KR20170133131A - Substrate cutting method and apparatus using tilted laser beam - Google Patents

Abstract

The present invention relates to a substrate cutting method, and a substrate cutting device using tilting radiation of laser. The present invention enables a damage layer to be formed to be tilted with respect to a surface of a substrate in a cutting area of the substrate in order to rapidly cut the substrate through a continuous process.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a substrate cutting method and apparatus using tilting of a laser,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate cutting method and apparatus using a tilting irradiation of a laser, and more particularly, to a substrate cutting method and apparatus using a laser tilting irradiation capable of rapidly cutting a moving substrate by a continuous process .

In accordance with recent tendency of information communication industry represented by speeding up, integration, lightening, etc., development of information processing devices having very fast information processing ability has been accelerated, and an interface for displaying information processed by high- Technology development of an information display device (hereinafter, referred to as 'display device') serving as a role plays an important role in the industry.

Conventional CRTs (Cathode Ray Tube) have limitations in meeting the demand for display devices which have been used steadily throughout the 20th century, and recently, increasingly important portability, high resolution, and light weight. Accordingly, a liquid crystal display (LCD), a plasma display panel (PDP), a thin film transistor (TFT), an organic light emitting diode (OLED), and an organic electroluminescence panel Various types of display devices have been used, and in recent years, flexible display devices have also been used.

The substrate used in such display devices is cut during the process of manufacturing a mother substrate by cutting an edge portion or producing a substrate of a desired size from a mother substrate. One of the technologies widely used in the cutting process is Diamond cutter technology.

A dicing method in which a groove for cutting is formed on a substrate by a diamond blade rotating at a high speed according to a method of using a diamond, or a dicing method in which a diamond scribing wheel is used for cutting And a scribing method in which a groove is formed and a crack is formed in the thickness direction of the substrate.

However, such a diamond cutter technique has been known to cause undesired cracks, cracks, or damage during cutting. Such undesirable damage can be caused by various factors, but mainly due to the application of a mechanical force such as a diamond cutter, the cutting surface is not smooth and the stress is concentrated on the roughly cut portion.

That is, when a cutting blade is drawn by applying a mechanical force with a sharp blade, a mark having a uniform shape in the direction of the x-axis as well as the y-axis is not generated and a very irregular groove is pierced. The cutting direction is moved differently from the intended direction, and partial damage is caused by the micro-pieces or fragments.

Such undesired damage is disadvantageous in that it is difficult to use in a manufacturing process of a display device using a thin substrate such as a flexible display device because the frequency of occurrence is increased as the thickness of the substrate becomes thinner.

In order to overcome such disadvantages, recently, a laser cutting method has been developed and used. The lasers used are slightly different depending on the characteristics of a material to be processed, such as a carbon dioxide laser, an Nd: YAG laser, etc. However, the operating principles are basically as follows.

1 is a view for explaining a substrate cutting method using a known laser beam.

Referring to Fig. 1, a known substrate cutting method using a laser beam uses a method of irradiating a laser beam to form a focus on the inside of the substrate g to form damage inside the substrate g .

That is, by irradiating the laser beam generated from the laser generation module along the cut region with the laser beam irradiation module focused on the inside of the substrate g, damage inside the substrate g, that is, .

The laser beam passes through the substrate g and is partially absorbed to transfer energy to the constituent molecules. Due to the characteristic of the laser pulse having a high energy density, the energy density absorbed is high and a plasma is instantaneously formed in the substrate g. This plasma is annihilated after a certain life time, and thus it is deformed into a structure different from that of the surrounding materials. However, according to the cutting processing conditions, the plasma beam is narrow in the thickness direction in the irradiated portion of the laser beam, . The internal defect formed by the laser beam is generally referred to as " damage ", and the substrate can be cut by using a process of continuously forming damage with the laser beam. Such a damage formation process may be called a filiamentation process or a time-shift process, and there may be some differences in the form of damage formation and the type of damage to be formed, but the technical principle is similar .

Referring to FIG. 1, a substrate cutting process using a known laser beam irradiates a laser beam along a cut region of a substrate to continuously form a series of damage d in the substrate g. Herein, a portion where the damage d is continuously formed in the row direction is defined as a damage layer.

Generally, since the thickness of the substrate g is larger than the height of the damage d, that is, the thickness of the damage layer, in order to cut the substrate, a plurality of damage layers must be formed in the cut region in the thickness direction of the substrate.

The movement of the laser beam is generally defined as a scan when the focal point of the laser beam is moved in the direction of the line and the damage d is continuously formed in the substrate g at predetermined intervals. In the case of the illustrated substrate, the focus of the laser beam is shifted in the direction of the line, and after forming the damage layer of one layer, an additional damage layer must be formed while adjusting the focus height by adjusting the laser beam in the Z axis direction. That is, in the example shown in FIG. 1, the laser beam is scanned three times in total while adjusting the laser beam in the Z-axis direction, so damage layers can be formed that enable cutting in the cut region.

However, since the substrate continuously moves in the continuous manufacturing process of the substrate g, it is not possible to repeatedly form another damage layer on the damage layer formed on the lower side of the substrate in the cut region in the substrate g. Therefore, there is a problem that the substrate cutting process using the known laser beam can not be used in the continuous manufacturing process in which the substrate g moves in one direction.

That is, since the cutting process must be performed in a state in which the movement of the substrate g is stopped, the work process is increased, and the efficiency of the work is lowered, and the productivity is lowered.

Korean Patent Publication No. 0876502 (December 22, 2008)

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above problems, and it is an object of the present invention to provide a method of manufacturing a semiconductor device, in which a damage layer is formed in a tilted direction with respect to a surface of a substrate, And to provide a method and apparatus for cutting a substrate using tilting irradiation of laser so that the substrate can be quickly cut by the process.

According to another aspect of the present invention, there is provided a method of cutting a substrate using a tilting laser, the method comprising: irradiating a laser beam onto a substrate along a cut region on the substrate to form a damage layer In the method of cutting a substrate using tilting irradiation, the damage layers are formed to be inclined with respect to the substrate surface.

According to the present invention, the substrate moves in one direction, and the damage layers are continuously formed in the cutting region in the opposite direction in which the substrate moves.

According to the present invention, the damage layers are at least partially overlapped with the upper end of one of the damage layers located in the front of the substrate moving direction and the lower ends of the other damage layers located behind the one moving direction of the one damage layer.

According to the present invention, at the time of formation of the damage layers, the direction of advance of the laser beam at the time of formation of one damage layer positioned forward in the movement direction of the substrate and the direction of movement of the other damage layer The advancing direction of the laser beam at the time of formation is opposite to each other.

According to the present invention, in the cut region, a damage layer inclined in one direction and a damage layer inclined in another direction intersecting with the inclined damage layer in the one direction are formed together.

A substrate cutting apparatus using tilting irradiation of a laser according to the present invention is arranged forward of a substrate moving direction and forms a damage layer by irradiating a laser beam along a predetermined cut region of the substrate, A laser beam irradiating module for irradiating a laser beam to the cut region so as to extend in an obliquely crossing direction; And a control unit controlling the transfer speed of the substrate such that the slantingly extended damage layer is continuously formed in the cut region in a direction opposite to the movement of the substrate.

According to the present invention, a plurality of laser beam irradiation modules are provided so as to face each other with respect to the substrate, and each of the laser beam irradiation modules irradiates a laser beam to the cut region to form a damage layer, The damage layer formed by the laser beam irradiation module crosses the damage layer formed by another laser beam irradiation module.

According to the present invention, the laser beam irradiation module is a scanner module that repeatedly irradiates a laser beam while moving the focus of the supplied laser beam within a designated section.

According to the present invention, the scanner module irradiates the laser beam in a zigzag shape while repeatedly reciprocating within a designated section.

According to the present invention, the control unit controls the advancing speed of the laser beam by the laser irradiation module and the moving speed of the substrate so that the damage layers formed obliquely to the cutting area overlap each other.

According to the substrate cutting method and the substrate cutting apparatus using the tilting irradiation of the laser according to the present invention having the above-described structure, the substrate which moves by irradiating the laser beam to the cut region of the substrate in the state of moving the substrate is continuously processed So that it is possible to cut not only the process but also the productivity.

In particular, since the laser beam is irradiated while the focal point of the laser beam is repeatedly moved within the designated irradiation area, adjustment of the Z axis for the laser beam is unnecessary.

The present invention can be used not only for cutting a substrate for display, particularly a glass substrate for a display, but also for cutting a building material, a glass substrate for an automobile, and also for cutting a tempered glass and a non-tempered glass substrate.

1 is a conceptual diagram for explaining a substrate cutting method using a known laser beam.
2 is a view for explaining the principle of a substrate cutting method using tilting irradiation of a laser according to an embodiment of the present invention.
3 is a view illustrating a state where a laser beam of a substrate cutting apparatus according to an embodiment of the present invention moves along a scan region.
4 is a view for explaining a scanner module used in a substrate cutting method and apparatus according to an embodiment of the present invention.
5 to 7 are views for explaining a substrate cutting method using a laser beam according to an embodiment of the present invention.
8 is a view showing a substrate cutting apparatus according to another embodiment of the present invention.
9 is a view for explaining a substrate continuous cutting apparatus using a substrate cutting apparatus according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to Figs. 2 to 9. Fig.

2 is a view for explaining the principle of a substrate cutting method using tilting irradiation of a laser according to an embodiment of the present invention.

The substrate cutting apparatus using the tilting irradiation of the laser according to the embodiment of the present invention irradiates the laser beam to the inside of the substrate 200 along the cut region 250 of the substrate 200, And a laser beam irradiation module for continuously forming the damage layers L1, L2, L3, and L4 in an inclined manner with respect to the surface of the substrate 200. [

In the present invention, the damage regions L1, L2, L3, and L4 extending along the cut region 250 and extending obliquely with respect to the surface of the substrate 200 are formed in the cut region 250, So that the substrate 200 can be cut through a process of successively forming successively.

The laser beam irradiation module irradiates the inside of the substrate 200 with the laser beam in the cut region 250 of the substrate 200 to form the damage d which is narrow and long and which is an internal defect in the direction of movement of the laser beam, In this specification, the damage d is defined as a damage layer L1, L2, L3, and L4, which are continuous in the moving direction of the laser beam.

According to the present invention, damage layers L1, L2, L3, and L4 extending in an inclined direction with respect to the extending direction of the cut region 250 of the substrate 200, that is, The substrate 200 is sequentially and continuously formed along the cut region 250 of the substrate 200 so that the substrate 200 can be cut in the cut region 250 of the substrate 200.

Preferably, the method of cutting a substrate using a laser beam according to the present invention includes the steps of moving a substrate 200 in one direction and removing damage layers L1, L2, L3, and L4 extending obliquely with respect to the surface of the substrate 200 So that the substrate 200 can be cut while continuously transferring the substrate 200 in one direction.

When the substrate 200 is manufactured through a series of manufacturing processes and supplied linearly through the substrate supply unit (not shown) continuously, the laser beam irradiation module is moved in a direction inclined with respect to the surface of the substrate 200 L2, L3 and L4 are formed by successively forming the damage d in a line while moving the focus of the laser beam to the substrate (L1, L2, L3, L4) 200 as well as with respect to the direction of movement of the substrate 200.

Since the substrate 200 is moving, when the laser beam is irradiated repeatedly while moving in the laser beam irradiation area by the laser beam irradiation module, the inclined damage layers L1, L2, L3 and L4 are irradiated onto the substrate 200 In the cutting region 250 of FIG.

That is, when the laser beam is moved to one side in the designated irradiation area to form a single damage layer, and the laser beam moves to one side in the designated irradiation area to form the damage layer, Another damage layer is formed on the upper portion of one of the damage layers extending obliquely to the front side. In this case, the damage layers L1, L2, L3, and L4 are successively formed along the direction opposite to the moving direction of the substrate 200 in the cut region 250 of the substrate 200. [

According to the embodiment of the present invention, the laser beam irradiation by the laser beam irradiation module in the set irradiation region is repeatedly performed while moving from one side to the other side and then from one side to the other side.

Therefore, the damage layers L1, L2, L3, and L4 are continuously formed in the cut region 250 while irradiating the laser beam in a staggered pattern while repeating reciprocal movement within the designated irradiation region.

As shown in FIG. 3, according to the present invention, the laser beam irradiation module preferably includes a scanner module 100 for irradiating a laser beam while repeatedly moving the focal point of the laser beam within a designated irradiation area. As such a scanner module 100, a galvanometer scanner module and the like are known.

FIG. 3 is a view for explaining an embodiment of a scanner module 100 as an example of a laser beam irradiation module used in a cutting apparatus using tilting irradiation of a laser according to the present invention.

The scanner module 100 includes a beam irradiator 20, a beam scanner 30 and a condenser lens 40 that allows the laser beam emitted from the beam scanner 30 to be converged to a desired focal position.

The beam scanner 30 includes a driver 310 and one or two motors 320 and 330 driven by the driver 310. The beam scanner 30 is connected to the rotation axis of the motors 320 and 330, And includes first and second mirrors 340 and 350 that repeat rotation according to the angle and direction.

A laser beam having a diameter of approximately 10 mu m and incident on the second mirror 350 from the laser light source 10 through the beam irradiation unit 20 is reflected by the first mirror 340 of the beam scanner 30. [ A variety of wavelengths of the laser beam can be used.

The laser beam reflected by the first mirror 340 is irradiated to the condenser lens 40. The condenser lens 40 irradiates the laser beam within the substrate 200 while keeping the focal distance of the irradiated laser beam constant. So that a damage layer is formed along the scan area, that is, the irradiation area of the set laser beam. Here, the first and second mirrors 340 and 350 may be used in different numbers depending on the processing purpose.

At this time, the first and second mirrors 340 and 350 can reciprocate in the directions and angles specified by the motors 320 and 330, thereby making it possible to reciprocate the laser beam along the scan region. It is also possible to adjust the focal depth of the laser beam to be irradiated by adjusting the height of the first and second mirrors 340 and 350.

According to the embodiment of the present invention, it is preferable to use the scanner module 100 configured as described above as the laser beam irradiation module. The laser beam is irradiated while moving along the cut region 250 of the substrate 200 in a state where the axis of the laser beam is tilted at a predetermined angle with respect to the surface of the substrate 200 so that the damage layers L1, L2, L3, .

4 is a view showing a laser beam irradiation module according to another embodiment of the present invention.

The laser beam irradiation module 100 'according to another embodiment of the present invention includes a scanner module 100' shown in FIG. 3 that repeatedly irradiates a laser beam while moving the focal point of the laser beam within a designated section while the scanner module is stopped 100 system, the laser beam irradiation module 100 'is set to irradiate a laser beam to a predetermined position, and the laser beam irradiation module 100' reciprocates in a predetermined section using a cam mechanism, a servo motor, or the like , And consequently, the laser beam is repeatedly irradiated within a designated section.

As described above, the laser beam irradiation module is not limited to the scanner module shown in FIG. 3, and can be configured as various embodiments.

Referring again to FIG. 2 and FIGS. 5 to 7, a method of cutting a substrate using tilting irradiation of a laser according to the present invention will be described.

The substrate cutting method using the tilting irradiation of the laser according to the present invention uses the scanner module 100 as the laser beam irradiating module as described above so that the laser beam is irradiated onto the moving substrate 200 more easily, The damage layers L1, L2, L3, and L4 can be formed.

Referring to FIG. 5, the scanner module 100 irradiates a laser beam to a cut region 250 of a moving substrate 200 to form a damage layer L1 extending in a direction inclined with respect to the surface.

The scanner module 100 continuously forms the damage d at predetermined intervals while moving the focal point of the laser beam within the designated irradiation area, i.e., the scan area. The scan area, which is the moving area of the ray point beam, The damper layer L1 is also formed by extending the damages d in an inclined direction with respect to the surface of the substrate 200. In this case, The extending direction of the damage layer L1 also has a predetermined inclination angle with respect to the moving direction of the substrate 200. [

6 shows a process of forming an L2 damage layer on the L1 damage layer.

The scanner module 100 forms a damage layer while moving the laser beam in the scan area, and then repeatedly moves the laser beam in the scan area to form a damage layer. During the transfer of the substrate 200 , And the L2 damage layer is formed while extending in an oblique direction on the upper portion of the L1 damage layer extending in the oblique direction toward the front of the substrate 200 in the moving direction. That is, the L2 damage layer is formed along the cut region of the substrate 200 so as to be sloped continuously to the upper portion of the L1 damage layer.

At this time, the formation direction of the L1 damage layer and the formation direction of the L2 damage layer are preferably opposite to each other. That is, the L1 damage layer is formed while moving the laser beam in the a direction in the scan area, and the L2 damage layer formed in the upper part is formed while moving the laser beam in the b direction in the scan area. In this case, after forming the L1 damage layer, it is possible to form the L2 damage layer while moving the laser beam in the direction b without returning to the starting position in the direction a, so that the damage layer can be formed more quickly . Therefore, the cutting process of the substrate 200 can be performed more quickly.

FIG. 7 is a view showing a process of forming an L3 damage layer on the upper part of the L2 damage layer, and the laser beam moves again in the direction a in the scan area to form an L3 damage layer.

5 and 6, as shown in FIG. 2, the damage layers L1, L2, L3, and L4 are continuously formed in the cut region 250 of the substrate 200 in an inclined direction . In this process, the moving speed of the substrate 200 is coordinated with the moving speed of the laser beam in the scanning area of the scanner module 100, that is, the scanning speed, so that the damage layers are moved in the moving direction of the substrate 200 As shown in Fig. 4 is a moving stage for guiding the substrate 200 to be transported.

Referring to FIG. 2 again, the damage layers L1, L2, L3, and L4 are formed so that the upper end of the lower damage layer and the lower end of the upper damage layer are in contact with each other.

However, according to the present invention, the damage layers L1, L2, L3 and L4 may be formed so as to be adjacent to each other or partially overlap in the thickness direction, It is possible to improve the cutting accuracy. This adjustment of the overlap length is possible by adjusting the moving speed and the scanning speed of the substrate 200. A control unit 400 (see FIG. 8) may be provided to adjust the moving speed and the scanning speed of the substrate 200 to correspond to each other.

As shown in FIG. 2, the laser beam is irradiated continuously in the zigzag direction by the scanner module 100 in the cutting area 250 with respect to the moving substrate 200 to form the damage d L2, L3 and L4 extend in the same direction as the surface of the substrate 200, the damage layers L1, L2, L3 and L4 move in the moving direction of the substrate 200 . Therefore, it is possible to continuously cut the substrate 200 while moving the substrate 200 without stopping the movement of the substrate 200.

8 is a view illustrating a substrate cutting apparatus according to another embodiment of the present invention. The first scanner module 100a mounted on the substrate 200 is tilted at a predetermined angle with respect to the surface of the substrate 200 L2, L3, and L4 by irradiating a laser beam along a cut region 250 of the substrate 200 and a second scanner module 100b installed at a lower portion of the substrate 200, The first scanner module 100a is arranged in a direction opposite to the first scanner module 100a with respect to the substrate 200 and along the cut region 250 of the corresponding substrate 200, A damage layer is formed in a direction intersecting with the direction of the surface of the substrate. That is, the first scanner module 100a and the second scanner module 100b are provided on the upper and lower surfaces of the substrate 200 in the directions opposite to each other with respect to the substrate 200, And the damage layers formed by the scanner modules 100a and 100b are overlapped with each other while being crossed with each other.

In this way, when the damage layer is continuously formed on the substrate 200 in a direction intersecting each other and overlapped with each other, the substrate 200 can be more easily cut, and the substrate cutting performance is improved.

9 is a view for explaining an apparatus for continuously cutting a substrate using a substrate cutting apparatus using tilting irradiation of a laser according to an embodiment of the present invention.

Referring to FIG. 9, the apparatus for continuously cutting a substrate using a substrate cutting apparatus using tilting irradiation of a laser according to an embodiment of the present invention includes a laser beam irradiation module and a control unit 400. The laser beam irradiation module is preferably a scanner module 100 that repeatedly irradiates the laser beam while moving the focus of the supplied laser beam within a designated irradiation area.

However, the present invention is not limited to this. As described with reference to Fig. 4, it can be constituted mechanically by a cam, a piezo, and a servo motor. Various laser beam irradiation modules capable of repeated irradiation can be employed.

According to the present invention, the substrate 200 is not particularly limited as long as it is a material that has high durability so that it can be sufficiently protected from external force by being applied to a liquid crystal display device, a touch screen panel, or the like, The substrate 200 to be used can be used without any particular limitation. For example, the substrate 200 may be made of glass, polyethersulphone (PES), polyacrylate (PAR), polyetherimide (PEI), polyethyelenenaphthalate (PEN) (PET), polyethyelene terepthalate, polyphenylene sulfide (PPS), polyallylate, polyimide, polycarbonate (PC), cellulose triacetate (TAC), cellulose acetate Cellulose acetate propionate (CAP) or the like may be used. The substrate cutting apparatus according to the present invention is particularly advantageous for cutting a class substrate and can be applied to both reinforced and unreinforced glass.

The substrate continuous cutting apparatus using the substrate cutting apparatus using the tilting irradiation of the laser according to the embodiment of the present invention continuously cuts the edge portion in the longitudinal direction while the substrate 200 is continuously supplied from the substrate supply unit, 200). ≪ / RTI >

The substrate continuous cutting apparatus using the substrate cutting apparatus using the laser tilting irradiation according to the embodiment of the present invention includes the scanner module 100 arranged in front of the moving direction of the substrate 200 supplied from the substrate supplying unit.

The scanner module 100 is preferably spaced apart from the substrate 200 in the width direction so that the widthwise ends of the continuously moving substrate 200 can be continuously cut in the longitudinal direction of the substrate 200, The laser beam is irradiated so that the damage layer is continuously formed in the slit region 250 of the substrate 200 in an inclined direction.

That is, the scanner module 100 irradiates the laser beam to the inside of the substrate 200 in the cut region 250 of the substrate 200 to form a damage layer in which the damage d is continuous in a row, So that the damage layer is formed to be inclined with respect to the moving direction of the substrate 200. At this time, the damage layers are continuously formed along the direction opposite to the movement of the substrate 200 while being adjacent or partially overlapped in the thickness direction of the damage layer.

The control unit 400 adjusts the moving speed of the substrate 200 supplied from the substrate supply unit and the scanning speed of the scanner module 100 to adjust the distance in the thickness direction between the damage layers. As described above, To be adjacent or partially overlapped.

Accordingly, damage layers are continuously formed along the cut-off region 250 of the substrate 200 supplied and transported from the substrate supply unit, thereby enabling cutting of the substrate 200.

8, an additional scanner module may be provided on the lower surface of the substrate 200 to form a damage layer so that the damage layers overlap with each other in the cut-off area.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It should be understood that various modifications made by the person skilled in the art are also within the scope of protection of the present invention.

10: Laser light source 20: Beam irradiation part
30: beam scanner 40: condenser lens
50: substrate 60: stage
100: scanner module 200: substrate
250: cutting area 280: moving stage
L1, L2, L3, L4: Damage layer
a, b: direction of movement of the laser beam

Claims (10)

A method of cutting a substrate using tilting irradiation of a laser which irradiates a laser beam on a substrate inside a cut region on the substrate to form a damage layer in which the damage is continuous in a row,
Wherein the damage layers are formed to be inclined with respect to the surface of the substrate.
The method according to claim 1,
Wherein the substrate moves in one direction and the damage layers are continuously formed in the cutting region in a direction opposite to the movement of the substrate.
3. The method of claim 2,
Wherein the damage layers are at least partially overlapped with an upper end of a damage layer positioned in front of the substrate in a moving direction of the substrate and a lower end of the other damage layer positioned behind the substrate in the moving direction of the one damage layer. A method of cutting a substrate.
The method according to claim 2 or 3,
Wherein the laser beam is irradiated at the time of formation of the damage layer and at the time of formation of the other damage layer located behind the direction of movement of the substrate of the one damage layer, Wherein the traveling direction of the laser beam is opposite to the traveling direction of the laser beam.
The method according to claim 1,
Wherein the cut-off region is formed with a damage layer inclined in one direction and a damage layer inclined in another direction intersecting with the one-directional inclined damage layer.
A laser beam is irradiated along a predetermined cut region of the substrate to form a damage layer so that the damage layer extends in a direction intersecting obliquely with the moving direction of the substrate, A laser beam irradiation module for irradiating the laser beam; And
And a controller controlling the transfer speed of the substrate so that the inclined extending damage layer is continuously formed in the cut region in a direction opposite to the movement of the substrate.
The method according to claim 6,
A plurality of laser beam irradiation modules are provided so as to face each other with respect to the substrate, and each of the laser beam irradiation modules irradiates a laser beam to the cut region to form a damage layer,
Wherein the damage layer formed by any one of the laser beam irradiation modules crosses a damage layer formed by another laser beam irradiation module.
The method according to claim 6,
Wherein the laser beam irradiation module is a scanner module for repeatedly irradiating a laser beam while moving the focus of the supplied laser beam within a designated section.
9. The method of claim 8,
Wherein the scanner module irradiates the laser beam in a zigzag shape while repeatedly reciprocating within a designated section.
The method according to claim 6,
Wherein the controller controls tilting irradiation of the laser to control the advancing speed of the laser beam by the laser irradiation module and the moving speed of the substrate so that the damage layers formed on the cutting area are partially overlapped with each other.

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