JP2013023417A - Processing apparatus of glass substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent ingress of water mist into a gap between a glass substrate and a glass substrate holding table even when a great amount of water mist is sprayed onto the glass substrate during scribe processing of tempered glass and thick glass.SOLUTION: In the processing apparatus of a glass substrate 1, cut grooves 21, 22, 23, and 24 are cut at positions corresponding to the outer circumference part of the glass substrate 1 in a glass substrate holding table 10. A drainage path 11 is communicated to these cut grooves 21, 22, 23, and 24. As a result, even when a great amount of water mist is sprayed onto the glass substrate 1 during scribe processing of the glass substrate 1, extra water mist flows into the cut grooves 21, 22, 23, and 24 in the glass substrate holding table 10 to be discharged outside of the processing apparatus through the drainage path 11. Accordingly, it is possible to prevent ingress of the water mist into a gap between the glass substrate 1 and the glass substrate holding table 10.

Description

The present invention is applied to a glass for flat panel displays used in smartphones, tablet terminals, notebook computers, touch table screens, television screens, etc., in particular aluminosilicate glass or float glass having a chemically strengthened glass surface, and then subjected to air cooling. The present invention relates to a glass substrate processing apparatus that processes tempered tempered glass or thick glass having a thickness of 3 mm or more (hereinafter collectively referred to as tempered glass).

Recently, in the glass cleaving, a thermal stress scribing method (hereinafter abbreviated as laser scribing) using laser beam irradiation has been used in place of the mechanical method using a diamond tip that has been used for the past century.

  According to laser scribing, defects inherent in the mechanical method, that is, a decrease in glass strength due to the occurrence of microcracks, contamination due to the occurrence of cullet at the time of cleaving, the presence of a lower limit value of the applied plate thickness, and the like can be eliminated.

In laser scribing, generally, glass is locally heated and irradiated with laser light to the extent that vaporization, melting, and cracks do not occur. At this time, the glass heating portion tries to expand thermally, but cannot sufficiently expand due to the reaction from the surrounding glass, and compressive stress is generated in this heating region. Even in the peripheral non-heated region, the peripheral portion is further distorted by the expansion from the heating portion, and as a result, compressive stress is generated. Such compressive stress is in the radial direction with the heating center point as the origin, and propagates throughout the glass plate almost at the speed of sound after heating occurs. When the object has a compressive stress, a tensile stress proportional to the Poisson's ratio is generated in the orthogonal direction.

If there is a crack at the position where the tensile stress is present, stress expansion occurs at the crack tip, and if the expanded stress exceeds the fracture toughness value of the material, the crack expands. That is, a controlled cleaving occurs in which the crack progresses from the crack tip toward the heating center. Therefore, the crack can be extended by scanning the laser irradiation point in advance.

Glass laser scribing uses this principle, and when cooling is performed near the maximum point of tensile stress, the tensile stress amplified by the shrinkage of the glass at this time is useful for strengthening the cleaving. It has been proposed that it can be realized efficiently (see Patent Document 1).

According to Patent Document 1, a CO ₂ laser beam is used as the heating laser beam. 99% of the energy in the beam spot of the CO ₂ laser light is absorbed in the glass surface layer having a depth of 3.7 μm of the glass plate 6 and is not transmitted through the entire thickness of the glass plate. This is due to the extremely large absorption coefficient of glass at the CO ₂ laser wavelength. As a result, heating occurs only in the surface layer of the glass plate, and compressive stress is generated in this heating region.

On the other hand, when the cooling is performed at a cooling point located outside the heating region, tensile stress is generated, and surface scribes starting from the initial crack are generated behind the cooling point. The depth of this scribe is usually about 100 μm for soda glass or the like. However, the glass plate is highly brittle and it is easy to mechanically cleave it by applying a bending stress in accordance with this scribe line. The process of cleaving with the application of bending stress is called breaking. The laser beam is scanned in the scanning direction. This method has many advantages compared with the conventional mechanical method, and has gradually been applied to the production of flat panel display devices.

Japanese Patent No. 3027768

On the other hand, in recent years, heat treatment has been applied to aluminosilicate glass and float glass whose glass surface has been chemically strengthened to increase the hardness of the glass surface as glass for flat panel displays such as smartphones, tablet terminals, laptop computers, touch table screens and TV screens. Tempered glass such as tempered glass tempered by air cooling or thick glass having a thickness of 3 mm or more is used.

The laser scribing method according to Patent Document 1 has no problem in the normal cleaving processing of soda glass, but there are some problems in the case of tempered glass. For example, in the case of tempered glass, it is extremely difficult to form a good initial crack by scratching the surface of the glass with a knife such as a normal diamond cutter, and a pulse oscillation type laser is used. Methods are being studied.

In addition, when the glass substrate is tempered glass, it is possible to process only those with a shallow scribe groove depth, so that the glass that is strongly chemically treated is more difficult to break, and even when the glass is thick, there is a large force for breaking. It becomes necessary and difficult. For this reason, in order to form a scribe groove in the tempered glass, it is necessary to process a scribe groove of a certain depth so that the break can be performed linearly and satisfactorily. A large amount of water mist is required.

However, when a large amount of water mist is sprayed on the glass substrate during the scribing process, the water of the mist enters the gap between the glass substrate and the table supporting the glass substrate, that is, the central portion of the glass substrate on the lower surface of the glass substrate, that is, The scribe line enters the traveling direction, the laser heating and cooling process control is disturbed, and the traveling direction and depth of the scribe groove are disturbed, and a desired scribe groove cannot be formed. .

The present invention solves such problems, and supports glass substrates and glass substrates even when a large amount of water mist is sprayed on the glass substrate during scribing in glass substrates, particularly tempered glass and thick glass. It aims at providing the processing apparatus of the glass substrate which can prevent that the water of mist enters into the clearance gap between the table which is carrying out.

In order to achieve the above object, according to the present invention, in a table holding a glass substrate, a groove is formed at a position corresponding to the outer peripheral portion of the glass substrate, and a drainage passage is communicated with the groove. It is.
According to the above configuration, even when a large amount of water mist is sprayed on the glass substrate during the scribing process of the glass substrate, particularly the glass substrate formed of tempered glass, Since it flows into the kerf on the outer periphery of the glass substrate and drains to the outside of the processing apparatus through the drainage passage communicating from there, the mist is formed in the gap between the glass substrate and the table supporting the glass substrate. Water can be prevented from entering. Therefore, since the water mist does not enter the central portion of the glass substrate on the lower surface of the glass substrate, that is, toward the traveling direction of the scribe line, there is no disturbance in the control of the laser heating and cooling processes, and the traveling direction and depth of the scribe groove. It is possible to form a good scribe groove without any disturbance. As a result, the break can be facilitated, and the break can run straight over the entire cutting line of the glass substrate, and even tempered glass that is difficult to break can be reliably processed.

Moreover, this invention is comprised so that the outer periphery of a glass substrate may be located in the approximate center part of the width direction of a kerf, respectively.
According to the above configuration, even when a large amount of water mist is sprayed on the glass substrate during the scribing process of the glass substrate, particularly the glass substrate formed of tempered glass, Since it flows into the kerf on the outer periphery of the glass substrate and drains to the outside of the processing apparatus through the drainage passage communicating from there, the mist is formed in the gap between the glass substrate and the table supporting the glass substrate. Water can be prevented from entering.

In the present invention, a plurality of kerfs corresponding to a plurality of glass substrates are formed on the glass substrate holding table.
According to the said structure, it can be made to respond | correspond to the several glass substrate from which a magnitude | size differs with one glass substrate holding table.

In the present invention, a plurality of types of glass substrate holding tables corresponding to the size of the glass substrate to be processed can be exchanged according to the size of the glass substrate to be processed.
According to the said structure, the glass substrate of various sizes can be processed with one processing apparatus.

In the present invention, the glass substrate is a tempered glass having a tempered layer formed on the surface thereof or a thick glass having a thickness of 3 mm or more.
According to the above configuration, in the scribe processing of tempered glass or thick glass, even if a large amount of water mist is sprayed on the glass substrate during the scribe processing, the mist is formed in the gap between the glass substrate and the table supporting the glass substrate. Can prevent water from entering

According to the present invention, in the table supporting the glass substrate, a kerf is formed at a position corresponding to the outer peripheral portion of the glass substrate, and the drainage passage is communicated with the kerf, so that it is sprayed during scribe processing. Even if a large amount of water mist is sprayed, the excess water mist after spraying can be drained from the kerf formed on the outer periphery of the glass substrate to the outside of the processing device through the drainage passage, Mist water can be prevented from entering the gap between the glass substrate and the table supporting the glass substrate.

Schematic of a brittle material processing apparatus according to an embodiment of the present invention The schematic perspective view of the table for glass substrate holding used for the brittle material processing apparatus which concerns on the Example of this invention.

In the present invention, a glass substrate is supported on a glass substrate holding table, heated with a laser beam along a cutting plan line of the glass substrate, and then the heating position is cooled, and the irradiation position and cooling point of the laser beam are applied to the glass substrate. On the other hand, in a glass substrate processing apparatus that forms a scribe on a glass substrate by relatively moving along a planned cutting line, a kerf is cut at a position corresponding to the outer peripheral portion of the glass substrate in the glass substrate holding table. A drainage passage is communicated with the kerf.
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings.

FIG. 1 is a conceptual diagram showing the overall configuration of a processing apparatus for tempered glass according to the present invention. The glass substrate 1 made of tempered glass is placed on a glass substrate holding table 10, and the glass substrate holding table 10 is moved in the XY plane by an XY driving device. In the figure, only the Y-axis drive servomotor 8 and the shaft 9 that are glass moving directions are shown, and the X-axis drive system is not shown.

As the laser oscillator 2 for heating the glass substrate 1, a laser light source that outputs a laser beam having an opaque wavelength to the glass substrate 1, for example, a CO ₂ gas laser light source that outputs a laser beam having a wavelength of 10.6 μm is used. The laser oscillator 2 is, for example, a gas sealing type with a maximum output of 100 W. In the case where the glass substrate 1 is thick and the glass substrate 1 is thick glass such as 3 mm or more thick, it is often difficult to break, so a laser oscillator with a maximum output of 200 W is used. It is preferable to do. The laser beam 3 output from the laser irradiation device 2 is reflected downward by the reflecting mirror 4 and enters the beam conversion device 12.

The laser oscillator 2 is, for example, a gas sealing type with a maximum output of 100 W. When the surface reinforcing layer of the glass substrate 11 is thick or the glass substrate 11 is thick such as 10 mm or more, it is often difficult to break, so it is preferable to use a laser oscillator with a maximum output of 200 W.

The beam conversion device 12 includes a total reflection surface and a partial reflection surface arranged in parallel to face each other. When one laser beam 3 reflected from the reflection mirror 4 is incident on the beam conversion device 12 obliquely, the laser beam 3 is a laser comprising a plurality of beams arranged in the direction of the planned cutting line by performing multiple reflections between the total reflection surface and the partial reflection surface a plurality of times and sequentially transmitting a part of the beam energy from the partial reflection surface. It is converted into a beam train 5. The laser beam train 5 is obliquely irradiated on the glass substrate 1.

An initial crack forming device 6 for forming a crack at the starting point of the planned cutting line of the glass substrate 1 is provided in front of the irradiation position of the laser beam row 5 composed of a plurality of beams. The initial crack forming apparatus 6 is constituted by a local heat source such as a laser beam or a diamond cutter.

On the other hand, a coolant such as water mist is sprayed on the surface of the heated glass substrate 1 while following the heating region by the laser beam train 5 with a space behind the irradiation position of the beam train 5 composed of a plurality of beams. A cooling device 7 for rapid cooling is disposed.
A coolant such as water mist sprayed on the surface of the glass substrate 1 is drained to the outside of the processing apparatus via the drainage passage 11. Details will be described later.

FIG. 2 is a perspective view of the glass substrate holding table 10. A glass substrate 1 to be processed is placed on one main surface of the glass substrate holding table 10. The glass substrate holding table 10 is provided with cut grooves 21, 22, 23, and 24 at positions corresponding to the outer peripheral portion of the placed glass substrate 1. The glass substrate 1 is placed so that the outer periphery thereof is located at the approximate center in the width direction of the kerfs 21, 22, 23, and 24. Therefore, the engraved positions of the kerfs 21, 22, 23, and 24 differ depending on the size of the glass substrate 1 to be processed.

In general, the size of the glass substrate 1 to be processed varies depending on the application, so that a plurality of kerfs corresponding to the glass substrate 1 of several sizes are engraved on one glass substrate holding table 10 or the glass to be processed It is preferable that a plurality of types of glass substrate holding tables 10 corresponding to the size of the substrate 1 are prepared and configured to be exchangeable in accordance with the size of the glass substrate 1 to be processed.

Next, the operation of the glass substrate processing apparatus according to the present invention will be described with reference to FIGS.
In order to process the tempered glass, first, the initial crack 26 is formed by the initial crack forming apparatus 7 at the start end of the planned cutting line 25 of the glass substrate 1. This initial crack 26 is a starting position for processing the glass substrate 11. In order to form the initial crack 26, first, the glass substrate 1 placed on the glass substrate holding table 10 is moved in the −Y direction by the servo motor 8, and the starting end of the planned cutting line 25 of the glass substrate 1 is first set. A crack that becomes the initial crack 26 is formed at the start end of the cutting line 25 of the glass substrate 11, which is positioned directly below the processing tool of the crack forming apparatus 6.

Next, the laser irradiation apparatus 2 is moved while separating the initial crack forming apparatus 6 from the surface of the glass substrate 1 and moving the glass substrate 1 placed on the glass substrate holding table 10 in the + Y direction by the servo motor 8. The laser beam 3 is emitted after being oscillated. The emitted laser beam 3 is reflected downward by the reflecting mirror 4 and obliquely incident on the beam conversion device 12, and is reflected multiple times between the total reflection surface and the partial reflection surface of the beam conversion device 12 to be partially reflected. The glass substrate 1 is converted into a laser beam array 5 composed of a plurality of beams arranged in the direction of the planned cutting line 25 from the surface and obliquely irradiated onto the glass substrate 1. As a result, the glass substrate 1 is heated by the laser beam train 5 along the planned cutting line 12 with the initial crack 26 as a starting end. When the movable table 10 is further moved in the + Y direction by the servo motor 8, the glass substrate 1 is further moved in the + Y direction, and the region heated by the laser beam row 5 reaches a position directly below the cooling device 7. At this time, when water mist serving as a refrigerant is sprayed from the cooling device 7, the glass substrate 1 is cracked in the thickness direction of the glass substrate 11, expanding from the initial crack 26 immediately below the cooling point.

The crack expanded in the plate thickness direction in the vicinity of the initial crack 26 is cracked along the planned cutting line 12 as the combination of the laser beam train 5 and the cooling point is transferred relative to the glass substrate 1. Can be enlarged. As a result, a scribe groove 27 is formed on the surface of the glass substrate 11.

By the way, when the glass substrate 1 is a tempered glass, the power density of the laser beam train 5 is large in order to propagate cracks, and a sufficient depth is required unless a large amount of water mist is used for cooling. The scribe groove 27 cannot be formed. However, as described above, when a large amount of water mist is sprayed on the glass substrate during the scribing process, the water of the mist enters the gap between the glass substrate and the table supporting the glass substrate, and the glass substrate is formed on the lower surface of the glass substrate. There is a risk of entering the central portion of the scribe groove 27, that is, toward the traveling direction of the scribe groove 27.

In order to prevent this phenomenon, in the present invention, as shown in FIG. 2, the glass substrate holding table 10 is provided with kerfs 21, 22, 23, 24 at positions corresponding to the outer peripheral portion of the glass substrate 1 placed thereon. ing. Therefore, a large amount of mist water sprayed during scribing flows into the kerfs 21, 22, 23, 24, and passes through the drainage passage 11 connected to the kerfs 21, 22, 23, 24. To be drained. The drained water can be reused in the cooling device 7 after filtration if necessary.

Thus, according to the present invention, even when a large amount of water mist is used when processing the scribe groove 27 having a certain depth so that the break can be performed linearly and satisfactorily in laser scribing of tempered glass. The water of mist enters the gap between the glass substrate and the table supporting the glass substrate and enters the central portion of the glass substrate, that is, toward the traveling direction of the scribe groove 27 on the lower surface of the glass substrate. Can be prevented. Therefore, the control of the laser heating or cooling process is not disturbed and the traveling direction and depth of the scribe groove 27 are not disturbed, and the desired scribe groove 27 can be formed reliably.

In recent years, a processing apparatus for tempered glass according to the present invention includes a tempered glass having a tempered layer formed on a glass surface used for flat panel displays such as liquid crystal displays and plasma displays, and display devices such as mobile phones and portable terminals. It is suitable for application to the mirror cleaving of thick thick glass.

DESCRIPTION OF SYMBOLS 1 Glass substrate 2 Laser oscillator 3 Laser beam 4 Reflecting mirror 5 Laser beam row | line | column 6 Initial crack formation apparatus 7 Cooling apparatus 8 Servo motor 9 Shaft shaft 10 Glass substrate holding table 12 Beam conversion apparatus 21, 22, 23, 24 Cut groove 25 Cutting Planned line 26 First crack 27 Scribe groove

Claims (5)

A glass substrate is supported on a glass substrate holding table, heated with a laser beam along the planned cutting line of the glass substrate, the heated position is cooled, and the irradiation position and cooling point of the laser beam are scheduled to be cut with respect to the glass substrate. A glass substrate processing apparatus that forms a scribe on a glass substrate by relatively moving along a line, and forming a kerf at a position corresponding to the outer periphery of the glass substrate in the glass substrate holding table. An apparatus for processing a glass substrate, characterized in that a drainage passage is communicated with the glass substrate. The glass substrate processing apparatus according to claim 1, wherein the outer periphery of the glass substrate is configured to be positioned at a substantially central portion in the width direction of the kerf. The glass substrate processing apparatus according to claim 1, wherein a plurality of kerfs corresponding to a plurality of glass substrates having a plurality of sizes are formed on the glass substrate holding table. The glass substrate processing apparatus according to claim 1, wherein a plurality of types of glass substrate holding tables corresponding to the size of the glass substrate to be processed can be exchanged according to the size of the glass substrate to be processed. . The glass substrate processing apparatus according to claim 1, wherein the glass substrate is a tempered glass having a tempered layer formed on a surface thereof or a thick glass having a thickness of 3 mm or more.