TWI394628B - The splitting device and segmentation method of brittle material substrate - Google Patents

Description

Fragmentation device and segmentation method for brittle material substrate

The present invention relates to a dividing device and a dividing method for dividing a brittle material substrate by local heating by laser irradiation and cooling after heating, and reheating by a second laser irradiation.

The brittle material substrate herein refers to a glass substrate, a ceramic of a sintered material, a single crystal germanium, a semiconductor wafer, a ceramic substrate, or the like.

At present, it is desired to have a method of dividing a brittle material substrate such as a glass substrate capable of producing a high-quality split surface having almost no chipping. As a division method capable of realizing such division, a method of dividing a substrate by a step of laser irradiation, cold coal injection, and second laser irradiation has been proposed (see Patent Document 1).

That is, local heating of the first laser beam is performed along an imaginary line (divided line) on the surface of the substrate to be divided, and cold coal is sprayed for cooling at a moment after heating, thereby forming a crack on the surface of the substrate. (dash). Then, along the formed crack (scribe line), re-heating of the second laser beam irradiation is performed, thereby causing the crack to extend to the deep portion of the substrate (hereinafter, in the present specification, when the crack is mentioned to grow in the depth direction of the substrate, In the case of circumstances, it is called "extension". At this time, the crack extends to the back surface of the substrate, and the substrate is completely broken. According to this document, one or a plurality of laser devices are used, and when processed by a laser device, an elongated circular laser spot is formed, and the first heating and the second heating are performed in the same shape. The spot is repeatedly irradiated. When a plurality of laser devices are used, the lens system of the barrel portion of each laser device can also be In the same time, the first time is irradiated with one long circle and the second time with multiple points.

Further, a method and apparatus for performing scribing are disclosed in which an elliptical first laser spot is heated along a predetermined line of a scribe line, and the first laser spot is cooled by a circular or rectangular cooling point. In the approaching region, the region close to the cooling point on the opposite side of the first laser beam is heated by the second laser beam at the second laser spot to perform scribing (see Patent Document 2). According to this document, a laser beam from a first laser oscillator and a second laser oscillator is processed by an optical system to form an elliptical first laser spot and a second laser spot. A stress gradient is then generated by the heating of the first laser spot and the cooling point to form a vertical crack on the substrate. Furthermore, the region close to the cooling point is heated again by the second laser spot, and the vertical crack is further extended to the back surface (when the crack reaches the bottom of the plate, the whole is cut). Next, the substrate is supplied to the dividing process, and a bending moment is applied to the left and right of the crack to divide the substrate.

Further, in the method of sequentially arranging the first laser spot, the cooling point, and the second laser spot, and simultaneously scanning the substrate to cut the brittle material substrate such as a glass substrate, the point of the first laser spot is revealed. The shape is bilaterally symmetrical with respect to the long axis (the direction of the line to be divided) and is asymmetrical in the longitudinal direction (the area of the front is larger than the area in the rear), thereby maximizing the division speed (see Patent Documents 3 and 8). ). According to the disclosure of this document, the cutting device includes two laser beam irradiation devices that generate the first laser beam and the second laser beam, and is formed into a first laser beam that is asymmetric in shape before and after the dot shape, and can be made first. When the first laser beam generated by the laser beam irradiation device passes through the lens group composed of the convex lens and the concave lens, it is generated by being offset from the focus of the lens group to one side.

Further, in the method of sequentially arranging the first laser spot, the cooling point, and the second laser spot, and simultaneously scanning the substrate to perform scribing of the brittle material substrate, it is revealed that the second laser point system is set to The largest thermal energy intensity region is biased toward the front end portion of the cooling point, and a large stress gradient is generated between the cooling point, whereby the vertical crack formed along the predetermined line of the scribe line is further extended to the back surface (refer to Patent Document 4). According to this document, two laser devices for the first laser spot and the second laser spot are loaded to respectively adjust the thermal energy intensity distribution of each laser spot, and each laser spot is diffracted by the lens system. The lens is processed so that the thermal energy intensity distribution becomes maximum on one end side.

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

[Patent Document 2] WO2003/026861

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2003-117921

[Patent Document 4] WO2003/013816

According to the description of these patent documents, it is possible to form a crack (scribe line) on the brittle material substrate by the first laser heating and cooling immediately after heating, and then perform the second laser heating to make the formed crack deep. extend.

In addition, when the crack is extended to the deep portion by the second laser heating, the crack will reach the back surface and completely divide the substrate, or the crack will not reach the back surface and stop in the substrate, depending on the thickness of the substrate and heating. Conditions, cooling conditions, especially the thickness of the substrate and heating conditions have a greater impact.

In general, a substrate having a thick plate thickness (thickness: 1 mm or more) can be easily extended to the back surface to completely divide the substrate by adjusting heating conditions or the like, but as the thickness of the substrate is thinned, By the second laser plus It is difficult to control the heat to cause the crack to extend in the depth direction to perform the division. The reason is that, in order to extend the crack formed on the surface of the substrate in the depth direction of the substrate, a stress gradient for causing the crack to extend in the depth direction must be formed in the substrate, but when the thickness of the substrate is thin, it is difficult. A temperature difference in the depth direction required to form the above stress gradient is formed. That is, when the thickness of the substrate is thin, the heat generated by the warm and cold coal jet generated by the laser irradiation is directly transmitted from the surface side to the back side, and it is difficult to generate a temperature difference. This tendency is particularly strong when the thickness of the substrate plate is as thin as 0.7 mm or less.

Therefore, as the thickness of the substrate is thinned, since the second laser irradiation alone does not necessarily divide the substrate, it is necessary to apply a bending moment along the crack (scribe line) as described in Patent Document 2. The step is added to the next step to perform the division.

Further, although it is described in Patent Document 1, when the thickness of the substrate is thin, the cooling may be suddenly caused by the first laser heating and heating due to the difference in heating conditions and cooling conditions. segmentation. This division is not caused by the stress gradient of the substrate due to the depth direction, but by the stress gradient of the laser beam in the scanning direction (the direction of the substrate), that is, the compressive stress generated near the position irradiated by the laser beam, and The stress gradient in the plane direction of the tensile stress generated near the position where the cold coal is sprayed is caused by the division into the direction of the substrate surface (in order to distinguish from the case where the crack extends in the depth direction, the stress gradient due to the plane direction is caused The division is not called "extension" and is called "going". This situation is called a transverse split. The division of the transverse split and the above-mentioned division of the stress gradient in the depth direction (referred to as longitudinal crack) differ in the composition of the split, and the straightness or quality of the split plane is worse than the split of the longitudinal split, so it is necessary to The heating conditions and the like are adjusted to avoid the division of the transverse crack. That is, even if the thickness of the substrate is thin, once the crack is formed by the first moment of laser heating and heating, the crack must be transmitted through the second laser heating. The depth direction is extended to perform division (longitudinal crack).

At this time, although it is easy to find the heating condition in which the first laser heating does not cause a transverse crack, in general, even in the case of the first laser heating, the heating condition which does not cause the transverse crack is generated. In addition to the second laser heating, it is still difficult to cause the crack to extend in the depth direction, and the second laser heating must be set to a heating condition different from the first heating condition (different thermal energy distribution, etc.) . Moreover, it has been experimentally confirmed that when the laser spot of the second laser irradiation is performed in the same shape and the same thermal energy distribution as the laser spot of the first laser irradiation, since only the first time is generated The stress distribution, so the cracks hardly extend.

As described above, as the thickness of the substrate is thinned, once the crack (dash) is formed by the first laser heating, cooling, and the second laser heating step, it is difficult to extend the formed crack and completely divide. The tendency of the substrate (longitudinal crack) is difficult to divide into a plurality of substrates having a high-quality split surface.

Therefore, it is desirable to have a dividing device and a dividing method, and it is possible to surely extend the crack to form a split (longitudinal crack) after forming a crack (scribe line) even when the thickness of the substrate is thin.

In the above-described Patent Document 4, the shape of the laser beam in the first laser beam and the second laser beam is changed, and the second laser beam is irradiated so that the front end near the cooling point side has a maximum energy intensity distribution. This makes the crack deeper In the method, the second heating condition is a heating condition different from the first heating condition, and this method is effective even when the substrate thickness is thin, and can be applied.

However, in the above document, two laser devices are mounted, so the device is relatively large. Moreover, when two laser devices are used, since the first laser irradiation and the second laser irradiation irradiate the laser to the substrate with different optical systems, it is necessary to adjust the formation of each laser device. Optical position between laser points. Further, in the above document, each laser device is mounted on a light path of a laser beam to form a special diffraction grating lens to form an asymmetric thermal energy intensity distribution, so that a laser device is used in a case where a laser device is used. It is quite difficult to utilize the thermal energy distribution of the illumination.

Accordingly, it is an object of the present invention to provide a dividing device and a dividing method capable of reliably realizing a division process of a first laser heating, cooling, and a second laser heating step required for realizing a substrate division of a longitudinal crack.

Further, an object of the present invention is to provide a dividing device which is improved in an optical system for performing laser irradiation so as to be able to easily switch or adjust the first laser heating and the second laser heating in a short time. And the segmentation method.

In order to solve the above problems, the apparatus for dividing a brittle material substrate according to the present invention includes: a laser irradiation means for selectively irradiating a first laser spot and a second laser spot having different dot shapes on a stage. a brittle material substrate; a cooling means for forming a cooling point near the first laser spot when the first laser spot is irradiated; and a moving means for causing the first laser spot, the second laser spot, and the cooling point to face the substrate Moving; and dividing the control unit to control The substrate is moved while the first laser beam is irradiated with the first laser beam, thereby heating at a temperature lower than the softening point of the substrate, and cooling is performed by moving the cooling point following the first laser spot. Forming a crack on the surface of the substrate, further moving the second laser spot along the crack while moving the second laser spot, thereby heating the substrate at a temperature lower than the softening point of the substrate, thereby causing the crack Extending the back surface of the substrate to divide the substrate, wherein the laser irradiation means forms the first laser spot by an optical path adjusting mechanism for adjusting an optical path of a laser beam emitted from a laser light source Or the second laser spot; when the laser irradiation means forms the first laser spot, the heat energy distribution having a symmetry with respect to the moving direction of the first laser spot is centered on the vertical incident beam that is perpendicularly incident on the substrate. When the laser beam is irradiated by the laser beam, the laser beam is incident on the substrate, and the oblique direction of the second laser spot is larger than the rear side. Thermal energy distribution Irradiated beam shape.

Here, the laser spot to be irradiated by the laser irradiation means may be formed by using a laser light source which is conventionally used for laser scribing a brittle material substrate, as long as the self-excimer is based on the type of the brittle material substrate. Laser, YAG laser, carbon dioxide laser, or carbon monoxide laser can be selected. For example, a glass substrate can use a carbon dioxide laser.

Further, the cooling means may be a cooling point capable of locally cooling the vicinity of the first laser spot, and a method of forming the cooling point may be used. For example, a cold coal injection mechanism that sprays cold coal from the surface of the substrate from the spray nozzle may be provided to form a cooling point. At this time, cold coal can use water (steam), compressed air, He gas, N ₂ gas, CO ₂ gas, or the like.

Further, the moving means can fix the positions of the first laser spot, the second laser spot, and the cooling point, and move the stage on which the brittle material substrate is mounted. Conversely, the first laser spot and the second mine can be moved. The position of the shot point, the cooling point, and the stage on which the substrate of the brittle material is loaded.

According to the invention, the division control unit controls the laser irradiation means, the cooling means, and the moving means to move the first laser spot while irradiating the first laser spot on the brittle material substrate, thereby lowering the softening point of the substrate. The temperature is heated, and the cooling point is cooled by following the movement of the first laser spot to form a crack (scribe line) on the surface of the substrate. Further, the second laser beam is moved while irradiating the second laser spot along the formed crack (scribe line), whereby the substrate is heated again at a temperature lower than the softening point of the substrate. In the above control, the laser irradiation means forms the first laser spot and the second laser spot by the optical path adjusting means for adjusting the optical path of the laser beam emitted from one of the laser light sources. The laser irradiation means irradiates a beam shape having a symmetrical thermal energy distribution centering on a vertical incident beam perpendicularly incident on the substrate when the first laser beam is formed. As a result, a first laser spot having a beam shape that is symmetrical with respect to the vertical incident beam is formed. Specifically, the first laser spot such as an elliptical shape, an oblong shape, or a circular shape is formed. When the second laser beam is formed by the laser beam irradiation means, the beam shape of the heat energy distribution having the larger side of the second laser beam moving direction and the rear side of the second laser beam moving direction is irradiated with the obliquely incident light beam obliquely incident on the substrate. . As a result, a laser spot that is asymmetric with respect to the oblique incident beam is formed. Specifically, a laser spot having an egg shape having a large heat energy distribution on the front side and the rear side is formed, for example.

As described above, the laser irradiation means switches the direction in which the laser beam is incident on the substrate by the optical path adjusting means to form a first laser spot centered on the vertically incident beam, and is formed to be centered on the oblique incident beam. 2nd laser point.

According to the present invention, since the first laser spot and the second laser spot having different shapes from each other can be formed by one laser light source, the number of use of the laser light source can be reduced without using two laser light sources. Position adjustment between the required laser beams.

Further, when the first laser heating, cooling, and the second laser heating step in the step of performing the division (longitudinal) of the substrate are performed, even if the first laser heating is selected, it is difficult to generate the transverse crack heating. The condition (the first laser spot) can be easily switched to the heating condition of the second laser spot different from the first laser spot during the second laser heating, and the crack can be extended to back.

In the above invention, the optical path adjusting means may be provided with a rotating mirror on the optical path of the laser beam, and an adjustment mechanism for adjusting the incident position of the laser beam incident on the rotating mirror.

Here, the rotating mirror may have a configuration in which the laser beam is scanned over a range of angles by irradiating the laser beam to the rotating reflecting surface. Specifically, although a polygonal mirror is generally used, in addition to this, an elliptical mirror (other than a circular mirror) or a rotating mirror in which a reflecting surface is formed into a special curved surface to change the thermal energy distribution of the irradiated surface may be used.

According to the present invention, the laser irradiation means injects a laser beam emitted from a laser source into a rotating mirror (for example, a polygonal mirror) in a high-speed rotation, thereby scanning the laser beam by the scanned laser beam. Beam forming laser point. Then, since the incident position of the laser beam incident on the reflecting surface of the rotating mirror can be changed by the adjusting mechanism to change the angle of the exit from the rotating mirror of the laser beam, the vertical incident beam can be simply formed. The first laser spot, or the second laser spot centered on the obliquely incident beam.

In the above invention, the optical path adjusting means may be provided with a mirror on the optical path of the laser beam and an adjustment mechanism for adjusting the incident angle of the laser beam incident on the mirror.

According to the invention, the laser beam is irradiated onto the substrate by reflecting the laser beam emitted from the laser light source on the reflecting surface of the mirror. The laser beam is changed by the incident angle of the incident mirror, and the angle of the exit from the mirror can be changed. Therefore, only by adjusting the mechanism to change the angle of incidence of the laser beam to the mirror, the laser beam can be formed. The first laser beam is centered on the beam, or the second laser beam is centered on the obliquely incident beam.

In the above invention, the optical path adjusting mechanism may further include an adjustment mirror or an adjustment lens disposed on the optical beam path for adjusting the beam shape.

Here, the adjusting mirror and the adjusting lens can use a laser beam to change the beam path or the beam spot of the laser beam when the optical element reflects or transmits. Specifically, a plano-convex lens, a concave mirror, a cylindrical lens, or the like can be used.

According to the present invention, the shape of the first laser spot and the second laser spot formed can be adjusted by adjusting the adjustment mirror or adjusting the position or angle of the lens on the optical path. In the above invention, the second laser spot may be adjusted to be at least larger than the first laser spot by the adjustment mirror or the adjustment lens.

According to the present invention, in the second laser irradiation, by the first The second laser spot having a large spot shape is heated again, that is, the substrate can be warped while the substrate is warped with a larger area than the heating region of the first laser irradiation, thereby promoting the extension of the crack.

In the above invention, the division control unit may move the first laser spot and the cooling point on the substrate to form a crack, and move the second laser spot on the substrate to extend the crack. Instead, the substrate is divided by a reciprocating movement.

According to the present invention, since cracks can be formed in the forward path and the cracks can be extended and extended in the return path, the work can be performed with good efficiency.

Further, according to another aspect of the present invention, in the method of dividing a brittle material substrate, the first laser beam is moved while being irradiated with the first laser beam set on a predetermined dividing line of the brittle material substrate, thereby The substrate is heated at a low softening point, and then the substrate is cooled by a cooling point following the first laser spot to form a crack on the surface of the substrate, and the second laser spot is further irradiated along the crack while the second laser beam is irradiated along the crack. Moving, thereby reheating the substrate at a temperature lower than a softening point of the substrate, thereby extending the crack to the back surface of the substrate for segmentation, wherein the light path adjusting mechanism adjusts emission from a laser light source An optical path of the laser beam to form the first laser spot or the second laser spot; the first laser spot has a relative first laser spot centering on a vertical incident beam that is incident perpendicularly to the substrate Irradiation of the shape of the heat energy distribution that is substantially symmetrical before and after the moving direction; the second laser spot has a second laser spot moving direction and a rear side of the second laser beam centered on the oblique incident beam that is obliquely incident on the substrate Big Shape of the thermal energy distribution is irradiated.

According to the present invention, since the first laser spot and the second laser spot can be formed by one laser light source, the number of used laser light sources can be reduced without performing the laser required for using two laser light sources. Position adjustment between beams.

Further, when the first laser heating, cooling, and the second laser heating step in the step of performing the division (longitudinal) of the substrate are performed, even if the first laser heating is selected, it is difficult to generate the transverse crack heating. The condition (first laser spot) can be easily switched to the heating condition of the second laser spot different from the first laser spot during the second heating, by changing the shape of the laser spot. The crack is surely extended to the back.

(Embodiment 1)

Hereinafter, embodiments of the present invention will be described based on the drawings. Fig. 1 is a schematic configuration diagram of a laser splitting device LC1 according to an embodiment of the present invention. Fig. 2 is a block diagram showing the configuration of a control system of the laser splitting device LC1 of Fig. 1.

First, the overall configuration of the laser splitting device LC1 will be described with reference to Fig. 1 .

A slide table 2 is provided which is movable in the direction in which the guide rails 3, 4 are alternately arranged in the front and rear directions of the paper of FIG. 1 (hereinafter referred to as the Y direction). A lead screw 5 is disposed between the two guide rails 3, 4 in the front-rear direction, and the lead screw 6 fixed to the slide table 2 is screwed to the lead screw 5, and the lead screw 5 is reversed by a motor (other than the drawing). The slide table 2 can be moved back and forth along the guide rails 3, 4 in the Y direction.

On the slide table 2, a water platform seat 7 that can reciprocate along the guide rail 8 in the left-right direction of FIG. 1 (hereinafter referred to as the X direction) is disposed. In the bracket 10 fixed to the pedestal 7, the lead screw 10a rotated by the motor 9 is screwed through, The lead screw 7a is rotated in the X direction along the guide rail 8 by reversing the lead screw 10a.

The turret 7 is provided with a rotary table 12 rotatable by a rotation mechanism 11, and the rotary table 12 is mounted with a glass substrate G on which a brittle material substrate to be cut is attached in a horizontal state. The rotating mechanism 11 can rotate the rotary table 12 about a vertical axis and can rotate at an arbitrary rotation angle with respect to a reference position. Moreover, the glass substrate G of the object to be divided is fixed to the turntable 12 by, for example, a suction jig.

Above the turntable 12, the laser oscillator 13 and the optical path adjusting mechanism 14 are held by the mounting bracket 15. The optical path adjusting mechanism 14 is provided by the optical path adjusting element group 14a (the plano-convex lens 31, the mirror 32, the polygon mirror 39) for adjusting the optical path of the laser beam emitted from the laser oscillator 13, and the position of the moving optical path adjusting element group 14a. The motor group 14b (motors 34 to 36) and the arm group 14c (arms 37 to 39) that connect the optical path adjusting element group 14a and the motor group 14b. The plano-convex lens 31 (the meniscus lens) is connected to the elevation motor 34 through the arm 37, and the position in the vertical direction can be adjusted. Further, the mirror 32 is connected to the elevation motor 35 via the arm 38, and the position in the vertical direction can be adjusted. Further, the polygon mirror 33 is connected to the elevation motor 36 via the arm 39, and the position in the vertical direction can be adjusted.

The laser beam emitted from the laser oscillator 13 is formed by the optical path adjusting element group 14a to form a light beam having a desired cross-sectional shape, and is irradiated onto the substrate G in the form of a laser spot. In the present embodiment, a laser beam that has been reduced in size is injected, and is scanned by the polygon mirror 33 to form an elliptical laser spot LS (Fig. 2) on the glass substrate G. Next, by adjusting the optical path adjusting element group 14a, the first laser spot used in the first laser irradiation and the second laser spot used in the second laser irradiation are switched. In addition, The optical path adjustment of each element of the optical path adjusting element group 14a is left to be described later.

The mounting bracket 15 is provided with a cooling nozzle 16 that is adjacent to the optical path adjusting mechanism 14. From this, the cooling nozzle 16 sprays a cooling medium such as cooling water, He gas, or carbonic acid gas onto the glass substrate G. The cooling medium is blown to the vicinity of the elliptical shape laser spot LS of the glass substrate G, and a cooling point CS is formed on the surface of the glass substrate G (FIG. 2).

The cutter wheel 18 is further attached to the mounting bracket 15 via the vertical movement adjustment mechanism 17. The cutter wheel 18 is made of a sintered diamond or a cemented carbide, and has a V-shaped ridge portion having a vertex as a blade edge on the outer peripheral surface, and the pressure contact force to the glass substrate G is finely adjusted by the vertical movement adjustment mechanism 17. The cutter wheel 18 is designed to temporarily lower the pedestal 7 while moving the pedestal 7 in the X direction when the initial crack TR (FIG. 2) is formed on the edge of the glass substrate G.

Next, the control system will be described based on Fig. 2 . The laser division device LC1 includes a control unit 50 that executes various processes by controlling parameters and programs (software) stored in the memory and the CPU. The control unit 50 controls a table driving unit 51 for driving a motor (motor 9 or the like) for positioning or moving the slide table 2, the pedestal 7, and the rotary table 12, and a laser for performing laser irradiation. The drive unit 52 includes a laser light source drive unit 52a that drives the laser oscillator 13, an optical path adjustment unit drive unit 52b that drives the motor group 14b for the optical path adjustment element group 14a, and a cold coal injection that controls the cooling nozzle 16. The nozzle drive unit 53 of the on-off valve (not shown), the blade drive unit 54 that forms the initial crack on the glass substrate G by the cutter wheel 18, and the positioning mark that is printed on the substrate G by the cameras 20 and 21 Each of the drive units such as the camera drive unit 55. Moreover, the control unit 50 is connected by a keyboard and a mouse. The input unit 56 and the display unit 57 for performing various displays on the display screen display desired information on the screen, and can input necessary instructions or settings.

Further, the control unit 50 includes an integrated drive table drive unit 51, a laser drive unit 52 (a laser light source drive unit 52a, an optical path adjustment unit drive unit 52b), a nozzle drive unit 53, and a blade drive unit 54 for performing a glass substrate G. The divided division control unit 58 performs the division of the first laser irradiation, the cooling, and the second laser irradiation by the division control unit 58.

Specifically, the division control unit 58 first controls the blade driving unit 54 and the table driving unit 51 to move the substrate G while the cutter wheel 18 is lowered, thereby performing the process of forming the initial crack TR. Next, the console drive unit 51, the laser drive unit 52, and the nozzle drive unit 53 move the substrate G while irradiating the laser beam (first laser spot) and injecting cold coal. Thereby, the first laser irradiation and cooling are performed to form a crack on the substrate. Next, the console drive unit 51 and the laser drive unit 52 move the substrate G in a state where the laser beam (second laser spot) is irradiated. Thereby, the second laser irradiation is performed to extend the crack.

Next, an operation of adjusting the optical path of the optical path adjusting mechanism 14 (the optical path adjusting element group 14a, the motor group 14b, and the arm group 14c) will be described.

3 is a view for explaining the operation of the optical path adjusting mechanism 14, and specifically, the action of changing the thermal energy distribution of the light beam irradiation region by changing the laser spot irradiated on the substrate G by the upper and lower movement of the mirror 32. Figure.

The direction of travel of the laser beam LB0 emitted from the laser source 13 is oriented Vertically below, the laser beam LB0 is incident on the plano-convex lens 31. The laser beam LB1 passing through the plano-convex lens 31 further travels in the vertical direction and is incident on the mirror 32. At this time, the mounting angle of the mirror 32 is adjusted so as to be incident on the reflecting surface of the mirror 32 at an incident angle of 45 degrees and emitted at a reflection angle of 45 degrees, and the laser beam LB2 reflected by the mirror 32 is horizontal. Directions.

The laser beam LB2 traveling in the horizontal direction is incident on the polygon mirror 33. At this time, by the relationship between the height position of the polygon mirror 33 and the height position of the mirror 32, the incident position of the laser beam LB2 incident on the polygon mirror 33 is changed, and as a result, the polygon mirror 33 can be adjusted to be incident on the reflecting surface. The angle of entry and the angle of incidence from the polygon mirror 33. That is, in a state where the height position of the polygon mirror 33 is fixed, the drive motor 35 (Fig. 1) raises and lowers the arm 38 to adjust the height of the mirror 32 with respect to the polygon mirror 33, thereby adjusting the laser incident on the polygon mirror 33. The incident position of the light beam LB2 is adjusted to the angle of the laser beam (beam) LB3 emitted from the polygon mirror 33 toward the substrate G.

Specifically, when the first laser beam is formed, the laser beam LB2 directed from the mirror 32 toward the polygon mirror 33 is incident at a central position of one of the reflection surfaces of the polygon mirror 33 at 45 degrees (a little chain line in the figure) Shown), and the reflection surface is emitted at a reflection angle of 45 degrees. As a result, the laser beam LB3a incident perpendicularly to the glass substrate G is formed as it travels vertically downward.

By rotating the reflecting surface of the polygon mirror 33 at a high speed, the laser beam LB3 emitted from the polygon mirror 33 is scanned centering on the laser beam LB3a, and as shown in FIG. 4, the heat energy distribution E is formed substantially symmetrically before and after the scanning direction of the beam. The first laser point LS1.

When the second laser beam is formed, the laser beam LB2 directed from the mirror 32 toward the polygon mirror 33 is incident on one of the polygon mirrors 33 at a deeper incident angle (for example, 60 degrees) than when the first laser beam is formed. The center position of the reflecting surface (shown by a broken line in the figure), and the reflecting surface of the polygon mirror 33 is emitted at a deep reflection angle. As a result, the laser beam LB3b traveling in the oblique direction toward the substrate G is formed.

By rotating the reflecting surface of the polygon mirror 33 at a high speed, the laser beam LB3 emitted from the polygon mirror 33 is scanned centering on the laser beam LB3b, and as shown in FIG. 4, the thermal energy distribution E is asymmetrical before and after the scanning direction. 2 laser point LS2.

FIG. 5 is a view for explaining the adjustment operation of the optical path adjusting mechanism 14 in a comprehensive manner. 3 shows an embodiment for adjusting the thermal energy distribution of the laser spot, but as shown by the arrow in FIG. 5(a), since the plano-convex lens 31, the mirror 32, and the polygon mirror 33 can be lifted and lowered independently, The shape (length or width) of the laser spot can be adjusted by changing the positional relationship, that is, in addition to the thermal energy distribution. Here is the main adjustment of the reconciliation instructions.

Fig. 5(b) is an adjustment when the laser spot is made to have an asymmetric thermal energy distribution. As previously explained (Fig. 3), an asymmetrical thermal energy distribution can be formed by fixing the polygonal mirror 33 and lowering the mirror 32 (moving in the direction of the solid arrow). On the other hand, by fixing the mirror 32 and raising the polygon mirror 33 (moving in the direction of the dotted arrow), the same asymmetric heat energy distribution can be formed.

Fig. 5(c) is an adjustment when the thermal energy distribution of the laser spot is asymmetrical in the opposite direction to Fig. 5(b). By fixing the polygon mirror 33 and making the reflection The mirror 32 is raised (moving in the direction of the solid arrow) or by fixing the mirror 32 and lowering the polygon mirror 33 (moving in the direction of the dotted arrow) to form an asymmetric thermal energy distribution.

Fig. 5(d) is an adjustment when the beam shape of the laser spot is reduced. By simultaneously lowering the mirror 32 and the polygon mirror 33 to reduce the laser spot on the substrate G, the beam length of the laser spot can be reduced. Further, although not shown in the drawings, since the laser beam 32 can be simultaneously enlarged by the simultaneous increase of the mirror 32 and the polygon mirror 33, the beam length of the laser beam can be enlarged.

With this adjustment, a second laser irradiation can be performed with a larger diameter than the heating area of the first laser irradiation. At this time, since the substrate can be warped with a large diameter, the extension of the crack can be promoted.

Fig. 5(e) is an adjustment when the beam shape of the laser spot is enlarged. By lowering the plano-convex lens 31 to enlarge the laser spot, the beam length can be enlarged. Further, although not shown in the drawings, since the projection point can be reduced by raising the plano-convex lens 31, the beam length can be reduced by a method different from that of FIG. 5(d).

As described above, the shape of the laser spot or the heat energy distribution can be adjusted by individually raising or lowering the respective elements of the optical path adjusting mechanism 14 up and down.

Further, in the present embodiment, the laser beam is scanned by the polygon mirror 33 to form a laser beam. However, instead of the polygon mirror, an elliptical mirror or another rotating mirror may be used for scanning, whereby the shapes may be different from each other. The first laser point and the second laser point.

Further, the division control unit 58 controls the optical path adjustment mechanism drive unit 52b of the laser control unit 52 to adjust the position of the mirror 32 to perform the first operation. The first laser spot LS1 is formed during the sub-laser irradiation, and the position of the mirror 32 is adjusted so that the second laser spot LS2 is formed when the second laser irradiation is performed.

Further, when the division control unit 58 performs the division operation of the first laser irradiation, the cooling, and the second laser irradiation, the console driving unit 51 moves the substrate G, but can also make the first The moving direction of the secondary laser irradiation and the moving direction of the second laser irradiation are opposite to end the division by the reciprocating action, thereby reducing the loss time of the movement.

(Embodiment 2)

Fig. 6 is a schematic configuration diagram of an optical path adjusting mechanism of the laser splitting device LC2 according to another embodiment of the present invention, wherein Fig. 6(a) shows a state in which a first laser spot is formed, and Fig. 6(b) shows a second mine. The state when shooting. The laser division device LC2 forms a first laser spot and a second laser spot by using an optical system in which an optical lens or an optical mirror is combined without using a rotating mirror (a polygonal mirror or the like).

Further, since the laser splitting device LC2 of the present embodiment and the laser splitting device LC1 described in the first embodiment are basically the same except for the optical path adjusting mechanisms 14 (14a to 14c), the portions other than the optical path adjusting mechanism are omitted. Description.

The optical path adjusting mechanism 61 is composed of a first mirror 62 on the fixed side, a second mirror 63 on the movable side, a plano-convex lens 64, and a cylindrical lens 65. Among the optical element groups, the second mirror 63, the plano-convex lens 64, and the cylindrical lens 65 are integrally held as the movable optical body 66, and are connected to the motor (not shown) so that the second mirror 63 can be connected. The fulcrum P moves obliquely near the reflecting surface.

The laser oscillator 13 adjusts the laser beam LB0 composed of a small-diameter beam to be emitted vertically downward, and the laser beam LB0 is incident on the first mirror 62. The first mirror 62 is adjusted in such a manner that the laser beam LB0 is incident on the reflecting surface at an incident angle of 45 degrees and is emitted at a reflection angle of 45 degrees, and the laser beam LB1 emitted from the first mirror 62 is attached. Travel in the horizontal direction.

The laser beam LB1 traveling in the horizontal direction is incident on the second mirror 63. At this time, as the incident angle of the laser beam LB1 entering the reflecting surface of the second reflecting mirror 63 is different, the angle of incidence from the reflecting surface of the second reflecting mirror 63 changes.

When the first laser beam is formed, the laser beam LB1 is incident on the reflection surface of the second mirror 63 at an incident angle of 45 degrees, and is emitted at a reflection angle of 45 degrees with respect to the reflection surface. As shown in Fig. 6(a), the laser beam LB2 travels vertically downward. The laser beam LB2 is reduced in beam diameter by the plano-convex lens 64, and is enlarged in the axial direction by the cylindrical lens 65 to form a light beam having an elliptical cross section. Next, the laser beam of the laser beam LB2 is straightly passed through the plano-convex lens 64 and the laser beam (center beam) of the lens optical axis of the cylindrical lens 65 to form a laser beam LB3a which is incident perpendicularly on the glass substrate G. Further, the other laser beam (other than the center beam) in the laser beam LB2 becomes an elliptical laser beam LB3 which is enlarged around the laser beam LB3a, and the elliptical first laser spot LS1 is formed on the substrate G. . At this time, the first laser spot LS1 has a heat energy distribution that is symmetrical in the long axis direction.

Further, when the second laser beam is formed, the laser beam LB1 is incident on the second mirror 63 by an incident angle (for example, 60 degrees) at a depth of 45 degrees. The reflecting surface is emitted toward the reflecting surface at a deeper reflection angle than when the first laser beam is formed, and as shown in FIG. 6(b), a laser beam LB2 that travels in the oblique direction with respect to the substrate G is formed.

The laser beam LB2 is reduced in beam diameter by the plano-convex lens 64, and is enlarged in the axial direction by the cylindrical lens 65 to form a light beam having an elliptical cross section. Next, the laser beam of the laser beam LB2 is straightly passed through the plano-convex lens 64 and the laser beam (center beam) of the lens optical axis of the cylindrical lens 65, thereby forming a laser beam LB3b obliquely incident on the glass substrate G. Further, the other laser beam (other than the center beam) in the laser beam LB2 becomes an elliptical laser beam LB3 which is enlarged around the laser beam LB3b, and the beam is obliquely incident on the substrate G, thereby forming a thermal energy distribution. The elliptical shape is the second laser point LS2 which is asymmetric in the long axis direction.

Next, the division control unit 58 adjusts the position of the movable optical body 66 to form the first laser spot LS1 when the first laser irradiation is performed, and adjusts the position of the movable optical body 66 when the second laser irradiation is performed. To form the second laser spot LS2.

(Embodiment 3)

Fig. 7 is a schematic configuration diagram of an optical path adjusting mechanism of the laser beam splitting device LC3 according to another embodiment of the present invention, wherein Fig. 7(a) shows a state in which a first laser spot is formed, and Fig. 7(b) shows a second mine. The state when shooting. The laser division device LC3 forms a first laser spot and a second laser spot by using an optical system of a plurality of optical mirrors.

Further, the laser splitting device LC3 of the present embodiment and the optical path adjusting mechanism 14 (14a to 14c) of the laser splitting device LC1 described in the first embodiment The components other than the components are basically the same, and therefore the description of the portions other than the optical path adjusting mechanism will be omitted.

The optical path adjusting mechanism 71 is composed of an optical element group of the first reflecting mirror 72, the concave mirror 73, the cylindrical mirror 74, and the second reflecting mirror 75. The second mirror 75 of the final stage is connected to a motor (not shown) so as to be tiltably movable with the vicinity of the reflecting surface as a fulcrum P.

The laser oscillator 13 adjusts the laser beam LB0 composed of a small-diameter beam to be emitted vertically downward, and the laser beam LB0 is incident on the first mirror 72. The mounting angle of the first reflecting mirror 72 is adjusted so that the laser beam LB0 is incident on the reflecting surface at an incident angle of 45 degrees and is emitted at a reflection angle of 45 degrees, and the laser beam LB1 exiting the first reflecting mirror 72 is directed to Travel in the horizontal direction.

The laser beam LB1 traveling in the horizontal direction is incident on the concave mirror 73, and the laser beam LB2 reflected there is incident on the cylindrical mirror 74 while being reduced in the beam diameter. The laser beam LB3 reflected by the cylindrical mirror 74 is expanded into a beam LB3 having an elliptical cross section in one axial direction, and is incident on the reflection surface of the second mirror 75. The second mirror 75 changes the angle of incidence by adjusting the angle of the reflecting surface.

When the first laser spot is formed, the angle of the second mirror 75 is adjusted so that the center beam LB3a centered on the beam of the laser beam LB3 emitted from the cylindrical mirror 74 is as shown in Fig. 7(a). It is shown that the laser beam LB4a is directed vertically downward. The laser beam other than the center beam LB3a of the laser beam LB3 is reflected by the second mirror 75 as the laser beam LB3 enlarged around the laser beam LB3a, and the first laser spot LS1 of the elliptical shape is formed on the substrate G. . At this time, the first laser point LS1 has a long axis direction Is the symmetrical thermal energy distribution.

Further, when the second laser beam is formed, the central beam LB3b is the center of the beam of the laser beam LB3 emitted from the cylindrical mirror 74, and the laser beam LB3b is incident on the reflection surface of the second mirror 75. The angle is adjusted to be shallower than when the first laser spot is formed. Thereby, the reflecting surface of the second reflecting mirror 75 is emitted at a shallow reflection angle, and as shown in FIG. 7(b), the laser beam LB4b that travels in the oblique direction with respect to the substrate G is formed. The beam other than the center beam LB3b of the laser beam LB3 becomes a laser beam LB3 which is enlarged around the laser beam LB3b and is reflected by the second mirror 75, and this beam is tilted by the laser beam LB4 which is enlarged around the laser beam LB4b. As a result of the incident on the substrate G, the second laser spot LS2 whose thermal energy distribution is an elliptical shape and whose axis in the long axis direction is asymmetrical is formed.

Next, the division control unit 58 adjusts the angle of the second mirror 75 to form the first laser point LS1 when the first laser irradiation is performed, and adjusts the second mirror 75 when the second laser irradiation is performed. The angle is formed to form the second laser spot LS2.

(Embodiment 4)

Fig. 8 is a schematic configuration diagram of an optical path adjusting mechanism of the laser beam splitting device LC4 according to another embodiment of the present invention, wherein Fig. 8(a) shows a state in which a first laser spot is formed, and Fig. 8(b) shows a second mine. The state when shooting. The laser division device LC4 replaces the arrangement of the cylindrical mirror 74 and the second mirror 75 in the optical path adjustment mechanism 71 (FIG. 7) of the division device LC3 described in the third embodiment, and the other configurations are the same.

That is, the optical path adjusting mechanism 81 is composed of the first reflecting mirror 82 and the concave mirror. 83. The optical element group of the second mirror 84 and the cylindrical mirror 85 is configured. The second mirror 84 is connected to a motor (not shown) so as to be tiltably movable with the vicinity of the reflecting surface as a fulcrum P.

The laser oscillator 13 adjusts the laser beam LB0 composed of a small-diameter beam to be emitted vertically downward, and the laser beam LB0 is incident on the first mirror 82. The first mirror 82 is adjusted in such a manner that the laser beam LB0 is incident at an incident angle of 45 degrees and is emitted at a reflection angle of 45 degrees, and the emitted laser beam LB1 travels in the horizontal direction.

The laser beam LB1 traveling in the horizontal direction is incident on the concave mirror 83, and the laser beam LB2 reflected by the concave mirror 83 is incident on the second mirror 84 while being reduced in the beam diameter. The second mirror 84 can change the angle of incidence by adjusting the angle of the reflecting surface.

When the first laser beam is formed, the angle of the second mirror 84 is adjusted so that the center beam LB3a centered on the beam of the laser beam LB3 emitted from the second mirror 84 is as shown in Fig. 8(a). As shown, the reflection surface of the cylindrical mirror 85 is reflected, and the center beam LB4a emitted from the reflection surface travels vertically downward. The laser beam other than the center beam LB3a of the laser beam LB3 becomes a laser beam LB3 which is enlarged by the laser beam LB3a and is reflected by the cylindrical mirror 85, and is formed in a laser beam LB4 whose axial direction is enlarged and whose cross section is elliptical. An elliptical first laser spot LS1 is formed on the substrate G. At this time, the first laser spot LS1 has a heat energy distribution that is symmetrical in the long axis direction.

Further, when the second laser beam is formed, the angle of the second reflecting mirror 84 is adjusted to be in the light beam of the laser beam LB3 emitted from the second reflecting mirror 84. The center beam LB3b is reflected to the reflection surface of the cylindrical mirror 85 as shown in Fig. 8(b), and the center beam LB4b emitted from the reflection surface travels toward the substrate G in the oblique direction. The light beam other than the center beam LB3b of the laser beam LB3 is reflected by the cylindrical mirror 85 as a laser beam LB3 which is enlarged around the laser beam LB3b, and is formed in a laser beam LB4 which is enlarged in one axial direction and has an elliptical cross section. As a result of the oblique incidence of the light beam on the substrate G, the second laser spot LS2 whose thermal energy distribution is asymmetric in the long axis direction is formed.

Next, the division control unit 58 adjusts the angle of the second mirror 84 to form the first laser point LS1 when the first laser irradiation is performed, and adjusts the second mirror 84 when the second laser irradiation is performed. The angle is formed to form the second laser spot LS2.

(Embodiment 5)

Fig. 9 is a schematic configuration diagram of an optical path adjusting mechanism of the laser splitting device LC5 according to another embodiment of the present invention, wherein Fig. 9(a) shows a state in which a first laser spot is formed, and Fig. 9(b) shows a second mine. The state when shooting. In the laser splitting device LC4 and the laser splitting device LC5 described in the fourth embodiment, the cylindrical mirror 85 can be moved up and down only in the optical path adjusting mechanism 81 (Fig. 8), and the second mirror 84 can be fixed so as not to move. This is different, and the other constructs are the same.

In other words, the optical path adjusting mechanism 91 is composed of an optical element group of the first reflecting mirror 92, the concave mirror 93, the second reflecting mirror 94, and the cylindrical mirror 95. Among them, the cylindrical mirror 95 can be moved up and down by an arm (not shown) and a motor (not shown).

The laser oscillator 13 adjusts the laser beam LB0 composed of a small-diameter beam to be emitted vertically downward, and the laser beam LB0 is incident on the first mirror 92. The first mirror 92 has a mounting angle adjusted so that the laser beam LB0 will be 45 The incident angle is incident and is emitted at a reflection angle of 45 degrees, and the emitted laser beam LB1 travels in the horizontal direction.

The laser beam LB1 traveling in the horizontal direction is incident on the concave mirror 93, and the laser beam LB2 reflected by the concave mirror 93 is incident on the second mirror 94 while being reduced in the beam diameter. The laser beam LB3 reflected by the second mirror 94 is incident on the cylindrical mirror 95. The angle of incidence is adjusted by moving the position of the cylindrical mirror 95 up and down to adjust the angle of incidence.

When the first laser spot is formed, the position of the cylindrical mirror 95 is adjusted so that the center beam LB3a centered on the beam of the laser beam LB3 emitted from the second mirror 94 is as shown in Fig. 9(a). It is reflected to the reflecting surface of the cylindrical mirror 95, and the central light beam LB4a emitted from the reflecting surface travels vertically downward. The laser beam other than the center beam LB3a of the laser beam LB3 becomes a laser beam LB3 which is enlarged by the laser beam LB3a and is reflected by the cylindrical mirror 95, and is formed in a laser beam LB4 which is enlarged in the axial direction and has an elliptical cross section. An elliptical first laser spot LS1 is formed on the substrate G. At this time, the first laser spot LS1 has a heat energy distribution that is symmetrical in the long axis direction.

Further, when the second laser beam is formed, the position of the cylindrical mirror 95 is adjusted so that the center beam LB3b of the beam of the laser beam LB3 emitted from the second mirror 94 is as shown in Fig. 9(b). The center beam LB4b reflected to the reflecting surface of the cylindrical mirror 95 and emitted from the reflecting surface travels toward the substrate G in an oblique direction. The laser beam other than the center beam LB3b of the laser beam LB3 is reflected by the cylindrical mirror 95 as a laser beam LB3 which is enlarged around the laser beam LB3b, and is formed in a laser beam LB4 which is enlarged in one axial direction and has an elliptical cross section. The result that the beam is obliquely incident on the substrate G is formed The thermal energy is distributed at the second laser spot LS2 which is asymmetric in the long axis direction.

Next, by the division control unit 58, the position of the cylindrical mirror 95 is adjusted to form the first laser spot LS1 when the first laser irradiation is performed, and the position of the cylindrical mirror 95 is adjusted when the second laser irradiation is performed. To form the second laser spot LS2.

Although several embodiments using an optical lens or an optical mirror have been described above, the present invention is not limited to the embodiment described above, and even if the combination or arrangement of the optical lens or the optical mirror is changed a little, the same as the above embodiment can be realized. The light path is adjusted.

The present invention can be utilized for a division device for dividing a brittle material substrate by localizing heating by laser irradiation and cooling after heating, and reheating by second laser irradiation.

2‧‧‧Slide table

7‧‧‧ pedestal

12‧‧‧Rotating table

13‧‧‧Laser oscillator

14‧‧‧Light path adjustment mechanism

14a‧‧‧Light path adjustment component group

14b‧‧‧Motor Group

14c‧‧‧arm group

16‧‧‧cooling nozzle

18‧‧‧Cutter wheel

31‧‧‧ Plano-convex lens

32‧‧‧Mirror

33‧‧‧Polygon mirror

34~38‧‧‧Motor

37~39‧‧‧arm

50‧‧‧Control Department

52‧‧‧ Laser Drive Department

52a‧‧‧Laser light source drive unit

52b‧‧‧Light path adjustment mechanism drive department

58‧‧‧ Division Control Department

61, 71, 81, 91‧‧‧Light path adjustment mechanism

62, 72, 82, 92‧‧‧1st mirror

63, 75, 84‧‧‧2nd mirror

64‧‧‧ Plano-convex lens

65, 74, 85, 95‧‧‧ cylindrical lens

66‧‧‧ movable optical body

73, 83, 93‧‧‧ concave mirror

LB0~LB4‧‧‧Laser beam

LB3a, LB3b, LB4a, LB4b‧‧‧ center beam

LS1‧‧‧1st laser point

LS2‧‧‧2nd laser point

Fig. 1 is a schematic block diagram showing a laser beam splitting apparatus according to an embodiment of the present invention.

Fig. 2 is a view showing the configuration of a control system in the laser division device of Fig. 1.

Fig. 3 is a view for explaining the operation of the optical path adjusting mechanism of Fig. 1.

Fig. 4 is a view showing an example of the distribution of thermal energy between the first laser spot and the second laser spot.

Fig. 5 is a view for explaining the adjustment operation of the optical path adjusting mechanism in a comprehensive manner.

Fig. 6 is a schematic block diagram showing an optical path adjusting mechanism of the laser splitting device LC2 according to another embodiment of the present invention.

Figure 7 is a view showing a laser splitting device LC3 according to another embodiment of the present invention. A schematic diagram of the optical path adjustment mechanism.

Fig. 8 is a schematic block diagram showing an optical path adjusting mechanism of the laser splitting device LC4 according to another embodiment of the present invention.

Fig. 9 is a schematic block diagram showing an optical path adjusting mechanism of the laser splitting device LC5 according to another embodiment of the present invention.

1‧‧‧ horizontal stand

2‧‧‧Slide table

3, 4, 8‧‧‧ rails

5, 10a‧‧‧ lead screw

6, 10‧‧‧ bracket

7‧‧‧ pedestal

9‧‧‧Motor

11‧‧‧Rotating mechanism

12‧‧‧Rotating table

13‧‧‧Laser oscillator

14‧‧‧Light path adjustment mechanism

14a‧‧‧Light path adjustment component group

14b‧‧‧Motor Group

14c‧‧‧arm group

15‧‧‧Installation bracket

16‧‧‧cooling nozzle

17‧‧‧Up and down movement adjustment mechanism

18‧‧‧Cutter wheel

31‧‧‧ Plano-convex lens

32‧‧‧Mirror

33‧‧‧Polygon mirror

34~38‧‧‧Motor

37~39‧‧‧arm

LC1‧‧‧Laser splitter

Claims (7)

A device for dividing a brittle material substrate, comprising: a laser irradiation means for selectively irradiating a first laser spot and a second laser spot having different dot shapes on a brittle material substrate on a stage; and cooling means Cooling a cooling point near the first laser spot when the first laser spot is irradiated; and moving the means to move the first laser spot, the second laser spot, and the cooling point relative to the substrate; and dividing the control unit Controlling, moving the first laser spot while irradiating the first laser spot on the substrate, thereby heating at a temperature lower than a softening point of the substrate, and causing the cooling point to follow the first laser spot Moving and cooling to form a crack on the surface of the substrate, and further moving the second laser spot along the crack while irradiating the second laser spot, thereby heating the substrate again at a temperature lower than the softening point of the substrate. Thereby, the crack is extended to the back surface of the substrate to divide the substrate, wherein the laser irradiation means is formed by an optical path adjusting mechanism for adjusting an optical path of a laser beam emitted from a laser light source. First laser Or the second laser spot; when the laser irradiation means forms the first laser spot, the light beam shape having a substantially symmetrical thermal energy distribution centering on the vertical incident beam of the substrate is irradiated; When the laser beam is used to form the second laser beam, the light beam having a thermal energy distribution that is larger in the moving direction of the second laser beam than the rear side is the center of the oblique incident light beam that is incident on the substrate. The shape is illuminated. The splitting device of claim 1, wherein the optical path adjusting mechanism is provided with a rotating mirror on the optical path of the laser beam, and is provided with an adjustment for adjusting an incident position of the laser beam incident on the rotating mirror. mechanism. The dividing device of claim 1, wherein the optical path adjusting mechanism is provided with a mirror on an optical path of the laser beam, and an adjusting mechanism for adjusting an incident angle of the laser beam incident on the mirror . The dividing device of claim 2, wherein the optical path adjusting mechanism further includes an adjusting mirror or an adjusting lens disposed on the optical beam path for adjusting a beam shape. The dividing device of claim 4, wherein the second laser spot is adjusted to be at least larger than the first laser spot by the adjusting mirror or the adjusting lens. The dividing device according to any one of claims 1 to 3, wherein the dividing control unit moves the first laser spot and the cooling point on the substrate to form a crack, and The second laser spot is moved on the substrate such that the moving direction of the crack is reversed, and the substrate is divided by reciprocating movement. A method for dividing a brittle material substrate by heating a first laser spot while irradiating a first laser spot along a predetermined dividing line of a brittle material substrate, thereby heating the substrate at a temperature lower than a softening point of the substrate. Secondly, the substrate is cooled by following the cooling point of the first laser spot to form a crack on the surface of the substrate, and the second laser spot is further moved along the crack while irradiating the second laser spot, thereby softening the substrate. Reheating the substrate at a low temperature, thereby causing the crack to extend to the back of the substrate to be divided, The first laser spot or the second laser spot is formed by adjusting an optical path of a laser beam emitted from a laser light source by an optical path adjusting mechanism; the first laser spot is vertically shot The vertical incident beam entering the substrate is centered and has a shape of a heat energy distribution that is substantially symmetrical with respect to a moving direction of the first laser spot; the second laser spot is obliquely incident on the substrate The light beam is centered, and the shape of the thermal energy distribution having a larger front side than the rear side in the moving direction of the second laser spot is irradiated.