JP2012224531A - Laser beam machining device of glass substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser beam machining device for a glass substrate preventing the occurrence of dirt and capable of shortening the processing time for dividing the glass substrate.SOLUTION: A machining marks 12 having pitch p are formed by one shot by emitting a pulse laser beam having a wavelength of 250-400 nm from a laser beam source and irradiating the laser beam 42 on the glass substrate 2 by a microlens array 40. After that, the machining marks 13 are formed at the midpoint of the machining marks 12 formed by a first shot by relatively moving a microlens array 40 to the glass substrate 2 by p/2. The irradiation position of the laser beam 42 is separated by p by the first shot and therefore an irregular crack is not generated on the surface of the glass substrate by the shot. The crack can be generated on the surface of the glass substrate by the second shot, but even in that case, the crack is progressed toward the machining marks 12 of the first shot, and therefore, the crack is not generated toward the irregular direction.

Description

  The present invention relates to a laser processing apparatus for a glass substrate suitable for dicing a surface-reinforced glass substrate.

  In manufacturing a liquid crystal display panel, exposure and development are repeated on a glass substrate to form a pattern composed of predetermined pixels and circuits. In this case, individual panels are manufactured by simultaneously forming patterns for a plurality of panels on a single glass substrate and then dividing the glass substrate. Conventionally, the division of the glass substrate is performed by mechanical dicing processing in which a planned cutting line is ground into a linear shape with a rotary blade (Patent Document 1).

JP 2007-229831 A

  However, in this mechanical dicing process, it is necessary to move the dicing blade along the planned cutting line at a low speed, and it takes a long processing time per glass substrate, and there is a problem that the manufacturing tact is poor. . In addition, the glass substrate is easily broken during the dicing process, the yield is low, and cutting waste is generated when cutting with the rotary blade. In particular, in the case of surface tempered glass, the above-mentioned problem becomes more remarkable.

  The present invention has been made in view of such problems, and provides a laser processing apparatus for a glass substrate capable of reducing the processing time for dividing the glass substrate and preventing the generation of dust. Objective.

  A laser processing apparatus for a glass substrate according to the present invention includes a laser light source that emits a pulsed laser beam having a wavelength of 250 to 400 nm and a plurality of microlenses arranged in a row or on a circumference at a predetermined pitch p. A microlens array installed so as to face the glass substrate, a driving device that moves the microlens array relative to the glass substrate in the arrangement direction of the microlens, and the laser light source and the driving device are controlled. A control device that irradiates the glass substrate with a single shot with the microlens array to form a processing mark at a pitch p, and then the microlens array is placed on the glass substrate. Is moved linearly by p / 2 in the direction of arrangement of the microlenses or rotated around the center of the circle By applying a laser beam to the glass substrate in the shot, and forming two working mark per distance p at equal intervals.

  Another glass substrate laser processing apparatus according to the present invention includes a laser light source that emits a pulsed laser beam having a wavelength of 250 to 400 nm and a plurality of microlenses arranged in a row or on a circumference at a predetermined pitch p. A microlens array installed so as to face the target glass substrate, a driving device that moves the microlens array relative to the glass substrate in the arrangement direction of the microlenses, the laser light source, and the driving device A control device for controlling the laser beam, the control device irradiates the glass substrate with laser light by the micro lens array to form a processing mark having a pitch p of the first shot, and the micro lens array Move the laser beam linearly in the direction of arrangement of the microlens with respect to the glass substrate or rotate it around the center of the circle. The glass substrate is irradiated to form a processing mark having a pitch p of the second shot at a position intermediate between the processing marks of the previous shot, and thereafter, similarly, the microlens array is relative to the glass substrate. To form a plurality of machining traces per distance p by repeating the step of irradiating the laser beam to the middle position of the machining traces of the previous shot by linearly moving to the center of the circle or rotating around the center of the circle It is characterized by.

  In still another glass substrate laser processing apparatus according to the present invention, a laser light source that emits a pulse laser beam having a wavelength of 250 to 400 nm and a plurality of microlenses are arranged in a row or on a circumference at a predetermined pitch p. A microlens array installed so as to face the glass substrate to be cut, a driving device for moving the microlens array relative to the glass substrate in the arrangement direction of the microlenses, the laser light source, and driving A control device for controlling the device, wherein the control device irradiates the glass substrate with laser light by the microlens array, where n is an integer, and then the microlens array with respect to the glass substrate The lens is moved in a straight line relative to the lens arrangement direction by p / n or rotated around the center of the circle. Further, light is irradiated, and the microlens array is further linearly moved by p / n relative to the glass substrate in the arrangement direction of the microlenses or rotated around the center of the circle, and further in the following order. By repeating the step of performing laser beam irradiation, n processing marks are formed at equal intervals per distance p.

  In the laser processing apparatus for a glass substrate described above, the microlens array preferably has the focal position of the laser light in the thickness direction of the glass substrate, and the focal depth is shorter than the thickness of the glass substrate. Is preferably set to 1/100 or less of the thickness of the glass substrate. Thereby, the process trace by irradiation of a laser beam can be formed in the inside of a glass substrate. This reliably prevents the surface from being cracked by the laser beam irradiation.

  The glass substrate laser processing apparatus of the present invention is beneficial when applied to a surface-reinforced glass substrate. Since the surface tempered glass substrate has a hard surface property, the surface tempered glass substrate is further broken in mechanical dicing using a dicing blade, and even in laser dicing, if the focal position is the surface of the glass substrate, it is broken during processing. In the present invention, the focal position of the laser light by the microlens is set in the thickness direction of the surface strengthened glass substrate and at a position deeper than the surface strengthened layer of the surface strengthened glass substrate. Even a tempered glass substrate is prevented from cracking during processing.

  According to the present invention, a laser beam having a wavelength of 250 to 400 nm is used, and a microlens array is used to first irradiate the laser beam at a large interval of a pitch p, thereby forming a processing trace at an interval of the pitch p. To do. Since the irradiation interval of the laser beam is large, the surface of the glass substrate is not irregularly cracked by the irradiation of the laser beam. Thereafter, the microlens array is moved in the arrangement direction of the microlens by a distance such as p / 2 or p / n, and the next laser beam irradiation is performed. In this way, a plurality of processing marks are formed per pitch. Since the irradiation of the first pulse laser beam has a large interval between the irradiation positions, the glass substrate is not irregularly broken by the irradiation of the first laser beam, and the glass substrate is obtained by one or more subsequent laser shots. In the second shot, processing marks are formed at finer intervals, but since the processing marks are formed by the first shot after the second shot, the glass substrate will not be irregularly cracked after the second shot. . Therefore, according to the present invention, the glass substrate can be cleaved along the planned cutting line with high accuracy.

It is a perspective view which shows the laser processing apparatus of 1st Embodiment of this invention. It is a schematic diagram which similarly shows the processing process by the irradiation of the laser beam. It is a graph which shows the permeation | transmission characteristic of a surface strengthened glass substrate. (A) is a figure which shows a microlens array in the laser processing apparatus of 4th Embodiment of this invention, (b) is a figure which shows the process process by irradiation of a laser beam, (c) is the process formed in the glass substrate It is a figure which shows a trace. In the laser processing apparatus shown in FIG. 4, it is the figure which rotated the micro lens array, (a) is a figure which shows a micro lens array, (b) is a figure which shows the process process by irradiation of a laser beam, (c) is glass It is a figure which shows the process trace formed in the board | substrate.

  Hereinafter, embodiments of the present invention will be specifically described with reference to the accompanying drawings. FIG. 1 is a perspective view showing a laser processing apparatus for a glass substrate according to an embodiment of the present invention. On the stage 1, a glass substrate 2 such as a surface-reinforced glass substrate after exposure and development processing, which is a workpiece, is placed. A gate-shaped moving member 3 straddling the entire region in the width direction of the stage 1 is supported on the stage 1 so as to be capable of reciprocating in the direction of arrow a. The moving member 3 is provided with a support portion 4 that can reciprocate in the width direction (arrow b direction) of the stage 1, and a pulse laser oscillator 6 is supported on the support portion 4. A microlens array 40 is provided below the pulse laser oscillator 6 so that the pulse laser light from the pulse laser oscillator 6 is condensed on the glass substrate 2.

  In this laser processing apparatus, a glass substrate 2 such as a surface tempered glass substrate is placed on a stage 1, the moving member 3 moves in the direction of arrow a, and pulsed laser light is emitted intermittently from a pulsed laser oscillator 6. Then, the pulsed laser light condensed by the microlens array 40 is irradiated onto the glass substrate 2. Thereby, a laser beam is irradiated to the glass substrate 2 at appropriate intervals on the planned cutting line. In this case, the laser beam may be emitted from the pulse laser oscillator 6 while the moving member 3 is moving, or the laser beam is emitted from the pulse laser oscillator 6 in a state where the moving member 3 is stopped after moving. May be irradiated. The irradiation position of the pulse laser beam on the glass substrate 2 can be adjusted by moving the support portion 4 on the moving member 3 in the direction of the arrow b in order to match the planned cutting line. Further, the microlens array 5 attached to the support portion 4 can be exchanged with a different focal length. As a result, a laser processing can be performed by selecting a microlens array having an optimum focal depth from these microlens arrays 5 according to the surface properties of the glass substrate 2 to be processed.

  2A and 2B are schematic views showing the laser processing steps, where FIG. 2A is a plan view of the glass substrate 2, FIG. 2B is a plan view of the microlens array 40, and FIG. 2C is a plan view of laser light by the microlens array. It is a front view which shows irradiation operation | movement. As shown in FIGS. 2B and 2C, the microlens array 40 is configured by arranging a plurality of microlenses 41 (only four are shown for simplification) arranged in a line. . Each microlens 41 of the microlens array 40 condenses the pulsed laser light 42 emitted from the pulsed laser oscillator 6 on the glass substrate 2. The pulsed laser light 42 has a wavelength of 250 to 400 nm, and the focal position of the pulsed laser light 42 is set in the thickness direction of the glass substrate 2 by the microlens 41, and the focal depth is set shorter than the thickness of the glass substrate. Preferably, it is set to a range of 1/100 or less of the thickness of the glass substrate 2.

  Further, the microlenses 41 of the microlens array 40 are arranged at equal intervals with a pitch of p, and the laser light 42 is formed into a beam shape such as a square or a rectangular rectangle by an aperture stop built in the microlens 41. It shapes and irradiates the glass substrate 2. The laser beam 42 is irradiated on a planned cutting line indicated by a broken line in FIG. The laser beam irradiation timing of the pulse laser oscillator 6 and the movement distance and movement timing of the moving member 3 are controlled by a control device (not shown).

  The wavelength of the pulse laser beam 42 is 250 to 400 nm. FIG. 3 is a graph showing the transmission characteristics of the surface-reinforced glass, with the horizontal axis representing wavelength and the vertical axis representing laser light transmittance. In the case of laser light having a wavelength of 532 nm, the transmittance with respect to the glass substrate is high, that is, the energy absorption rate of the glass substrate is poor, and it is difficult to form a processing mark on the glass substrate. On the other hand, energy absorption starts near the i-line (wavelength 365 nm) of a mercury lamp, and a processing mark can be formed. Further, by using a laser beam having a wavelength of 266 nm, an extremely high energy absorption rate can be obtained. Therefore, in this invention, a process trace is formed in a glass substrate in the wavelength range of 250-400 nm.

  Next, the operation of this embodiment will be described together with the control mode of the control device. First, as shown in FIG. 2C, the control device moves the microlens array 40 to one end of the glass substrate 2 with respect to the glass substrate 2 by the moving device 3, and arranges the pulse laser oscillator. The laser beam 42 emitted from the laser beam 6 is shaped into a rectangular beam-shaped laser beam 42 by the microlens 41 of the microlens array 40 and irradiated onto the glass substrate 2. Thereby, a plurality of processing marks 12 are formed at a pitch p on the glass substrate 2 by the irradiation of the laser light 42. Thereafter, as shown in FIG. 2C, the control device moves the microlens array 40 relative to the glass substrate 2 in the direction of the arrow, and the position of the microlens 41 is changed from the position of the first laser shot. When moved by p / 2, the second laser light irradiation is performed. As a result, a second shot processing mark 13 is formed at an intermediate position of the first shot processing mark 12. In this way, the first shot machining trace 12 and the second shot machining trace 13 are formed side by side on the planned cutting line at a pitch of p / 2. Then, the microlens array 40 is further moved so that the microlens array 40 again causes the glass substrate 2 to be moved from the position separated by p from the processing marks 12 at the end of the plurality of processing marks 12 of the first shot. By irradiating laser beam, the third shot forms the processing trace 12 that is continuous with the same pitch p with respect to the processing trace 12 of the first shot. Thereafter, by moving the microlens array 40 by p / 2 and irradiating the laser beam 42, the fourth shot processing trace 13 is formed at an intermediate position of the third shot processing trace 12. By repeating this, the processing marks 12 and 13 are formed at a pitch of p / 2 over the entire cutting line of the glass substrate 2.

  When the first shot is repeated, and further, in the third shot and the subsequent odd shots, the processing marks 12 are formed at the pitch p. Since this pitch p is a relatively large interval, the laser beam 42 does not cause cracks in irregular directions on the surface of the glass substrate 2, and cracks do not advance in messy directions. In other words, the pitch p is set to a sufficient size so that irregular cracks or cracks do not occur on the surface of the glass substrate 2. When the second shot is repeated, and in the subsequent even-numbered shots, the laser beam is irradiated to the position of the distance of p / 2 with respect to the processing marks 12 of the first shot and the odd-numbered shots. . There is a possibility that the glass substrate 2 is cracked by the second shot and the even number of shots. However, when the crack is generated, the processing marks 12 of the first shot and the odd number of shots exist in the vicinity. In addition, the crack proceeds in the direction from the position of the second shot and the even number of shots toward the machining mark 12, and the crack does not occur in an irregular direction. Thereby, the glass substrate 2 can be accurately cleaved along the planned cutting line. When the glass substrate 2 is not cracked by the second shot laser irradiation, the processing marks 12 and 13 are formed so as to be alternately connected at a pitch of p / 2 on the planned cutting line. By applying the stress, the glass substrate 2 can be cleaved along the planned cutting line.

For example, when laser light having a wavelength of 532 nm is used, the pulse width is about 7 nsec, the irradiation energy density is 25 J / cm ² , and laser light is irradiated inside the surface-reinforced glass substrate, cracks develop in the glass substrate. The entire glass substrate is broken randomly. In contrast, when laser light having a wavelength of 355 nm is used, the pulse width is about 7 nsec, the irradiation energy density is 10 J / cm ² , and the laser light is irradiated inside the surface-reinforced glass substrate, the inside of the glass substrate is When a processing mark is formed and bending stress is applied to the glass substrate by hand, it can be cleaved neatly by a straight cutting line based on the processing mark.

  Further, the focal position of the laser beam 42 may be the surface of the glass substrate. When the laser beams 42 are irradiated at positions close to each other, that is, when the interval between the irradiation positions of the laser beams 42 shown in FIG. 2 is short, cracks develop in a messy direction due to the laser beam irradiation. And irregular cracks will occur. However, in this embodiment, the irradiation position of the laser beam 42 is set at a sufficiently large interval (pitch p). There is no regular cracking.

  However, by setting the focal position of the laser light 42 to the inside of the glass substrate 2, it is possible to prevent the occurrence of cracks in the glass substrate more reliably. That is, the focal position of the laser beam 42 is set in the thickness direction of the glass substrate 2, and the focal depth is set shorter than the thickness of the glass substrate 2, preferably 1/100 or less of the thickness of the glass substrate 2. By doing so, even if it is a surface tempered glass substrate, the modification part of the surface can be avoided and the energy of a laser beam can be concentrated in the inside. When the glass substrate 2 is a surface tempered glass substrate, if the laser beam is focused not on the inside of the glass substrate 2 but on the modified portion of the surface of the surface tempered glass substrate, the glass substrate 2 is messy. Cracks are generated and easily broken randomly. Further, when the focal depth of the laser light is equal to or greater than the thickness of the glass substrate, the laser light reaches the back surface of the glass substrate, and the glass substrate is broken. For this reason, the focal depth of the laser light is shorter than the thickness of the glass substrate, and preferably within a range of 1/100 or less of the thickness of the glass substrate.

  Of course, the focal position of the laser beam 42 that forms the processing mark 12 and the focal position of the laser beam 42 that forms the processing mark 13 may be different in the thickness direction of the glass substrate 2. For example, a pulse laser beam having a wavelength of 266 nm is used as the laser beam 42 for forming the processing mark 12, and a pulse laser beam having a wavelength of 355 nm is used as the laser beam 42 for forming the processing mark 13. The focal position can be set so that the laser beam for the machining mark 12 is shallower and the laser beam for the machining mark 13 is deeper. In this way, by varying the focal position of the laser light 42 in the depth direction of the glass substrate due to the difference in the irradiation position, the energy concentration position differs in the depth direction of the glass substrate 2 and the energy is concentrated. It is possible to prevent the areas from overlapping.

  The beam shape of the laser light 42 is not limited to a square as in the above-described embodiment, and various shapes such as a rectangle, a circle, and an ellipse can be used.

  Next, a second embodiment of the present invention will be described. In the first embodiment shown in FIG. 2, the control device irradiates the glass substrate 2 with the laser light 42 by the microlens array 40 to form the processing marks 12 having the pitch p of the first shot. The glass substrate 2 is moved with respect to the glass substrate 2 to irradiate the glass substrate 2 with the processing mark 13 having the pitch p of the second shot at a position intermediate to the processing mark 12 of the first shot. Thereby, laser processing can be performed so that the processing marks 12 and 13 are connected at a pitch of p / 2. In the second embodiment, another laser shot is performed by the microlens array 40 at an intermediate position between the processing marks 12 and the processing marks 13 arranged at the p / 2 pitch. In this way, a processing mark having the pitch p of the second shot is formed at an intermediate position of the processing mark having the pitch p of the first shot, and the pitch of the processing mark is set to p / 2. A processing mark having a pitch p of the third shot is formed at an intermediate position of a processing mark having a pitch of 4 mm, and the pitch of the processing mark is set to p / 4. If necessary, a laser is further used by using the microlens array 40. By performing the light irradiation, the pitch of the processing marks can be reduced to p / 8, p / 16, and so on. In this way, by performing laser shots a plurality of times on the same region of the glass substrate 2, the pitch of the processing marks can be made finer, so that it can be cleaved with higher accuracy along the planned cutting line. . Also in this embodiment, there is a possibility that the glass substrate breaks when the laser beam is shot. In this case, too, the glass substrate breaks toward the previous processing mark, and therefore, the glass substrate can be broken along the planned cutting line.

  Next, a third embodiment of the present invention will be described. In the third embodiment, the control device irradiates the glass substrate 2 with laser light by the microlens array 40. After one shot, n is an integer and the microlens array 40 is attached to the glass substrate 2. , The laser beam is irradiated by the next order after being moved by p / n, and the process of irradiating the laser beam by the next order by moving by p / n is repeated for each distance p. The processing trace is formed. Thereby, it is possible to form processing marks having a pitch of p / n at regular intervals. In this way, extremely fine machining marks can be formed on the planned cutting line at equal intervals, and can be cleaved with higher accuracy along the planned cutting line. Also in this embodiment, there is a possibility that the glass substrate breaks when the laser beam is shot. In this case, too, the glass substrate breaks toward the previous processing mark, and therefore, the glass substrate can be broken along the planned cutting line.

  Next, a fourth embodiment of the present invention will be described. In the present embodiment, processing marks are formed on the same circumference, and the glass substrate is cut into a circle. 4A is a view showing a microlens array in a laser processing apparatus according to a fourth embodiment of the present invention, FIG. 4B is a view showing a processing step by laser light irradiation, and FIG. It is a figure which shows the process trace formed in the board | substrate. In the first to third embodiments, the microlenses 41 of the microlens array 40 are arranged in a line at a pitch p. However, in the present embodiment, as shown in FIG. The microlenses 41 are arranged at equal intervals on the same circumference at a pitch p (distance on the circumference). In the present embodiment, the laser processing apparatus shown in FIG. 1 is further provided with a mechanism (not shown) for rotating the microlens array 43 around the center 44 of the circle in which the microlenses 41 are arranged. The microlens array 43 is rotated around the center 44 of the circle in the direction of arrow c. The control device is configured to control the rotation angle and the rotation timing of the microlens array 43 in addition to the laser beam irradiation timing of the pulse laser oscillator 6, the movement distance of the moving member 3, and the movement timing. . That is, the control device moves the pulse laser oscillator 6 and the microlens array 43 to a predetermined scheduled cutting area on the glass substrate 2 by moving the moving member 3, and emits one shot of pulse laser light from the pulse laser oscillator 6. The rotation mechanism and the like are controlled so as to form a plurality of processing marks arranged on the same circumference by irradiation, and further rotate the microlens array 43 by the rotation mechanism to irradiate the second shot pulse laser beam. In the present embodiment, while the microlens array 43 is rotated by a rotation mechanism, the pulse laser oscillator 6 intermittently irradiates the pulse laser beam at the timing when each microlens 41 reaches a predetermined shot position, thereby processing traces. Can also be formed.

  Next, the operation of this embodiment will be described together with the control mode of the control device. First, as shown in FIG. 4 (b), the control device moves the microlens array 43 by moving the microlens array 43 above the planned cutting area on the glass substrate 2 and emits it from the pulse laser oscillator 6. The glass substrate 2 is irradiated with the laser beam 42 by the microlens 41 of the microlens array 43. Thereby, a plurality of processing marks 14 are formed on the glass substrate 2 at the pitch p on the same circumference by the irradiation of the laser beam 42. Thereafter, as shown in FIG. 5A, the control device rotates the microlens array 43 around the center 44 of the circle in the direction of the arrow c, and each microlens 41 of the microlens array 43 with respect to the glass substrate 2. Rotate relatively around the center 44. Then, when the position of the microlens 41 is moved by p / 2 pitch on the circumference from the position of the first laser shot, the second laser light irradiation is performed (FIG. 5B). As a result, as shown in FIG. 5C, a second shot machining mark 15 is formed at an intermediate position of the first shot machining mark 14. In this way, the first shot machining trace 14 and the second shot machining trace 15 are formed side by side on the same circumferential cut planned line at a pitch of p / 2.

  After that, the control device moves the pulse laser oscillator 6 and the microlens array 43 onto the next scheduled cutting area on the glass substrate 2 by the movement of the moving member 3. After irradiating one shot of laser light to form a plurality of processing marks 14 arranged on the same circumference, the microlens array 43 is rotated by a rotating mechanism to irradiate the second shot with pulsed laser light. The pulse laser oscillator, the rotation mechanism, and the like are controlled so as to form 15.

  Also in the present embodiment, in the first shot, the processing marks 14 are formed at the pitch p on the same circumference. Since this pitch p is a relatively large interval, the laser beam 42 does not cause cracks in irregular directions on the surface of the glass substrate 2, and cracks do not advance in messy directions. In other words, the pitch p is set to a sufficient size so that irregular cracks or cracks do not occur on the surface of the glass substrate 2. In the second shot, the laser beam is irradiated to the position of the distance p / 2 with respect to the processing mark 14 of the first shot. There is a possibility that the glass substrate 2 is cracked by the second shot. However, when the crack is generated, the processing mark 14 of the first shot is present in the vicinity, and therefore the processing mark 14 from the position of the second shot. Cracks proceed in the direction toward the surface, and cracks do not occur in irregular directions. Thereby, the glass substrate 2 can be cut | disconnected correctly along a circular scheduled cutting line. When cracks do not occur in the glass substrate 2 due to the second shot laser irradiation, the processing marks 14 and 15 are formed so as to be alternately connected at a pitch of p / 2 on the planned cutting line of the same circumference. By applying a pressing force by hand, the glass substrate 2 can be cut into a circle along a planned cutting line.

Also in this embodiment, for example, when a laser beam having a wavelength of 355 nm is used, the pulse width is set to about 7 nsec, the irradiation energy density is set to 10 J / cm ² , and the laser beam is irradiated inside the surface-reinforced glass substrate, the glass substrate When a processing mark is formed inside the glass substrate and a pressing force is applied to the glass substrate by hand, the processing mark can be cleanly cut with a circular cutting line.

  Also in this embodiment, the focal position of the laser beam 42 may be the surface of the glass substrate, and the irradiation position of the laser beam 42 is set at a sufficiently large interval (pitch p), so that the focal position is glass. Even on the surface of the substrate, irregular cracks do not occur due to the irradiation of the laser beam 42. However, by setting the focal position of the laser light 42 to the inside of the glass substrate 2, it is possible to more reliably prevent the glass substrate from being cracked. That is, the focal position of the laser beam 42 is set in the thickness direction of the glass substrate 2, and the focal depth is set shorter than the thickness of the glass substrate 2, preferably 1/100 or less of the thickness of the glass substrate 2. To do. Thereby, even if it is a surface strengthened glass substrate, the modification part of the surface can be avoided and the energy of a laser beam can be concentrated inside.

  Further, the focal position of the laser beam 42 that forms the processing mark 14 and the focal position of the laser beam 42 that forms the processing mark 15 may be different in the thickness direction of the glass substrate 2. For example, a pulse laser beam having a wavelength of 266 nm is used as the laser beam 42 for forming the processing mark 14, and a pulse laser beam having a wavelength of 355 nm is used as the laser beam 42 for forming the processing mark 15, The focal position can be set so that the laser beam for the machining mark 14 is shallower and the laser beam for the machining mark 15 is deeper. In this way, by varying the focal position of the laser light 42 in the depth direction of the glass substrate due to the difference in the irradiation position, the energy concentration position differs in the depth direction of the glass substrate 2 and the energy is concentrated. It is possible to prevent the areas from overlapping.

  Also in the present embodiment, the beam shape of the laser light 42 is not limited to a circle as in the above embodiment, and various shapes such as a square, a rectangle, and an ellipse can be used.

  Next, a modification of this embodiment will be described. In the fourth embodiment, the pulse laser oscillator 6 and the microlens array 43 are arranged on one cutting scheduled area on the glass substrate 2, and the microlens is irradiated by the pulse laser light from the pulse laser oscillator 6 and the rotation mechanism. By alternately rotating the array 43 and forming a processing trace in one cutting scheduled region, the moving member 3 moves to move the pulse laser oscillator 6 and the microlens array 43 to the next on the glass substrate 2. This is a case where the machining trace is formed in the planned cutting area after the movement. On the other hand, in this modification, the control device completes the pulse laser oscillator 6 and the microlens array 43 by moving the moving member 3 after completing the irradiation of the first shot of the pulse laser light in one scheduled cutting region. Is moved to the next planned cutting region, and the pulse laser oscillator 6 and the microlens are formed so that a processing trace is formed by irradiating the pulse laser light of the first shot from the pulse laser oscillator 6 in the planned cutting region after the movement. The array 43 and the moving member 3 are controlled. Then, by repeating this, all the planned cutting regions are irradiated with the first shot of pulsed laser light to form processing marks. Thereafter, after the irradiation of the first-shot pulsed laser light with respect to all the planned cutting regions is completed, the control device rotates the microlens array 43 by a rotation mechanism. Then, similarly to the above case, the control device repeats the movement of the pulse laser oscillator 6 and the microlens array 43 by the moving member 3 and the irradiation of the pulse laser light from the pulse laser oscillator 6. Etc. are controlled, and a processing trace is formed by irradiating the second shot pulse laser beam to each of the planned cutting regions. Even in this case, the processing traces in which the processing traces 14 and 15 are alternately arranged can be formed on the glass substrate 2 as in the fourth embodiment, and the same effect as in the fourth embodiment can be obtained.

  Next, another modification of the fourth embodiment will be described. In the second modification, the control device controls the moving device 3 and the like so that the pulse laser beam 6 is intermittently irradiated from the pulse laser oscillator 6 while moving the moving device 3. That is, when the moving speed of the moving device 3 is sufficiently slow compared to the time (irradiation time) for shooting the pulse laser beam, the distance that the irradiation position of the pulse laser beam moves during the shot of the pulse laser beam is , Small enough for the size of the processing mark. Therefore, even if the pulse laser oscillator 6 and the microlens array 43 are irradiated with the pulsed laser light at the timing when the moving device 3 is moved and reach the respective scheduled cutting regions, the processing trace can be formed with high accuracy. . Also in the present modification, after the irradiation of the first shot pulse laser beam to all the scheduled cutting regions is completed, the control device rotates the microlens array 43 by the rotation mechanism. Similarly to the above case, while moving the moving device 3, the moving device 3 and the like are controlled so as to intermittently irradiate the pulse laser beam from the pulse laser oscillator 6, and the second shot of the pulse laser beam is irradiated. The processing mark is formed by. Even in this case, the processing marks 14 and 15 similar to those of the fourth embodiment can be formed on the glass substrate 2, and the same effects as those of the fourth embodiment can be obtained.

  Next, still another modification of the fourth embodiment will be described. In the third modified example, in the laser processing apparatus of the second modified example, the control device is configured to change the moving speed of the moving device 3. Then, the pulse laser oscillator 6 and the microlens array 43 move at high speed during moving from one scheduled cutting area to the next scheduled cutting area, and move closer to each scheduled cutting area. 3 is slowed down to sufficiently reduce the moving speed of the pulse laser oscillator 6 and the microlens array 43, and the laser beam is irradiated while moving at the same speed as in the second modification. In the present modification, the second modification is performed by synchronizing the movement speed change of the pulse laser oscillator 6 and the microlens array 43 due to the movement of the moving device 3 and the irradiation timing of the pulse laser light from the pulse laser oscillator 6. Similarly, the processing marks 14 and 15 are formed by the first-shot laser beam irradiation of all the planned cutting regions and the second-shot laser beam irradiation of all the planned cutting regions. This modification can obtain the same effect as that of the fourth embodiment, and can shorten the processing time required for forming the processing marks as compared with the second modification.

  Next, a fifth embodiment of the present invention will be described. In the fourth embodiment shown in FIGS. 4 and 5, the control device irradiates the glass substrate 2 with the laser light 42 by the microlens array 43 to form the processing marks 14 having the pitch p of the first shot, and the microlens. The array 43 is rotated around the center 44 of the circle in which the microlenses 41 are arranged in the direction of the arrow c to irradiate the glass substrate 2 with the laser light 42 to form the processing marks 15 having the pitch p of the second shot. It is formed at an intermediate position of the shot processing mark 14. Thereby, it is possible to perform laser processing so that the processing marks 14 and 15 are continuous at a pitch of p / 2. In the fifth embodiment, another laser shot is further performed by the microlens array 40 at an intermediate position between the processing marks 14 and the processing marks 15 arranged at the p / 2 pitch. In this way, a processing mark having the pitch p of the second shot is formed at an intermediate position of the processing mark having the pitch p of the first shot, and the pitch of the processing mark is set to p / 2. A processing mark having a pitch p of the third shot is formed at an intermediate position of the processing mark having a pitch of / 4, and the pitch of the processing mark is set to p / 4. If necessary, a laser is further used by using the microlens array 43. By performing the light irradiation, the pitch of the processing marks can be reduced to p / 8, p / 16, and so on. As described above, by performing laser shots a plurality of times on the same region of the glass substrate 2, the pitch of the processing marks can be made finer, and thereby the glass substrate 2 can be more accurately along the circular planned cutting line. Can be cut with. Also in this embodiment, there is a possibility that the glass substrate breaks when the laser beam is shot. However, in this case as well, the glass substrate is broken toward the previous processing mark, so that it can be cut along the planned cutting line.

  In this embodiment, various modifications similar to those in the fourth embodiment are possible. For example, the control device forms a processing mark in one scheduled cutting region, and then moves the moving member 3 to move the pulse laser oscillator 6 and the microlens array 43 onto the next scheduled cutting region on the glass substrate 2. The moving member 3 or the like may be controlled so as to move and form a processing mark in the planned cutting area after the movement, and the pulse laser beam is intermittently emitted from the pulse laser oscillator 6 while moving the moving device 3. The irradiation timing of the pulse laser beam from the pulse laser oscillator 6 may be controlled so as to irradiate. In addition, for example, the control device synchronizes the movement speed change of the pulse laser oscillator 6 and the microlens array 43 due to the movement of the moving device 3 and the irradiation timing of the pulse laser light from the pulse laser oscillator 6. Etc. may be controlled.

  Next, a sixth embodiment of the present invention will be described. In the sixth embodiment, the control device irradiates the glass substrate 2 with laser light by the microlens array 43, but after one shot of irradiation, the microlens 41 is arranged in the microlens array 43 with n being an integer. By rotating around the center 44 of the formed circle, each microlens 41 is moved by p / n on the circumference to irradiate the next laser beam, and further moved by this p / n. The process of performing the next sequential laser light irradiation is repeated to form n processing traces for each distance p. Thereby, it is possible to form processing marks having a pitch of p / n at regular intervals. In this way, extremely fine processing marks can be formed on the planned cutting line at equal intervals, and the glass substrate 2 can be cut with higher accuracy along the circular cutting planned line. Also in this embodiment, there is a possibility that the glass substrate breaks when the laser beam is shot. However, in this case as well, the glass substrate is broken toward the previous processing mark, so that it can be cut along the planned cutting line.

  In this embodiment, various modifications similar to those in the fourth and fifth embodiments are possible.

1: Stage 2: Glass substrate 3: Moving member 4: Support member 6: Pulse laser oscillator 12, 13, 14, 15: Processing mark 40, 43: Micro lens array 41: Micro lens 42: Laser light 44: (circle )center

Claims (5)

A laser light source that emits a pulse laser beam having a wavelength of 250 to 400 nm, and a microlens in which a plurality of microlenses are arranged in a row or on the circumference at a predetermined pitch p and are opposed to a glass substrate to be cut. An array, a drive device that moves the microlens array relative to the glass substrate in the arrangement direction of the microlenses, and a control device that controls the laser light source and the drive device,
The controller irradiates the glass substrate with laser light in one shot by the microlens array to form a processing mark at a pitch p, and then the microlens array is arranged with respect to the glass substrate. By moving the glass substrate linearly by p / 2 or rotating around the center of the circle and irradiating the glass substrate with the laser beam in the next shot, two processing marks are formed at equal intervals per distance p. A laser processing apparatus for a glass substrate. A laser light source that emits a pulse laser beam having a wavelength of 250 to 400 nm, and a microlens in which a plurality of microlenses are arranged in a row or on the circumference at a predetermined pitch p and are opposed to a glass substrate to be cut. An array, a drive device that moves the microlens array relative to the glass substrate in the arrangement direction of the microlenses, and a control device that controls the laser light source and the drive device,
The controller irradiates the glass substrate with laser light from the microlens array to form a processing mark having a pitch p of the first shot, and the microlens array is arranged with respect to the glass substrate. Or rotating around the center of the circle and irradiating the glass substrate with a laser beam to form a processing mark having a pitch p of the second shot at a position intermediate between the processing marks of the previous shot, Thereafter, in the same manner, the microlens array is linearly moved relative to the glass substrate or rotated around the center of the circle to irradiate a laser beam at a position intermediate between the processing marks of the previous shot. A glass substrate laser processing apparatus, wherein a plurality of processing traces are formed per distance p by repeating the step of performing. A laser light source that emits a pulse laser beam having a wavelength of 250 to 400 nm, and a microlens in which a plurality of microlenses are arranged in a row or on the circumference at a predetermined pitch p and are opposed to a glass substrate to be cut. An array, a drive device that moves the microlens array relative to the glass substrate in the arrangement direction of the microlenses, and a control device that controls the laser light source and the drive device,
The control device irradiates the glass substrate with laser light by the microlens array, where n is an integer, and then the microlens array is relatively relative to the glass substrate by p / n in the arrangement direction of the microlenses. It is moved linearly or rotated around the center of the circle to irradiate the next laser beam, and the microlens array is relative to the glass substrate by p / n in the arrangement direction of the microlenses. In this case, n processing traces are formed at equal intervals per distance p by repeating the step of performing linear laser movement or rotating around the center of the circle and further irradiating the next sequential laser beam. A laser processing apparatus for a glass substrate. The microlens array has a focal position of the laser light in the thickness direction of the glass substrate and a depth of focus set to be shorter than the thickness of the glass substrate. The laser processing apparatus of the glass substrate of any one of these. The glass substrate is a surface tempered glass substrate, and the microlens array has a focal position of laser light by the microlens in the thickness direction of the surface tempered glass substrate, The laser processing apparatus for a glass substrate according to any one of claims 1 to 4, wherein the laser processing apparatus is set at a position deeper than the surface reinforcing layer.

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