TWI461251B - Method for cutting brittle material substrates - Google Patents

Description

Cutting method of brittle material substrate

The present invention relates to a method of irradiating a brittle material substrate with a laser beam and cutting the brittle material substrate in a direction intersecting each other.

Conventionally, as a method of cutting a brittle material substrate such as a glass substrate or a ceramic substrate, a method of cutting a substrate by applying an external force along a scribe line after a scribe line is formed by pressing a cutter wheel or the like to form a scribe line is widely used.

In general, when the squeegee of the brittle material substrate is performed using the cutter wheel, the mechanical stress applied to the brittle material substrate by the cutter wheel causes the defect of the substrate to easily occur, and the breakage or the like due to the defect occurs when the breakage occurs.

In response to the above problems, in recent years, a method of cutting a brittle material substrate using a laser has been put into practical use. In this method, after the laser beam is irradiated onto the substrate to heat the substrate until the melting temperature is not full, the substrate is cooled by the cooling medium to generate thermal stress, so that the thermal stress is caused from the surface of the substrate in a substantially vertical direction. Crack formation. In this way, the cutting method of the brittle material substrate using the laser beam utilizes thermal stress, so that the tool does not directly contact the substrate, and the cut surface becomes a smooth surface with less cracks and the like, and the strength of the substrate is maintained.

Further, for example, Patent Document 1 also proposes a method of cutting a brittle material substrate by using a laser in a direction intersecting each other. In the proposed method, after the laser beam is irradiated onto the brittle material substrate to form the first crack in the half-cut state, the second crack is formed in the half-cut state of the first crack by the irradiation of the laser beam, and then the first crack is formed. Re-illuminate the laser with the 2nd crack The beam is completely cut.

Prior technical literature Patent literature

Patent Document 1: Japanese Laid-Open Patent Publication No. 2001-130921

However, as described above, when the first and second cracks are irradiated with the laser beam to completely cut the brittle material substrate, cracks may occur at the intersection of the first crack and the second crack. If the crack occurs at the intersection of the brittle material substrate at the corner portion after the cutting, the dimensional accuracy of the brittle material substrate after the cutting is lowered, and the generated glass frit adheres to the surface of the substrate, which is a cause.

The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a method for suppressing occurrence of cracking at an intersection portion when a brittle material substrate is cut in a direction in which two laser beams are intersected with each other.

According to the present invention, there is provided a method for cutting a brittle material substrate, comprising: a step of forming a first scribe line and a second scribe line formed of vertical cracks which are mutually intersected on a brittle material substrate, and a step along the first scribe line a step of stretching the laser beam while the second scribe line is relatively moved, causing the vertical crack to extend, and cutting the substrate by the first scribe line and the second scribe line, and is characterized by: The scribe line and/or the second scribe line illuminate the laser beam The amount of laser beam irradiation to the intersection of the first score line and the second score line is reduced by the amount of laser beam irradiation outside the intersection area.

Here, it is preferable that the irradiation amount of the laser beam to the intersection region of the first scribe line and the second scribe line is 50% or less of the irradiation amount of the laser beam other than the intersection region.

Further, by controlling the output of the laser beam, the amount of laser beam irradiation to the intersection of the first scribe line and the second scribe line may be reduced. Further, the intersection of the first score line and the second score line is covered by the covering member that absorbs or reflects the laser beam, and the amount of the laser beam irradiated to the intersection region may be reduced. Further, the intersection of the first score line and the second score line is covered with a liquid that absorbs or reflects the laser beam, and the amount of the laser beam irradiated to the intersection region may be reduced.

Further, it is preferable that the intersection region is a region having a width of 5 mm or less from the intersection of the first scribe line and the second scribe line to the upstream side and the downstream side in the relative movement direction of the laser beam.

Further, the first scribe line and the second scribe line are irradiated to the substrate while the laser beam is relatively moved, and the substrate is heated to a temperature at which the melting temperature is not completed, and then the cooling medium is blown to the substrate to be cooled. The thermal stress generated by the aforementioned substrate is preferably formed.

According to the cutting method of the brittle material substrate of the present invention, it is possible to suppress the occurrence of cracking at the intersection portion when the brittle material substrate is cut in the direction of the mutual intersection. Thereby, the dimensional accuracy of the brittle material substrate after cutting is upward, and the problem of glass swarf is particularly suppressed.

Although the cutting method of the brittle material substrate of the present invention will be described in more detail below, the present invention is not limited to these embodiments.

Fig. 1 is a schematic view showing an example of a cutting device which can implement the cutting method of the present invention. In the cutting device of Fig. 1, the gantry 11 is provided with a sliding platform 12 movable in the vertical direction (Y direction) of the paper surface, and a pedestal 19 movable on the sliding platform 12 in the left-right direction (X direction) of the drawing. The rotating mechanism 25 on the pedestal 19 freely moves the brittle material substrate 50 placed and fixed to the rotating platform 26 provided on the rotating mechanism 25 in the horizontal plane by the moving means.

The sliding platform 12 is movably mounted on the rails 14 and 15 in a pair of parallel positions on the gantry 11 at a predetermined distance. Further, a ball screw 13 that can be positively and reversely rotated by a motor (not shown) is provided between the pair of guide rails 14 and 15 in parallel with the pair of guide rails 14, 15. Further, a ball nut 16 is attached to the bottom surface of the sliding platform 12. This ball nut 16 is screwed to the ball screw 13. By the forward or reverse rotation of the ball screw 13, the ball nut 16 is moved in the Y direction, whereby the slide platform 12 on which the ball nut 16 is mounted is moved in the Y direction on the pair of guide rails 14, 15.

Further, the pedestal 19 is movably supported on the sliding platform 12 by a pair of guiding members 21 arranged in parallel with a predetermined distance. Further, a ball screw 22 that can be positively and reversely rotated by the motor 23 is provided between the pair of guide members 21 in parallel with the pair of guide members 21. Further, a ball nut 24 is attached to the bottom surface of the pedestal 19. The ball nut 24 is screwed to the ball screw twenty two. By the forward rotation or the reverse rotation of the ball screw 22, the ball nut 24 is moved in the X direction, whereby the pedestal 19 moves together with the ball nut 24 on the pair of guide members 21 in the X direction.

A rotating mechanism 25 is provided on the pedestal 19. Further, a rotating platform 26 is attached to the rotating mechanism 25. The brittle material substrate 50 for cutting the object is attached to the rotating platform 26 by vacuum suction. The rotating mechanism 25 rotates the rotating platform 26 about the central axis of the vertical direction.

Above the rotating platform 26, the support table 31 is supported by the holding member 33 suspended from the mounting table 32 so as to be separated from the rotating platform 26. The support table 31 is provided with a cutter wheel 35 that forms a trigger crack on the surface of the brittle material substrate 50, an opening (not shown) for irradiating the brittle material substrate 50 with a laser beam, and a cold known surface for the brittle material substrate 50. The nozzle 37 is cooled.

The cutter wheel 35 is held by the cutter holder 36 so as to be movable up and down at a position where the brittle material substrate 50 is pressed against the non-contact position, and is directed to the brittle material substrate 50 only when a trigger crack which is the starting point of the score line is formed. The position of the crimp is lowered. The position at which the trigger crack is formed is preferably formed on the inner side of the surface side end of the brittle material substrate 50 in order to suppress the occurrence of cracks from the trigger crack to the unpredictable direction.

A laser output device 34 is attached to the mounting table 32. The laser beam LB emitted from the laser output device 34 is reflected downward by the mirror 44, and passes through the optical system held in the holding member 33 from the opening formed in the support table 31 to the brittle material substrate fixed to the rotary table 26. 50 irradiation.

Further, the cooling nozzle 37 provided near the opening of the laser beam LB from the support table 31 is connected to the brittle material substrate 50 as a cooling medium. Water is sprayed with the air. The position on the brittle material substrate 50 ejected from the cooling medium is on the cut-off line 51 and on the rear side of the irradiation area of the laser beam LB (refer to FIG. 2).

The mounting table 32 is provided with CCD cameras 38 and 39 for identifying one of the alignment marks previously imprinted on the brittle material substrate 50. The pair of CCD cameras 38 and 39 detect the positional deviation of the brittle material substrate 50 at the time of setting, for example, when the brittle material substrate 50 is offset by the angle θ, the amount of rotation of the rotating platform 26 is -θ, and the brittle material substrate The occasion of the 50 offset Y is the amount by which the sliding platform 12 moves -Y.

In the case of cutting the brittle material substrate 50 in the cutting device having such a configuration, the brittle material substrate 50 is first placed on the rotary table 26 and fixed by suction means. Thereafter, the alignment marks provided on the brittle material substrate 50 are imaged by a pair of CCD cameras 38 and 39, and the brittle material substrate 50 is positioned at a predetermined position based on the image data as described above.

Next, a trigger crack is formed on the brittle material substrate 50 by the cutter wheel 35 as described above. Thereafter, the laser beam LB is emitted from the laser output device 34. The laser beam LB is irradiated to the surface of the brittle material substrate 50 substantially perpendicularly by the mirror 44 as shown in FIG. Further, water as a cooling medium is ejected from the cooling nozzle 37 near the rear end of the laser beam irradiation region. By irradiating the brittle material substrate 50 with the laser beam LB, the brittle material substrate 50 is not heated at the melting temperature in the thickness direction, and the brittle material substrate 50 is intended to be thermally expanded, but cannot be expanded due to local heating, and the irradiation point is compressed at the center. Stress occurs. Further, immediately after heating, the surface of the brittle material substrate 50 is cooled by water, and the brittle material substrate 50 is contracted this time and has tensile stress. Health. By the action of the tensile stress, a vertical crack 53 is formed on the brittle material substrate 50 along the cut planned line 51 with the trigger crack as a starting point.

Thereafter, by moving the laser beam LB and the cooling nozzle 37 relatively along the cut planned line 51, the vertical crack 53 is stretched and the fringe material substrate 50 is formed with the score line 52. In the case of this embodiment, the brittle material substrate 50 is moved by the sliding mechanism 12, the pedestal 19, and the rotating mechanism 25 of the rotating platform 26 in a state where the laser beam LB and the cooling nozzle 37 are fixed at a predetermined position. Of course, it is also possible to move the laser beam LB and the cooling nozzle 37 in a state where the brittle material substrate 50 is fixed. Alternatively, the brittle material substrate 50 and both the laser beam LB and the cooling nozzle 37 may be moved.

Next, the cutting method of the present invention will be described. Fig. 3 is a view showing the steps of an example of the cutting method of the present invention. As shown in (a), by moving the laser beam LB and the cooling nozzle 37 relatively along the planned cutting line 51, the vertical crack 53a starting from the trigger crack (not shown) is extended in the relative moving direction. The brittle material substrate 50 is formed by a first scribe line 52a.

The laser beam LB used here is not particularly limited, and may be appropriately determined depending on the material or thickness of the substrate, the depth of the vertical crack to be formed, and the like. When the brittle material substrate is a glass substrate, a laser beam having a large absorption wavelength of 9 to 11 μm on the surface of the glass substrate is suitably used.

As such a laser beam system, a carbon dioxide laser can be cited. The illumination shape of the laser beam to the substrate is preferably an elliptical shape in which the relative movement direction of the laser beam is elongated, and the irradiation length L in the relative movement direction is in the range of 10 to 60 mm, and the irradiation width W is in the range of 1 to 5 mm. More suitable.

As a cooling medium that is ejected from the cooling nozzle 37, water or wine can be cited. Fine and so on. Further, it is also possible to add an additive such as a surfactant to a range in which no adverse effect is exerted on the brittle material substrate after cutting. The amount of blowing as a cooling medium is usually about several ml/min. The cooling of the substrate caused by the cooling medium is preferably a so-called water jet method in which water is sprayed together with a gas (usually air) from the viewpoint of quenching the substrate heated by the laser beam. The cooling zone caused by the cooling medium is preferably an original shape or an elliptical shape having a long diameter of 1 to 5 mm. Further, it is preferable that the distance between the cooling region and the center point of the heating region in the cooling region is a range of several mm to several tens of mm in the relative movement direction of the heating region caused by the laser beam.

The relative moving speed of the laser beam LB and the cooling nozzle 37 is not particularly limited, and may be appropriately determined depending on the depth of the vertical crack to be obtained. Generally, the slower the relative movement speed, the deeper the vertical crack formed. Usually, the relative speed coefficient is about 100 mm/sec.

The depth of the vertical crack 53a constituting the first score line 52a is not particularly limited. However, in order to increase the conditions for irradiating the laser beam to the bridging material substrate in the subsequent step, for example, the relative movement speed or the laser output, etc. The margin is preferably a depth of 25% or more with respect to the thickness of the substrate.

Next, as shown in FIG. 3(b), the second scribe line 52b is formed by relatively moving the laser beam LB and the cooling nozzle 37 along the cut line 51b orthogonal to the first scribe line 52a. The conditions for forming the second score line 52b are the same as those for forming the first score line 52a.

Next, as shown in the diagram (c), the laser beam LB is again irradiated along the second scribe line 52b. Thereby, the vertical crack 53h extends in the thickness direction of the substrate, The brittle material substrate 50 is cut by the second scribe line 52b to form a cut line 54. Further, the vertical crack 53b may be stretched to a depth at which the brittle material substrate 50 is cut without applying an external force, and does not necessarily reach the reverse side of the brittle material substrate 50.

The irradiation condition of the laser beam LB for extending the vertical crack 53b in the thickness direction of the substrate may be appropriately determined by the thickness of the brittle material substrate 50 or the depth of the vertical crack 53b, etc., but the second scribe line is usually formed. The irradiation conditions at 52b are also exemplified herein.

Next, as shown in the diagram (d), the laser beam LB is again irradiated along the first scribe line 52a. Thereby, the vertical crack 53a extends in the thickness direction of the substrate, and the brittle material substrate 50 is cut by the first scribe line 52a. The depth of the vertical crack 53a after stretching in the thickness direction of the substrate is the same as that of the vertical crack 53b, and the depth of the brittle material substrate 50 may be cut as long as the external force is not applied, and it is not necessary to reach the reverse side of the brittle material substrate 50. side.

Here, the main point is that when the laser beam LB is irradiated again along the first scribe line 52a, the irradiation amount of the laser beam LB to the intersection region of the first scribe line 52a and the cut line 54 is made larger than that of the other portions. The amount of exposure is reduced. By reducing the amount of irradiation of the laser beam LB to the intersection of the first score line 52a and the cut line 54 as compared with the other portions as described above, it is possible to effectively suppress the breakage of the intersection portion of the corner portion after the cut. The ideal laser beam irradiation amount in the intersection region is 50% or less of the laser beam irradiation amount outside the intersection region, and is preferably 10% or less, more preferably 0%.

Further, in the embodiment described above, the first scribe line 52a and the cut line are made to be irradiated to the laser beam LB again along the first scribe line 52a. The irradiation amount of the laser beam LB at the intersection point of 54 is smaller than that of the other portions, but the irradiation amount of the laser beam LB toward the intersection region is made when the laser beam LB is irradiated again along the second scribe line 52b. The amount of exposure in other parts can also be reduced. Or, when the laser beam LB is irradiated again along the first scribe line 52a and the laser beam LB is irradiated again along the second scribe line 52b, the irradiation amount of the laser beam LB toward the intersection region is irradiated more than other portions. The amount can be reduced.

The adjustment of the amount of irradiation of the laser beam LB to the intersection of the first score line 52a and the second score line 52b can be performed, for example, by control of the output of the laser beam. When the irradiation point of the laser beam is an elliptical shape elongated in the relative movement direction of the laser beam by an optical system such as a cylindrical lens, as shown in FIG. 4(a), the first scribe line 52a and the second line are used. The intersection of the scribe line 52b is centered, and the area from the flow side covering the downstream side of the laser beam LB to the downstream side is set to a region where the laser beam LB is not irradiated. The irradiation amount of the laser beam LB at this time is shown in Fig. 4(b). As understood from Fig. 4(b), the irradiation amount of the laser beam LB gradually decreases from the normal irradiation amount to the intersection of the first scribe line 52a and the second scribe line 52b, and gradually increases back to the normal point after the intersection becomes zero. The amount of exposure. As described above, by reducing the amount of irradiation of the laser beam to the intersection region between the first score line 52a and the second score line 52b, the occurrence of cracks in the intersection portion is suppressed.

The region where the irradiation amount of the laser beam LB is reduced, that is, the intersection region between the first score line 52a and the second score line 52b is from the first score line 52a and the second score line 52b. The intersection point has a width of 5 mm or less between the flow side and the downstream side in the relative movement direction of the laser beam LB. miss you.

In addition, in the case where the irradiation point of the laser beam LB is scanned using a polygon mirror, a galvanometer mirror, a cylindrical mirror or the like and the elliptical shape is elongated in the relative movement direction of the laser beam, the lightning in the irradiation point The intensity of the shot becomes uniform and can also cover a predetermined range such that the amount of laser exposure is zero. Fig. 5(a) shows a diagram showing the illumination state of the laser beam LB over time. After the laser beam LB reaches the intersection of the first score line 52a and the second score line 52b, the laser oscillation is turned off in the scan intersection area, but the laser oscillation is turned on after exiting the intersection area. . As a result, as shown in FIG. 5(b), the amount of irradiation of the laser beam LB to the intersection region between the first scribe line 52a and the second scribe line 52b can be made zero.

FIG. 6 shows another means for adjusting the amount of irradiation of the laser beam LB to the intersection of the first score line 52a and the second score line 52b. In the figure shown in the figure, the intersection region between the first score line 52a and the second score line 52b is covered with the covering member 61, and the region to the intersection of the first score line 52a and the second score line 52b is changed. The amount of irradiation of the beam LB is reduced. According to this means, it is not necessary to control the opening and closing of the laser oscillation as in the above embodiment, and the irradiation amount of the laser beam LB can be reduced by a simple operation of placing the covering member 61.

The covering member 61 used in the present invention is not particularly limited as long as it is a member that absorbs or reflects the laser beam LB, and examples thereof include a glass substrate, a metal plate such as aluminum, and dry ice. When the glass substrate is used, since the laser beam LB is absorbed by the glass substrate, the irradiation amount of the laser beam LB to the brittle material substrate 50 can be adjusted by the material or thickness thereof. In addition, in use In the case of a metal plate such as aluminum, the amount of irradiation of the laser beam LB reflected on the metal plate to the brittle material substrate 50 becomes zero.

FIG. 7 shows still another means for adjusting the amount of irradiation of the laser beam LB to the intersection of the first score line 52a and the second score line 52b. The means shown in this figure is that the intersection of the first score line 52a and the second score line 52b is covered with the liquid 62, and the laser is applied to the intersection of the first score line 52a and the second score line 52b. The amount of irradiation of the light beam LB is reduced. According to this embodiment, as in the above-described embodiment, it is not necessary to control the opening and closing of the laser oscillation as in the above-described embodiment, and the irradiation amount of the laser beam LB can be reduced by a simple operation such as dropping or coating of the liquid 62.

The liquid 62 to be used in the present invention is not particularly limited as long as it absorbs or reflects the laser beam LB. For example, water or alcohol is suitably used. The adhesion of the liquid 62 to the intersection region of the brittle material substrate 50 can be performed, for example, by dropping or coating a scrubber or the like. The amount of adhesion of the liquid 62 may be appropriately determined by the size of the intersection region, the type of the laser to be used, or the output, and is preferably in the range of 0.01 mL to 0.05 mL in the case of using water.

As described above, in each of the embodiments, the first scribe line 52a and the second scribe line 52b are formed in one piece to cut the substrate. However, the first scribe line 52a is formed on the large-area brittle material substrate 50. The second cutting line 52b is formed by forming a plurality of strips and then cutting into a plurality of small-area substrates. The cutting method of the present invention is of course applicable. Further, the cutting method of the present invention is of course applicable to the case where the intersection is made at a desired angle, except for the case where the two scribe lines are orthogonal.

[Examples] Example 1

The cutting device shown in FIG. 1 is used to form a plurality of lines orthogonal to each other in a chemically-strengthened soda glass substrate having a thickness of 0.55 mm so as to have 40 intersection points, and the laser beam is irradiated along one of the square lines. After the substrate was cut, a glass plate (5 mm ^* 5 mm ^* thickness 0.4 mm) was placed on the intersection of the cut line and the other line. Thereafter, the laser beam is irradiated along the other of the aforementioned scribe lines to cut the substrate into a plurality of pieces. The cutting of the glass substrate was carried out using the method shown in FIG. The results are shown in Table 1. In addition, the specific irradiation conditions of the laser beam are as follows.

(Laser beam irradiation conditions formed by the first score line 52a)

Laser type: carbon dioxide laser

Laser output: 100W

Relative movement speed: 100mm/sec

Laser point: oval

(Laser beam irradiation conditions formed by the second score line 52b)

Laser type: carbon dioxide laser

Laser output: 120W

Relative movement speed: 200mm/sec

Laser point: oval

(Laser broken laser beam irradiation conditions)

Laser type: carbon dioxide laser

Laser output: 320W

Relative movement speed: 1500mm/sec

Laser point: oval

Comparative example 1

The substrate was cut in the same manner as in Example 1 except that the glass plate was not placed in the intersection region. The results are shown together in Table 1.

"rupture": there is a break in the intersection

"Intersection jump": from the intersection point to the relative movement direction of the laser beam, the downstream side cut line does not stretch

As understood from Table 1, the cuts were good at all intersections among the 40 intersections of the method of Example 1, and only 3 intersections of the cut method of Comparative Example 1 were well cut, and cracks occurred at the remaining 37 intersections. .

Example 2

The substrate was cut in the same manner as in Example 1 except that water (adhesion amount: 0.04 mL, diameter: 8 to 10 mm) in place of the glass plate was attached to the intersection region. The results are shown in Table 2. In addition, the specific irradiation conditions of the laser beam are as follows.

(Laser beam irradiation conditions formed by the first score line 52a)

Laser type: carbon dioxide laser

Laser output: 100W

Relative movement speed: 100mm/sec

Laser point: oval

(Laser beam irradiation conditions formed by the second score line 52b)

Laser type: carbon dioxide laser

Laser output: 130W

Relative movement speed: 180mm/sec

Laser point: oval

(Laser broken laser beam irradiation conditions)

Laser type: carbon dioxide laser

Laser output: 240W

Relative movement speed: 1500mm/sec

Laser point: oval

Comparative example 2

The substrate was cut in the same manner as in Example 2 except that the water droplets were not adhered to the intersection region. The results are shown together in Table 2.

As understood from Table 2, among the 40 intersection points of the cutting method of Example 2 in which the water droplets were adhered to the intersection region, the cutting was good at all the intersections, and the cutting method of Comparative Example 2 only had two intersections which were well cut. A rupture occurred at the remaining 38 intersections.

[Industrial availability]

According to the cutting method of the present invention, it is useful to suppress the occurrence of cracking at the intersection portion in the case where the brittle material substrate is cut by the laser in the direction of the mutual intersection.

37‧‧‧Cooling nozzle

50‧‧‧Battery material substrate

51, 51a, 51b‧‧‧ cut line

52‧‧•marking

52a‧‧‧1st line

52b‧‧‧2nd line

53, 53a, 53b‧‧‧ vertical cracks

61‧‧‧covered components

62‧‧‧Liquid

LB‧‧‧Laser beam

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view showing an example of a cutting device which can implement the cutting method of the present invention.

Figure 2 is a diagram illustrating the operational state of the laser scribing.

Fig. 3 is a view showing the steps of an example of the cutting method of the present invention.

Fig. 4 is a view showing an example of the irradiation amount adjustment to the intersection region of the laser beam LB and the laser irradiation amount in the intersection region.

Fig. 5 is a view showing an example of adjustment of the amount of irradiation to the intersection region of the laser beam LB and a laser irradiation amount in the intersection region.

Fig. 6 is a view showing an example in which the irradiation amount to the intersection region of the laser beam LB is adjusted by the covering member.

Fig. 7 is a view showing an example in which the irradiation amount to the intersection region of the laser beam LB is adjusted to be liquid.

37‧‧‧Cooling nozzle

50‧‧‧Battery material substrate

51a, 51b‧‧‧ cut line

52a‧‧‧1st line

52b‧‧‧2nd line

53a, 53b‧‧‧ vertical cracks

54‧‧‧Cut line

LB‧‧‧Laser beam

Claims (11)

A method for cutting a brittle material substrate, comprising: forming a first scribe line and a second scribe line formed by vertical cracks on a brittle material substrate, along a first scribe line and a second scribe line; a step of causing the laser beam to be relatively moved while being irradiated to extend the vertical crack and to cut the substrate by the first scribe line and the second scribe line, and is characterized by: following the first scribe line and/or When the second scribe line is irradiated with the laser beam, the amount of the laser beam irradiated to the intersection of the first scribe line and the second scribe line is smaller than the amount of the laser beam irradiated outside the intersection region. The method for cutting a brittle material substrate according to the first aspect of the invention, wherein the laser beam irradiation amount to the intersection of the first scribe line and the second scribe line is a laser beam irradiation amount other than the intersection region 50% or less. The method for cutting a brittle material substrate according to claim 1, wherein the laser beam output is reduced to reduce the amount of laser beam irradiation to the intersection of the first scribe line and the second scribe line. A method for cutting a brittle material substrate according to claim 2, wherein the laser beam output is reduced to reduce the amount of laser beam irradiation to the intersection of the first scribe line and the second scribe line. The method for cutting a brittle material substrate according to claim 1, wherein the covering member that absorbs or reflects the laser beam covers the first scribe line and The intersection area of the second scribe line reduces the amount of laser beam irradiation to the intersection area. The method for cutting a brittle material substrate according to claim 2, wherein the covering member that absorbs or reflects the laser beam covers an intersection region between the first scribe line and the second scribe line, so that the ray to the intersection region The amount of radiation of the beam is reduced. The method for cutting a brittle material substrate according to claim 1, wherein the liquid that absorbs or reflects the laser beam covers the intersection of the first scribe line and the second scribe line to make the laser toward the intersection region The amount of beam exposure is reduced. The method for cutting a substrate of a brittle material according to claim 2, wherein the liquid that absorbs or reflects the laser beam covers the intersection of the first scribe line and the second scribe line to make the laser toward the intersection region The amount of beam exposure is reduced. The method for cutting a brittle material substrate according to any one of claims 1 to 8, wherein the intersection region is flowed from a point of intersection of the first scribe line and the second scribe line to a relative movement direction of the laser beam. The side and the downstream side each have an area of a width of 5 mm or less. The method for cutting a substrate of a brittle material according to any one of claims 1 to 8, wherein The first scribe line and the second scribe line are irradiated while the laser beam is relatively moved on the substrate, and after heating the substrate to a temperature at which the melting temperature is not full, the substrate is blown to the substrate to be cooled to be cooled by the substrate. The thermal stress is formed. The method for cutting a brittle material substrate according to claim 9, wherein the first scribe line and the second scribe line are irradiated to the substrate while the laser beam is relatively moved, and the substrate is heated to a melting temperature of less than Thereafter, the cooling medium is blown to the substrate to be cooled to be formed by thermal stress generated by the substrate.