JP5729604B2 - Glass substrate processing equipment - Google Patents

Description

The present invention relates to a glass substrate processing apparatus used for flat panel display glass used for smartphones, tablet terminals, notebook computers, touch table screens, television screens, and the like, and in particular, aluminosilicate having a chemically strengthened glass surface. The present invention relates to an apparatus for processing a glass substrate suitable for processing tempered glass obtained by heat-treating glass or float glass by air cooling, 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.

In laser laser scribing, glass is placed on a glass substrate holding table and locally heated by irradiation with laser light that does not cause vaporization, melting, or cracking of the glass along the planned cutting line of the glass. When the position outside the heating region is cooled, a surface scribe groove starting from the initial crack is formed behind the cooling position. Thereafter, the glass is cleaved by performing a so-called breaking process along the scribe grooves.

When laser scribing the glass, a flat table made of a porous material such as carbon is used as a glass substrate holding table for placing the glass in order to maintain the flatness of the glass, and the glass is placed on the porous flat table. A method is adopted in which the placed glass substrate is vacuum-adsorbed from below and fixed while maintaining the flatness of the glass substrate (see, for example, Patent Document 2).

Japanese Patent No. 3027768 JP 2010-1000049 A

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 glass tempered by adding air and thick glass having a thickness of 3 mm or more is used.

When the glass substrate is tempered glass, warpage tends to occur at the outer peripheral portion of the glass substrate. When a warped glass substrate is placed on a porous glass substrate holding table and vacuum-adsorbed from below, the outer periphery of the glass substrate floats from the surface of the glass substrate holding table if the vacuum adsorption force is small. Therefore, when the scribing is performed in this state, the vicinity of the end face of the glass substrate is largely cracked, the crack reaches the back surface, and a bent fractured section deviating from the planned cutting line is formed in the outer peripheral portion. Therefore, the scribe groove along the planned cutting line cannot be formed.

To prevent this, if the vacuum adsorption force is increased and the outer periphery of the glass substrate is brought into close contact with the surface of the glass substrate holding table, the inner portion other than the outer periphery of the glass substrate is strongly pulled against the porous glass substrate holding table. Because of the suction, the internal part of the glass substrate is distorted, and the scribe force controlled by laser irradiation and cooling is affected by the distortion, which adversely affects the scribe quality, especially inside the glass substrate. If the vacuum suction force in the portion is too large, the distortion force becomes larger than the scribe force, and there is a problem that the scribe process cannot be performed and a desired scribe groove cannot be formed.

The present invention solves such problems, and reliably prevents the influence of the warpage of the outer peripheral portion of the glass substrate even in the tempered glass in which the warpage is likely to occur in the glass substrate, in particular, the inner portion of the glass substrate. An object of the present invention is to provide a glass substrate processing apparatus capable of performing high-quality scribe processing along a planned cutting line without distortion.

In order to achieve the above object, the present invention uses a planar table made of a porous material such as carbon as a glass substrate holding table for placing a glass substrate, and the outer peripheral portion of the glass substrate placed on the porous planar table. The particle size of the porous member in the portion corresponding to the portion and the particle size of the porous member in the portion corresponding to the inner portion of the glass substrate are made different so that the adsorption force at the outer peripheral portion of the porous flat table is strong and the adsorption at the inner portion It is a weakened force. To increase the adsorption force at the outer peripheral portion of the porous flat table, to increase the particle size of the porous member at the outer peripheral portion of the porous flat table, and to weaken the adsorption force at the inner portion of the porous flat table, What is necessary is just to make the particle size of a porous member smaller than the particle size of an outer peripheral part.

According to the above configuration, when the glass substrate is placed on the glass substrate holding table and vacuum-sucked from below the glass substrate holding table to fix the glass substrate, the suction force of the portion corresponding to the outer peripheral portion of the glass substrate Therefore, even if the outer peripheral portion is a glass substrate such as tempered glass warped upward, the outer peripheral portion of the glass substrate is adsorbed to the glass substrate holding table with a relatively strong force, and the inner portion of the glass substrate is Adsorbed to the glass substrate holding table with a relatively weak force. As a result, the inner peripheral portion of the glass substrate is not distorted while the outer peripheral portion of the glass substrate that is likely to float is securely fixed on the glass substrate holding table surface, that is, the warpage in the outer peripheral portion of the glass substrate is corrected. It can be fixed in a flat shape. Therefore, when scribing the glass substrate, it is possible to perform scribing with good quality without adversely affecting the scribing force controlled by laser irradiation and cooling.

When making the particle size different between the outer peripheral portion of the porous flat table and the inner portion of the porous flat table, the entire outer peripheral portion is made the first particle size having a large particle size,
The entire inner portion may be the second particle size having a small particle size, but a part of the outer peripheral portion is a first particle size having a large particle size, and a part of the inner portion is partially particle size The second flat particle size may be made small, and the porous flat table as a whole may be configured such that the adsorption force at the outer peripheral portion is strong and the adsorption force at the inner portion is weak.

As the porous flat table, various porous materials such as graphite, porous metal, ceramics, silica, alumina, and zeolite can be used.

According to the present invention, a plane table made of a porous material is used as a glass substrate holding table on which a glass substrate is placed, and a portion of the porous member particles corresponding to the outer peripheral portion of the glass substrate placed on the porous plane table. The diameter and the particle size of the porous member in the portion corresponding to the inner portion of the glass substrate are made different so that the suction force at the outer peripheral portion of the porous flat table is strong and the suction force at the inner portion is weakened. According to the above configuration, when the glass substrate is placed on the glass substrate holding table and vacuum-sucked from below the glass substrate holding table to fix the glass substrate, the suction force of the portion corresponding to the outer peripheral portion of the glass substrate Therefore, even if it is a glass substrate such as tempered glass whose outer periphery warps upward, the outer periphery of the glass substrate is adsorbed to the glass substrate holding table with a relatively strong force, and the inner part of the glass substrate is made of glass. Adsorbed to the substrate holding table with a relatively weak force. As a result, it is possible to fix the inner peripheral portion of the glass substrate without distortion while securely fixing the outer peripheral portion of the glass substrate that is likely to float on the glass substrate holding table surface. Therefore, it is possible to perform scribing with good quality without affecting the scribing force controlled by laser irradiation and cooling.

Schematic of the processing apparatus of the glass substrate which concerns on the Example of this invention. The schematic perspective view of the table for glass substrate holding used for the processing apparatus of the glass substrate which concerns on the Example of this invention.

The present invention uses a planar table made of a porous member as a glass substrate holding table for placing a glass substrate, and the particle size of the porous member in a portion corresponding to the outer peripheral portion of the glass substrate placed on the porous planar table The particle size of the porous member in the portion corresponding to the inner portion of the glass substrate is made different so that the adsorption force at the outer peripheral portion of the porous flat table is strong and the adsorption force at the inner portion is weakened.
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings.
In the following examples, tempered glass whose periphery is likely to warp will be described as an example of the glass substrate, but it is needless to say that the present invention can also be applied to a normal glass substrate that is not tempered glass.

FIG. 1 is a conceptual diagram showing the overall configuration of a glass processing apparatus according to the present invention. The tempered glass substrate 1 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 of a tempered glass having a thick surface reinforcing layer on the glass substrate 1 or a thick glass having a thickness of 3 mm or more such as a glass substrate 1, the break is often difficult. Is preferably used. 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. In the case of a tempered glass substrate having a thick surface reinforcing layer on the glass substrate 11 or a thick glass substrate 11 having a thickness of 3 mm or more, it is often difficult to break, so use a laser oscillator with a maximum output of 200 W. Is preferred.

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 7 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 7 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 6 for rapid cooling is arranged.

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 composed of a porous flat table made of a porous member, and an outer peripheral portion 15 that supports a portion corresponding to the outer peripheral portion of the glass substrate 1 placed on the porous flat table is provided with a first grain. The inside 16 that supports the portion corresponding to the inside of the glass substrate 1 placed on the porous flat table is made of a member having the second particle size, and is made different in particle size. Specifically, the particle size of the outer peripheral portion 15 of the porous flat table is increased, the particle size of the inner portion 16 of the porous flat table is decreased, and the adsorbing force at the outer peripheral portion 15 of the porous flat table is increased. The adsorption force in the interior 16 of the texture plane table is weakened.
As the porous member constituting the glass substrate holding table 10, various porous materials such as graphite, porous metal, ceramics, silica, alumina, and zeolite can be used.

In the case where the outer peripheral portion 15 of the porous flat table constituting the glass substrate holding table 10 is constituted by a porous member having a first particle size, and the inside 16 is constituted by a member having a second particle size, FIG. 2, the entire outer peripheral portion 15 may be configured with a porous member having a first particle size, and the entire inner portion 16 may be configured with a member having a second particle size. A portion may be partially the first particle size, and a portion of the interior 16 may be partially the second particle size, when the glass substrate 1 is placed on the glass substrate holding table 10, What is necessary is just to comprise so that the adsorption | suction force in the outer peripheral part with respect to the glass substrate 1 may be strong as a whole, and the adsorption | suction force in an inside may become weak.

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 to be the initial crack 26 is formed at the start end of the planned cutting line 25 of the glass substrate 11 by being positioned immediately below the processing tool of the crack forming apparatus 7.

Next, the laser irradiation apparatus 2 is moved while separating the initial crack forming apparatus 7 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 25 starting from the initial crack 26. When the movable table 10 is further moved in the + Y direction by the servo motor 8, the glass substrate 1 is also moved in the + Y direction, and the region heated by the laser beam row 5 reaches a position directly below the cooling device 6. At this time, when water mist serving as a refrigerant is ejected from the cooling device 6, 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 is formed on the surface of the glass substrate 11.

As described above, when the glass substrate 1 made of tempered glass is placed on the glass substrate holding table 10, it tends to float from the surface of the glass substrate holding table 10 due to warping. Even when the warped glass substrate 11 is placed on the glass substrate holding table 10 and vacuum-sucked from below, if the vacuum suction force is weak, the outer periphery of the glass substrate 1 is lifted from the surface of the glass substrate holding table 10. If the scribing is performed in this state, the vicinity of the end surface of the glass substrate 1 is greatly cracked, and the crack reaches the back surface, so that a bent split section is formed at the outer peripheral portion of the glass substrate 1 and deviated from the planned cutting line 25. End up. Therefore, a scribe groove along the planned cutting line 25 cannot be formed.

In the present invention, a planar table made of a porous member is used as the glass substrate holding table 10, and the particle size and the inside of the portion corresponding to the outer peripheral portion of the glass substrate 1 in the glass substrate holding table 10 correspond to the inside. Since the particle sizes of the porous members of the portions are different, when the glass substrate 1 is placed on the glass substrate holding table 10 and vacuum suction is performed from below the glass substrate holding table 10, suction at the outer peripheral portion of the glass substrate 1 is performed. Since the force is stronger than the suction force in the inner portion, even if the outer peripheral portion of the glass substrate 1 is warped and lifted, the outer peripheral portion that is floating is fixed to the glass substrate holding table 10 with a strong suction force and is caused by warpage. The float of the glass substrate 1 is removed. On the other hand, the inner portion of the glass substrate 1 has a smaller suction force than the outer peripheral portion, so that no distortion force is applied to the inner portion. Accordingly, the entire glass substrate 1 is fixed on the glass substrate holding table 10 in a stable flat shape.

Therefore, there is no formation of a curved split section deviating from the planned cutting line 25 in the outer peripheral portion of the glass substrate 1, and no distorting force is applied inside, so that the scribe controlled by laser irradiation and cooling is performed. A straight, high-quality split section can be formed along the planned cutting line 25 without adversely affecting the force.

In recent years, a glass substrate processing apparatus 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 Cooling device 7 Initial crack formation apparatus 8 Servo motor 9 Shaft shaft 10 Glass substrate holding table 12 Beam converter 15 The outer peripheral part 16 of a porous plane table Porous Inside of flat table 25 Planned cutting line 26 First crack

Claims (4)

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 for forming a scribe on a glass substrate by relatively moving along a line, wherein a porous plane table made of a porous member is used as the glass substrate holding table, and the porous plane The particle size of at least a portion of the porous member of the portion corresponding to the outer peripheral portion of the glass substrate of the table is made larger than the particle size of the porous member of the portion corresponding to the inner portion of the glass substrate, strong suction force at the portion corresponding to the outer peripheral portion of the glass substrate, processing of the glass substrate, characterized in that weaken the suction force inside portion of the glass substrate Location. 2. The processing of a glass substrate according to claim 1 , wherein the entire outer peripheral portion of the porous flat table has a first particle size with a large particle size, and the entire inner portion has a second particle size with a small particle size. apparatus. A part of the outer peripheral portion of the porous flat table is partially set to a first particle size having a large particle size, and a part of an inner portion is partially set to a second particle size having a small particle size. The processing apparatus of the glass substrate of Claim 1 . 2. The glass substrate processing apparatus according to claim 1, wherein the porous member is any one of graphite, porous metal, ceramics, silica, alumina, and zeolite.