) will be described. 2 schematically shows a cross-sectional view taken along the line B-B 'including the region irradiated with the laser beam 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 21 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 21, the glass is vaporized and a through hole is formed in the irradiation direction of the laser beam (the thickness direction of the glass substrate) in a short time.

The peripheral portion 22 of the laser light irradiating portion 21 is also heated by the heat from the laser light irradiating portion.

As described above, without supplying the assist gas to the laser light irradiating portion (without using the assist gas) at the time of the heating step or immediately after that, that is, at the time of laser light irradiation (during glass vaporization) It is possible to vaporize the glass with respect to the laser beam irradiation section in a short time. As a result, the positional deviation of the glass substrate does not occur, so that it is possible to perform machining with high precision 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) May be selected so as to be heated above the vaporization temperature of the glass.

Specifically, for example, the laser beam irradiating portion is heated as described above from the thickness of the glass substrate, the glass composition, the transport speed of the glass substrate (the relative moving speed of the irradiated region with respect to the glass substrate) The energy density of the laser light and the like may be selected. 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 / hr), the energy density of the laser beam 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 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 is irradiated with laser light at a temperature Or more.

But the present invention 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 according to 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 to the irradiated portion by irradiating laser light oscillated on the glass substrate. Specifically, a CO ₂ laser, an excimer laser, a copper deposition laser, a YAG (Yttrium Aluminum Garnet) laser, or the like can be used.

In the heating process, the glass is vaporized with respect to the laser light irradiating portion 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 or a mechanism for blowing out 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. 2, as indicated by reference numeral 23, it may be arranged in the vicinity of a portion irradiated with a laser beam.

When a mechanism for blowing off a glass component vaporized by a gas is used, the kind 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 displacement of the position of the glass substrate, it is preferable to supply the glass substrate so 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 region irradiated with the glass substrate and / or the laser beam moves so that the laser beam irradiating portion (already irradiated with the laser beam) after the laser beam irradiation is moved away from the irradiated region of the laser beam, The peripheral portion of the light irradiation portion is cooled.

In the cooling process, as shown in Fig. 2, the peripheral portion 22 of the laser beam irradiation portion (the portion 21 irradiated with the laser beam in the heating process and vaporized) is cooled. At least a part of the peripheral portion 22 is precipitated on the glass substrate surface (one surface and / or the other surface of the glass substrate) as the precipitate 31 of the filament as shown in Fig. 3 have. This is because the glass has a low thermal conductivity and therefore a temperature gradient is generated in the peripheral portion 22 in the cooling process after the heating process so that stress is generated in the peripheral portion 22 of the peripheral portion 22 At least a part of which is excluded. Although the precipitate 31 is deposited on the upper surface (one surface) of the glass substrate in the drawing, it may be precipitated on the lower surface (the other surface) side. As described above, since at least a part of the peripheral portion 22 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.

It is preferable that the peripheral portion of the laser light irradiating portion is cooled at an appropriate cooling rate in order to generate the precipitate in the cooling step and obtain a uniform cut surface. The cooling rate can be changed by the relative moving speed of the irradiated region 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 precipitate 31 generated in the cooling step sometimes interferes with cooling, so it is desirable 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 with a gas, removing by suction, or removing by a brush or an obstruction plate.

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

The cooling step is to cool the peripheral portion 22 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 irradiating portion is cooled to a temperature not higher than the glass transition temperature after heating the laser light irradiating 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. Here, the ambient temperature means at least the temperature around the portion where the cooling process is performed, and it is preferable that the ambient temperature includes the entire glass substrate on which the cutting is performed.

As described above, the method of cutting the glass substrate of the present invention has been described. However, in the method of cutting the glass substrate, since the assist gas is not jetted onto the glass substrate, displacement of the position of the glass substrate is suppressed, Road cutting can be done. 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 glass substrate cutting method explained above can be applied to the glass substrate manufacturing process and the glass substrate cutting method using the glass substrate cutting method can be used.

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

Example

Hereinafter, the present invention will be described by way of 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 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.

1, 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 a non-alkali borosilicate glass, Was irradiated with a laser beam using a CO ₂ laser along a line along which the object was intended to be cut, with a spot diameter of about 0.3 mm so as to have a predetermined energy density while carrying the glass substrate 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).

As for the glass substrate after the cutting, it was possible to cut the glass substrate which could not be cut with C, but the precipitate was not observed in the portion irradiated with the laser and the cut surface was not uniformly determined by visual inspection, The occurrence of cracks on the substrate was evaluated as B. The glass substrate was cut, and a sample A which was confirmed to be a uniform cut surface by the naked eye was evaluated. The results are shown in Table 1 and Fig. Fig. 4 is a graph showing a part of the results of Table 1. Fig.

In the graph shown in Fig. 4, the straight line X represents v (m / hour), the energy density of the laser light is E (W / mm < 2 >), ) And a 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 (here, the conveying speed of the glass substrate) with respect to the glass substrate in the irradiated area of the laser beam which caused the precipitates in the cooling step, and in this case, 144 m / hour.

According to Fig. 4, 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.

First, in the case of irradiating laser light having an energy density equal to or higher than a straight line X at a relative moving speed (conveying speed of the glass substrate) of the irradiation region of each laser beam with respect to the glass substrate, It is possible to reliably heat the laser light irradiating part from the surface to the other surface to a temperature higher than the vaporization temperature of the glass.

Further, by setting the conveying speed to be equal to or higher than the straight line Y, it is considered that the peripheral portion of the laser beam irradiating portion after the laser beam irradiation is sufficiently cooled and excluded from the cut surface portion as the precipitate, .

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

Further, since the glass substrate subjected to the B evaluation can irradiate laser light having a sufficient energy density to the relative moving speed of the irradiated region of the laser light to the glass substrate (transport speed of the glass substrate), the glass substrate is cut .

However, since 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 laser beam irradiated portion after laser beam irradiation is slowed, , It is conjectured that the cut surfaces are not uniform. Alternatively, when the temperature of the peripheral portion of the laser beam irradiating portion after the laser beam irradiation is cooled by conveying 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 other hand, it is considered that the glass substrate for evaluation A can appropriately select the energy density of the laser light in accordance with the relative moving speed of the irradiation region of the laser light to the glass substrate (the transporting speed of the glass substrate). Therefore, it is considered that the glass 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. Further, since the conveying speed of the glass substrate is appropriate, the peripheral portion of the laser light irradiating portion after the laser light irradiation is cooled at an appropriate cooling rate, and the peripheral portion of the laser light irradiating portion after the laser light irradiation is excluded as a precipitate, .

[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, And the cut surface of the glass substrate after the cutting was evaluated.

The results are shown in Table 2 and Fig. FIG. 5 is a graph of the results of Table 2. FIG.

In the graph shown in Fig. 5, the straight line X is a straight line having the above-mentioned E = 50 x t x v (t = 0.2 mm).

In addition, the straight line Y represents the minimum value of the relative moving speed (here, the conveying speed of the glass substrate) of the irradiated area of the laser beam to the glass substrate which caused the precipitate in the cooling step, in this case, 144 m / hour.

As a result, 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, And the cut surface of the glass substrate after the cutting was evaluated.

The results are shown in Table 3 and Fig. Figure 6 is a graphical representation of the results of Table 3;

In the graph shown in Fig. 6, the straight line X is a straight line having the above-mentioned E = 50 x t x v (t = 0.3 mm).

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 laser beam is irradiated to the laser beam irradiation area from one surface of the glass substrate to the other surface And it was confirmed that it was A evaluation.

[Experimental Example 4]

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 0.6 mm, And the cut surface of the glass substrate after the cutting was evaluated.

The results are shown in Table 4 and FIG. Fig. 7 is a graph showing the results of Table 4. Fig.

Also in the graph shown in Fig. 7, the straight line X is a straight line having the above-mentioned E = 50 x t x v (t = 0.6 mm).

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 region irradiated with the laser beam with respect to the glass substrate (the transporting speed of the glass substrate), and the laser light is irradiated onto the other surface of the glass substrate It is considered that the substrate could not be heated above the vaporization temperature. Therefore, it is considered that the glass substrate can not be cut and the C evaluation is obtained.

INDUSTRIAL APPLICABILITY The present invention can be applied to various glass substrate cutting methods and various glass substrate manufacturing methods.

This application is based on Japanese Patent Application No. 2012-145991 filed with the Japanese Patent Office on June 28, 2012 and Japanese Patent Application No. 2013-004667 filed with the Japanese Patent Office on January 15, 2013, Which claims the benefit of and is incorporated by reference in its entirety.

11: glass substrate
12: Laser light
21: Laser light irradiation part
22: peripheral portion of the laser light irradiating portion
31: Precipitate

Claims

A method of cutting a glass substrate by irradiating a laser beam to cut the glass substrate,
Wherein the glass substrate is heated to a temperature not lower than a temperature at which the laser light irradiating portion from one surface of the glass substrate to the other surface thereof is vaporized in the irradiation region of the laser light irradiated with the laser light on one surface of the glass substrate,
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.

The method according to claim 1,
Wherein the peripheral portion of the laser light irradiating portion is cooled to a temperature not higher than the glass transition temperature after the heating of the laser light irradiating portion.

3. The method according to claim 1 or 2,
When the relative moving speed of the laser light irradiated region 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)

Of the glass substrate.

4. The method according to any one of claims 1 to 3,
And removing the glass component of the vaporized laser light irradiating portion.

5. The method according to any one of claims 1 to 4,
And a precipitate generated in a peripheral portion of the laser light irradiating portion is removed.

6. The method according to any one of claims 1 to 5,
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 6.