HK1069797B - Scribing device and method for fragile material substrate and scribing method for fragile material substrate - Google Patents

Description

Scribing device and scribing method for brittle material substrate

Technical Field

The present invention relates to a scribing apparatus (スクライブ apparatus) used for cutting a brittle material substrate such as a glass substrate or a semiconductor wafer used for a flat panel display (hereinafter referred to as FPD).

Background

An FPD in which a pair of glass substrates are bonded together is manufactured by bonding a pair of mother glass substrates having a large size to each other and then cutting the substrates into a predetermined size. When cutting the mother glass substrate, a scribe line is formed on the mother glass substrate by a cutter (カツタ). When a scribe line is formed by a cutter or when a glass substrate is cut after the scribe line is formed, fine glass powder and cullet chips are generated, causing various problems.

In recent years, a method of using a laser beam for forming a scribe line has been put into practical use in order to avoid generation of fine glass powder and cullet when scribing and cutting are performed using a cutter. In the method of forming a scribe line on a glass substrate using a laser beam, as shown in fig. 5, the glass substrate 50 is irradiated with a laser beam emitted from a laser oscillation device 61. The laser beam emitted from the laser oscillator 61 forms an oblong laser spot LS on the glass substrate 50 along the planned scribe line formed on the glass substrate 50. The glass substrate 50 and the laser beam irradiated from the laser oscillator 61 are relatively moved along the longitudinal direction of the laser spot.

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

Further, a cooling medium such as cooling water is sprayed from the cooling nozzle 62 to form a scribe line in the vicinity of the region irradiated with the laser beam on the surface of the glass substrate 50. On the surface of the glass substrate irradiated with the laser beam, a compressive stress is generated by heating with the laser beam, and then a tensile stress is generated by spraying a cooling medium. Since tensile stress is generated in the region close to the region where compressive pressure is generated in this way, a stress gradient is generated between the two regions by each stress, and a scribe line in which a vertical crack BC in the thickness direction of the glass advances is formed on the glass substrate 50 along the planned scribe line from a slit formed in advance in the end portion of the glass substrate 50.

Since the vertical crack formed on the surface of the glass substrate 50 is fine and is not observed with the naked eye in general, it is called a dark crack (ブラインドクラツク) BC.

Fig. 6 is a perspective view schematically showing a state of light beam irradiation on the glass substrate 50 to be scribed by the laser scribing apparatus, and fig. 7 is a plan view schematically showing a state of physical change on the glass substrate 50.

The laser beam LB emitted from the laser oscillation device 61 forms an oblong laser spot LS on the surface of the glass substrate 50. The laser spot LS has an oblong shape with a long diameter b of 30.0mm and a short diameter a of 1.0mm, for example, and is irradiated so that the long axis coincides with the direction of the formed scribe line.

In this case, the laser spot LS formed on the glass substrate 50 has a beam intensity at the outer peripheral portion larger than that at the central portion. Accordingly, the beam intensity is maximized at each end portion in the longitudinal direction on the scribe line, and the beam intensity at the central portion of the laser spot LS sandwiched between the end portions is smaller than that at each end portion.

The glass substrate 50 is relatively moved in the long axis direction of the laser spot LS, so that the glass substrate 50 is heated by a small beam intensity corresponding to the central portion of the laser spot LS after being heated by a large beam intensity corresponding to one end portion of the laser spot LS along the scribe intended line, and thereafter is heated by a large beam intensity. Meanwhile, after that, with respect to the end irradiation area of the laser spot LS, cooling water is sprayed from the cooling nozzle 62 at the cooling point CP on the scribe predetermined line spaced apart by the interval L of 2.5mm in the long axis direction of the laser spot LS, for example.

This causes a temperature gradient (hooking) to occur in the region between the laser spot LS and the cooling point CP, and a large tensile stress is generated in the region opposite to the laser spot LS with respect to the cooling point CP. At the same time, the tensile stress causes a dark crack BC to develop along the planned scribing line from the cut formed by the wheel cutter 35 at the end of the glass substrate 50.

The glass substrate 50 is heated by the oblong laser spot LS. In this case, the glass substrate 50 is heated by the large beam intensity at one end of the laser spot LS, and heat is transferred from the surface thereof to the inside in the vertical direction, but by relatively moving the laser beam with respect to the glass substrate 50, after the portion heated by the end of the laser spot LS is heated by the small beam intensity corresponding to the central portion of the laser spot LS, it is heated again by the large beam intensity corresponding to the end of the laser spot LS.

In this way, the heat of the portion of the surface of the glass substrate 50 that is initially heated by the large beam intensity is reliably transferred to the inside of the glass substrate while the portion is subsequently heated by the small beam intensity. Further, it is necessary to prevent the surface of the glass substrate 50 from being continuously heated with a large beam intensity in order to prevent melting of the surface of the glass substrate 50. Then, when the glass substrate 50 is heated again with a large beam intensity to reliably heat the inside of the glass substrate 50, compressive stress is generated on the surface and inside of the glass substrate 50. Then, after such a time has elapsed, tensile stress is generated by spraying cooling water at the cooling point CP in the vicinity of the region where compressive stress occurs.

When a compressive stress is generated in the region heated by the laser spot LS and a tensile stress is generated at the cooling point CP by the cooling water, a large tensile stress is generated in the region on the opposite side of the laser spot with respect to the cooling point CP by the compressive stress generated in the thermal diffusion region HD between the laser spot LS and the cooling point CP. At the same time, the tensile stress causes a dark crack BC to develop along the planned scribing line from the cut formed by the wheel cutter 35 at the end of the glass substrate 50.

Further, by reducing the relative movement speed of the laser beam with respect to the glass substrate 50, the dark crack BC (vertical crack) spreads in the thickness direction of the glass substrate 50 and progresses along the planned scribing line in a state of penetrating the glass substrate 50 (scribing performed in this way is generally referred to as cutting the entire glass substrate 50).

In the above description of the conventional example, the dark crack BC progresses from the slit formed by the wheel cutter (ホイ - ル カツタ)35 at the end of the glass substrate 50, but the slit formed by the wheel cutter 35 does not necessarily have to be at the end of the glass substrate 50.

In addition, it is not always necessary to form the slits on the glass substrate 50 in order to form the dark cracks BC.

When the dark crack BC is formed as a scribe line on the glass substrate 50, the glass substrate 50 is subjected to the following cutting step, and a bending moment is applied to the glass substrate so as to act in the width direction of the dark crack BC in the direction indicated by the arrow in fig. 6. Thereby, the glass substrate 50 is cut along the scribe line which is the line of the dark crack BC.

In such a scribing apparatus, when conditions such as a material and a thickness of the glass substrate 50 are changed, it is necessary to change a heating condition by the laser beam. In order to form a predetermined oblong laser spot LS on the glass substrate 50 by the emitted laser beam, the laser oscillation device needs to set the arrangement, focal point, and the like of an optical system such as a lens in advance, and when the heating condition by the laser beam is changed, the shape of the laser spot LS formed on the surface of the glass substrate 50 needs to be changed. Therefore, in order to change the shape of the laser spot LS, it is necessary to replace a lens of the optical system or the like, and to adjust the focal point, and further, it is necessary to adjust the mode of the laser beam emitted from the laser oscillator, and the adjustment is not easy.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a scribing apparatus for a brittle material substrate, which can easily cope with conditions of the brittle material substrate even when the conditions such as a material and a thickness of the brittle material substrate are changed when a scribing line is formed on the brittle substrate such as a glass substrate.

Disclosure of Invention

The scribing apparatus for a brittle material substrate according to the present invention for forming a vertical crack along a planned scribing line includes: at least one laser oscillator for emitting a laser beam intermittently irradiated continuously or at a high speed to form a laser irradiation spot having a temperature lower than a softening point of a brittle material substrate along a region on a surface of the brittle material substrate where a scribe line is to be formed; an optical mechanism for optically processing the laser beam oscillated by the laser oscillator, and adjusting the scanning speed and scanning path of the spot, or forming a single or multiple spots, or changing the intensity distribution; a cooling mechanism for supplying a cooling medium for continuously cooling the vicinity of the laser irradiation spot, wherein the optical mechanism is configured as follows: irradiating a laser beam oscillated by the laser oscillator, forming a plurality of laser spots on the brittle material substrate by the irradiated laser beam, and adjusting a scanning speed and a scanning path of the irradiated laser beam, wherein each of the plurality of laser spots has a plurality of peak values of intensity distribution; when the brittle material substrate is thicker than the brittle material substrate suitable for the preset interval of the laser spots and when the brittle material substrate has lower thermal conductivity than the brittle material substrate suitable for the preset interval of the laser spots, in at least one case, the optical mechanism adjusts the interval of the laser spots formed along the scratch preset line to be smaller than the preset interval of the laser spots and sets the peak interval of the intensity distribution of the laser spots to be smaller than the preset peak interval of the intensity distribution of the laser spots; when the thickness of the brittle material substrate is smaller than the thickness of the brittle material substrate suitable for the preset interval of the plurality of laser spots, and when the thermal conductivity of the brittle material substrate is higher than the thermal conductivity of the brittle material substrate suitable for the preset interval of the plurality of laser spots, in at least one case, the interval of the plurality of laser spots formed along the predetermined scribing line is set to be larger than the interval of the plurality of laser spots by the optical mechanism, and the peak interval of the intensity distribution of the plurality of laser spots is set to be larger than the preset peak interval of the intensity distribution of the plurality of laser spots.

The scribing apparatus for a brittle material substrate according to the present invention is characterized in that the intensity distribution of the plurality of laser spots is in a non-gaussian mode.

The scribing method of the brittle material substrate of the invention forms the vertical crack along the predetermined scribing line, comprising the following steps: a step of intermittently irradiating a laser beam continuously or at a high speed from at least one laser oscillator to form a laser irradiation spot having a temperature lower than the softening point of the brittle material substrate along a region on the surface of the brittle material substrate where a scribe line is to be formed; a step of optically processing the laser beam from the laser oscillator by an optical mechanism, adjusting the scanning speed and scanning path of the spot, forming one or more spots, or changing the intensity distribution, and a step of continuously cooling the vicinity of the laser spot by a cooling mechanism for supplying a cooling medium for cooling, the optical mechanism being configured as follows: irradiating a laser beam oscillated by the laser oscillator, forming a plurality of laser spots on the brittle material substrate by the irradiated laser beam, and adjusting a scanning speed and a scanning path of the irradiated laser beam, wherein each of the plurality of laser spots has a plurality of peak values of intensity distribution; the optical mechanism performs the following operations: when the brittle material substrate is thicker than the brittle material substrate suitable for the preset interval of the laser spots and when the brittle material substrate has lower thermal conductivity than the brittle material substrate suitable for the preset interval of the laser spots, in at least one case, the optical mechanism adjusts the interval of the laser spots formed along the scratch preset line to be smaller than the preset interval of the laser spots and sets the peak interval of the intensity distribution of the laser spots to be smaller than the preset peak interval of the intensity distribution of the laser spots; when the thickness of the brittle material substrate is smaller than the thickness of the brittle material substrate suitable for the preset interval of the plurality of laser spots, and when the thermal conductivity of the brittle material substrate is higher than the thermal conductivity of the brittle material substrate suitable for the preset interval of the plurality of laser spots, the interval of the plurality of laser spots formed along the predetermined scribing line is set to be larger than the interval of the plurality of laser spots by the optical mechanism, and the peak interval of the intensity distribution of the plurality of laser spots is set to be larger than the preset peak interval of the intensity distribution of the plurality of laser spots.

Drawings

Fig. 1 is a front view showing an example of an embodiment of a scribing apparatus for a brittle material substrate according to the present invention.

Fig. 2 is a schematic configuration diagram showing an example of a laser oscillation device and an optical system used in the scribing device of the present invention.

Fig. 3(a) is a schematic configuration diagram showing another example of a laser oscillation device and an optical system used in the scribing device of the present invention, and fig. 3(b) and (c) are schematic diagrams showing intensity distributions of laser spots irradiated from the laser oscillation device onto a glass substrate.

Fig. 4(a) is a schematic configuration diagram showing another example of a laser oscillation device and an optical system used in the scribing device of the present invention, and fig. 4(b) and (c) are schematic diagrams showing the intensity distribution of a laser spot irradiated from the laser oscillation device onto a glass substrate.

Fig. 5 is a schematic view illustrating the operation of the scribing device using the laser beam.

Fig. 6 is a perspective view schematically showing a state of the glass substrate during the operation of forming the scribe line by the laser scribing apparatus.

Fig. 7 is a plan view schematically showing the state of the glass substrate.

Fig. 8(a) is a schematic view showing a plurality of laser spots formed on a glass substrate by the laser oscillator and the optical system used in the scribing apparatus of the present invention shown in fig. 3(a) and 4(b), and fig. 8(b) is an enlarged view and an intensity distribution diagram of the laser spots.

Detailed Description

Embodiments of the present invention will be described below with reference to the drawings.

Fig. 1 is a schematic configuration diagram showing an embodiment of a scribing apparatus for a brittle material substrate according to the present invention. The scribing apparatus is, for example, for forming a scribing line on a glass substrate 50 when cutting the glass substrate for the FPD, and as shown in fig. 1, has a slide table 12 that reciprocates in a predetermined horizontal direction (Y direction) on a horizontal frame 11.

The slide table 12 is supported by a pair of guide rails 14 and 15 arranged in parallel in the Y direction on the upper surface of the frame 11, and the slide table 12 is slidable in a horizontal state along the respective guide rails 14 and 15. In the intermediate portion of the two guide rails 14 and 15, a ball screw 13 is provided in parallel with each of the guide rails 14 and 15 so as to be rotated by a motor (not shown). The ball screw 13 is capable of forward rotation and reverse rotation, and the ball nut 16 is attached to the ball screw 13 in a state of being screwed. The ball nut 16 is integrally attached to the slide table 12 in a non-rotatable state, and the ball nut 16 slides in two directions along the ball screw 13 by normal rotation and reverse rotation of the ball screw 13. Thereby, the slide table 12 integrally attached to the ball nut 16 slides in the Y direction along the guide rails 14 and 15.

On the slide table 12, a base 19 is disposed in a horizontal state. The base 19 is slidably supported by a pair of guide rails 21 arranged in parallel on the slide table 12. Each guide rail 21 is arranged along an X direction orthogonal to a Y direction as a sliding direction of the slide table 12. In addition, a ball screw 22 is disposed in parallel with each guide rail 21 at a central portion between the guide rails 21, and the ball screw 22 can be rotated in the normal direction and the reverse direction by a motor 23.

A ball nut 24 is screwed to the ball screw 22. The ball nut 24 is integrally attached to the base 19 in a non-rotating state, and the ball nut 24 moves in two directions along the ball screw 22 by normal rotation and reverse rotation of the ball screw 22. Thereby, the pedestal 19 slides in the X direction along the respective guide rails 21.

A rotation mechanism 25 is provided on the pedestal 19, and a rotary table 26 on which a glass substrate 50 to be cut is placed is provided in a horizontal state on the rotation mechanism 25. The rotation mechanism 25 rotates the rotation table 26 around a central axis in the vertical direction (θ direction). The glass substrate 50 is fixed to the turntable 26 by, for example, a suction chuck.

Above the turntable 26, a support table 31 is disposed at an appropriate interval from the turntable 26. The support table 31 is supported horizontally at the lower end of an optical holder 33 disposed vertically. The upper end of the optical holder 33 is attached to the lower surface of the mount table 32 provided on the chassis 11. On the mount table 32, a laser oscillation device 34 that emits a laser beam is provided.

The laser oscillator 34 irradiates a laser beam emitted from a laser oscillator to an optical system held in the optical holder 33.

A wheel cutter 35 for forming a slit at an end surface of the glass substrate 50 is provided on the support base 31 attached to the lower end portion of the optical holder 33. The wheel cutter 35 is disposed at an appropriate distance from the end of the laser beam in the longitudinal direction of the laser beam irradiated onto the glass substrate 50 and linearly along the longitudinal direction of the laser beam, and is held by the blade holder 36 so as to be movable up and down.

Further, a cooling nozzle 37 is provided on the support base 31 near the optical holder 33. A cooling medium such as cooling water, He gas, N2 gas, or CO2 gas is sprayed from the cooling nozzle 37 onto the glass substrate 50. The cooling medium ejected from the cooling nozzle 37 is blown to a position close to the end in the longitudinal direction of the laser spot irradiated from the optical holder 33 onto the glass substrate 50.

Further, a pair of CCD cameras (or cameras) 38 and 39 for picking up alignment marks engraved in advance on the glass substrate 50 are provided on the mount table 32, and monitors 28 and 29 for displaying images picked up by the respective CCD cameras 38 and 39 are provided on the mount table 32, respectively.

Fig. 2 is a schematic configuration diagram of an optical system provided in the laser oscillator 34 and the optical holder 33. The laser oscillator 34 includes a laser oscillator 34a for emitting one laser beam, and the laser beam emitted from the laser oscillator 34a is irradiated onto the glass substrate 50 via an X-axis current mirror (ガルバノミラ)34b, a Y-axis current mirror (galvano mirror)34c, and an f- θ lens 33a disposed in the optical holder 33.

The X-axis galvano mirror 34b rotates at a high speed, scans the laser beam emitted from the laser oscillator 34a at a high speed, and reflects the laser beam toward the Y-axis galvano mirror 34 c. Further, the Y-axis galvano mirror 34c is also rotated at a high speed, thereby scanning the laser beam irradiated from the X-axis galvano mirror 34b at a high speed and reflecting it toward the glass substrate 50. The laser beam reflected by the Y-axis galvano mirror 34c is irradiated onto the glass substrate 50 through the f- θ lens 33 a.

The laser beams irradiated onto the glass substrate 50 via the f-theta lens 33a form elliptical laser spots LS1 and LS2 in the Y-axis direction and the X-axis direction, respectively, according to the respective rotation speeds of the X-axis current mirror 34b and the Y-axis current mirror 34 c.

The lens for the laser beam reflected by the above-described Y-axis galvano mirror 34c is not limited to the f- θ lens.

The intervals between the laser beams LS1 and LS2 are changed by adjusting the rotation speeds of the X-axis galvano mirror 34b and the Y-axis galvano mirror 34 c. At the same time, cooling water is sprayed from the cooling nozzle 37 to a position close to the elliptical LS2 in the X-axis direction.

When scribing the glass substrate 50 by using such a scribing apparatus, first, the glass substrate 50 divided into a predetermined size is placed on the turntable 26 of the scribing apparatus and fixed by a suction device. Then, the alignment marks provided on the glass substrate 50 are imaged by the CCD cameras 38 and 39. The photographed alignment marks are displayed on monitors 28 and 29, and the glass substrate 50 is positioned at a predetermined position according to the display.

Scribing is performed on the glass substrate 50 positioned with respect to the support table 31 located at the lower end of the optical holder 33 by laser light. When scribing the glass substrate 50, the respective laser spots LS1 and LS2 irradiated from the optical holder 33 onto the surface of the glass substrate 50 are formed on the scribe lines of the glass substrate 50. The positioning of the rotary table 26 is performed by sliding the slide table 12, sliding the base 19, and rotating the rotary table 26 by the rotating mechanism 25.

When the rotary table 26 is positioned with respect to the support table 31, the rotary table 26 is slid in the X direction, and the end of the glass substrate 50 faces the wheel cutter 35. Then, the wheel cutter 35 is lowered. At the end of the glass substrate 50, a slit is formed along a predetermined line of the scratch.

Then, while the rotary table 26 is slid in the X direction along the planned scribing line, the laser beam from the laser oscillation device 34 is oscillated, and a cooling medium, for example, cooling water and compressed air, is sprayed together from a cooling nozzle.

On the glass substrate 50, an elliptical laser spot LS1 that is elongated in the Y-axis direction and an elliptical laser spot LS2 that is elongated in the X-axis direction are formed along the scanning direction of the glass substrate 50 at predetermined distances from each other by the oscillated laser beam from the laser oscillator 34. At the same time, the laser spot LS2 is sprayed with cooling water in a region spaced apart from the side opposite to the moving direction of the glass substrate 50 by a predetermined interval. Thereby, a dark crack is formed as a scribe line on the glass substrate 50.

When a dark crack is formed as a scribe line on the glass substrate 50, the glass substrate 50 is subjected to the subsequent cutting step, and a bending moment is applied to the glass substrate so as to act in the width direction of the scribe line. Thereby, the glass substrate 50 is cut along the scribe line.

When the type of the glass substrate 50 on which the scribe line is formed by the scribing apparatus is changed, the rotational speeds of the X-axis current mirror 34b and the Y-axis current mirror 34c in the laser oscillator 34 are adjusted, respectively, to adjust the interval between the laser spots LS1 and LS2 formed on the surface of the glass substrate 50 by the laser beam.

Further, by changing the scanning pattern of the laser beam by the X-axis galvano mirror 34b and the Y-axis galvano mirror 34c, the intensity distributions of the laser spots LS1 and LS2 in the respective long axis directions can be made to have a plurality of peaks.

With this, the interval between the laser spots LS1 and LS2 and the state of the intensity distribution thereof are changed to a state suitable for the type of material of the glass substrate 50, and the glass substrate 50 is heated to a state necessary for forming a dark crack deep inside the glass substrate 50 because the laser beam is irradiated onto the glass substrate 50.

Further, by changing the scanning pattern of the laser beam by the X-axis galvano mirror 34b and the Y-axis galvano mirror 34c to form a plurality of laser spots LS2 in series at predetermined intervals, the intensity distribution state of the plurality of laser spots formed can be set variously.

Preferably, by arranging the peaks of the plurality of intensity distributions forming the plurality of laser spots LS2 on a straight line, it is possible to further adapt to the type of material or the like of the glass substrate 50, and it becomes easy to set the conditions necessary for forming deep dark cracks.

As described above, a plurality of laser spots are formed by adjusting the scanning speed and scanning path of the laser beam at high speed. The plurality of laser spots are formed on the glass substrate 50 as if a multimode laser spot were formed.

When the glass substrate 50 is relatively thick or when the thermal conductivity is low, the interval between the laser spots LS1 and LS2 is set to be small, and when there are a plurality of LS2, the interval between the LS2 is set to be small, and further, the interval between the peaks of the intensity distribution of the laser spots along the X axis is also set to be small. Conversely, when the glass substrate 50 is relatively thin or has high thermal conductivity, the interval between the laser spots LS1 and LS2 is set to be large, and when there are a plurality of LS2, the interval between the LS2 is set to be large, and further, the interval between the peaks of the intensity distribution of the plurality of laser spots along the X axis is also set to be large.

In this way, when changing the conditions such as the material of the glass substrate 50 to be scribed, the laser beam irradiated to the glass substrate can be easily changed to a state suitable for the glass substrate 50, and therefore, it is possible to easily cope with glass substrates of various conditions.

The laser spot LS1 was formed in such a manner that the intensity distribution of the entire spot was uniform. Alternatively, it is preferable that the laser spot LS1 is formed along the Y axis in such a manner as to sandwich the scribe intended line with two intensity distribution peaks.

Thereby, when a compressive stress is applied to the planned scribing line on the glass substrate 50 from both sides of the line and the laser spot LS1 is used to heat the planned scribing line on the glass substrate 50, abnormal cracks different from dark cracks can be prevented from being generated at the end of the glass substrate 50.

In the above description, the case of the scribing apparatus having the laser oscillation device 34a and the optical system, and the laser oscillation device 34 and the optical holder 33 which emit one laser beam from the laser oscillation device 34a, as shown in fig. 2, has been described, but the scribing apparatus may be provided with a plurality of laser oscillation devices and a plurality of optical holders corresponding thereto, and the optical system shown in fig. 2 may be provided on the plurality of optical holders.

In this way, by providing a plurality of laser oscillation devices and a plurality of optical holders, laser beams having a plurality of different wavelengths can be irradiated onto the glass substrate 50. In general, a material has a wavelength region of light optimal for absorbing light, and when the material is irradiated with a laser beam close to the wavelength region, the material can be heated in a short time. Therefore, by irradiating the brittle material substrate with a laser beam having a light absorption wavelength close to that of the brittle material substrate, a dark crack is easily formed.

In order to form an optimum dark crack line by cutting various brittle material substrates, it is necessary to adjust the intervals between a plurality of laser spots formed on the brittle material substrate, the intensity distribution of the plurality of laser spots, and the wavelength of the laser beam forming the plurality of laser spots to an optimum state. Therefore, a scribing device equipped with a plurality of laser oscillation devices and a plurality of optical holders is employed.

Furthermore, the intensity distributions of the laser spot LS1 and the plurality of laser spots LS2 may be in a non-gaussian mode (ガウスモ to ド).

Fig. 3 is a schematic configuration diagram showing another example of the laser oscillator 34 and the optical system. The laser oscillator 34 includes a first laser oscillator 34a and a second laser oscillator 34 g. The first and second laser oscillators 34a and 34g irradiate laser beams having a gaussian mode intensity distribution in parallel with each other in the horizontal direction.

The laser beam oscillated by the first laser oscillator 34a is vertically reflected toward the glass substrate 50 by the first mirror 33c attached to the moving stage 33 d. The first mirror 33c is moved by the moving stage 33d in a direction to move closer to and away from the first laser oscillator 34 a. The moving stage 33d is moved by a stepping motor, thereby finely adjusting the position of the first mirror 33c with respect to the first laser oscillator 34 c.

The laser beam emitted from the second laser oscillator 34g is applied to the first half-round mirror 33f fixed to the movable stage 33 d' below the first mirror 33 c. The first half mirror 33f transmits the laser beam reflected by the first mirror 33c disposed above the first half mirror, and reflects the laser beam emitted from the second laser oscillator 34g downward.

The oscillating laser beams emitted from the first and second laser oscillators and irradiated onto the first half-round mirror 33f are shifted in phase, and the laser beams having a pair of intensity distribution peaks are combined at the first half-round mirror 33 f. In this case, the intervals between the respective intensity distribution peaks can be changed and reset as needed by adjusting the positions of the first mirror 33c and the first half-circle mirror 33f by the moving stages 33d and 33 d'.

In this way, the laser beam synthesized by the first half-round mirror 33f so as to have a pair of peaks of the intensity distribution is irradiated onto the glass substrate 50 through the f- θ lens 33 a.

Further, the lens for the laser beam synthesized by the first half-round mirror 33f is not limited to the f- θ lens.

The laser beam synthesized by the first half-round mirror 33f is irradiated onto the glass substrate 50 in a state where the peak of the intensity distribution is along the X-axis direction which is the moving direction of the glass substrate 50.

The scribing apparatus having such a laser oscillation apparatus and an optical system irradiates a laser beam having a pair of intensity distribution peaks in the X-axis direction onto the glass substrate 50 moving in the X-axis direction, and heats the surface of the glass substrate 50. At the same time, on the surface of the glass substrate 50 near the portion heated by the irradiation of the laser beam, a cooling medium is sprayed, thereby forming a dark crack as a scribe line on the glass substrate.

In this case, when the material, thickness, or the like of the glass substrate 50 on which the dark crack is formed by the scribing apparatus changes, the position at which the laser beam is reflected by the first mirror 33c toward the first half-circle mirror 33f is adjusted by the moving stage 33d and/or 33 d', and the interval of the peak of the intensity distribution of the laser spot formed on the surface of the glass substrate 50 by the laser beam is adjusted. This makes the glass substrate 50 suitable for its material. In this way, when a laser spot having a pair of peaks of intensity distribution is formed on the glass substrate 50 along the moving direction of the glass substrate 50, the inside of the glass substrate 50 is effectively heated to a state necessary for forming a dark crack across the entire inside.

Accordingly, the scribing apparatus having the optical system shown in fig. 3 can easily change various physical parameters of the laser beam irradiated onto the glass substrate to a state suitable for the glass substrate 50 even when conditions such as the material of the glass substrate 50 to be scribed are changed, and can easily cope with glass substrates even when various conditions are changed.

Fig. 3(b) is a schematic diagram illustrating a state in which a laser spot having a pair of peaks of intensity distribution with respect to the glass substrate 50 is obtained when the intensity distribution of the laser beams oscillated from the laser oscillators 34a, 34g is in a gaussian mode.

Further, the distance between the peaks can be changed by adjusting the mobile stations 33d and 33 d', and the order of arrangement of the two peaks can be changed as necessary.

Further, by moving the first mirror 33c shown in fig. 3(a) by feeding at a high speed by a plurality of pitches (pitch), a plurality of laser spots shown in fig. 8 can be formed on the glass substrate 50. The interval between the laser spots formed at this time is equal to the amount of movement of pitch feeding of the first mirror 33 c. By changing the amount of movement, when the conditions such as the material of the glass substrate 50 to be scribed are changed, the intervals between the plurality of laser beams irradiated onto the glass substrate can be easily changed to a state suitable for the glass substrate 50, and the glass substrate can be easily adapted to various conditions.

When the intensity distribution of the laser beams oscillated from the laser oscillators 34a and 34g is in the gaussian mode, the outer peripheral portion of the laser spot formed on the glass substrate 50 does not directly participate in heating the glass substrate 50, and there is a possibility that the heating efficiency of the glass substrate 50 is reduced. Therefore, as shown in fig. 3(c), it is preferable that the intensity distribution of the laser beams oscillated by the laser oscillators 34a and 34g is made to be in a non-gaussian mode.

Further, it is preferable to adopt a configuration in which a plurality of laser oscillators, corresponding half mirrors, and a mechanism for moving the half mirrors are added to the configuration shown in fig. 3, and a plurality of laser beams are irradiated onto the glass substrate 50 through a lens of 33a to form a laser spot on the glass substrate 50 and obtain a plurality of peaks of intensity distribution in the moving direction of the glass substrate 50.

Further, the plurality of laser oscillators may be laser oscillators that oscillate laser beams of different wavelengths.

Fig. 4 is a schematic configuration diagram showing another example of the laser oscillator 34 and the optical system. In this case, only the first laser oscillator 34a is provided in the laser oscillator 34, and the laser beam oscillated and emitted by the laser oscillator 34a is irradiated onto the second semi-transmissive/semi-reflective mirror (ハ - フミラ -one) 33b fixedly disposed on the moving stage 33 b'. The second semi-transmissive and semi-reflective mirror 33b divides the laser beam emitted from the laser oscillator 34a into a beam transmitted to the first mirror and a beam reflected downward.

The laser beam reflected downward by the second semi-transmissive and semi-reflective mirror 33b is irradiated onto the first semi-circular mirror 33f by a second reflecting mirror 33e disposed below the second semi-transmissive and semi-reflective mirror 33 b.

The other structures are the same as those of the laser oscillation device and the optical system shown in fig. 3.

In the case of this configuration, the laser beams divided by the second semi-transmissive semi-reflective mirror 33b are combined by the first semi-circular mirror 33f and irradiated onto the glass substrate 50 through the f- θ lens 33a, thereby forming a laser spot having a pair of peaks of intensity distribution on the surface of the glass substrate 50. Similarly to the case of fig. 3, by adjusting the reflection position when the laser beam is reflected by the first mirror 33c toward the first half-circle mirror by the movement of the moving stages 33d, 33d ', and 33 b', the interval between the peaks of the pair of intensity distributions of the laser spot can be appropriately set. Therefore, even when the conditions such as the material of the glass substrate 50 to be scribed are changed, the intensity distribution and the mutual interval of the laser beams irradiated to the glass substrate 50 can be easily changed to a state suitable for the glass substrate 50, and the glass substrate can be easily adapted to various conditions.

Fig. 4(b) is a schematic diagram depicting a state in which a laser spot having a pair of thermal energy peaks is obtained with respect to the glass substrate 50 when the intensity distribution of the laser mode oscillated by the laser oscillator 34a is gaussian mode.

Further, the distance between the peaks can be changed by adjusting the mobile stations 33d, 33d ', and 33 b', and the arrangement order of the two peaks can be changed if necessary.

Further, by moving the first mirror 33c of fig. 4(a) at high speed by multiple pitch feeding, a plurality of laser spots shown in fig. 8 can be formed on the glass substrate 50. The interval between the laser spots formed at this time is equal to the amount of movement of pitch feeding of the first mirror 33 c. By changing the amount of movement, when the conditions such as the material of the glass substrate 50 to be scribed are changed, the intervals between the plurality of laser beams irradiated onto the glass substrate can be easily changed to a state suitable for the glass substrate 50, and the glass substrate can be easily adapted to various conditions.

In addition, when the laser beams oscillated by the single laser oscillator 34a are divided and combined in this manner, if the intensity distribution of the laser beam emitted by the laser oscillator 34a is in the gaussian mode, the outer peripheral portion of the laser spot formed on the glass substrate 50 is not directly heated too much after being irradiated during the scribing process of the glass substrate 50, and the heating efficiency of the glass substrate 50 is lowered. Therefore, as shown in fig. 4(c), it is preferable to make the intensity distribution of the laser beam emitted from the laser oscillator 34a non-gaussian mode.

Industrial applicability of the invention

The invention relates to a scribing device for brittle material substrate, which can easily correspond to the type, thickness and the like of the brittle material substrate such as glass substrate for forming dark crack even if the type, thickness and the like of the brittle material substrate are changed, and can reliably form deep dark crack corresponding to various brittle material substrates.

Claims (3)

1. A scribing apparatus for a brittle material substrate for forming a vertical crack along a scribe line, comprising: at least one laser oscillator for emitting a laser beam intermittently irradiated continuously or at a high speed to form a laser irradiation spot having a temperature lower than a softening point of a brittle material substrate along a region on a surface of the brittle material substrate where a scribe line is to be formed; an optical mechanism for optically processing the laser beam oscillated by the laser oscillator, and adjusting the scanning speed and scanning path of the spot, or forming a single or multiple spots, or changing the intensity distribution; a cooling mechanism for supplying a cooling medium for continuously cooling the vicinity of the laser irradiation spot,

it is characterized in that the preparation method is characterized in that,

the optical mechanism is composed of: irradiating a laser beam oscillated by the laser oscillator, forming a plurality of laser spots on the brittle material substrate by the irradiated laser beam, and adjusting a scanning speed and a scanning path of the irradiated laser beam, wherein each of the plurality of laser spots has a plurality of peak values of intensity distribution;

when the brittle material substrate is thicker than the brittle material substrate suitable for the preset interval of the laser spots and when the brittle material substrate has lower thermal conductivity than the brittle material substrate suitable for the preset interval of the laser spots, in at least one case, the optical mechanism adjusts the interval of the laser spots formed along the scratch preset line to be smaller than the preset interval of the laser spots and sets the peak interval of the intensity distribution of the laser spots to be smaller than the preset peak interval of the intensity distribution of the laser spots; and the number of the first and second electrodes,

when the thickness of the brittle material substrate is thinner than the thickness of the brittle material substrate suitable for the preset interval of the laser spots, and when the thermal conductivity of the brittle material substrate is higher than the thermal conductivity of the brittle material substrate suitable for the preset interval of the laser spots, in at least one case, the interval of the laser spots formed along the scratch preset line is set by the optical mechanism to be larger than the interval of the laser spots, and the peak interval of the intensity distribution of the laser spots is set to be larger than the preset peak interval of the intensity distribution of the laser spots.

2. The scribing apparatus for a brittle material substrate according to claim 1, wherein the intensity distribution of the plurality of laser spots is a non-gaussian pattern.

3. A method for scribing a brittle material substrate, wherein a vertical crack is formed along a predetermined scribing line, the method comprising: a step of intermittently irradiating a laser beam continuously or at a high speed from at least one laser oscillator to form a laser irradiation spot having a temperature lower than the softening point of the brittle material substrate along a region on the surface of the brittle material substrate where a scribe line is to be formed;

a step of optically processing the laser beam from the laser oscillator by an optical mechanism and adjusting the scanning speed and scanning path of the spot, or forming a single or a plurality of spots, or changing the intensity distribution,

continuously cooling the vicinity of the laser spot by a cooling mechanism for supplying a cooling medium for cooling,

it is characterized in that the preparation method is characterized in that,

the optical mechanism is composed of: irradiating a laser beam oscillated by the laser oscillator, forming a plurality of laser spots on the brittle material substrate by the irradiated laser beam, and adjusting a scanning speed and a scanning path of the irradiated laser beam, wherein each of the plurality of laser spots has a plurality of peak values of intensity distribution;

the optical mechanism performs the following operations:

when the brittle material substrate is thicker than the brittle material substrate suitable for the preset interval of the laser spots and when the brittle material substrate has lower thermal conductivity than the brittle material substrate suitable for the preset interval of the laser spots, in at least one case, the optical mechanism adjusts the interval of the laser spots formed along the scratch preset line to be smaller than the preset interval of the laser spots and sets the peak interval of the intensity distribution of the laser spots to be smaller than the preset peak interval of the intensity distribution of the laser spots; and the number of the first and second electrodes,

when the thickness of the brittle material substrate is thinner than the thickness of the brittle material substrate suitable for the preset interval of the laser spots, and when the thermal conductivity of the brittle material substrate is higher than the thermal conductivity of the brittle material substrate suitable for the preset interval of the laser spots, in at least one case, the interval of the laser spots formed along the scratch preset line is set to be larger than the interval of the laser spots by the optical mechanism, and the peak interval of the intensity distribution of the laser spots is set to be larger than the preset peak interval of the intensity distribution of the laser spots.