JP5907019B2 - Thin glass cutting method and thin glass - Google Patents

Description

  The present invention relates to improvement of a cutting technique for fusing a thin glass plate having a thickness of 500 μm or less.

  Conventionally, as a method of cutting a glass plate, a method of forming a scribe line on the surface of the glass plate with a diamond cutter and then cleaving the scribe line by applying a bending stress (cleaving by a bending stress) is widely used. ing.

  However, in the case of the cutting method using the above bending stress, a crack is likely to be formed on the cut surface, and there is a concern that the glass plate may be damaged starting from the crack. Therefore, instead of the above-described cutting method using bending stress, so-called fusing may be employed in which a laser beam is irradiated onto a cutting portion of a glass plate and the cutting portion is melted and cut by the irradiation heat.

  As a method for cutting a glass plate by this type of fusing, for example, Patent Document 1 discloses a carbon dioxide laser beam obtained by condensing a carbon dioxide laser beam focused on a minute point after preheating with a defocused carbon dioxide laser beam. It is disclosed that fusing is performed by irradiating a portion to be cut.

JP-A-60-251138

  By the way, in patent document 1, although it is made into the subject to mainly cut | disconnect thick glass of 1 mm or more in a predetermined shape, such thick glass is excellent in mechanical strength.

  On the other hand, in the case of a thin glass used for display applications in recent years, particularly a thin glass having a thickness of 500 μm or less, the mechanical strength is much weaker than that of the above thick glass. Therefore, when cutting such a thin glass plate by fusing, the following specific problems may occur.

  That is, first, there is a problem that the thin glass is easily damaged when the melted end faces come into contact with each other when the thin glass is separated after the melting. Therefore, it is necessary to melt and remove the cut portion of the thin glass by fusing, and to secure a certain gap between the fusing end faces of the thin glass facing each other after fusing.

  Second, when the amount of heat applied to the thin glass increases, as shown in FIG. 13, the cut portion C in a molten state hangs down, and a shape defect occurs in the vicinity of the fused end surface of the thin glass G. There is. When such a shape defect occurs, the product cannot be used as a product and must be handled as a defective product. Such a defective shape in the vicinity of the cut end surface of the thin glass becomes more prominent as the amount of melt removal of the thin glass is increased to increase the gap between the cut end surfaces. Therefore, the gap between the melted end faces of the thin glass cannot be excessively increased. Furthermore, since the amount of heat increases, the glass temperature in the vicinity of the fused end surface also rises, and there is a possibility that the thin glass is deformed or broken due to strain.

  Therefore, when the thin glass is cut by fusing, it is necessary to strictly manage the gap between the fusing end faces formed by fusing, but measures have been taken from this point of view, including Patent Document 1. The fact is not.

  In view of the above circumstances, the present invention manages the gap between the melted end faces of the thin glass when the thin glass is melted by the irradiation heat of the laser beam, and maintains a good shape near the melted end face. And

  The invention devised to solve the above problems is a thin glass cutting method for irradiating a cutting portion of a thin glass having a thickness of 500 μm or less with a laser beam and fusing the thin glass, and the thickness of the thin glass A, and when the minimum gap between the melted end faces of the thin glass facing each other at the cutting part is b, the minimum gap is managed so as to satisfy the relationship of 0.1 ≦ b / a ≦ 2. Characterized.

  According to such a method, since the gap between the fused end faces of the thin glass is strictly managed in a relative relationship with the thickness of the thin glass, the shape in the vicinity of the fused end face of the thin glass is favorably maintained. Meanwhile, the blown thin glass can be safely separated. Furthermore, it becomes possible to avoid the deformation | transformation and damage of the sheet glass by distortion. On the other hand, if b / a exceeds 2, the amount of thin glass that is melted and removed by fusing increases too much, and the amount of heat applied to the vicinity of the fusing end surface becomes excessively large. As a result, there is a possibility that a shape defect such as sagging may occur in the vicinity of the fused end surface of the thin glass, or deformation or breakage of the thin glass due to strain may occur. Moreover, when b / a is less than 0.1, the melted end surfaces are too close to each other, and the melted end surfaces are in contact with each other at the time of separation, and the thin glass plate may be damaged.

  In the above method, it is preferable to irradiate the cutting portion with the laser beam in a defocused state.

  That is, since the thin glass is a target to be melted, the cut portion can be sufficiently melted even with a defocused laser beam. When the laser beam thus defocused is irradiated onto the cutting part, the energy density of the laser beam is reduced at a position corresponding to the cutting part, and thus the amount of change in energy around the irradiation position is also reduced. Therefore, even if the irradiation position varies somewhat due to warpage or vibration of the glass plate, there is an advantage that the irradiation heat applied to the cutting portion hardly changes and the fusing can be executed under substantially the same conditions.

  In the above method, it is preferable that a spot diameter of the laser beam is smaller than a minimum gap between the melted end faces of the thin glass.

  In this way, the laser beam is irradiated in a narrower range than the range that is actually melted and removed. Therefore, it can be expected that annealing treatment is performed on the cut end surface of the thin glass sheet by heat conduction from the laser beam irradiation part. Therefore, when there is an annealing effect in this way, it is possible to simultaneously perform the fusing of the thin glass and the annealing of the cut end surface by one laser beam irradiation, and it is necessary to separately carry out the annealing treatment in a subsequent process or the like. Disappear.

  In the above method, it is preferable that the fusing end surface has a convex curved surface.

  If it does in this way, the effect more than equivalent to the case where chamfering is performed will be acquired and the end surface intensity | strength will raise the fusing end surface of thin glass. For this reason, there is an advantage that chipping is unlikely to occur on the end face when flowing to the process after the cutting process, and handling is facilitated and the yield is improved.

  In the above method, the fusing end surface is preferably a fire-making surface.

  If it does in this way, since the surface of the fusing end surface of thin glass will continue smoothly, dust generation from a fusing end surface can be prevented. In addition, when the surface of the fusing end surface becomes smooth in this way, it becomes difficult for particles to enter, and thus contamination in the process can be prevented.

  In the above method, it is preferable that the arithmetic average roughness Ra of the fusing end face is 0.3 μm or less, and the average length RSm of the roughness curve element is 150 μm or more. Here, the arithmetic average roughness Ra and the average length RSm of the roughness curve element are based on JIS 2001.

  If it does in this way, since the surface of the fusing end surface of thin glass will continue smoothly, dust generation from a fusing end surface can be prevented. In addition, when the surface of the fusing end surface becomes smooth in this way, it becomes difficult for particles to enter, and thus contamination in the process can be prevented. On the other hand, when Ra exceeds 0.3 μm or RSm is less than 150 μm, the melted end surface of the thin glass becomes a rough surface (a rough state), and particles enter the melted end surface and are difficult to remove.

  In said method, it is preferable that the residual compressive stress of the said fusing end surface is 20 MPa-500 MPa.

  In this way, since compressive stress acts on the fused end surface of the thin glass, even if a defect such as a crack is formed on the fused end surface, a force acts in the direction of closing the defect. As a result, the end face strength of the thin glass can be improved. Furthermore, even if a crack occurs in the end face of the thin glass plate, since the tension layer is in the vicinity of the crack, the crack progresses along the end face and does not progress to the plane side. Therefore, the shape as a glass substrate can be maintained and the performance as a glass substrate is not impaired. On the other hand, when the compressive stress is smaller than 20 MPa, when the thin glass is broken, the direction in which the cracks run becomes arbitrary, and the performance as a glass substrate may be impaired. When the compressive stress is greater than 500 MPa, the thin glass may self-destruct due to the influence of the tension layer near the crack.

  The present invention devised to solve the above problems is a thin glass having a thickness of 500 μm or less and having a fused end surface melted by a laser beam, and the arithmetic average roughness Ra of the fused end surface is 0. .3 μm or less, and the average length RSm of the roughness curve element is 150 μm or more.

  In this case, it is preferable that the residual compressive stress of the fusing end face is 20 MPa to 500 MPa.

  According to the present invention as described above, the gap between the fusing end surfaces of the thin glass is strictly managed in a relative relationship with the thickness of the thin glass. As a result, the shape can be favorably maintained in the vicinity of the cut end surface of the thin glass. Moreover, the melted thin glass can be safely separated without bringing the melted end faces into contact with each other.

It is a vertical side surface which shows the glass plate cutting device which concerns on 1st Embodiment of this invention. It is a top view which shows the glass plate cutting device which concerns on 1st Embodiment. It is XX sectional drawing of FIG. It is a figure which shows typically the state of the glass substrate immediately after fuse | melting with the glass plate cutting device which concerns on 1st Embodiment. It is a longitudinal cross-sectional view which shows the glass plate cutting device which concerns on 2nd Embodiment of this invention. It is a longitudinal cross-sectional view which shows the glass plate cutting device which concerns on 3rd Embodiment of this invention. It is a longitudinal cross-sectional view which shows the glass plate cutting device which concerns on 4th Embodiment of this invention. It is a longitudinal cross-sectional view which shows the glass plate cutting device which concerns on 5th Embodiment of this invention. It is a perspective view which shows the 2nd suction nozzle of the glass plate cutting device which concerns on 5th Embodiment. It is a longitudinal cross-sectional view which shows the glass plate cutting device which concerns on 6th Embodiment of this invention. It is a figure which shows another example of the glass plate used as the cutting object of this invention. It is a figure which shows the state which is evaluating the intensity | strength of thin glass. It is a figure for demonstrating the problem which arises when thin glass is cut | disconnected by fusing.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the thin glass is a glass substrate for a flat panel display having a thickness of 500 μm or less. Of course, the thin glass to be cut is not limited to a glass substrate for a flat panel display. For example, the present invention can be applied to a thin glass substrate used in various fields such as a solar cell, an organic EL lighting, a touch panel, and a digital signage, and a laminate with the organic resin. In addition, it is preferable that the thickness of thin glass is 300 micrometers or less, especially 200 micrometers or less.

(First embodiment)
As shown in FIG. 1, a glass sheet cutting apparatus 1 according to the first embodiment of the present invention includes a support stage 2 that supports a glass substrate G in a flat position from below, and a glass substrate that is supported by the support stage 2. And a laser beam irradiator 3 for fusing and separating G.

  The support stage 2 includes a stage main body 21 and a conveyor 22 that moves along the upper surface of the stage main body 21. The glass substrate G is transported downstream in the transport direction (in the direction of arrow A in the figure) along the planned cutting line CL by the movement of the conveyor 22. At this time, the stage main body 21 serves to guide the conveyor 22. The conveyor 22 is formed with a large number of ventilation holes (not shown), and the glass substrate G is conveyed and held on the conveyor 22 through the ventilation holes. Of course, other transport methods may be employed such as transporting the glass substrate G while holding the glass substrate G from both the front and back sides without adsorbing the glass substrate G.

  As shown in FIG. 2, the stage main body 21 and the conveyor 22 are separated into two at intervals in the width direction of the glass substrate G, and the unsupported space S is positioned below the planned cutting line CL of the glass substrate G. have. In this non-supporting space S, the lower surface of the glass substrate G and the support stage 2 are not in contact, and the lower surface of the glass substrate G is exposed to the non-supporting space S.

  As shown in FIG. 3, the laser beam irradiator 3 has an internal space for propagating the laser beam LB, and includes a lens 31 in this space. In this embodiment, the laser beam LB focused by the lens 31 is focused on a fine focus and is in a state where the focal position FP is aligned with the upper surface of the glass substrate G. The portion C) is irradiated to C. Then, the glass substrate G is melted along the planned cutting line CL by the irradiation heat of the laser beam LB, and separated into a product part Ga that is a product and a non-product part Gb that is discarded and is not a product. The focal position FP of the laser beam LB may be an intermediate position in the thickness direction of the glass substrate G. Further, the focal position FP of the laser beam LB may be set above the glass substrate G, and the cutting part C may be irradiated with the laser beam LB defocused.

  Furthermore, the glass plate cutting device 1 includes a side assist gas injection nozzle 4 that injects the side assist gas A1 obliquely downward from the upper position on the side that becomes the product part Ga toward the cutting part C. The side assist gas A1 plays a role of blowing molten foreign matters such as dross to the non-product part Gb side.

  Operation | movement of the glass plate cutting device 1 comprised as mentioned above is demonstrated.

  As shown in FIGS. 1 and 2, the glass substrate G is transported by the conveyor 22 of the support stage 2, and the laser beam LB irradiated from the laser beam irradiator 3 placed in a stationary state on the transport path is used as the glass substrate G. Scan along the planned cutting line CL.

  Then, while irradiating the laser beam LB in this manner, as shown in FIG. 3, the glass substrate G is scheduled to be cut from the side assist gas injection nozzle 4 disposed at the upper position on the side that becomes the product portion Ga of the glass substrate G. The side assist gas A1 is injected obliquely downward toward the cutting portion C located on the line CL. Thereby, a molten foreign material is removed from the cutting part C, and fusing is performed efficiently. Moreover, since the molten foreign material is blown off to the non-product part Gb side, the situation where a molten foreign material adheres to the product part Ga can be prevented. Here, “molten foreign matter” means foreign matters such as dross generated when the glass substrate G is melted, and includes both those in a molten state and those in a solidified state.

  In addition, the side assist gas injection nozzle 4 is the only means for injecting gas to the glass substrate G in the space above the glass substrate G. And since this side assist gas injection nozzle 4 injects side assist gas A1 diagonally with respect to the cutting part C of the glass substrate G, it injects substantially perpendicularly with respect to the cutting part C of the glass substrate G from right above. Compared to the case (for example, when the center assist gas is injected), the force that presses down the vicinity of the cutting portion C in the molten state is less likely to act. Therefore, it is possible to prevent the glass substrate G in a molten state from drooping downward in the vicinity of the cut portion C. And in the state which prevented the dripping of the cutting part C in this way, since the molten foreign material which arises in the cutting part C by side assist gas A1 is scattered preferentially to the side used as the non-product part Gb, the fusing end surface of the product part Ga It is difficult for molten foreign matter to accumulate in Ga1.

  Furthermore, if the glass substrate G is melted as described above, a part of the cut portion C of the glass substrate G is melted and removed, and between the melted end surface Ga1 of the product part Ga and the melted end surface Gb1 of the non-product part Gb. A gap is formed. Therefore, since the melted end face Ga1 of the product part Ga and the melted end face Gb1 of the non-product part Gb are separated by the gap, the situation where the melted end faces Ga1 and Gb1 are in contact with each other and damaged is prevented. The product part Ga and the non-product part Gb can be separated smoothly.

  In detail, as shown in FIG. 4, when the thickness of the glass substrate G is a, and the minimum gap between the melted end surface Ga1 of the product part Ga and the melted end face Gb1 of the non-product part Gb after the melting is b In addition, the minimum gap b satisfying the relationship of 0.1 ≦ b / a ≦ 2 is controlled by fusing. In this way, the gap between the melted end face Ga1 of the product part Ga and the melted end face Gb1 of the non-product part Gb is strictly managed in a relative relationship with the thickness of the glass substrate G. The product part Ga and the non-product part Gb can be safely separated while maintaining the shape in the vicinity of the fusing end face Ga1. That is, when b / a exceeds 2, the amount of the thin glass G that is melted and removed by fusing increases too much, and there is a risk that a defective shape occurs in the fusing end surface Gb1 of the product part Ga. Furthermore, there is a risk of deformation or breakage of the thin glass due to strain. On the other hand, if b / a is less than 0.1, the fusing end faces Ga1 and Gb1 are too close to each other, and the fusing end faces Ga1 and Gb1 come into contact with each other at the time of separation and the product part Ga (or the non-product part Gb) may be damaged. There is.

  Here, as a method of adjusting the size of the minimum gap b, (1) changing the output power of the laser beam LB, (2) changing the size of the spot diameter with respect to the glass substrate G, (3) the glass substrate (4) Injection pressure of gas supplied to the glass substrate G, such as the side assist gas A1, to change the inclination angle α1 (see FIG. 3) of the virtual center line L1 of the side assist gas A1 with respect to the surface (upper surface) of G And (5) changing the fusing conditions such as changing the pulse width and pattern of the laser beam.

  Various conditions of the laser beam LB and the side assist gas A1 are as follows. Of course, the conditions of the laser beam LB and the side assist gas A1 are not limited to these.

  The spot diameter of the laser beam LB is set smaller than the minimum gap b in FIG.

The irradiation energy of the laser beam LB is set to 100 to 100,000 [W / mm ² ] on the upper surface of the glass substrate G.

  The injection pressure of the side assist gas A1 is set to 0.01 to 0.5 [MPa].

  The inclination angle α1 of the side assist gas A1 is set to 25 ° to 60 °, preferably 30 ° to 50 °, more preferably 35 ° to 45 °. That is, when the inclination angle of the side assist gas A1 with respect to the surface of the glass substrate G is less than 25 °, the side assist gas A1 is excessively shallowly incident on the glass substrate G, and the side assist gas A1 is efficiently supplied to the cutting part C. There is a risk that it may not be possible. On the other hand, when the inclination angle of the side assist gas A1 with respect to the surface of the glass substrate G exceeds 60 °, the side assist gas A1 is excessively incident on the glass substrate G, and the force for pressing the vicinity of the cutting portion C downward increases. There is a fear. Therefore, the inclination angle α1 of the side assist gas A1 is preferably within the above numerical range, and within this range, the side assist gas A1 is efficiently supplied to the cutting part C, and the side assist gas A1 is supplied to the cutting part C. The force which presses the vicinity downward can be suppressed appropriately.

  Note that, from the viewpoint of preventing adhesion of molten foreign matter to the product part Ga, the inclination angle α1 of the side assist gas A1 is preferably set to 15 ° to 45 °. Therefore, when considering the shape of the fused end face Ga1 of the product part Ga and the adhesion of the molten foreign matter to the product part Ga, the inclination angle α1 of the side assist gas A1 may be set to 25 ° to 45 °. preferable.

  The directing direction of the side assist gas A1 may be in the vicinity of the cutting part C. For example, in the illustrated example, the virtual center line L1 of the side assist gas A1 intersects with the cutting part C, but the glass center G is closer to the product part Ga than the cutting part C. You may make it cross | intersect the upper surface and lower surface of.

  As the side assist gas A1, for example, a gas such as oxygen (or air), water vapor, carbon dioxide, nitrogen, and argon is used alone or mixed with other gases. Further, the side assist gas A1 may be injected as hot air.

  The glass substrate G fused as described above has the following characteristics.

  First, as shown in FIG. 4, the shape of the fused end surface Ga <b> 1 of the product portion Ga is a good convex curved surface shape having a substantially arc shape. If it adds, the fusing end surface Ga1 of the product part Ga will be comprised with a fire-making surface. Note that molten foreign matter (such as dross) blown off by the side assist gas A1 adheres to the fused end surface Gb1 of the non-product portion Gb, and the shape of the fused end surface Gb1 may deviate from a substantially arc shape.

  Secondly, the arithmetic average roughness Ra of the cut end face Ga1 of the product part Ga is 0.3 μm or less, and the average length RSm of the roughness curve element is 150 μm or more. Here, if the lower limit value of Ra and the upper limit value of RSm are described, Ra is preferably as close to zero as possible, and RSm is preferably as close as possible to infinity. However, since there is a limit due to processing equipment and the like in practice, it is not meaningful to define the lower limit value of Ra and the upper limit value of RSm. Therefore, in the above, the lower limit value of Ra and the upper limit value of RSm are not provided.

  Third, the residual compressive stress of the fused end face Ga1 of the product part Ga is 20 MPa to 500 MPa.

(Second Embodiment)
As shown in FIG. 5, the glass plate cutting device 1 according to the second embodiment of the present invention is obtained by adding a center assist gas injection nozzle 5 to the configuration of the glass plate cutting device 1 according to the first embodiment. It is. Hereinafter, description of common points will be omitted, and only differences will be described.

  The center assist gas injection nozzle 5 is connected to the tip of the laser beam irradiator 3 and supplies the center assist gas A2 to the internal space of the laser beam irradiator 3 (the space below the lens 31). The center assist gas A2 supplied to the internal space of the laser beam irradiator 3 is jetted directly from the front end of the laser beam irradiator 3 toward the cutting portion C of the glass substrate G. That is, the laser beam LB is emitted from the tip of the laser beam irradiator 3, and the center assist gas A2 is injected. The center assist gas A2 protects optical parts such as the lens 31 of the laser beam irradiator 3 from the role of removing the molten foreign matter generated when the glass substrate G is melted from the cutting portion C of the glass substrate G. It also plays a role of cooling the heat of the lens.

  When the injection pressure of the side assist gas A1 is P1 and the injection pressure of the center assist gas A2 is P2, P2 / P1 is set to 0-2. Specifically, for example, the injection pressure of the center assist gas A2 is set to 0 to 0.02 [MPa], and the injection pressure of the side assist gas A1 is set to 0.01 to 0.5 [MPa]. . Preferably, the injection pressure of the side assist gas A1 is set larger than the injection pressure of the center assist gas A2. For example, P2 / P1 is set to 0.1 to 0.5. In this case, the injection pressure of the center assist gas A2 is preferably set to a pressure that can protect the optical components such as the lens 31 of the laser beam irradiator 3 from molten foreign matter.

  In this way, since the injection pressure of the center assist gas A2 is relatively weakened, the molten foreign matter generated mainly in the cutting part C by the side assist gas A1 is blown off. Since the side assist gas A1 is injected obliquely downward from the upper position on the side that becomes the product part Ga toward the cutting part C, the cutting part of the glass substrate G in a molten state as compared with the center assist gas A2. The force for pressing the vicinity of C downward is weak. Therefore, by making the injection pressure of the side assist gas A1 larger than the injection pressure of the center assist gas A2, it is possible to prevent the cutting portion C of the glass plate G in the molten state from drooping. And in the state which prevented the dripping of the cutting part C in this way, since the molten foreign material which arises in the cutting part C by side assist gas A1 is scattered preferentially to the side used as the non-product part Gb, the fusing end surface of the product part Ga It is difficult for molten foreign matter to accumulate in Ga1. Therefore, similarly to the case shown in FIG. 4, the shape of the fused end surface Ga1 of the product part Ga can be maintained in a good shape having a substantially arc shape.

  The side assist gas A1 and the center assist gas A2 may be the same type of gas or different types of gas.

(Third embodiment)
As shown in FIG. 6, the glass plate cutting device 1 according to the third embodiment of the present invention is different from the glass plate cutting device 1 according to the first and second embodiments in the space below the glass substrate G. The auxiliary side assist gas injection nozzle 6 is provided. Hereinafter, description of common points will be omitted, and only differences will be described. In the illustrated example, the center assist gas injection nozzle 5 is provided, but may be omitted.

  The auxiliary side assist gas injection nozzle 6 is disposed at a lower position on the side of the glass substrate G that becomes the product part Ga, and injects the auxiliary side assist gas A3 obliquely upward toward the cutting part C.

  Further, in this embodiment, the side surface portion 21a facing the non-supporting space S of the stage main body 21 on the product portion Ga side has a tapered surface that is inclined so that the upper portion is closer to the cutting portion C of the glass substrate G than the lower portion. There is no. The side surface portion 21a having a tapered surface guides the auxiliary side assist gas A3 injected from the auxiliary side assist gas injection nozzle 6 obliquely upward, and supplies the auxiliary side assist gas A3 to the cutting portion C of the glass substrate G. . In the illustrated example, the side surface portion 21a facing the non-supporting space S of the stage main body 21 on the non-product portion Gb side is also tapered so that the upper portion is closer to the cutting portion C of the glass substrate G than the lower portion. There is no. Of course, only the side surface portion 21a of the stage main body 21 on the product portion Ga side may be a tapered surface.

  If it carries out as mentioned above, it will become possible to blow away the fusion | melting foreign material which arose in the cutting part C of the glass substrate G to the non-product part Gb side efficiently by side assist gas A1 and side assist gas A3. Further, since the auxiliary side assist gas A3 acts on the lower surface of the glass substrate G, an effect of supporting the vicinity of the cut portion C of the glass substrate G from below can be expected, and it is considered that it contributes to prevention of drooping in the vicinity of the cut portion C. It is done.

  The injection pressure of the auxiliary side assist gas A3 is set to 0.01 to 0.5 [MPa], for example.

  The inclination angle α2 of the auxiliary side assist gas A3 with respect to the back surface (lower surface) of the glass substrate G is set to 15 ° to 70 °, preferably 20 ° to 60 °, more preferably 25 ° to 45 °.

  The directing direction of the auxiliary side assist gas A3 may be in the vicinity of the cutting part C. For example, in the illustrated example, the virtual center line L2 of the auxiliary side assist gas A3 intersects with the cutting part C, but the glass center is closer to the product part Ga than the cutting part C. You may make it cross | intersect the upper surface and lower surface of G.

  The auxiliary side assist gas A3 may be the same type of gas as the side assist gas A1 or a different type of gas.

  In the third embodiment, the side assist gas A1 and the auxiliary side assist gas A3 are simultaneously injected to the cutting part C of the glass substrate G, but the present invention is not limited to this. For example, until the cutting part C of the glass substrate G penetrates, the molten foreign matter of the cutting part C is blown off with the side assist gas A1, and after the cutting part C of the glass substrate G penetrates, the side assist gas A1 is stopped, You may make it blow off the molten foreign material of the cutting part C with auxiliary side assist gas A3.

(Fourth embodiment)
As shown in FIG. 7, the glass plate cutting device 1 according to the fourth embodiment of the present invention is different from the glass plate cutting device 1 according to the third embodiment in the supply method of the auxiliary side assist gas A3. . Hereinafter, description of common points will be omitted, and only differences will be described.

  In the fourth embodiment, a gas flow passage 21 b that extends obliquely upward and has one end communicating with the non-support space S is formed in the stage main body 21 of the support stage 2. The injection port of the auxiliary side assist gas injection nozzle 6 is connected to the other end of the gas flow passage 21b. The auxiliary side assist gas A3 injected from the auxiliary side assist gas injection nozzle 6 is guided obliquely upward through the gas flow passage 21b to open to the non-supporting space S, and is supplied to the cutting part C of the glass substrate G.

(Fifth embodiment)
As shown in FIG. 8, the glass plate cutting device 1 according to the fifth embodiment of the present invention is different from the glass plate cutting device 1 according to the third embodiment in that the molten foreign matter generated in the fusing process is sucked. It is in the point equipped with. Hereinafter, description of common points will be omitted, and only differences will be described.

  That is, the first suction nozzle 7 disposed at the upper position on the side to be the non-product part Gb and the second suction nozzle 8 disposed at the lower position on the side to be the non-product part Gb are provided.

  The first suction nozzle 7 is disposed so as to face the side assist gas injection nozzle 4 in a state where the virtual center line L3 is directed to the cutting part C, and sucks molten foreign matter in the space above the glass substrate G. The inclination angle β1 of the virtual center line L3 of the first suction nozzle 7 with respect to the surface (upper surface) of the glass substrate G is within a range of α1 ± 15 °, preferably within α1 ± 10 °, more preferably within a range of α1 ± 5 °. Set to

  On the other hand, the second suction nozzle 8 is disposed so as to face the auxiliary side assist gas injection nozzle 6 with its suction port directed upward, in other words, the lower space of the glass substrate G, in other words, unsupported. The melted foreign matter in the space S is sucked. Here, the second suction nozzle 8 is arranged so as to be biased toward the non-product part Gb side from directly below the cutting part C because the molten foreign matter is not supported by the side assist gas A1 or the auxiliary side assist gas A3. It is because it descends while being blown away to the non-product part Gb side in S.

  The first suction nozzle 7 and the second suction nozzle 8 suck the molten foreign matter blown to the non-product part Gb side by the side assist gas A1 and the auxiliary side assist gas A3. In this way, it is possible to reliably prevent the molten foreign matter blown off from the cutting part C by the side assist gas A1 and the auxiliary side assist gas A3 from floating in the surrounding space and adhering to the product part Ga again. .

  In the fifth embodiment, the molten foreign matter is simultaneously sucked by the first suction nozzle 7 and the second suction nozzle 8, but the present invention is not limited to this. For example, the molten foreign matter is sucked by the first suction nozzle 7 until the cutting portion C of the glass substrate G penetrates, and the molten foreign matter is melted by the second suction nozzle 8 after the cutting portion C of the glass substrate G penetrates. You may make it attract | suck a foreign material. Alternatively, the first suction nozzle 7 may be omitted, and the molten foreign matter may be sucked only by the second suction nozzle 8.

  Here, the 2nd suction nozzle 8 arrange | positioned in the downward space of the glass substrate G has the elongate suction opening 81 along the cutting plan line CL direction of the glass substrate G, as shown in FIG. This is because, in the space below the glass substrate G, the molten foreign matter tends to scatter over a wide area along the direction of the planned cutting line CL. If there is no space restriction by the laser beam irradiator 3 or the like, the first suction nozzle 7 disposed in the upper space of the glass substrate G is also a long suction port along the extending direction of the planned cutting line CL. You may make it have.

(Sixth embodiment)
Of course, as shown in FIG. 10, you may arrange | position the 1st suction nozzle 7 and the 2nd suction nozzle 8 to the glass plate cutting device 1 (refer FIG. 7) which concerns on 4th Embodiment.

  In addition, this invention is not limited to the said 1st-6th embodiment, A various deformation | transformation is possible.

  For example, when the glass substrate G is formed by the overflow downdraw method or the like, the thickness of both end portions in the width direction of the glass substrate G is relatively larger than the thickness of the center portion in the width direction of the glass substrate G as shown in FIG. It becomes thick. And the width direction center part is made into the product part Ga, and the width direction both ends are made into the non-product part (it calls an ear | edge part) Gb. Therefore, the cutting method and the cutting device according to the present invention may be used for removing the ear portion that becomes the non-product portion Gb of the glass substrate G.

  In the above-described embodiment, the case where one of the thin glass sheets G that has been cut and separated is the product part Ga and the other is the non-product part Gb has been described. Can be applied.

  A comparison test was conducted to demonstrate the usefulness of the present invention.

The test conditions for this comparison test are as follows. First, in the form shown in FIG. 3, while blowing the assist gas, the cut glass glass having a size of 300 mm in length and 300 mm in width is irradiated with a CO ₂ laser having a wavelength of 10.6 μm to obtain the thin glass. Cut by cutting. Next, an annealing treatment is performed by performing secondary processing (for example, annealing by laser or annealing by electric heating) on the vicinity of the cut end surface of the thin glass thus blown. Such a series of cutting steps is performed by changing the thickness a of the thin glass and the minimum gap b between the fusing end faces. And about the thin glass blown through each cutting process, (1) The state of rubbing of a fusing end surface, (2) Shape of a fusing end surface, (3) Strength was inspected, respectively. As shown in FIG. 12, the strength of the melted thin glass is such that each thin glass G is sequentially sandwiched between two plate bodies 9 and bent in the longitudinal direction in a U-shape at a speed of 50 mm / min. The strength was evaluated by two-point bending in which it was pushed and bent so as to generate. In this evaluation, the breaking strength is calculated based on the distance between the two plate-like bodies 9 when they are broken by pushing and bending. The test results are as shown below.

  According to Table 1 and Table 2 above, when b / a is 0.1 or more, there is no rubbing caused by contact between the melted end surfaces of the thin glass at the time of separation, or it is suppressed to a level that does not substantially cause a problem. It can be recognized that it is possible. Therefore, if it manages in such a range, the situation where the fusion | melting end surfaces of thin glass will contact and break at the time of isolation | separation can be reduced reliably.

  Moreover, when b / a is 2 or less, it can recognize that the shape of the fusing end surface of thin glass is maintained favorable. Therefore, if it manages in such a range, the situation that the product quality of thin glass will fall or the thin glass will be damaged starting from a fusing end face in a post process can be reduced reliably.

  Therefore, if the minimum gap b is managed so as to satisfy the relationship of 0.1 ≦ b / a ≦ 2, the shape of the thin glass sheet is maintained at the time of separation or in the subsequent process while maintaining the shape near the fusing end surface of the thin glass. It is possible to reliably reduce the situation where the glass is broken. Such an effect can be enjoyed without requiring preheating or annealing treatment other than irradiating a laser beam for fusing.

  In addition, when more stable quality is requested | required, you may perform the annealing process by a laser etc. immediately after fusing.

  The arithmetic average roughness Ra of the cut end face formed in Examples 8 to 10 is 0.08 to 0.18 μm, the average length RSm of the roughness curve element is 250 to 400 μm, and the fusing end face is dirty. Could be easily removed. On the other hand, when a cleaved end face obtained by performing diamond polishing after breaking a thin glass plate along a scribe line is given as a comparative example, the cleaved end face has an Ra of 0.4 to 0.6 μm and an RSm of 80 to 140 μm. In addition, the dirt on the cleaved end face could not be removed sufficiently.

  Moreover, the compressive strain (residual compressive stress) of the fusing end surface formed in Examples 1 to 10 was 80 to 180 MPa. When the end face was scratched to generate a crack, the crack progressed along the edge, and the performance as a glass substrate was not impaired. On the other hand, the compression strain of the end face of the laser-cleaved thin glass produced as a comparative example is 0 to 15 MPa, and when cracks are generated by generating scratches, the crack progresses in the plane direction and the thin glass becomes two. It broke and ended up losing its performance as a glass substrate.

DESCRIPTION OF SYMBOLS 1 Glass plate cutting device 2 Support stage 21 Stage main body 22 Conveyor 3 Laser beam irradiation device 31 Lens 4 Side assist gas injection nozzle 5 Center assist gas injection nozzle 6 Auxiliary side assist gas injection nozzle 7 1st suction nozzle 8 2nd suction nozzle A1 Side assist gas A2 Center assist gas A3 Auxiliary side assist gas C Cutting part G Glass substrate Ga Product part Ga1 Fusing end face Gb Non-product part Gb1 Fusing end face LB Laser beam S Unsupported space

Claims (7)

A thin glass cutting method of irradiating a cutting portion of a thin glass having a thickness of 500 μm or less with a laser beam and fusing the thin glass,
When the thickness of the thin glass is a and the minimum clearance between the melted end faces of the thin glass facing each other at the cutting portion is b, the minimum gap is set so as to satisfy the relationship of 0.1 ≦ b / a ≦ 2. A method of cutting a thin glass, characterized by managing the glass. The method for cutting thin sheet glass according to claim 1, characterized in that irradiating the cutting portion in a state of defocusing the laser beam.   The method for cutting a thin glass according to claim 1 or 2, wherein a spot diameter of the laser beam is smaller than the minimum gap.   The thin glass cutting method according to any one of claims 1 to 3, wherein the fusing end surface forms a convex curved surface.   The thin glass cutting method according to any one of claims 1 to 4, wherein the fusing end surface is a fire-making surface.   6. The arithmetic average roughness Ra of the fusing end face is 0.3 μm or less, and the average length RSm of the roughness curve element is 150 μm or more. 6. A method for cutting thin glass as described in 1.   The thin glass cutting method according to any one of claims 1 to 6, wherein a residual compressive stress of the fusing end face is 20 MPa to 500 MPa.

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