JP2010253752A - Device and method of cutting brittle material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device and a method of cutting a brittle material capable of full body cutting straight linearly extended over the whole length of a planned cutting line without generating uncut remainders while obtaining high quality possessed by thermal stress cutting by a laser. <P>SOLUTION: A brittle material 11 is heated in a first beam irradiated area 13 wherein a first laser beam 22 is shaped into an approximately round shape and a second laser beam irradiated area 14 wherein a second laser beam 26 is shaped into a shape in which the direction along the planned cutting line 12 is longer and thinner than the right angle direction, the first beam irradiated area 13 is positioned in front of the direction along the planned cutting line 12 with respect to the second beam irradiated area 14, the position separated from the rear end of the second beam irradiated area 14 by a predetermined position is locally cooled by a cooling device 30 as a cooling point 15, and a gas flow is sprayed to the terminal end of the planned cutting line 12 of the brittle material 11 with a gas jetting device 34 after the cooling point 15 passes through the terminal end of the planned cutting line 12. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a brittle material cleaving apparatus and a brittle material cleaving method for full-body cleaving of a brittle material, particularly flat panel display glass. Hereinafter, glass will be described as an example of the brittle material, but the present invention can be applied to other brittle materials such as quartz, ceramics, and semiconductors in addition to glass.

Recently, in the glass cleaving, a thermal stress scribing method (hereinafter abbreviated as “laser scribing”) using laser light irradiation has been used in place of the diamond chip mechanical method 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, existence of a lower limit value of the applied plate thickness, etc. can be eliminated.

  The principle of laser scribing is as follows. Only glass is heated locally, and the laser beam is irradiated to such an extent that vaporization, melting and cracks do not occur. At this time, the glass heating section tries to expand thermally, but cannot sufficiently expand due to the reaction from the surrounding glass, and compressive stress is generated around the irradiation point. 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. These compressive stresses are radial. By the way, when the object has a compressive stress, a tensile stress related to the Poisson's ratio is generated in the orthogonal direction. The direction is a tangential direction. This is shown in FIG.

FIG. 1 shows changes in the radial stress component σ _x and the tangential stress component σ _y when there is a temperature increase in the Gaussian distribution centered at the origin. The radial stress component σ _x is a compressive stress (negative value in FIG. 1) from beginning to end, while the tangential stress component σ _y is a compressive stress at the heating center (distance r = 0), but tensile stress when it is away from the heating center. (Positive value in FIG. 1).

Among these stresses, the tensile stress is related to the cleaving. When the tensile stress exceeds the fracture toughness value that is a material specific value, fracture occurs everywhere and is uncontrollable. In the case of the laser cleaving method, the tensile stress is selected to be equal to or less than the fracture toughness value, so that no fracture occurs. However, when there is a crack at the position where the tensile stress is present, stress expansion occurs at the tip of the crack, and the crack expands when the stress intensity factor due to this stress exceeds the fracture toughness value of the material. That is, controlled cleaving occurs. Therefore, the crack can be extended by scanning the laser irradiation point.

A typical example of this glass laser scribing method is described in Patent Document 1. FIG. 2A shows the principle of the laser cleaving method according to Patent Document 1. As the laser light, CO ₂ laser light is used, and 99% of the energy in the beam spot 1 of the CO ₂ laser light is absorbed in the glass surface layer having a depth of 3.7 μm of the glass 2, and is spread over the entire thickness of the glass 2. Not transparent. This is due to the extremely large absorption coefficient of glass at the CO ₂ laser wavelength. The depth of the laser scribe is usually about 100 μm even if it is assisted by the heat conduction 4 in the glass 2.

The glass 2 is highly brittle, and can be mechanically cleaved by applying a stress in accordance with the scribe line. This process of breaking all by application of mechanical stress is called breaking. That is, when the laser scribing method is employed, a subsequent process called “break” is indispensable for dividing the glass. Considering the desire to completely sever the glass using a laser beam, laser scribing is not necessarily sufficient because laser scribing adds an after-process called breaking.

Therefore, a full-body cleaving technique using a laser beam is needed and expected. When the laser light 5 that is transmitted through the glass 2 as shown in FIG. 2 (b) and is partially absorbed is irradiated, the transmitted light generates the cleave 6 with respect to the total thickness of the glass 2. The glass 2 can be cleaved only in this step, and no break is required. This cleaving is called full-body cleaving with a laser.
By adopting full body cleaving, in addition to the technical features of the laser cleaving method described above, breaks are no longer necessary, and a great improvement can be expected in the flat panel manufacturing process. Remi Co., Ltd. has proposed Patent Documents 2, 3, 4, etc. for this full-body cleaving technology.

Japanese Patent No. 3027768 JP 2007-76077 A Japanese Unexamined Patent Publication No. 2007-261885 Japanese Patent Application No. 2008-320251 JP 2000-233936 A

Since the cleaving according to Patent Document 1 is not a full-body cleaving, the breaking process is necessary and the practicality is limited as described above. In the full-body cleaving technology using lasers proposed in Patent Documents 2 and 3, when a highly versatile CO ₂ laser beam is used as a laser light source, most of the light is absorbed by the glass surface, and thus is used as it is. It cannot be applied. In addition, as pointed out in Patent Document 1 in the full-body cleaving technique, when the cleaving position is separated from the workpiece end due to the so-called size effect, the cleaving speed is remarkably reduced, and the cleaving position is close to the end of the glass. There is a disadvantage that the split section is bent.

The disadvantage due to the size effect will be described with reference to FIG. First, the low speed property, which is the first drawback of full body breaking of glass, will be described. In FIG. 3 (a), consider a case where breaking the glass plate 2 in a large state width W ₁ and W _2. When the laser beam 5 is scanned along the cleaving line 7 in the cleaving direction 3, a tensile tension is generated on the glass plate 2 by the above-described principle due to heating by laser beam irradiation, and the glass plate 2 follows the scanning locus of the laser beam 5. It will be divided. In FIG. 3A, this deformation is exaggerated, and the actual movement of the glass after breaking is about several microns.

At this time, if the widths W ₁ and W ₂ of the glass plate 2 on both sides of the breaking line 7 are large, the scanning speed of the laser beam 5 is significantly reduced. First, the tensile stresses F ₀ and F ₁ necessary for cleaving the glass plate 2 must overcome the resistance to deformation described above. This resistance acts on the area of the glass plate 2 and increases remarkably when the widths W ₁ and W _{2 of} the glass plate ₂ are large. Since the cleaving of the glass plate 2 must be performed against a large resistance, it is necessary to reduce the scanning speed of the laser beam 5 and relatively increase the amount of heating by the laser beam 5.

As a result, the scanning speed of the laser beam 5 has to be low, so the cleaving speed is naturally limited. This tendency becomes more prominent as the distance between the position of the breaking line 7 and the end of the glass plate 2 is larger, that is, as the widths W ₁ and W _{2 of the} broken glass plate 2 in FIG. For example, when the widths W ₁ and W ₂ of the glass plate 2 after cleaving are a distance of 500 mm, full body cleaving cannot be performed unless the scanning speed of the laser light 5 is set to a remarkably low speed of about 10 mm / s. .

Next, the fact that the fractured surface of the brittle material is curved with respect to the planned fracture position, which is another drawback of full body cleavage of the brittle material, will be described. As described with reference to FIG. 3A, the cleaving when the laser beam 5 is scanned in the cleaving direction 3 along the cleaving line 7 is performed in the creeping direction by the tensile stresses F ₀ and F ₁ acting on the glass plate 2. . At that time, when there is an imbalance in the above-described resistance force on both sides, a force is exerted on the split section to bend with respect to the planned cutting line. This is shown in FIG.

FIG. 3B shows that when the width W ₃ is small, the resistance on the side of the width W ₃ is small, so that the curve is greatly curved, and the split section after cleaving is curved in a bow shape. This tendency is remarkable when the width W ₁ and W ₃ of the glass plate 2 after cleaving imbalance, especially one having a width W ₃ is particularly small. Also in this case, as described above, the deformation of the workpiece is shown exaggerated more than the actual one of several microns.
Patent Document 4 can solve these problems in the full-body cleaving techniques of Patent Documents 2 and 3, but it is often impossible to perform full-body cleaving at the end portion of the cleaving, and an uncut portion often remains. .

Further, in Patent Document 5, it is described that the nozzle for spraying the coolant is inclined when laser scribing is performed, but the object of the invention disclosed in this Patent Document is to provide a beam spot and a cooling part. It is an object of the present invention to provide a glass cutting device provided with a nozzle that does not allow a refrigerant to flow into a heated portion even when approaching. Accordingly, the invention described in Patent Document 5 is completely different from the invention described in this specification in recognition of the problem, and the object and effect of the invention.

It is an object of the present invention to provide a brittle material cleaving apparatus and method capable of full body cleaving without leaving uncut portions over the entire length of the planned cleaving line.

In order to achieve the above object, the present invention heats along the planned cutting line from the side of the initial crack formed at the end position of the planned cutting line with respect to the planned cutting line assumed for the brittle material. And a brittle material cleaving apparatus for cooling and cleaving by moving a heating and cooling position relative to the brittle material, the heating portion being formed in the brittle material along the planned fracture line A laser beam irradiating means for irradiating a laser beam to generate a gas; a cooling means for cooling a position behind the heating portion along the planned cutting line; and a gas toward the end portion of the brittle material on the planned cutting line A gas injection device for injecting a flow, and injecting the gas flow to displace the end portion of the brittle material by wind pressure, thereby dividing the end portion of the brittle material.

Further, the present invention heats and cools along the planned cutting line from the side of the initial crack formed at the end position of the planned cutting line with respect to the planned cutting line assumed for the brittle material, And a method for cleaving the brittle material by moving the cooling position relative to the brittle material, heating the brittle material with a first laser beam and a second laser beam, The first laser beam is a beam positioned in front of the second laser beam in the direction along the planned cutting line, and the second laser beam has a direction along the planned cutting line in a direction perpendicular to the perpendicular direction. A beam having an elongated shape, locally cooled at a predetermined position away from the rear end of the second laser beam, and after the cooling point has passed the end of the planned cutting line, the brittle material Of the planned cutting line It is intended to inject the gas flow to the end.

According to the present invention, it is possible to provide a brittle material cleaving apparatus and method capable of full-body cleaving without leaving uncut portions over the entire length of the planned cleaving line.

The brittle material cleaving apparatus according to the present invention is configured to heat and cool the planned fracture line assumed for the brittle material from the side of the initial crack formed at the end position of the planned fracture line along the planned fracture line. And a cleaving device for the brittle material that moves the heating and cooling positions relative to the brittle material, and generates a heated portion formed in the brittle material along the planned fracture line. A laser beam irradiating means for irradiating a laser beam, a cooling means for cooling a position behind the heated portion along the planned cutting line, and a gas flow toward the end portion of the brittle material on the planned cutting line A gas injection device for injecting the gas, jetting the gas flow, displacing the end portion of the brittle material by wind pressure, and dividing the end portion of the brittle material.

The brittle material cleaving apparatus according to the present invention includes a first beam irradiating unit in which the laser beam irradiating unit forms a first laser beam irradiating region positioned forward along the planned cutting line in the heating portion. And a second beam irradiation unit for forming a second laser beam irradiation region having a shape in which a direction along the planned cutting line is longer than a perpendicular direction behind the first laser beam irradiation region.

Moreover, the method for cleaving the brittle material according to the present invention is based on the planned fracture line from the side of the initial crack formed at the end position of the planned fracture line with respect to the planned fracture line assumed for the brittle material. A brittle material cleaving apparatus that heats and cools and cleaves the heating and cooling positions relative to the brittle material, wherein the brittle material is heated by the first laser beam and the second laser beam. The first laser beam is a beam positioned forward of the second laser beam in a direction along the planned cutting line, and the second laser beam is along the planned cutting line. The beam has a shape elongated in the direction perpendicular to the perpendicular direction, and a position separated from the rear end of the second laser beam by a predetermined position is locally cooled, and the cooling point passes through the end of the planned cutting line. After the brittle Characterized by injecting a gas stream at the end of the expected splitting line of the material.

According to the brittle material dividing apparatus and the brittle material cleaving method, the laser beam is irradiated along the planned cutting line to generate a heated portion, and then cooling is performed by cooling the rear of the heated portion with cooling means. A crack that reaches the back side of the brittle material is generated just below the position, and after the cooling point passes through the end of the planned cutting line, the gas injection device injects a gas flow at the end of the planned cutting line of the brittle material. Full body can be cleaved in a straight line over the entire length of the planned cleaving line without leaving any residue

Hereinafter, the principle and embodiments of the present invention will be described in detail with reference to the drawings. In the following description, a glass substrate will be described as an example of the brittle material.

FIG. 4 schematically shows the structure of a brittle material cleaving apparatus according to the present invention. The glass substrate 11 is placed on a movable table 32, and the movable table 32 can be moved independently in each of the X-axis and Y-axis directions by an XY drive device, and the glass is placed in a plane direction. Can be moved. In FIG. 4, only the Y-axis drive servomotor 33 and the Y-axis shaft are shown, and the X-axis drive system is not shown. The direction in which the glass is linearly cut coincides with the movement direction of the Y axis in FIG.

In this embodiment, _two laser oscillators for heating the glass, that is, a CO ₂ laser oscillator 21 having an output of 200 W and a CO ₂ laser oscillator 25 having an output of 100 W are used. The laser beam 22 emitted from the CO ₂ laser oscillator 21 is reflected vertically downward by the reflecting mirror 23 and shaped so as to have a predetermined beam diameter through the condenser lens 24. The beam that has passed through the condensing lens 24 is irradiated on the surface of the glass substrate 11 as it is, but depending on the case, the beam shape can be formed by arranging a beam shield 35 as a beam attenuator on the beam transmission path. Is also partially deformed. In any case, a first beam irradiation region by the first laser beam is formed on the glass substrate 11 by the laser beam 22. The position at which the first beam irradiation region (see FIG. 5) is formed on the glass substrate 11 is adjusted by changing the folding angle of the reflecting mirror 23.

In FIG. 4, the folding angle of the reflecting mirror 23 is set to be close to 90 °, but the folding angle is swung from about 80 ° to 110 ° and the position of the condenser lens 24 is aligned at the same time. Position adjustment in the Y-axis direction of the one-beam irradiation area is performed. Alternatively, it is possible to adjust the position of the first beam irradiation region by assembling one unit that fixes the relative position between the reflecting mirror 23 and the condenser lens 24 and moving the unit in parallel with the movement direction of the Y axis. Become. The cross-sectional shape of the first beam irradiation region is a circle or an ellipse, and these are collectively referred to as a substantially circle throughout the specification and claims. The first beam irradiation region 13 is a laser beam having such an intensity that only the glass substrate 11 is locally heated and no melting or cracking occurs.

A laser beam 26 emitted from the CO ₂ laser oscillator 25 is reflected vertically downward by a reflecting mirror 28 via a beam expander 27. When the laser beam 26 having a beam diameter of φ4 mm passes through the beam expander 27, the beam diameter is expanded by a factor of about 4 to become a beam having a φ16 mm. The expanded beam passes through a beam shaping means 29 such as a diffractive optical element or a planoconvex cylindrical lens, and is shaped into an elongated beam. A second beam irradiation area by the second laser beam is formed on the glass substrate 11. Form.

As a result, the glass substrate 11 is heated by the first laser beam from the CO ₂ laser oscillator 21 and the second laser beam from the CO ₂ laser oscillator 25. In this case, the laser power applied to the first laser irradiation region formed by the first laser beam is greater than the laser power applied to the second laser irradiation region formed by the second laser beam, and the first The laser beam is a beam having a predetermined beam diameter located in front of the second laser beam in the direction along the cutting line, and the second laser beam is cut by the beam expander 27 and the beam shaping unit 29. The beam is shaped into a beam having a shape that is longer than that of the right angle direction.

A cooling device 30 is installed behind the second beam irradiation region by the second laser beam. As the cooling device 30, a two-tube type cooling nozzle is used, and water is injected from the inner cylindrical tube and gas is injected from the outer cylindrical tube. A cooling point is formed on the glass substrate 11 by spraying the mixed medium of water and gas toward the glass. An initial crack forming device 31 is provided in front of the first laser beam. The initial crack forming apparatus 31 includes a diamond cutter at a lower end portion, and has an elevating mechanism that moves the diamond cutter up and down. An initial crack can be formed at the end of the glass substrate 11 by interlocking with the lifting mechanism and the Y-drive servomotor 33 for Y-axis drive.

A gas injection device 34 is installed behind the cooling device 30. The gas injection device 34 has, for example, a gas injection nozzle having a diameter of 3 mm, and the gas injection nozzle has an angle θ1 of less than 90 degrees in the range of 65 degrees to 90 degrees with respect to the table surface, and is on the surface of the table. On the other hand, it is formed so as to inject a gas flow from an oblique direction. As will be described later, the gas injection device 34 may be omitted, and the cooling device 30 may have two functions of cooling and gas injection.

In this embodiment, two CO ₂ lasers are used. However, only one CO ₂ laser is used, a beam splitter is arranged on the beam transmission path, and beam transmission is divided into two paths. May be performed. In this case, the energy distribution rate by the beam splitter is such that energy of 50% or more is distributed to the first laser beam side that irradiates the front side, and energy that is less than 50% is applied to the second laser beam side that irradiates the rear side. Is preferably distributed so that the laser power of the first laser beam is larger than the laser power of the second laser beam.

As shown in FIG. 5 (a), the basic principle of the brittle material cleaving method according to the present embodiment is that the first beam irradiation region 13 and the second one from the front of the cleaving along the cleaving line 12 of the glass substrate 11. The beam irradiation region 14 and the cooling point 15 are arranged in order.
The first beam irradiation region 13 preheats the forefront part of the cleaving of the glass substrate 11 and heats the position by the subsequent second beam irradiation region 14 to a state immediately before the cleaving starts. FIG. 5B is a temperature profile on the surface of the glass substrate 11 at this time. That is, the temperature profile 141 by the second beam irradiation region 14 is superimposed on the temperature profile 131 by the first beam irradiation region 13, and the position irradiated with the second beam irradiation region 14 on the surface of the glass substrate 11 is a high temperature just before the start of cleaving. To be heated. The heat due to this heating is conducted in the thickness direction of the glass substrate 11.

The second beam irradiation region 14 is located behind the first beam irradiation region 13, and the cross-sectional shape thereof is shaped into an elongated shape in a direction along the planned cutting line 12 of the glass substrate 11. That is, in the second beam irradiation region 14, as shown in FIG. 5A, the length a in the direction along the planned cutting line 12 of the glass substrate 11 is longer than the length b in the width direction, which is the perpendicular direction. It is a circular beam. The ratio a / b of the length a in the length direction along the planned cutting line 12 to the length b in the width direction of the elongated non-circular beam is preferably about 26 to 30. As described above, such an elongated non-circular beam is obtained by spreading the laser beam 26 from the CO ₂ laser 25 to a predetermined magnification with the beam expander 27 and reflecting the laser beam 26 with a reflecting mirror 28 in a predetermined direction. It is generated by passing through a beam shaping means 29 such as a diffractive optical element or a planoconvex cylindrical lens and shaping it. The second beam irradiation region 14 is also a laser beam having such an intensity that only heating locally occurs on the glass substrate 11 and melting and cracks do not occur.

Next, the operation will be described with reference to FIGS. In FIG. 6, first, the initial crack 16 is formed by the initial crack forming device 31 at the end of the planned cutting line 12 of the glass substrate 11. This initial crack 16 is the starting position for cleaving the glass substrate 11. Next, the glass substrate 11 placed on the table 32 is moved in the Y direction by the Y drive servomotor 33 for Y axis drive, and an initial crack corresponding to the starting position of the planned cutting line 12 of the glass substrate 11 is obtained. Heating of the glass is started from 16 directions. As shown in FIG. 5A, the direction of the first beam irradiation region 13, the second beam irradiation region 14, and the cooling point 15 is arranged in a straight line. It can be moved to match. At this time, as shown in FIG. 5C, due to insufficient adjustment, the center position of the first beam irradiation region 13 and the center position of the second beam irradiation region 14 with respect to the planned cutting line 12 of the glass substrate 11 are minute values Δd. Since the surface quality of the divided glass cross section may be deteriorated if it is shifted by only a distance, the center position of the first beam irradiation region 13 and the center position of the second beam irradiation region 14 are not shifted from the planned cutting line 12. It is preferable that the position is accurately adjusted.

Next, from the state in which the position of the initial crack 16 formed in the glass substrate 11 and the direction of the first beam irradiation region 13, the second beam irradiation region 14, and the column of the cooling point 15 coincide, When the glass substrate 11 placed on the table 32 is moved in the + Y direction by the Y drive servomotor 33 while the laser beam is emitted, the coolant is ejected from the cooling device 30 and placed on the table 32. The first beam irradiation region 13, the second beam irradiation region 14, and the row of cooling points 15 due to the refrigerant move relatively along the planned cutting line 12 of the glass substrate 11, and the cutting action starts.

When the coolant is jetted from the cooling device 30 onto the glass substrate 11 preheated in the substantially circular first beam irradiation region 13 and heated in the elongated second beam irradiation region 14, as shown in FIG. A crack expanded directly from the initial crack 16 immediately below proceeds in the depth direction of the glass substrate 11, and the crack is the X direction of the row of the glass substrate 11, the first beam irradiation region 13, the second beam irradiation region 14, and the cooling point 15. In accordance with the relative movement, the glass substrate 11 further proceeds along the planned cutting line 12. As a result, a split section 17 is generated over the entire thickness of the glass substrate 11. At this time, the gas jetting device 34 is relative to the glass substrate 11 in conjunction with the substantially circular first beam irradiation region 13 by the first laser beam, the elongated irradiation region 14 by the second laser beam, and the cooling device 30. However, the air injection device 34 does not inject the gas flow until it moves to the terminal portion of the glass substrate 11.

In the embodiment of the present invention using the CO ₂ laser, the thermal energy supplied by the first laser beam irradiated forward in the traveling direction propagates to the back surface of the glass substrate 11, thereby cutting the full body. It is used as an energy source. In order to perform such full body cleaving, it is necessary that the thermal energy absorbed on the surface of the glass substrate 11 is thermally diffused evenly in the glass substrate 11 to some extent. Here, along the planned cutting line 12, the distance between the cooling point 15 and the first beam irradiation region 13 is L, the relative moving speed of the glass substrate 11 and the laser beam is V, and the first beam irradiation region 13 is. If the movement time taken to move to the position of the cooling point by the cooling device 30 is τ, the relationship L = V · τ holds.

By the way, in order for the temperature of the front and back of the glass substrate 11 to become substantially the same, a time of 200 to 300 msec is required. In other words, if the moving speed of the glass is 180 mm / s, the distance is moved by 36 mm for an elapsed time of 200 msec and 54 mm for an elapsed time of 300 msec. Therefore, the distance L between the cooling point and the irradiation region of the first laser beam needs to be at least 36 mm, desirably 54 mm or more.

Since the crack expanded from the initial crack 16 immediately below the cooling point 15 proceeds in the depth direction of the glass substrate 11, there is no imbalance in tensile stress acting in the creeping direction of the glass substrate 11, so It does not curve with respect to the splitting line 12. On the other hand, at the end portion on the planned fracture line 12 on the side opposite to the initial crack 16, the tensile stress sufficient for full-body breaking of the glass is lost. The cleaving stops when approaching the edge. At this time, as shown in FIG. 7, an uncut region 18 in which the fractured surface 17 is not generated remains at the end of the glass substrate 11. In this region 18, the split section 17 does not occur, but a crack groove 19 is formed on the surface.

Since the full body cannot be cleaved when the region 18 where the fractured surface 17 does not occur is left at the end of the glass substrate 11, the glass substrate 11 must be broken along the crack groove 19 on the surface in order to cleave it completely. However, in this embodiment, as shown in FIGS. 4 and 6, this uncut portion is broken using the gas injection device 34. In FIG. 6, the first beam irradiation region 13, the elongated irradiation region 14, the cooling device 30, and the gas injection device 34 are arranged in this order as arranged in the planned cutting line, but the cooling device 30 and the gas injection device 34 are arranged. The arrangement order of and may be changed. As described above, since the gas injection device 34 does not discharge the gas flow on the glass substrate 11, the cooling action of the cooling device 30 is not hindered, and the glass breaking is performed normally.

FIGS. 8 and 9 are conceptual perspective views for explaining the principle of completely cutting off the uncut portion of the glass substrate 11 using the gas injection device 34. Due to the relative movement of the substantially circular first beam irradiation region 13, the elongated irradiation region 14, and the cooling device 30 and the glass substrate 11, the full-body split section 17 proceeds, and the cooling device 30 causes the initial crack 16 of the glass substrate 11. If the end portion on the planned cutting line 12 on the opposite side is exceeded, the progress of the split section 17 is stopped as described above, and the uncut region 18 where the split section 17 is not generated remains. Therefore, as shown in FIGS. 8 and 9, a strong gas flow is instantaneously injected from the nozzle 341 of the gas injection device 34 toward the uncut region 18. As a specific process for injecting the gas flow, compressed air is supplied to the gas injection device 34 through a pipe connected to an air compressor (not shown), and a solenoid valve provided in the middle of the pipe is opened and closed. To inject compressed air. The gas to be injected may be nitrogen gas, carbon dioxide or the like, but dry air is particularly preferable.

The nozzle 341 of the gas injection device 34 is attached obliquely so as to have an angle inclined forward with respect to the front of the planned cutting line. That is, the nozzle 341 jets a gas flow from an oblique direction with respect to the surface of the table 32 so that the nozzle 341 preferably has an angle θ ₁ of less than 90 degrees in the range of 65 to 90 degrees. It is formed to be inclined. When a gas flow of, for example, about 6 atmospheres is ejected from the nozzle 341 for 0.5 seconds, a part of the gas flow 36 enters the back side of the glass substrate 11 and the end including the uncut region 18 of the glass substrate 11 is indicated by an arrow B. Since it is lifted upward in the direction, the uncut region 18 is divided by extending the split section 17 by the power of the gas flow 36, and the glass substrate 11 is completely broken up to the end. That is, by injecting a gas flow, an air current enters between the end portion of the glass substrate 11 along the planned cutting line and the table 32, a gap is generated, and buoyancy is generated at the end portion of the glass substrate 11, Since the glass substrate 11 is warped, it can be divided without contact. The gas flow injected from the nozzle 341 preferably has a pressure of about 5 to 10 atmospheres and an injection time of 0.5 seconds or less.

In the above description, the glass substrate 11 moves. That is, the case where the table 32 is moved in the direction of the planned cutting line 12 of the glass substrate 11 by the XY driving device has been described. However, without fixing the table 32 and moving the glass substrate 11, a set of the first beam irradiation region 13, the second beam irradiation region 14, and the cooling point 15 is moved in the direction of the planned cutting line 12 of the glass substrate 11. May be. In short, the glass substrate 11 placed on the table 32 and the set of the first beam irradiation region 13, the second beam irradiation region 14, and the cooling point 15 are relatively moved in the direction of the planned cutting line 12 of the glass substrate 11. Just do it.

In the first embodiment, the embodiment in which the glass substrate 11 is completely broken up to the end by blowing the gas flow from the gas injection device 34 to the uncut region 18 of the glass substrate 11 has been described. In this embodiment, when the gas flow from the gas injection device 34 is stopped immediately after full body cleaving, the end including the uncut region 18 of the glass substrate 11 lifted by the gas flow 36 falls on the table 32. Further, returning to the original position, the fractured surface 17 and the fractured surface of the cleaved uncut region 18 may be damaged. The second embodiment is an embodiment that solves this problem.

In the present embodiment, the description of the part where the cleaving process is the same as that in the first embodiment will be omitted. That is, the first circular beam irradiation region 13, the long and narrow irradiation region 14, and the relative movement of the cooling device 30 and the glass substrate 11 cause the full-body split section 17 to advance in the glass substrate 11. The progress of the split section 17 stops when the end portion on the planned split line 12 on the side opposite to the initial crack 16 of the substrate 11 is stopped, and the uncut region 18 where the split section 17 described with reference to FIG. The process until the remaining state is processed is the same as that in the first embodiment.

As shown in FIG. 10, the pair of suction cups 37 and 38 provided on both sides of the gas injection device 34 are separated by about several millimeters, preferably about 2 to 3 mm, so as not to contact the surface of the glass substrate 11. Is installed. After the uncut region 18 is formed, the pair of suction cups 37 and 38 on both sides of the planned cutting line are positioned at the position of the terminal portion of the glass substrate 11, and the table (not shown) stops moving at that position. To do. With the table stopped, the suction cups 37 and 38 are once lowered and come into contact with the glass substrate 11. In the contacted state, the air inside the suction cups 37 and 38 is pushed out and a portion having a low atmospheric pressure is formed, so that the suction cups 37 and 38 are adsorbed to the glass substrate 11. Thereafter, when the suction cups 37 and 38 are raised to the base height by several millimeters, the terminal portion including the uncut region 18 of the glass substrate 11 is lifted upward.

A strong gas flow is instantaneously injected from the gas injection device 34 toward the uncut region 18 while being slightly lifted from a table (not shown). As a result, as in the first embodiment, the uncut region 18 is divided by extending the split section 17 by the wind pressure of the gas flow 36, and the glass substrate 11 is completely broken up to the end. At this time, even if the gas flow from the gas injection device 34 is stopped immediately after the full body breakage and the injection of the gas flow for the break is stopped, the end of the glass substrate 11 is moved upward by the suction cups 37 and 38. Since it is lifted, it does not fall on the table, and it is possible to prevent damage to the cut section 17 and the cut section of the cleaved uncut region 18. Thereafter, the glass substrate 11 lifted upward by the suction cups 37, 38 is gradually lowered together with the suction cups 37, 38, and if the suction cups 37, 38 are removed when the glass substrate 11 returns to the table, the full body is cleaved on the table. The glass substrate 11 remains, and the full body cleaving of the glass substrate 11 is completed.

This embodiment is another embodiment for preventing the fractured surface 17 and the fractured surface of the cleaved uncut region 18 from being damaged. Also in the present embodiment, the description of the parts where the cleaving process is the same as that in the first embodiment will be omitted. That is, the first circular beam irradiation region 13, the long and narrow irradiation region 14, and the relative movement of the cooling device 30 and the glass substrate 11 cause the full-body split section 17 to advance in the glass substrate 11. The progress of the split section 17 stops when the end portion on the planned split line 12 on the side opposite to the initial crack 16 of the substrate 11 is stopped, and the uncut region 18 where the split section 17 described with reference to FIG. Since it is the same as Example 1 and Example 2 until it processes to the remaining state, description is abbreviate | omitted.

  In FIG. 11, the difference from the second embodiment is that electrostatic suction pads 41 and 42 are used instead of the suction cups 37 and 38 in the second embodiment. The electrostatic suction pads 41 and 42 are suction systems using Coulomb force. As in the second embodiment, the electrostatic suction pads 41 and 42 are provided on both sides of the uncut region 18 of the glass substrate 11 and a power source (illustrated). When a voltage is applied to the electrodes of the electrostatic suction pads 41 and 42, a reverse voltage is induced on the surface of the glass substrate 11, and a Coulomb force is generated by the potential difference between the electrode and the glass substrate 11 to be sucked and supported. is there. The electrostatic suction by the electrostatic suction pads 41 and 42 does not give local stress to the glass substrate 11 and can perform clean suction without generating dust. As the electrostatic adsorption pads 41 and 42, for example, soft palm manufactured by Tsukuba Seiko Co., Ltd. can be used. The electrostatic suction pads 41 and 42 are also installed at positions separated by several millimeters from the upper surface of the glass substrate 11. Since the operation after the glass substrate 11 is attracted and lifted by the electrostatic suction pads 41 and 42 is the same as that of the second embodiment, the description thereof is omitted.

According to the present embodiment, compared to the second embodiment, the glass substrate 11 is not subjected to local stress, and clean suction without generating dust is possible. Quality can be further improved.

This embodiment is another embodiment for preventing the fractured surface 17 and the fractured surface of the cleaved uncut region 18 from being damaged. Also in this embodiment, a part of explanation of common parts is omitted. That is, the first circular beam irradiation region 13, the long and narrow irradiation region 14, and the relative movement of the cooling device 30 and the glass substrate 11 cause the full-body split section 17 to advance in the glass substrate 11. The progress of the split section 17 stops when the end portion on the planned split line 12 on the side opposite to the initial crack 16 of the substrate 11 is stopped, and the uncut region 18 where the split section 17 described with reference to FIG. Since it is the same as Example 1-Example 3 until it processes to the remaining state, description is abbreviate | omitted.

As shown in FIG. 12, in the fourth embodiment, without using the suction cups 37 and 38 of the second embodiment and the electrostatic suction pads 41 and 42 of the third embodiment, the table (not shown) is penetrated from below. The end including the uncut region 18 of the glass substrate 11 is lifted upward by a pin 44 that can freely enter and exit, and a strong gas flow is instantaneously applied from the gas injection device 34 toward the uncut region 18 in a state where it is floated from the table. Spray. In a state where the full-body split section 17 is advanced to the glass substrate 11 by the relative movement between the substantially circular first beam irradiation region 13, the elongated irradiation region 14 and the cooling device 30 and the glass substrate 11, the pin 44 is It is below the back surface of the glass substrate 11 and is not in contact with the glass substrate 11. When the cooling device 30 passes over the end portion on the cutting line 12 opposite to the initial crack 16 of the glass substrate 11, when the pin 44 is pushed upward as indicated by an arrow C, the pin 44 penetrates the table and passes through the glass. The end including the uncut region 18 of the substrate 11 is lifted upward to be lifted from the table, and in this state, a strong gas flow is instantaneously injected from the gas injection device 34 toward the uncut region 18. As a result, as in the first to third embodiments, the uncut region 18 is divided by the split section 17 being extended by the power of the gas flow 36, and the glass substrate 11 is completely broken up to the end. The Thereafter, the pins 44 are gradually lowered, the glass substrate 11 returns to the table, and the full body cleaving of the glass substrate 11 is completed.

In Example 1 to Example 4, the glass substrate 11 was completely broken up to the end by blowing a gas flow from the gas injection device 34 to the uncut region 18 of the glass substrate 11, but this example These are the Example which uses the gas flow injected from the cooling device 30 without using the gas injection apparatus 34. FIG. The fifth embodiment is another embodiment that can prevent the fractured surface 17 and the fractured surface of the cleaved uncut region 18 from being damaged.

In the present embodiment, as shown in FIG. 13, the gas flow in the cooling device 30 is used without using the gas injection device 34 used in the first to fourth embodiments. That is, the injection nozzle 301 of the cooling device 30 has an angle θ2 of less than 90 degrees within a range of 65 degrees to 90 degrees with respect to the surface of the table 32 so as to be inclined forward with respect to the front direction of the cutting line. It is tilted so as to have a fixed angle θ2. While moving on the glass substrate 11, the cooling device 30 plays a role of cooling the surface of the glass by ejecting a refrigerant in which a liquid and a gas are mixed, and a position beyond the terminal portion of the glass substrate 11. In this case, it plays a role of blowing gas into the gap between the glass substrate 11 and the table 32. That is, the cooling device 30 also serves as the gas injection device 34.

As an explanation of the operation, when the cooling device 30 is at a position deviated from the end portion of the glass substrate 11, the injection of water from the cooling device 30 is stopped and only the gas flow 45 is injected. By stopping the injection of the liquid and injecting only the gas flow 45, the amount of the liquid mixed into the back surface of the glass is reduced, and the effect of preventing the back surface of the glass substrate 11 and the table 32 from becoming familiar and closely contacting each other is achieved. is there. In order to stop the water injection, the water pipe connected to the cooling device 30 is shut off by the electromagnetic valve. At the same time, the pressure of the gas for injecting the gas flow 45 is increased (for example, from 5 atm to 8 atm). ). As the pressure rises, the protrusion pressure of the gas flow 45 increases to increase buoyancy, that is, a part of the gas flow 45 enters the back side of the glass substrate 11 and includes the uncut region 18 of the glass substrate 11. The buoyancy that lifts the part upward in the direction of arrow B can be increased. The uncut region 18 is divided by the split section 17 being extended by the power of the gas flow 45, and the glass substrate 11 is completely cut into the full body until reaching the end. The height d at which the end including the uncut region 18 of the glass substrate 11 is lifted may be smaller than the thickness of the glass substrate 11. Also in the present embodiment, the gas flow preferably has a pressure of about 5 to 10 atmospheres and an injection time of 0.5 seconds or less.

In the fifth embodiment, the cooling device 30 including the injection nozzle 301 is installed at a fixed angle, but the installation angle may be variably controlled. For this purpose, an angle control device for inclining the cooling device 30 and a gas flow control device for stopping and injecting water from the injection nozzle 301 are required. For example, a control system for tilting the cooling device 30 may be provided with a control system for rotating the cooling device 30 about an axis parallel to the surface of the table 32. Control of the water flow and gas flow injected from the injection nozzle 301 is performed by electrically controlling a drive system such as a pump for injecting the water flow and gas flow and a control valve for controlling the injection amount of the water flow and gas flow. That's fine.

In the fifth embodiment, any one of the suction cups 37 and 38 described in the second embodiment, the electrostatic suction pads 41 and 42 described in the third embodiment, and the pin 44 described in the fourth embodiment can be used in combination. .

The brittle material cleaving method and brittle material dividing apparatus according to the present invention are suitable for cleaving glass used in flat panel displays such as liquid crystal displays and plasma displays, and full-body cleaving of various brittle materials such as quartz, ceramics, and semiconductors. It is.

Characteristic diagram showing changes in radial stress component σ _x and tangential stress component σ _y when there is a temperature rise in the Gaussian distribution centered at the origin for explaining the principle of thermal stress generation in the laser cleaving method It is a conceptual perspective view explaining the conventional laser cleaving method of glass, (a) is a surface scribe, (b) is a schematic diagram in the case of full cut The conceptual perspective view explaining the size effect in the laser cleaving method of the conventional glass, (a) when the cleaving width on both sides of the glass plate is large, (b) is a diagram when the cleaving width on one side of the glass plate is small The conceptual diagram which shows the structure of the cleaving apparatus of a brittle material by this invention BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a conceptual diagram showing the positional relationship and temperature characteristics of a laser beam for explaining the principle of a brittle material cleaving method according to the present invention, where (a) shows the irradiation position of a first laser beam and the irradiation position of a second laser beam. FIG. 2B is a conceptual plan view showing the positional relationship between the cooling positions and the cooling position. FIG. 1B shows a temperature profile when heating by the first laser beam and the second laser beam in FIG. The figure shown, (c) is a conceptual plan view for explaining the phenomenon due to the positional deviation of the first laser beam and the second laser beam in FIG. 5 (a) The conceptual perspective view of the principal part for demonstrating the principle of the cutting method of a brittle material by this invention The perspective view explaining the broken cross section of the glass substrate cut | disconnected by the cleaving method of the brittle material by this invention The conceptual perspective view explaining the principle of the cleaving method of a brittle material in Example 1 of this invention Conceptual side view for explaining the principle of a brittle material cleaving method in Embodiment 1 of the present invention The conceptual perspective view explaining the principle of the cleaving method of the brittle material in Example 2 of this invention The conceptual perspective view explaining the principle of the cleaving method of the brittle material in Example 3 of this invention The conceptual perspective view explaining the principle of the cleaving method of the brittle material in Example 4 of this invention Conceptual side view for explaining the principle of a brittle material cleaving method in Embodiment 5 of the present invention

11 Glass substrate 12 Planned cutting line 13 First beam irradiation region 14 Second beam irradiation region 15 Cooling point 16 Initial crack 17 Split section 18 Uncut region 19 Crack groove 32 Table 33 Servo motors 21 and 25 CO ₂ laser oscillators 22 and 26 Laser beam 23, 28 Reflector 24 Condensing lens 35 Beam shield 27 Beam expander 29 Beam shaping means 30 Cooling device 31 Initial crack forming device 33 XY drive device 34 Gas injection device 37, 38 Suction cup 41, 42 Electrostatic Suction pad 44 Pin 131 Temperature profile 141 by first beam irradiation region Temperature profile 341 by second beam irradiation region Nozzle

Claims (22)

With respect to the planned fracture line assumed for the brittle material, heating and cooling are performed along the planned fracture line from the side of the initial crack formed at the end position of the planned fracture line, and the heating and cooling positions are A brittle material cleaving device that cleaves by moving relative to a brittle material,
Laser beam irradiation means for irradiating a laser beam for generating a heated portion formed in the brittle material along the planned cutting line;
A cooling means for cooling a position behind the heating portion along the planned cutting line;
A gas injection device for injecting a gas flow toward a terminal portion of the brittle material on the planned cutting line,
An apparatus for cleaving a brittle material, wherein the gas stream is jetted to displace the end portion of the brittle material by wind pressure to divide the end portion of the brittle material. The laser beam irradiation means includes a first beam irradiation unit that forms a first laser beam irradiation region positioned in front of the planned cutting line in the heating portion, and the cleaving behind the first laser beam irradiation region. The brittle material cleaving apparatus according to claim 1, further comprising: a second beam irradiation unit that forms a second laser beam irradiation region whose shape along the predetermined line is longer than a perpendicular direction. 2. The brittle material cleaving apparatus according to claim 1, wherein the gas jetting device relatively moves along a planned fracture line assumed for the brittle material in conjunction with the laser beam irradiation means and the cooling means. The gas injection nozzle of the gas injection device is set to have an angle of less than 90 degrees in the range of 65 degrees to 90 degrees with respect to the table surface, and the gas flow is injected obliquely from above the table surface. The brittle material cleaving device according to any one of claims 1 to 3, wherein: The brittle material cleaving device according to any one of claims 1 to 4, wherein a gas jetting system of cooling means is used as the gas jetting device. The cooling means includes means for inclining the spray nozzle of the cooling means so as to have an angle of less than 90 degrees within a range of 65 degrees to 90 degrees with respect to the surface of the table, and stops water spray from the spray nozzle. The brittle material cleaving apparatus according to claim 5, further comprising means for injecting only a gas flow. The brittle material cleaving apparatus according to any one of claims 1 to 6, further comprising means for lifting upward a terminal portion of the planned cutting line in the glass substrate placed on the table. The brittle material cleaving device according to claim 7, wherein the upward lifting means is a suction cup. The brittle material cleaving apparatus according to claim 7, wherein the upward lifting means is an electrostatic adsorption member. 8. The brittle material cleaving apparatus according to claim 7, wherein the upward lifting means is a pin that passes through the table on which the brittle material is placed and can freely enter and exit from below. With respect to the planned fracture line assumed for the brittle material, heating and cooling are performed along the planned fracture line from the side of the initial crack formed at the end position of the planned fracture line, and the heating and cooling positions are A method of cleaving a brittle material that is moved relative to a brittle material to cleave the brittle material, wherein the brittle material is heated with a first laser beam and a second laser beam, and the first laser beam is The second laser beam is a beam positioned forward in the direction along the planned cutting line, and the second laser beam is a beam whose shape along the planned cutting line is longer than the perpendicular direction. , Locally cooling a position away from the rear end of the second laser beam by a predetermined position, and after the cooling point passes through the end of the planned cutting line, to the end of the planned cutting line of the brittle material Jet of gas Cleaving method of the brittle material, characterized by. The method for cleaving a brittle material according to claim 11, wherein the pressure of the gas flow is 5 to 10 atmospheres and the injection time is 0.5 seconds or less. The gas flow is jetted from an oblique direction with respect to the surface of the table at an angle of less than 90 degrees in a range of 65 to 90 degrees with respect to the surface of the table. A method for cleaving brittle materials. 14. The gas flow used for locally cooling a position separated from the rear end of the second laser beam by a predetermined position as the gas flow is used by increasing the pressure. A method for cleaving brittle materials according to any one of the above. The method for cleaving a brittle material according to any one of claims 11 to 14, wherein a gas flow is jetted by lifting up a terminal portion of a planned cleaving line in a glass substrate placed on a table. The method for cleaving a brittle material according to claim 15, wherein the end portion of the cleaving line on the glass substrate is lifted upward by a suction cup. The method for cleaving a brittle material according to claim 15, wherein an end portion of a cleaving line on the glass substrate is lifted upward by an electrostatic adsorption pad. 16. The method for cleaving brittle material according to claim 15, wherein a terminal portion of the cleaving line on the glass substrate is lifted upward by a pin that passes through the table and freely enters and exits from below. 12. The laser power applied to the first laser irradiation region formed by the first laser beam is larger than the laser power applied to the second laser irradiation region formed by the second laser beam. The brittle material cleaving method described. The laser power density of the first laser irradiation region formed by the first laser beam is lower than the laser power density of the second laser irradiation region formed by the second laser beam. The brittle material cleaving method described. The distance between the beam irradiation position formed by the first laser beam and the cooling position formed by locally cooling the position away from the rear end of the second laser beam depends on the breaking speed and thickness of the brittle material. The brittle material cleaving method according to claim 11, wherein the setting is based on at least one of the thicknesses. The method for cleaving a brittle material according to claim 11, wherein the shape at the irradiation position of the first laser beam is substantially circular.