KR100551527B1 - Method and device for scribing brittle material substrate - Google Patents

Abstract

The laser beam oscillated from the laser oscillator 34 is irradiated along the scribe scheduled line on the surface of the mother glass substrate 50. As a result, a laser spot is formed on the mother glass substrate 50. Cooling water is injected from the cooling nozzle 37 in proximity to the laser spot. The laser spot has a maximum thermal energy intensity only at an end portion close to the region where the coolant is sprayed, so that a large stress gradient is formed between the laser spot and the region where the coolant is sprayed. As a result, cracks along the vertical direction are reliably formed in the mother glass substrate 50. As a result, a scribe line can be reliably and efficiently formed on the mother glass substrate.

Description

Scribing method and scribing apparatus for brittle material substrates {METHOD AND DEVICE FOR SCRIBING BRITTLE MATERIA             

The present invention is brittle to cut brittle material substrates such as glass substrates, semiconductor wafers, and the like used in flat panel displays (hereinafter referred to as flat panel displays). A scribe method and a scribe device for forming a scribe line on a surface of a material substrate.

An example will be described in which a scribe line is formed on a mother glass substrate of a liquid crystal display panel formed by bonding a glass substrate, which is a kind of a brittle material substrate.

An FPD such as a liquid crystal display panel formed by bonding a pair of glass substrates is bonded to each other by bonding a pair of large mother glass substrates to each other so that each mother glass substrate is cut to have a size of a glass substrate constituting the FPD. Each mother glass substrate has a scribe line formed by a cutter made of diamond in advance and cut along the scribe line.

When a scribe line is mechanically formed by a cutter or the like, stress is accumulated in the periphery of the formed scribe line. When the mother glass substrate is cut along the scribe line, stress is accumulated at edges and peripheral portions of the edges of the cut glass substrate to form stress condensation. In such stress condensation, potential stresses that cause cracks to accumulate near the surface of the glass substrate are accumulated, and when the stress accumulated in the stress condensation is released, cracks may occur and the edge portion may fall off. Debris generated by the edge portion falling off may adversely affect the FPD to be produced.

Recently, a method of using a laser beam for forming a scribe line on the surface of a mother glass substrate has been put to practical use. In the method of forming a scribe line on a mother glass substrate using a laser beam, a laser beam is irradiated from the laser oscillator 61 with respect to the mother glass substrate 50 as shown in FIG. The laser beam irradiated from the laser oscillation device 61 forms an elliptical laser spot LS on the surface of the mother glass substrate 50 along a scribe predetermined line SL formed on the mother glass substrate 50. . The laser beam irradiated from the mother glass substrate 50 and the laser oscillation device 61 can be relatively moved along the longitudinal direction of the laser spot LS.

The mother glass substrate 50 is heated by the laser beam to a temperature lower than the temperature at which the mother glass substrate 50 is melted. As a result, the surface of the mother glass substrate 50 irradiated with the laser spot LS is heated without melting.

In the vicinity of the laser beam irradiation area on the surface of the mother glass substrate 50, a cooling medium such as cooling water is injected from the cooling nozzle 62 so that a scribe line is formed. On the surface of the mother glass substrate 50 to which the laser beam is irradiated, compressive stress is generated by heating by the laser beam and tensile stress is generated by spraying a cooling medium. As the tensile stress is generated close to the region where the compressive stress is generated, a stress gradient based on the respective stresses is generated between the regions, and the mother glass substrate 50 has an end portion of the mother glass substrate 50. Vertical cracks are generated along the scribe scheduled line SL from the cut TR of the thin groove previously formed in the groove.

The vertical cracks formed on the surface of the mother glass substrate 50 in this manner are so small that they are usually not visible to the naked eye, so they are called blind cracks.

FIG. 5 is a schematic perspective view showing the formation of blind cracks on the mother glass substrate 50 scribed by the laser scribing apparatus, and FIG. 6 is a plan view schematically showing the state of physical change on the mother glass substrate 50.

The laser beam oscillated from the laser oscillation device 61 forms an elliptical laser spot LS on the surface of the mother glass substrate 50. The laser spot LS is irradiated so that a long axis may coincide with the scribe plan line SL, for example, with an elliptical shape of 30.0 mm long diameter b and 1.0 mm short diameter a.

In this case, in the laser spot LS formed on the mother glass substrate 50, the thermal energy intensity of the outer edge portion is larger than the thermal energy intensity of the central portion. Such a laser spot LS is formed by adjusting the heat energy intensity distribution so that each end part in the long axis direction becomes the maximum heat energy intensity in the laser beam whose heat energy intensity is Gaussian distribution. Therefore, the thermal energy intensity becomes the largest at each end part in the long axis direction located on the scribe plan line SL, and the thermal energy intensity of the center part of the laser spot LS between both ends becomes smaller than the thermal energy intensity in each end part. have.

The mother glass substrate 50 is relatively moved along the major axis direction of the laser spot LS, and therefore, the mother glass substrate 50 has a large thermal energy intensity at one end of the laser spot LS along the scribe scheduled line SL. After heating, it is heated to a small thermal energy intensity at the center of the laser spot LS, and then to a large thermal energy intensity thereafter. After that, the coolant is injected from the cooling nozzle 62 to the cooling point CP on the scribe line, which is, for example, 2.5 mm apart from the rear end of the laser spot LS.

As a result, a temperature gradient occurs between the laser spot LS and the cooling point CP, and a large tensile stress is generated in the region on the side opposite to the laser spot LS with respect to the cooling point CP. Using this tensile stress, vertical cracks are formed from the cut marks formed at the ends of the mother glass substrate 50 in the thickness t direction of the mother glass substrate 50 along the predetermined scribe line.

The mother glass substrate 50 is heated by an elliptical laser spot LS. In this case, the heat transfer from the surface of the mother glass substrate 50 to the inside of the mother glass substrate 50 by the large thermal energy intensity at one end portion of the laser spot LS is performed relative to the mother glass substrate 50. The part heated by the front end of the laser spot LS by moving is heated by the small thermal energy intensity in the center part of the laser spot LS, and then again at the rear end of the laser spot LS. Heated by thermal energy intensity.

In this way, the surface of the mother glass substrate 50 is reliably conducted to the inside while the surface of the mother glass substrate 50 is heated by a large thermal energy intensity and then heated by a small thermal energy intensity. In addition, at this time, the surface of the mother glass substrate 50 is prevented from being continuously heated by a large thermal energy intensity, and the melting of the surface of the mother glass substrate 50 is prevented. After that, when the mother glass substrate 50 is heated again by the large thermal energy strength, the mother glass substrate 50 is surely heated up to the inside of the mother glass substrate 50 to generate a compressive stress on the surface and the inside of the mother glass substrate 50. The tensile stress is generated by cooling water being injected to the cooling point CP near the region where such compressive stress is generated.

When compressive stress is generated in the heating area by laser spot LS and tensile stress is generated at cooling point CP by cooling water, the compressive stress is generated in the heat diffusion region between laser spot LS and cooling point CP. A large tensile stress is generated in the region on the side opposite to the laser spot LS with respect to the cooling point CP. By using the tensile stress, blind cracks are generated along the scribe scheduled line from the cut TR formed at the end of the mother glass substrate 50.

When a blind crack as a scribe line is formed on the mother glass substrate 50, the mother glass substrate 50 is supplied to the following cutting process so that a bending moment occurs to cause the bending crack to widen on both sides of the blind crack. Force is exerted. Accordingly, the mother glass substrate 50 is cut along the blind crack formed along the scribe line SL.

In such a scribing apparatus, the laser spot LS formed on the surface of the mother glass substrate 50 has a heat energy intensity distribution so that the heat energy intensity is maximized in the major axis direction. As described above, since the thermal energy intensity is maximum at each end portion in the major axis direction, the absolute value of the thermal energy intensity at each end portion is relatively small. Therefore, if the relative speed of the laser spot LS and the mother glass substrate 50 is increased, the rear end portion of the laser spot LS close to the cooling point CP may not be sufficiently heated despite the maximum thermal energy intensity. There is a fear that a sufficient stress gradient cannot be obtained between the cooling point CP.

In such a case, the relative movement speed between the mother glass substrate 50 and the laser spot LS must be slowed to increase the heating time by the end of the laser spot LS, and as a result, there is a possibility that the blind crack cannot be efficiently formed.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an object thereof is to provide a scribing method and a scribing apparatus for a brittle material substrate which can efficiently and reliably form a scribe line on a brittle material substrate such as a mother glass substrate.

The scribe method of the brittle material substrate of the present invention is lower than the softening point of the brittle material substrate along the scribe predetermined line on the surface of the brittle material substrate. The laser beam is continuously irradiated so that a laser spot of temperature is formed, while the area adjacent to the laser spot is successively cooled along the scribe line by continuously cooling the laser beam. A method of scribing a brittle material substrate in which cracks are formed along a line, wherein the laser spot has a maximum thermal energy intensity only at one end portion close to the region to be cooled. It is characterized in that.

The cooling region is characterized in that the elongated along the scheduled scribe line.

The cooling zone is characterized in that the region adjacent to the cooling zone is a second heating zone that is continuously heated along the scribe scheduled line.

The second heating region is heated by a laser spot formed by a laser beam.

The laser spot of the second heating region has a maximum thermal energy intensity at an end portion close to the region to be cooled.

In addition, the scribing method of the brittle material substrate of the present invention moves the laser beam continuously while irradiating a laser spot at a temperature lower than the softening point of the brittle material substrate along a scribe scheduled line on the surface of the brittle material substrate. A method of scribing a brittle material substrate in which cracks are formed along a scribe scheduled line by continuously cooling an area adjacent to the laser spot along a scribe scheduled line in succession to the laser spot, the scribing method of a brittle material substrate heated by the laser spot. The temperature distribution is at a maximum temperature only at one end close to the region to be cooled.

The cooling region is characterized in that the elongated along the scheduled scribe line.

An area close to the cooling area, on the side opposite to the laser spot with respect to the cooling area, is added as a second heating area continuously heated to the cooling area along the scribe scheduled line.

The second heating zone is characterized by a maximum temperature at an end near the cooling zone.

The scribing apparatus of the brittle material substrate of the present invention is a scribing apparatus of a brittle material substrate which forms a crack along a predetermined scribe line on the surface of the brittle material substrate, wherein a laser spot having a temperature lower than the softening point of the brittle material substrate is formed. Means for irradiating the laser beam as continuously as possible, and means for continuously cooling the vicinity of the region heated by the laser spot along a predetermined scribe line, the laser spot being maximum only at an end proximate to the region to be cooled. It is characterized in that the heat energy intensity of.

In addition, the scribing apparatus for a brittle material substrate of the present invention is a scribing apparatus for a brittle material substrate that forms a crack along a predetermined scribe line on the surface of the brittle material substrate, wherein the first laser has a temperature lower than the softening point of the brittle material substrate. Means for continuously irradiating a laser beam so that a spot and a second laser spot are formed, and means for continuously cooling the vicinity of an area heated by the first laser spot along a scribe scheduled line, the first laser The spot and the second laser spot are characterized in that they have a maximum thermal energy intensity only at the end close to the region to be cooled.

Fig. 1 (a) is a schematic plan view showing an embodiment of the scribing method of the present invention, and Fig. 1 (b) is a heat energy intensity distribution of each laser spot used in the method.

2 is a front view showing an example of an embodiment of a scribing apparatus of the present invention.

3 is a schematic configuration diagram showing an example of a laser oscillation apparatus and an optical apparatus used in the scribing apparatus of the present invention.

4 is a schematic diagram for explaining the operation of the scribing apparatus using the laser beam.

Fig. 5 is a perspective view schematically showing a state of formation of blind cracks on a mother glass substrate scribed by a laser scribe device.

Fig. 6 is a plan view schematically showing a physical change state on a mother glass substrate scribed by a laser scribe device.

EMBODIMENT OF THE INVENTION Hereinafter, the Example of this invention is described based on drawing.                 

Fig. 1 (a) is a schematic plan view of the surface of a mother glass substrate showing an embodiment of a scribing method of a brittle material substrate of the present invention. This scribing method is, for example, by cutting a large mother glass substrate to form a plurality of glass substrates constituting a flat panel display such as a liquid crystal display panel. Prior to cutting the substrate, it is carried out to form a blind crack that becomes a scribe line on the mother glass substrate.

As shown in Fig. 1 (a), a first laser spot is formed on the surface of the mother glass substrate by irradiation of a laser beam along a scribe predetermined line SL. spot) LS1 is formed. Further, a thin groove-shaped cut along the scribe line is formed at an end portion of the mother glass substrate on the extension line of the scribe line SL on the surface of the mother glass substrate.

The first laser spot LS1 is, for example, an oval shape having a long diameter of 30.0 mm and a short diameter of 1.0 mm, and has an arrow A with respect to the surface of the mother glass substrate in a state where the long diameter is along the scribe line SL. It is relatively moved in the direction indicated by.

In this case, the distribution of the thermal energy intensity along the long axis direction of the first laser spot LS1 formed on the surface of the mother glass is sheared in the advancing direction with respect to the mother glass substrate as shown in Fig. 1 (b). Although gradually increasing from the front part to the rear end part, the strength level is relatively small, and at the rear end part of the advancing direction, the strength level rapidly increases, The maximum thermal energy intensity is obtained only at the end portion. The elliptical first laser spot LS1 moves along the scribe scheduled line SL on the surface of the mother glass substrate and sequentially heats the scribe scheduled line SL.

The first laser spot LS1 heats the mother glass substrate while moving at a high temperature with respect to the mother glass substrate at a temperature lower than the temperature at which the mother glass substrate is melted. As a result, the surface of the mother glass substrate irradiated with the laser spot LS1 is heated without melting.

On the surface of the mother glass substrate, a rectangular cooling point CA is formed in the rear of the traveling direction of the first laser spot LS1 extending along the scribe plan line SL in proximity to the first laser spot LS1. Cooling point CA is formed by the cooling nozzle cooling water, He gas, N ₂ gas, spraying a cooling medium (冷却媒體), such as CO ₂ gas (噴射) on the surface of the mother glass substrate from (冷却nozzle), a mother glass substrate Is moved along the scribe schedule line SL of the surface of the mother glass substrate at the same speed in the same direction as the first laser spot LS1 for.

On the surface of the mother glass substrate, an elliptical second laser spot LS2 is formed, which extends along the scribe plan line in the rear of the advancing direction of the cooling point CA and close to the cooling point CA. For example, the second laser spot LS2 has an elliptical shape having a long diameter of 30.0 mm and a short diameter of 1.0 mm, similarly to the first laser spot LS1, and with respect to the surface of the mother glass substrate in a state where the long diameter is along the scribe scheduled line SL. It moves at the same speed in the same direction as the first laser spot LS1 and the cooling point CA.

In this case, the distribution of the thermal energy intensity along the long axis direction of the second laser spot LS2 formed on the surface of the mother glass substrate is symmetrical with the intensity distribution of the first laser spot LS1 as shown in FIG. The maximum heat energy intensity level is taken only at the front end portion of the mother glass substrate in the advancing direction, and gradually decreases from the portion of the maximum heat energy intensity level to a relatively small heat energy intensity level from the rear end portion.

The second laser spot LS2 also heats the mother glass substrate at a temperature lower than the temperature at which the mother glass substrate is melted and moving at a high speed with respect to the mother glass substrate.

The surface of the mother glass substrate is sequentially heated by the first laser spot LS1 along the scribe scheduled line SL, and then the heating portion thereof is sequentially cooled by the cooling point CA, and after that, the second laser spot LS2 is cooled. Heated sequentially.

In this case, the first laser spot LS1 has a maximum thermal energy intensity only at the rear end portion of the mother glass substrate in the advancing direction, and is heated strongly at the rear end thereof after the surface of the mother glass substrate is gently heated. . The portion strongly heated by the rear end of the first laser spot LS1 is cooled by the cooling point CA.

Thus, compressive stress is generated by the heating by the maximum thermal energy intensity at the rear end of the first laser beam LS1, and tensile stress is generated when cooled by the cooling point CA. In this case, because the absolute value of the thermal energy intensity at the rear end of the first laser beam LSl is large, and a large compressive stress is generated, a stress gradient with the tensile stress generated by the cooling point CP is used. the gradient becomes large.

As such, since the absolute value of the thermal energy intensity at the rear end of the first laser beam LS1 is large, the heating time of the scribe scheduled line SL can be shortened, so that the relative movement speed between the first laser beam LS1 and the mother glass substrate can be reduced. I can do it at high speed. As a result, the distance between the first laser beam LS1 and the cooling point CA can be shortened, whereby the stress gradient between the first laser beam LSl and the cooling point CA can be increased.

As such, a large stress gradient is generated between the first laser beam LS1 and the cooling point CA so that a blind crack in the vertical direction along the scribe line SL is surely formed on the mother glass substrate. In addition, since the relative movement speed between the first laser beam LS1 and the mother glass substrate can be made high, blind cracks can be efficiently formed.                 

In this way, when a vertical crack is formed along the scribe scheduled line SL, the area where the blind crack is formed is heated again by the second laser spot LS2. As a result, a stress gradient is generated between the region where the tensile stress is generated by the cooling of the cooling point CA and the region where the compressive stress is generated by the heating of the second laser spot LS2, and the stress gradient perpendicularly forms the mother glass substrate. Cracks are formed deeper along the vertical direction.

In this case, since the cooling point CA is formed long along the scribe scheduled line SL, the area heated by the 1st laser spot LS1 is surely cooled. Since the second laser spot LS2 formed at the rear of the region cooled by the cooling point CA has the maximum thermal energy intensity only at the front end portion close to the cooling point CA, the absolute value of the thermal energy intensity at the front end portion is increased and the cooling point is increased. A large stress gradient occurs between CA. As a result, the vertical cracks formed along the scribe scheduled line SL are formed deeper toward the rear surface of the mother glass substrate.

In addition, the second laser spot LS2 has only a maximum heat energy intensity at the front end portion thereof, and is then heated to a relatively small heat energy intensity. As a result, the structure of the peripheral region in which the vertical crack is formed may be annealed to change, thereby alleviating the stress remaining on the mother glass substrate.

Fig. 2 is a schematic block diagram showing an embodiment of a scribing apparatus for a brittle material substrate of the present invention. The scribing apparatus of this invention is an apparatus which forms the scribe line for cutting into the several glass substrate used for FPD, for example from a large mother glass substrate. This scribe apparatus is provided with the slide table 12 which reciprocates along a predetermined horizontal direction (Y direction) on the horizontal mounting base 11 as shown in FIG.

The slide table 12 is supported by a pair of guide rails 14 and 15 arranged parallel to the upper surface of the mounting table 11 to slide along the guide rails 14 and 15 in a horizontal state. Can be. In the middle part of both guide rails 14 and 15, the ball screw 13 is provided in parallel with each guide rail 14 and 15 so that a ball screw 13 may rotate with a motor (not shown). The ball screw 13 is capable of forward rotation and reverse rotation, and a ball nut 16 is attached to the ball screw 13 in a state of being screwed together. The ball nut 16 is integrally attached to the slide table 12 in a non-rotating state, and slides in both directions along the ball screw 13 by the forward and reverse rotation of the ball screw 13. As a result, the slide table 12 integrally attached to the ball nut 16 slides along the guide rails 14 and 15 in the Y direction.

On the slide table 12, the pedestal 19 is arranged in a horizontal state. The pedestal 19 is supported by a pair of guide rails 21 arranged in parallel on the slide table 12 and can slide. Each guide rail 21 is arrange | positioned along the X direction orthogonal to the Y direction which is the slide direction of the slide table 12. As shown in FIG. Further, a ball screw 22 is arranged in the center between each guide rail 21 in parallel with each guide rail 21, and the ball screw 22 is rotated forward and reverse by the motor 23.

A ball nut 24 is attached to the ball screw 22 in a state of being screwed in. The ball nut 24 is integrally attached to the pedestal 19 in a non-rotating state and moves in both directions along the ball screw 22 by forward and reverse rotation of the ball screw 22. Accordingly, the pedestal 19 slides in the X direction along each guide rail 21.

A rotating mechanism 25 is provided on the base 19, and the rotating table 26 on which the mother glass substrate 50 to be cut is placed on the rotating mechanism 25 in a horizontal state. It is installed. The rotary mechanism 25 is configured to rotate the rotary table 26 about the central axis along the vertical direction, and can rotate the rotary table 26 so as to have an arbitrary rotation angle θ with respect to the reference position. On the rotary table 26, a mother glass substrate 50 is fixed by, for example, a suction chuck.

The support table 31 is arrange | positioned above the rotating table 26 at the appropriate interval from the rotating table 26. As shown in FIG. This support 31 is supported in a horizontal state at the lower end of the first optical holder 33 which is arranged in a vertical state. The upper end of the first optical holder 33 is attached to the lower surface of the mounting table 32 provided on the mounting table 11. A first laser oscillator 34 for oscillating the first laser beam is provided on the mounting table 32, and the laser beam oscillated from the first laser oscillator 34 is supported in the first optical holder 33. Irradiated with the device.

The laser beam oscillated from the first laser oscillator 34 exhibits a normal distribution of thermal energy intensity, and is shown in FIG. 1 (b) by an optical device installed in the first optical holder 33. An elliptical first laser spot LS1 having a predetermined thermal energy intensity distribution as described above is formed and irradiated so that its major axis direction is parallel to the X direction of the mother glass substrate 50 placed on the turntable 26.

In addition, the mounting table 32 is provided with a second laser oscillator 41 which oscillates the second laser beam adjacent to the first laser oscillator 34, and the laser beam oscillated from the second laser oscillator 41 is adjacent to the first optical holder 33. It is irradiated with the optical device in the second optical holder 42 installed on the support 31. The laser beam oscillated from the second laser oscillator 41 has an elliptical shape having a normal distribution of thermal energy intensity and having a predetermined thermal energy intensity distribution as shown in FIG. 1 (b) by an optical device installed in the second optical holder 42. The second laser beam LS2 on the image is formed, and is irradiated with a suitable distance from the first laser spot LS1 in the state in which the major axis direction thereof is along the X direction of the mother glass substrate 50 placed on the turntable 26.

Between the first optical holder 33 and the second optical holder 42 on the support base 31, a cooling nozzle 37 is disposed to face the mother glass 50 placed on the turntable 26. The cooling nozzle 37 is configured to spray cooling water in a rectangular shape along the longitudinal axis between the first laser spot LS1 irradiated from the first optical holder 33 and the second laser spot LS2 irradiated from the second optical holder 42.

As the cooling nozzle 37, instead of the configuration in which the cooling water is sprayed in a rectangular shape, a configuration in which a plurality of cooling nozzles for spraying the cooling water in a narrow area are lined up in the X direction may be employed.

In addition, the support 31 is provided with a wheel cutter 35 on the opposite side to the cooling nozzle 37 with respect to the first laser spot LSl irradiated from the first optical holder 33 and facing the mother glass 50 placed on the rotary table 26. have. The wheel cutter 35 is arranged along the major axis direction of the first laser spot LS1 irradiated from the first optical holder 33 and forms a cut in the direction along the scribe line in the edge portion of the mother glass 50 placed on the turntable 26. do.

In addition, the positioning of the slide table 12 and the pedestal 9, the control of the rotating mechanism 25, the first laser oscillator 34, the second laser oscillator 41, and the like are controlled by a controller.

3 is a schematic configuration diagram of an optical device installed in the first optical holder 33. The first laser beam oscillated from the first laser oscillator 34 is totally reflected by a reflecting mirror 33a provided in the first optical holder 33 and irradiated with a diffraction grating lens 33b. The diffraction grating lens 33b has a grating such that the thermal energy intensity distribution of the irradiated laser beam is sequentially changed in the intensity distribution of the first laser spot LS1 shown in Fig. 1 (b), that is, along the major axis direction and maximized at one end. Pitch and lattice width are set.

Also in the second optical holder 42 is provided with a reflecting mirror which totally reflects the second laser beam oscillated from the second laser oscillator 41 and a diffraction grating lens to which the light reflected by the reflecting mirror is irradiated. The lattice pitch and lattice width are set such that the thermal energy intensity distribution of the laser beam to be changed in the intensity distribution of the second laser spot LS2 shown in FIG. 1 (b), that is, sequentially along the major axis direction and maximized at one end thereof. have.

When blind cracks are formed on the surface of the mother glass substrate 50 by such a scribing apparatus, information such as the size of the mother glass substrate 50, the position of the scribe line to be input, and the like are first input to the controller.

Then, the mother glass substrate 50 is placed on the turntable 26 and fixed by the suction means. In this state, alignment marks formed on the mother glass substrate 50 are captured by the CCD cameras 38 and 39. The photographed alignment marks are displayed by monitors 28 and 29, and the positional information of the alignment marks is processed by the image processing apparatus.

When the rotary table 26 is positioned relative to the support 31, the rotary table 26 slides along the X direction so that the scribe scheduled line at the edge of the mother glass substrate 50 faces the wheel cutter 35. The wheel cutter 35 is lowered to form a cut along the end of the scribe line of the mother glass substrate 50.

Thereafter, the rotary table 26 slides in the X direction along the scribe scheduled line, so that the first laser beam and the second laser beam are oscillated from the first laser oscillator 34 and the second laser oscillator 41, respectively, and the cooling water from the cooling nozzle 37 It is injected with compressed air to form a long rectangular cooling point CA along the scribe line.

The laser beam oscillated from the first laser oscillation device 34 forms an elliptical first laser spot LS1 long in the X-axis direction along the scanning direction of the mother glass substrate 50 on the mother glass substrate 50. Cooling water is injected along the scribe scheduled line behind the laser spot LS1 to form the cooling point CA. Further, the second laser spot LS2 having an elongated shape along the X axis direction is formed on the mother glass substrate 50 at the rear of the cooling point CA by the laser beam oscillated from the second laser oscillation device 41.

In this case, the first laser spot LS1 formed on the surface of the mother glass substrate 50 has a maximum thermal energy intensity only at the rear end portion close to the cooling point CA through which the coolant is injected, and thus the mother glass substrate 50 at the rear end portion thereof. This is surely heated. As described above, a blind crack is formed on the mother glass substrate 50 by the stress gradient between the heating at the end of the laser spot LS1 and the cooling by the cooling point CA. In addition, the second laser spot LS2 has a maximum thermal energy intensity only at the front end portion close to the cooling point CA at which the coolant is injected, so that the mother glass substrate 50 is reliably heated at the front end portion, thereby forming the blind crack. Advance deeper toward the back side of the glass substrate 50.

When the blind crack is formed on the mother glass substrate 50, the mother glass substrate 50 is supplied to the next cutting process so that a force is applied to the mother glass substrate so that a bending moment acts in the width direction of the blind crack. As a result, the mother glass substrate 50 is cut along the blind crack from the cuts formed at the end thereof.

In the above description, the example in which the first laser spot LS1 and the second laser spot LS2 are heat energy intensity distributions as shown in FIG. 1 has been described, but the temperature of the brittle material substrate heated by the first laser spot LS1 and the second laser spot LS2 is shown. Only the distribution may have the same distribution as the intensity distribution of the first laser spot LS1 and the second laser spot LS2 in FIG.

Further, the intensity distributions of the first laser spot LS1 and the second laser spot LS2 are as shown in Fig. 1, so that the temperature distribution of the heating region heated by the first laser spot LS1 and the second laser spot LS2 is the first laser spot. It is preferable that the intensity distributions of LS1 and the second laser spot LS2 have the same distribution.

In the above embodiment, a mother glass substrate of a liquid crystal display panel has been described as an example of a brittle material substrate, but a bonded glass substrate, a single plate glass, a semiconductor wafer, ceramics The same effect is obtained also in scribing process, such as).

In the scribing method and apparatus for the brittle material substrate of the present invention, since the laser spot formed on the surface of the brittle material substrate such as the mother glass substrate has a maximum thermal energy intensity only at an end portion close to the cooling point, A large stress gradient can be formed between and the blind crack can be formed reliably and efficiently.

Claims (18)

A scribing method of a brittle material substrate in which vertical cracks are formed along a scribe scheduled line on the surface of the brittle material substrate, The softening point of the brittle material substrate, the laser spot of the first irradiated at a temperature lower than (軟化點) (laser spot) to open said first and irradiated with a continuous laser beam (laser beam) of the first to form a first heating zone Moving the first heating region formed by the irradiation of the laser beam of 1 along the scribe schedule line; A cooling zone is formed by continuously cooling the region close to the first heating region along the scribe scheduled line in the rear of the moving direction of the first heating region, and the cooling region is formed along the movement of the first heating region. Moving along the scribe schedule line ; A second heating region is formed by continuously heating a region close to the cooling region to a temperature lower than the softening point of the brittle material substrate in the rear of the moving direction of the cooling region, and moving the second heating region to the cooling region. Along the scheduled scribe line Including, The first heating region formed by the first laser spot has a maximum thermal energy intensity only at one end portion close to the cooling region. A method for scribing a brittle material substrate, characterized in that. The method of claim 1, And the cooling region is elongated along the scribe line. The method of claim 1, And said second heating region is formed by a second laser spot which is formed by being irradiated by a second laser beam. The method of claim 3, And the second heating region has a maximum thermal energy intensity at an end portion close to the cooling region. The method of claim 4, wherein And the annealed substrate is annealed by the second heating zone. The method of claim 1, The temperature distribution of the said 1st heating area | region formed by the said 1st laser spot becomes the maximum temperature only in the one edge part which adjoins the said cooling area | region, The scribing method of the brittle material board | substrate characterized by the above-mentioned. The method of claim 3, The temperature distribution of the said 2nd heating area | region formed by the said 2nd laser spot is the maximum temperature only in the one edge part which adjoins the said cooling area | region, The scribing method of the brittle material board | substrate characterized by the above-mentioned. In the scribing apparatus of a brittle material substrate which forms a vertical crack along the scribe plan line in the surface of a brittle material substrate, First laser beam irradiation means for continuously irradiating the first laser beam at a temperature lower than the softening point of the brittle material substrate; A first optical device for irradiating said first laser beam along said scribe line of said brittle material substrate, and for forming a first heating region by said first laser spot formed by said irradiation; Cooling means for forming a cooling zone by continuously cooling an area near the first heating zone along the scribe scheduled line; Second laser beam irradiation means for continuously irradiating a second laser beam at a temperature lower than a softening point of the brittle material substrate; A second optical device for irradiating the second laser beam along the scribe line of the brittle material substrate, and forming a second heating region by a second laser spot formed by the irradiation; Equipped, The first optical device adjusts the intensity distribution of the first laser spot so that the maximum thermal energy intensity is only at the end of the first heating region which is in contact with the cooling region. A scribe device for a brittle material substrate, characterized in that. The method of claim 8, The second optical device adjusts the intensity distribution of the second laser spot so as to have the maximum thermal energy intensity only at the end in contact with the cooling region in the second heating region. A scribe device for a brittle material substrate, characterized in that. delete delete delete delete delete delete delete delete delete

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