WO2014175147A1

WO2014175147A1 - Method for cutting glass plate

Info

Publication number: WO2014175147A1
Application number: PCT/JP2014/060872
Authority: WO
Inventors: 齋藤　勲; 孝弘永田
Original assignee: 旭硝子株式会社
Priority date: 2013-04-26
Filing date: 2014-04-16
Publication date: 2014-10-30
Also published as: JP2016128365A

Abstract

Provided is a method that is for cutting a glass plate and that has superior production characteristics. One embodiment of this method for cutting a glass plate is provided with a step for forming scribe lines (31, 32) at the first primary surface (11) and second primary surface (12) of the glass plate (10) by means of scanning laser light (20) while causing the laser light (20) to be transmitted from the first primary surface (11) to the second primary surface (12). The laser light (20) is scanned while cooling regions (40a, 40b) offset from the scanning path of the laser light (20) to the rear of the scanning laser light (20).

Description

Cutting method of glass plate

The present invention relates to a method for cutting a glass plate, and more particularly to a method for cutting a glass plate using internal heating by laser light.

The glass plate is usually cut by introducing a scribe line mechanically into the main surface with a hard roller or chip such as diamond and applying a bending force along the scribe line. In such a technique, a lot of fine cracks are generated on the cut end face of the glass plate by introducing the scribe line. Therefore, there is a problem that sufficient strength cannot be obtained at the cut end.

In recent years, with respect to such problems, there is a method of cutting a glass plate by heating the inside of the glass plate by laser light irradiation and controlling the extension of initial cracks introduced into the end surface instead of the main surface of the glass plate. It has been proposed (for example, Patent Document 1). In such cutting using laser light (hereinafter also referred to as “laser cutting”), it is not necessary to mechanically introduce a scribe line into the main surface of the glass plate. Therefore, the above-mentioned fine crack is not generated on the cut end face, and a glass plate excellent in strength at the cut end can be obtained.

Japanese Unexamined Patent Publication No. 2006-256944

The inventor has found the following problems.
Generally, a chamfering process is performed on a cut end surface (particularly a corner portion) of a glass plate after cutting from the viewpoint of preventing breakage. For example, in the method for cutting a glass plate described in Patent Document 1, it is necessary to perform chamfering separately after laser cutting the glass plate. Thus, in the conventional method for cutting a glass plate, it is necessary to perform cutting and chamfering separately, and there is a problem of poor productivity.

The present invention has been made in view of the above, and an object of the present invention is to provide a method for cutting a glass plate with excellent productivity.

One aspect of the present invention provides the following glass plate cutting method.
(1) A step of forming a scribe line on the first main surface and the second main surface by scanning the laser light while transmitting the laser light from the first main surface of the glass plate to the second main surface. Prepared,
A method for cutting a glass plate, wherein the laser beam is scanned behind the laser beam to be scanned while cooling a region shifted from the scanning path of the laser beam.
(2) In a right-handed xyz orthogonal coordinate space, the first principal surface constitutes an xy plane, the scanning direction of the laser light is an x-axis plus direction, and the first direction in the normal direction of the first principal surface When the main surface side is the z-axis direction plus side and the second main surface side is the z-axis direction minus side,
The glass plate cut end surface on the y-axis direction plus side of the glass plate divided into the y-axis direction plus side and the y-axis direction minus side by shifting the region from the scanning path to the y-axis direction plus side. The method for cutting a glass plate according to (1), wherein a chamfered portion is formed on the glass plate.
(3) forming a protrusion on the cut end surface of the glass plate on the negative side in the y-axis direction;
The cutting method of the glass plate as described in said (2).
(4) In a right-handed xyz orthogonal coordinate space, the first main surface constitutes an xy plane, the scanning direction of the laser beam is an x-axis plus direction, and the first direction in the normal direction of the first main surface When the main surface side is the z-axis direction plus side and the second main surface side is the z-axis direction minus side,
The glass plate cut end surface on the y-axis direction minus side of the glass plate divided into the y-axis direction plus side and the y-axis direction minus side by shifting the region from the scanning path to the y-axis direction minus side. The method for cutting a glass plate according to (1), wherein a chamfered portion is formed on the glass plate.
(5) forming a protrusion on the cut end surface of the glass plate on the positive side in the y-axis direction;
The cutting method of the glass plate as described in said (4).
(6) The method according to any one of (1) to (5), further comprising a step of dividing the glass plate along the scribe line by applying a bending force to the glass plate on which the scribe line is formed. A method for cutting a glass plate as described in 1.
(7) The optical axis of the laser beam is parallel to the normal direction of the first main surface.
The method for cutting a glass plate according to any one of the above (1) to (6).
(8) The method for cutting a glass plate according to any one of (1) to (7), further comprising a step of forming an initial crack serving as a starting point of the scribe line on an end surface of the glass plate.
(9) The wavelength of the laser beam is 250 to 5000 nm.
The method for cutting a glass plate according to any one of the above (1) to (8).

According to the present invention, it is possible to provide a method for cutting a glass plate with excellent productivity.

It is a perspective view for demonstrating the method of forming a scribe line in the upper and lower surfaces of a glass plate, respectively. It is a top view which shows the beam shape of the laser beam in the upper surface of the glass plate of FIG. It is a top view which shows the beam shape of the laser beam in the lower surface of the glass plate of FIG. FIG. 4 is an axial sectional view taken along line IV-IV in FIG. 2. FIG. 5 is a cross-sectional view taken along line VV in FIG. 2. It is sectional drawing of the cooling nozzle used for the cutting | disconnection of a glass plate. It is the top view which looked at the glass plate 10 from the upper surface 11 side. It is the side view which looked at the glass plate 10 cut along the scribe line formed by the laser scanning shown in FIG. 7 from the end surface 13 side (x-axis direction minus side). It is the side view which looked at the glass plate 10 which is scanning the laser beam 20 to the x-axis plus direction from the y-axis direction plus side. It is the top view which looked at the glass plate 10 from the upper surface 11 side. It is the side view which looked at the glass plate 10 cut along the scribe line formed by the laser scanning shown in FIG. 10 from the end surface 13 side (x-axis direction minus side). It is the top view which looked at the glass plate 10 from the upper surface 11 side. It is the side view which looked at the glass plate 10 cut along the scribe line formed by the laser scanning shown in FIG. 12 from the end surface 13 side (x-axis direction minus side). It is a top view of the glass plate 10 which shows test conditions typically. It is the photograph which observed the cut part of Test Examples 11 and 12 from the x-axis direction minus side.

Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiment. In addition, for clarity of explanation, the following description and drawings are simplified as appropriate.

<Embodiment 1>
First, a method of forming scribe lines on the upper and lower surfaces of a glass plate will be described with reference to FIGS. FIG. 1 is a perspective view for explaining a method of forming scribe lines on the upper and lower surfaces of a glass plate. FIG. 2 is a plan view showing a beam shape of laser light on the upper surface of the glass plate of FIG. FIG. 3 is a plan view showing a beam shape of laser light on the lower surface of the glass plate of FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. FIG. 5 is a sectional view taken along line VV in FIG.

1 to 4, the arrow direction indicates the displacement direction of the irradiation position of the laser beam on the glass plate. In FIG. 5, the arrow direction indicates the direction of action of stress. 4 and 5, the thermal deformation of the glass plate is exaggerated. The state of thermal deformation of the glass plate can be confirmed by finite element analysis.
In the right-handed xyz orthogonal coordinate space shown in FIGS. 1 to 5, both main surfaces (upper surface 11 and lower surface 12) of the glass plate 10 are both parallel to the xy plane. The laser light is irradiated in the z-axis minus direction and scanned in the x-axis plus direction. The optical axis of the laser beam is parallel to the z axis.

The glass plate cutting method includes a scribing step of forming

scribe lines

31 and 32 on the glass plate 10. Although the kind of glass of the glass plate 10 is not specifically limited, For example, soda-lime glass, an alkali free glass, etc. are mentioned. The thickness of the glass plate 10 is appropriately set according to the use of the glass plate 10, and is, for example, 0.005 cm to 2.5 cm. The glass plate 10 may be either non-tempered glass or tempered glass, but non-tempered glass is preferred.

In the scribing process, the glass plate 10 is locally heated by the laser light 20 that passes through the glass plate 10 from the upper surface 11 side to the lower surface 12 side, and the irradiation position of the laser light 20 on the glass plate 10 is displaced. The scribe lines 31 are formed on the lower surface 12 of the glass plate 10 at the same time as the scribe lines 31 are formed on the upper surface 11 of the glass plate 10 due to the thermal stress generated in the glass plate 10. Thereby, it is possible to cleave the glass plate 10 by applying an external force to the glass plate 10 without turning the glass plate 10 upside down. For example, by placing the glass plate 10 on an elastic body without turning over and pushing the glass plate 10 from above, tensile stress is generated on the lower surface 12 of the glass plate 10, and the glass plate 10 can be cleaved along the scribe line 32. .

In this embodiment, since the scribe line 31 is also formed on the upper surface 11 of the glass plate 10, the cutting accuracy on the upper surface 11 and the lower surface 12 of the glass plate 10 is good. Furthermore, in the present embodiment, the scribe lines are simultaneously formed on the upper surface 11 and the lower surface 12 of the glass plate 10 with one laser beam 20, so that the scribe lines formed on the upper surface 11 and the lower surface 12 of the glass plate 10 are formed. The positional relationship tends to be a desired positional relationship. For example, when the laser beam 20 is perpendicularly incident on the upper surface 11 of the glass plate 10, a scribe line 31 formed on the upper surface 11 of the glass plate 10 when viewed from the normal direction of the upper surface 11 of the glass plate 10; The scribe line 32 formed on the lower surface 12 of the glass plate 10 tends to overlap. Therefore, the fractured surface of the glass plate 10 tends to be perpendicular to the upper surface 11 and the lower surface 12 of the glass plate 10.

The initial crack 33 which becomes the starting point of the scribe lines 31 and 32 may be formed in advance on the end surface 13 of the glass plate 10 as shown in FIG. The initial crack 33 may reach the upper surface 11 and the lower surface 12 of the glass plate 10, and may also be formed on the upper surface 11 and the lower surface 12 of the glass plate 10. The initial crack 33 is a common starting point for the scribe lines 31 and 32.

In addition, when an initial crack is formed in the end surface 13 of the glass plate 10, it may reach only the upper surface 11 of the glass plate 10, may reach only the lower surface 12 of the glass plate 10, or the glass plate 10 The upper surface 11 and the lower surface 12 may not be reached. Further, the initial crack may be formed on each of the upper surface 11 and the lower surface 12 of the glass plate 10, and in this case, it may reach the end surface 13 or may not reach the end surface 13. The initial crack may be formed on at least one of both the upper surface 11 and the lower surface 12 of the glass plate 10 and the end surface 13 of the glass plate 10.

The formation method of the initial crack 33 may be a general method, for example, a method using a cutter, a file, a laser, or the like. When the end surface 13 of the glass plate 10 is ground with a grindstone, microcracks formed by grinding can be used as initial cracks.

Part of the upper surface 11 of the glass plate 10 is heated by the laser beam 20 and bulges upward and symmetrically about the movement locus of the irradiation position of the laser beam 20 as shown in FIGS. In the portion that bulges upward, a tensile stress in a direction orthogonal to the direction of displacement of the irradiation position of the laser beam 20 is generated. Due to this tensile stress, the crack starting from the initial crack 33 extends along the movement locus of the irradiation position of the laser beam 20, and the scribe line 31 is formed. The tip of the scribe line 31 is at the irradiation position of the laser beam 20 on the upper surface 11 of the glass plate 10 or in the vicinity of the front thereof.

Similarly, a part of the lower surface 12 of the glass plate 10 is heated by the laser beam 20, and as shown in FIGS. 4 and 5, protrudes downward symmetrically about the movement locus of the irradiation position of the laser beam 20. Swell. In the portion that bulges downward, a tensile stress in a direction orthogonal to the direction of displacement of the irradiation position of the laser beam 20 is generated. Due to the tensile stress, the crack starting from the initial crack 33 extends along the movement locus of the irradiation position of the laser beam 20, and the scribe line 32 is formed. The tip of the scribe line 32 is at the irradiation position of the laser beam 20 on the lower surface 12 of the glass plate 10 or in the vicinity of the front thereof.

The scribe lines 31 and 32 both extend with the displacement of the irradiation position of the laser beam 20 on the glass plate 10. The displacement of the irradiation position of the laser beam 20 on the glass plate 10 is performed by the movement or rotation of the support of the glass plate 10 relative to the frame of the cutting device, or the movement of the light source 22 of the laser beam 20, even if both are performed. Good. Further, the displacement of the irradiation position of the laser beam 20 on the glass plate 10 may be performed by rotation of a galvanometer mirror that reflects the laser beam 20 emitted from the light source 22 toward the glass plate 10.

Whether or not a scribe line can be formed on each of the upper surface 11 and the lower surface 12 of the glass plate 10 is mainly determined by the formation position of the initial crack 33 and the irradiation condition of the laser beam 20. The irradiation conditions of the laser beam 20 include, for example, (1) the output of the light source 22, (2) the transmittance of the laser beam 20 with respect to the glass plate 10, and (3) the beam of the laser beam 20 on the upper surface 11 and the lower surface 12 of the glass plate 10. (4) Ratio (P1 / P2) of the power density (P1) of the laser beam 20 on the upper surface 11 of the glass plate 10 and the power density (P2) of the laser beam 20 on the lower surface 12 of the glass plate 10 It is done.

Assuming that the intensity of the laser beam 20 on the upper surface 11 of the glass plate 10 is I ₀ and the intensity of the laser beam 20 when moving through the glass plate 10 by a distance (D) (unit [cm]) is I, I = I The expression ₀ × exp (−α × D) is established. This equation is called Lambert-Beer's law. α represents the absorption coefficient (unit [cm ⁻¹ ]) of the glass plate 10 with respect to the laser light 20, and is determined by the wavelength of the laser light 20, the chemical composition of the glass plate 10, and the like. α is measured by an ultraviolet visible near infrared spectrophotometer or the like.

The absorption coefficient (α) (unit [cm ⁻¹ ]) of the glass plate 10 with respect to the laser beam 20, the distance (M) (unit [cm]) that the laser beam 20 moves from the upper surface 11 to the lower surface 12 of the glass plate 10, The product of (α × M) is preferably larger than 0 and not larger than 3.0. The internal transmittance of the laser beam 20 with respect to the glass plate 10 is high, and the lower surface 12 of the glass plate 10 can be sufficiently heated. α × M is more preferably 2.3 or less (internal transmittance of 10% or more), and further preferably 1.6 or less (internal transmittance of 20% or more). If α × M is too small, the internal transmittance is too high and the absorption efficiency is too low. Therefore, it is preferably 0.002 or more (internal transmittance 99.8% or less), more preferably 0.01 or more (internal transmittance). 99% or less), more preferably 0.02 or more (internal transmittance of 98% or less). The internal transmittance is a transmittance when there is no reflection on the upper surface 11 of the glass plate 10.

In addition, it is preferable that the heating temperature of the glass plate 10 is the temperature below the annealing point of glass. When the heating temperature of the glass plate exceeds the temperature of the annealing point of the glass, the glass is viscously flowed, the thermal stress is relaxed, and the scribe lines 31 and 32 are difficult to form.

When the laser beam 20 is perpendicularly incident on the upper surface 11 of the glass plate 10, the distance (M) that the laser beam 20 moves from the upper surface 11 to the lower surface 12 of the glass plate 10 is the same as the thickness (t) of the glass plate 10. Value. On the other hand, when the laser beam 20 is incident obliquely on the upper surface 11 of the glass plate 10, the laser beam 20 is refracted according to Snell's law. Therefore, when the refraction angle is γ, the laser beam 20 moves from the upper surface 11 to the lower surface 12 of the glass plate 10. The distance (M) to be obtained is approximately obtained by the equation M = t / cos γ.

As the light source 22, for example, a near-infrared (hereinafter simply referred to as “near-infrared”) laser having a wavelength of 800 to 1100 nm is used. As the near-infrared laser, for example, a Yb fiber laser (wavelength: 1000 to 1100 nm), a Yb disk laser (wavelength: 1000 to 1100 nm), an Nd: YAG laser (wavelength: 1064 nm), a high-power semiconductor laser (wavelength: 808 to 980 nm) ). These near-infrared lasers are high-powered and inexpensive, and it is easy to adjust α × M within a desired range.

In the present embodiment, a high-power and inexpensive near-infrared laser is used as the light source 22, but a light source having a wavelength of 250 to 5000 nm can be used. For example, UV laser (wavelength: 355 nm), green laser (wavelength: 532 nm), Ho: YAG laser (wavelength: 2080 nm), Er: YAG laser (2940 nm), laser using a mid-infrared light parametric oscillator (wavelength: 2600) To 3450 nm). The oscillation method of the laser beam 20 is not limited, and either a CW laser that continuously oscillates the laser beam or a pulse laser that oscillates the laser beam intermittently can be used. The intensity distribution of the laser beam 20 is not limited, and may be a Gaussian type or a top hat type.

In the case of a near-infrared laser, the absorption coefficient (α) increases as the content of iron (Fe), the content of cobalt (Co), and the content of copper (Cu) in the glass plate 10 increase. In this case, the absorption coefficient (α) increases in the vicinity of the absorption wavelength of the rare earth atom as the content of the rare earth element (for example, Yb) in the glass plate 10 increases. The adjustment of the absorption coefficient (α) uses iron from the viewpoints of glass transparency and cost, and cobalt, copper, and rare earth elements may not be substantially contained in the glass plate 10.

By the way, the smaller the beam width W1 of the laser beam 20 in the y-axis direction on the upper surface 11, the steeper the portion that bulges upward, and the direction perpendicular to the displacement direction (x-axis direction) of the laser beam 20 (y-axis direction). ) Tensile stress is large. Similarly, the smaller the beam width W2 of the laser beam 20 in the y-axis direction on the lower surface 12, the steeper the portion that bulges downward, and the direction (y-axis) orthogonal to the displacement direction (x-axis direction) of the laser beam 20 Direction) tensile stress is large.

Therefore, the laser beam 20 preferably has a beam width W1 in the y-axis direction on the upper surface 11 equal to or less than the thickness of the glass plate 10. Further, the laser beam 20 preferably has a beam width W2 in the y-axis direction on the lower surface 12 equal to or less than the thickness of the glass plate 10. A portion bulging upward on the upper surface 11 of the glass plate 10 and a portion bulging downward on the lower surface 12 of the glass plate 10 are sufficiently steep, and scribe lines are formed on the upper surface 11 and the lower surface 12 of the glass plate 10. Sufficient tensile stress is generated to do this.

The beam width L1 in the displacement direction (x-axis direction) of the laser beam 20 on the upper surface 11 and the beam width L2 in the displacement direction (x-axis direction) of the laser beam 20 on the lower surface 12 are not particularly limited. If L1 and L2 are short, the

curved scribe lines

31 and 32 can be easily formed. Moreover, if L1 and L2 are long, when the heating time of the specific position in the glass plate 10 is the same, the displacement speed of the irradiation position of the laser beam 20 in the glass plate 10 is fast, and the scribe lines 31 and 32 can be formed in a short time. .

The beam shape of the laser beam 20 on the upper surface 11 and the lower surface 12 of the glass plate 10 is not particularly limited, but is preferably circular. When the curved portion of the scribe line is formed, the width of the locus of the irradiation position of the laser beam 20 is constant, and the position accuracy of the scribe line is good.

While the laser beam 20 passes through the glass plate 10 from the upper surface 11 side to the lower surface 12 side, the intensity (W) of the laser beam 20 is attenuated according to Lambert-Beer's law. And the temperature of the part which the laser beam 20 of the glass plate 10 permeate | transmits is mainly determined by the power density (unit [W / cm < ² >]) of the laser beam 20, etc. FIG.

Therefore, the laser beam 20 has a ratio (P1 / P2) of the power density (P1) on the upper surface 11 of the glass plate 10 and the power density (P2) on the lower surface 12 of the glass plate 10 to 0.5-2. 0 is preferred. P1 / P2 is calculated by the equation P1 / P2 = S2 / S1 / exp (−α × M). S1 represents the irradiation area of the laser beam 20 on the upper surface 11 of the glass plate 10, and S2 represents the irradiation area of the laser beam 20 on the lower surface 12 of the glass plate 10. When P1 / P2 is 0.5 to 2.0, the temperature of the irradiation position of the laser beam 20 on the upper surface 11 of the glass plate 10 and the temperature of the irradiation position of the laser beam 20 on the lower surface 12 of the glass plate 10 are the same. It will be about. Accordingly, the portion that bulges upward on the upper surface 11 of the glass plate 10 and the portion that bulges downward on the lower surface 12 of the glass plate 10 are steep to the same extent. As a result, the depth of the scribe line 31 formed on the upper surface 11 of the glass plate 10 and the depth of the scribe line 32 formed on the lower surface 12 of the glass plate 10 are approximately the same depth. P1 / P2 is more preferably 0.6 or more, and further preferably 0.67 or more. Further, P1 / P2 is more preferably 1.67 or less, and further preferably 1.5 or less.

In order to adjust the ratio (S1 / S2) between the irradiation area (S1) of the laser beam 20 on the upper surface 11 of the glass plate 10 and the irradiation area (S2) of the laser beam 20 on the lower surface 12 of the glass plate 10, A condensing lens or the like (not shown) is disposed between the glass plate 10 and the like. When the condensing position of the laser beam 20 is below the glass plate 10, S1 / S2 is larger than 1.

The method for cutting the glass plate may further include a breaking step in which an external force is applied to the glass plate 10 and the glass plate 10 is cut along the scribe lines 31 and 32. A glass plate can be cut.
In addition to forming the scribe lines 31 and 32 separately as shown in FIG. 1, the scribe lines 31 and 32 are coupled to each other by adjusting the irradiation condition of the laser light 20 and changing the generated thermal stress. You can also. That is, a full cut can be performed only by laser irradiation without going through a break process.

In the rear of the irradiation position of the laser light 20, unlike the vicinity of the irradiation position of the laser light 20, a tensile stress is generated in the entire plate thickness. This tensile stress is formed behind the irradiation position of the laser beam 20 as a reaction force of the compressive stress generated by heating at the irradiation position of the laser beam 20. Therefore, when the tensile stress behind the irradiation position of the laser beam 20 is larger, the scribe line 31 on the upper surface 11 side and the scribe line 32 on the lower surface 12 side extend in the plate thickness inside direction and are combined. Here, the shape of the crack formed by combining the scribe lines 31 and 32 is determined by the difference in the thermal stress field and the rigidity of the glass plate 10.

Whether or not the scribe lines 31 and 32 are coupled by the thermal stress based on the irradiation of the laser beam 20 is mainly determined by the transmittance of the laser beam 20 with respect to the glass plate 10 and the output of the light source 22. When the output of the light source 22 is large and the tensile stress behind the irradiation position of the laser beam 20 becomes large, the scribe lines 31 and 32 are coupled. When the output of the light source 22 is small, the glass plate 10 may be irradiated with heating light emitted from a heating light source different from the light source 22 in order to combine the scribe lines 31 and 32.

The cutting of the glass plate 10 according to the present embodiment has better cutting accuracy on the upper surface 11 and the lower surface 12 of the glass plate 10 than the full cut disclosed in Patent Document 1. In the full cut disclosed in Patent Document 1, tensile stress is generated by cooling the rear of the irradiation position of the laser beam with a refrigerant, and a crack penetrating the glass plate 10 in the thickness direction is formed by this tensile stress. That is, in Patent Document 1, no scribe line is formed by laser light irradiation.

In contrast, in the present embodiment, the scribe lines 31 and 32 are formed by the tensile stress generated at the irradiation position of the laser beam 20 on the upper surface 11 and the lower surface 12 of the glass plate 10. Therefore, the tip positions of the scribe lines 31 and 32 are close to the irradiation position of the laser light 20, and the positions of the scribe lines 31 and 32 and the locus of the laser light 20 are likely to coincide with each other. Therefore, the positional accuracy of the scribe lines 31 and 32 formed on the upper surface 11 and the lower surface 12 of the glass plate 10 is good, and the cutting accuracy on the upper surface 11 and the lower surface 12 of the glass plate 10 is good.

Further, in the method for cutting a glass plate according to the present embodiment, cooling is performed by blowing air to the irradiation region of the laser beam 20. FIG. 6 is a cross-sectional view of a cooling nozzle used for cutting a glass plate. Gas is blown to the upper surface 11 of the glass plate 10 by the cooling nozzle 28 shown in FIG. As shown in FIG. 6, the cooling nozzle 28 is formed with a tapered cavity so that gas (air, nitrogen, etc.) flows in the direction of the arrow. Here, the axis of the cooling nozzle 28 coincides with the optical axis of the laser beam 20, and the laser beam 20 collected by the lens 25 passes through the inside of the cooling nozzle 28 and is provided at the tip of the cooling nozzle 28. The light is emitted from an opening having a diameter φn. Further, it can move in synchronization with the movement of the irradiation region of the laser beam 20 (that is, at the same scanning speed as the laser beam). With such a configuration, the laser irradiation unit is cooled by the gas. It is preferable to cool an area wider than the laser irradiation part. By this cooling, tensile stress is easily generated in the laser light irradiation region. That is, a scribe line is easily generated and stable processing is possible.

The cooling gas flow rate, the diameter φn of the opening of the cooling nozzle 28, and the gap G2 between the tip of the cooling nozzle 28 and the upper surface 11 of the glass plate 10 can be arbitrarily determined. Here, the smaller the diameter φn of the opening of the cooling nozzle 28, the faster the flow rate of the gas blown to the glass plate 10, and the cooling capacity on the upper surface 11 of the glass plate 10 is improved. Moreover, the cooling capability in the upper surface 11 of the glass plate 10 improves, so that the gap G2 between the front-end | tip of the cooling nozzle 28 and the upper surface 11 of the glass plate 10 is small. For example, room temperature cooling air is blown at a flow rate of 20 L / min using a cooling nozzle 28 having a diameter φn = 1 mm to a laser irradiation portion having a beam diameter of 0.3 mm. It is more effective if a similar cooling nozzle is provided on the lower surface 12 side.

Subsequently, the glass plate cutting method according to the present embodiment will be described in detail with reference to FIGS. FIG. 7 is a plan view of the glass plate 10 as viewed from the upper surface 11 side. In the example of FIG. 7, the glass plate 10 is divided into a main body portion 10a on the positive side in the y-axis direction and a cut-out portion 10b on the negative side in the y-axis direction by scanning the laser beam 20 in the positive direction along the x-axis. FIG. 8 is a side view of the glass plate 10 cut along the scribe line formed by the laser scanning shown in FIG. 7 as viewed from the end face 13 side (the negative side in the x-axis direction). Note that the xyz coordinates in FIGS. 7 and 8 coincide with those in FIG.

As shown in FIG. 7, in the cutting method according to the present embodiment, the upper surface 11 and the lower surface 12 are rearward (a negative amount in the x-axis direction) by a predetermined distance (shift amount) Δx from the optical axis of the laser light 20 and laser scanning is performed. Cooling is performed aiming at a position shifted from the path by a predetermined distance Δy in the y-axis direction. Thereby, behind the laser beam 20, the region 40a on the upper surface 11 and the region 40b on the lower surface 12 that are shifted from the laser scanning path by the distance Δy in the y-axis direction are cooled. Note that only one of the region 40a on the upper surface 11 and the region 40b on the lower surface 12 may be cooled, but it is preferable to cool both. In particular, when the plate is thick, it is effective to cool both.

In the example of FIG. 7, the

regions

40a and 40b that are shifted from the laser scanning path to the positive side in the y-axis direction are cooled. In this case, as shown in FIG. 8, chamfered portions 10c are formed at both corner portions of the cut end surface of the main body portion 10a. On the other hand, protrusions 10d are formed at both corners of the cut end surface of the cut portion 10b. In this way, by scanning the laser beam 20 while cooling the region behind the laser beam 20 and shifted from the laser scanning path, the scribe lines 31 and 32 are formed, and at the same time, the chamfered portion 10c is formed on the cut end surface. can do.

Specifically, the laser beam is cooled while cooling the region 40a on the upper surface 11 and the region 40b on the lower surface 12 which are shifted from the laser scanning path to the plus side in the y-axis direction behind the laser beam 20 (minus side in the x-axis direction). 20 is scanned. Thereby, as shown in FIG. 8, the chamfering part 10c can be formed in the glass plate (main-body part 10a) of the plus side of a y-axis among the divided | segmented two glass plates. Here, the scribe lines 31 and 32 extend from the upper surface 11 and the lower surface 12 of the glass plate 10 in the depth direction while being inclined in the y-axis direction minus side instead of the z-axis direction (perpendicular to the main surface). The scribe lines 31 and 32 inclined in the depth direction are chamfered portions 10c. That is, the method for cutting a glass plate according to the present embodiment can perform chamfering simultaneously with the introduction of the scribe line, and thus has higher productivity than the conventional method for cutting a glass plate.

Here, FIG. 9 is a side view of the glass plate 10 that is scanning the laser beam 20 in the positive x-axis direction as viewed from the positive y-axis direction. As shown in FIG. 9, the region 40a is cooled by the cooling nozzle 29a from the upper surface 11 side, and the region 40b is cooled by the cooling nozzle 29b from the lower surface 12 side. The cooling

nozzles

29a and 29b move in the plus direction of the x axis in synchronization with the laser beam 20. In the example of FIG. 9, the angle between the central axis of the

cooling nozzles

29a and 29b and the main surface (upper surface 11 and lower surface 12) of the glass plate 10 is set to an angle θ (0 ° ≦ θ ≦ 90 °). ing. The angle θ is not particularly limited, but the cooling efficiency of the glass plate 10 increases as the angle θ increases. That is, when θ = 90 ° (when the central axes of the

cooling nozzles

29a and 29b coincide with the normal line of the main surface of the glass plate 10), the cooling efficiency of the glass plate 10 is maximized. Note that the xyz coordinates in FIG. 9 coincide with those in FIG.

Subsequently, with reference to FIG. 10 and FIG. 11, the method for cutting the glass plate according to the present embodiment will be described in detail. 10 and 11 show a case where the

regions

40a and 40b that are shifted from the laser scanning path to the negative side in the y-axis direction are cooled. 10 and 11 correspond to FIGS. 7 and 8, respectively. That is, FIG. 10 is a plan view of the glass plate 10 viewed from the upper surface 11 side. In the example of FIG. 10, the glass plate 10 is divided into a main body portion 10a on the negative side in the y-axis direction and a cut-out portion 10b on the positive side in the y-axis direction in the same manner as FIG. The That is, in FIG. 7, the upper end of the drawing is cut away, whereas in FIG. 10, the lower end of the drawing is cut off. Therefore, the positional relationship between the main body portion 10a and the cut portion 10b is reversed. FIG. 11 is a side view of the glass plate 10 cut along the scribe lines 31 and 32 formed by the laser scanning shown in FIG. 10 when viewed from the end face 13 side (x-axis direction minus side). In addition, the xyz coordinate in FIG. 10, FIG. 11 corresponds with FIG.

As shown in FIG. 10, when cooling the

regions

40a and 40b shifted from the laser scanning path to the negative side in the y-axis direction, as shown in FIG. 11, chamfered portions are formed at both corners of the cut end surface of the main body 10a. 10c is formed. On the other hand, protrusions 10d are formed at both corners of the cut end surface of the cut portion 10b. In this way, by scanning the laser beam 20 while cooling the region behind the laser beam 20 and shifted from the laser scanning path, the scribe lines 31 and 32 are formed, and at the same time, the chamfered portion 10c is formed on the cut end surface. can do.

Specifically, the laser beam is cooled while cooling the region 40a on the upper surface 11 and the region 40b on the lower surface 12 which are shifted from the laser scanning path to the minus side in the y-axis direction behind the laser beam 20 (minus side in the x-axis direction). 20 is scanned. Accordingly, as shown in FIG. 11, the chamfered portion 10c can be formed on the glass plate (main body portion 10a) on the negative side in the y-axis direction among the two divided glass plates. Here, the scribe lines 31 and 32 extend from the upper surface 11 and the lower surface 12 of the glass plate 10 in the depth direction so as to incline in the y-axis direction plus side rather than in the z-axis direction (perpendicular to the main surface). The scribe lines 31 and 32 inclined in the depth direction are chamfered portions 10c. That is, the method for cutting a glass plate according to the present embodiment can perform chamfering simultaneously with the introduction of the scribe line, and thus has higher productivity than the conventional method for cutting a glass plate.

<Modification of Embodiment 1>
Next, with reference to FIG. 12 and FIG. 13, a glass plate cutting method according to a modification of the first embodiment will be described in detail. 12 and 13 show a case where the

regions

40a and 40b that are shifted from the laser scanning path to the minus side in the y-axis direction are cooled, as in FIGS. 12 and 13 correspond to FIGS. 10 and 11, respectively. That is, FIG. 12 is a plan view of the glass plate 10 viewed from the upper surface 11 side. In the example of FIG. 12, the glass plate 10 is divided into a main body portion 10a on the positive side in the y-axis direction and a cut-out portion 10b on the negative side in the y-axis direction in the same manner as in FIG. The That is, in FIG. 10, the lower end of the drawing is cut out, whereas in FIG. 12, the upper end of the drawing is cut off. Therefore, the positional relationship between the main body portion 10a and the cut portion 10b is reversed. FIG. 13 is a side view of the glass plate 10 cut along the scribe lines 31 and 32 formed by the laser scanning shown in FIG. 12 when viewed from the end face 13 side (x-axis direction minus side). Note that the xyz coordinates in FIGS. 12 and 13 are the same as those in FIG.

As shown in FIG. 13, when cooling the

regions

40a and 40b shifted from the laser scanning path to the negative side in the y-axis direction, as in FIG. A chamfered portion 10c is formed on the glass plate. Therefore, a protrusion 10d is formed on the main body portion 10a on the y axis direction plus side, and a chamfered portion 10c is formed on the cut portion 10b on the minus side in the y axis direction. Thus, by the method for cutting a glass plate according to the present embodiment, the protruding portion 10d can be formed on the cut end surface of the main body portion 10a instead of the chamfered portion 10c.

Here, the scribe lines 31 and 32 extend from the upper surface 11 and the lower surface 12 of the glass plate 10 in the depth direction of the glass plate 10 while being inclined in the y-axis direction plus side instead of the z-axis direction (perpendicular to the main surface). is doing. The scribe lines 31 and 32 inclined in the depth direction become the protrusions 10d. That is, the glass plate cutting method according to the present embodiment can form a protrusion on the cut end face simultaneously with the introduction of the scribe line. Therefore, it is excellent in productivity of such an end surface-shaped glass plate. In addition, the glass plate which has a projection part in an end surface in this way is useful for the use which fixes the said end surface to a resin material, for example. By having the protrusion, it is easy to fix to the resin material.

As described above, in the glass plate cutting method according to the first embodiment, the

regions

40a and 40b that are shifted in the y-axis direction from the laser scanning path are cooled behind the laser beam 20 (minus side in the x-axis direction). While scanning, the laser beam 20 is scanned. Thereby, the chamfered portion 10 c can be formed on the cut end surface of the glass plate 10 at the same time when the scribe lines 31 and 32 are introduced into the glass plate 10. Therefore, the cutting method of the glass plate which concerns on Embodiment 1 is excellent in productivity compared with the cutting method of the conventional glass plate. Specifically, by cooling the

regions

40a and 40b that are shifted to the y-axis direction plus side from the laser scanning path, the chamfered portion 10c is formed on the y-axis direction plus side glass plate out of the two divided glass plates. Can be formed. On the other hand, by cooling the

regions

40a and 40b shifted from the laser scanning path to the negative side in the y-axis direction, the chamfered portion 10c is formed on the glass plate on the negative side in the y-axis direction among the two divided glass plates. Can do. Further, by adjusting the laser output and the size of the laser light irradiation region on the upper surface 11 or the lower surface 12, the inclination of the scribe lines 31 and 32, that is, the inclination of the chamfered portion 10c can be controlled.

Hereinafter, specific examples of the present invention will be described, but the present invention is not limited thereto.

(Example 1)
In Example 1, in Test Examples 11 and 12, the distance from the laser scanning path of the

regions

40a and 40b to be cooled (shift amount in the y-axis direction) Δy was changed for each test example, and the shape of the cut end face was investigated. .

[Test Examples 11 and 12]
FIG. 14 is a plan view of the glass plate 10 schematically showing test conditions. In both Test Examples 11 and 12, on the upper surface of a rectangular glass plate (long side 100 mm, short side 50 mm, plate thickness 3.1 mm, green colored transparent soda lime silica glass manufactured by Asahi Glass Co., Ltd.), as shown in FIG. On the other hand, a laser beam was vertically incident. A Yb fiber laser (wavelength: 1070 nm) was used as a laser light source. The absorption coefficient (α) of the glass plate with respect to the laser beam was 2.86 cm ⁻¹ , and α × M was 0.89 (that is, the internal transmittance was 41.2%). The laser output was 30 W, the upper surface beam width of the laser light was 2.73 mm, the lower surface beam width was 1.75 mm, and the scanning speed was 10 mm / s.

The beam shape of the laser light was circular on the upper and lower surfaces of the glass plate 10. For both test examples, as shown in FIG. 14, the laser beam was scanned from one long side of the glass plate 10 to the other long side in parallel with the short side of the glass plate 10. The distance d from the short side of the glass plate 10 at the laser scanning position was set to d = 10 mm.

The shift amount Δx in the x-axis direction from the optical axis of the laser light 20 in the

cooling regions

40a and 40b is both set to Δx = −2 mm.
The diameter of the opening provided at the tip of the

cooling nozzles

29a and 29b was 1.0 mm. The flow rates of the cooling air blown from the cooling

nozzles

29a and 29b to the

regions

40a and 40b were 10 L / min, respectively. The angle θ between the central axes of the

cooling nozzles

29a and 29b and the main surface (upper surface 11 and lower surface 12) of the glass plate 10 was set to 45 °.
The distances Δy from the laser scanning path of the

cooling regions

40a and 40b, which are variables, were Δy = −2 mm in Test Example 11 and Δy = 2 mm in Test Example 12.

The initial crack was formed in the end surface 13 of the glass plate 10 so that it might reach the lower surface 12 from the upper surface 11 of the glass plate 10 using the wheel cutter. In both Test Examples 11 and 12, the scribe lines 31 and 32 were introduced into the upper and lower surfaces by laser light irradiation, and then cleaved by applying a bending force.

Similarly to the description of the above-described embodiment, the main surface of the glass plate 10 is parallel to the xy plane, laser light is irradiated in the z-axis minus direction, and scanned in the x-axis plus direction. The test results will be described. FIG. 15 is a photograph of the cut parts of Test Examples 11 and 12 observed from the minus side in the x-axis direction. Note that the xyz coordinates in FIG. 15 coincide with those in FIG.

In Test Example 11 in which a region shifted from the laser scanning path (x axis) to the y axis direction minus side is cooled behind the laser beam 20 (x axis direction minus side), the y axis of the two divided glass plates A chamfered portion 10c was formed on the glass plate on the minus side in the direction, and a protrusion 10d was formed on the glass plate on the plus side in the y-axis direction. That is, it became the same as the cross-sectional shape shown in FIG. In FIG. 15, the photograph of the cut part about the test example 11 was shown.

On the other hand, in Test Example 12 in which the region shifted from the laser scanning path (x axis) to the y axis direction plus side is cooled behind the laser beam 20 (x axis direction minus side), among the two divided glass plates, A chamfered portion 10c was formed on the glass plate on the positive side in the y-axis direction, and a protrusion 10d was formed on the glass plate on the negative side in the y-axis direction. That is, it became the same as the cross-sectional shape shown in FIG. In FIG. 15, the photograph of the cut part about the test example 12 was shown.

In Example 1, the laser beam 20 was scanned while cooling a region shifted in the y-axis direction from the laser scanning path (x-axis) behind the laser beam 20 (minus side in the x-axis direction). Thereby, the chamfered part 10c was able to be formed in the cut end surface of the glass plate 10 simultaneously with introducing the scribe lines 31 and 32 into the glass plate 10. Therefore, the cutting method of the glass plate which concerns on Example 1 is excellent in productivity compared with the cutting method of the conventional glass plate.

(Example 2)
Next, also in Example 2, in Test Examples 21 to 23, the distance (shift amount in the y-axis direction) Δy from the laser scanning path of the

regions

40a and 40b to be cooled is changed for each test example, and the shape of the cut end face investigated. In Example 1, the scribe lines 31 and 32 were introduced by laser light irradiation, and then manually cleaved. On the other hand, in Example 2, the laser power absorbed by the glass plate is increased and a full cut is performed only by laser light irradiation. Also in this case, the scribe lines 31 and 32 are formed on the upper and lower surfaces by laser light irradiation. And these two

scribe lines

31 and 32 couple | bond together behind a laser beam irradiation position, and a glass plate is cut | disconnected. That is, the cutting method disclosed in Patent Document 1 is different in cutting mechanism even with the same full cut.

[Test Examples 21 to 23]
In all Test Examples 21 to 23, as shown in FIG. 14, the upper surface of a rectangular glass plate (long side 100 mm, short side 50 mm, plate thickness 3.1 mm, green colored transparent soda lime silica glass manufactured by Asahi Glass Co., Ltd.) The laser beam was made to enter perpendicularly to. A Yb fiber laser (wavelength: 1070 nm) was used as a laser light source. The absorption coefficient (α) of the glass plate with respect to the laser beam was 2.86 cm ⁻¹ , and α × M was 0.89 (that is, the internal transmittance was 41.2%). The laser output was 70 W, the top beam width of the laser light was 5.19 mm, the bottom beam width was 4.22 mm, and the scanning speed was 10 mm / s.

The beam shape of the laser light was circular on the upper and lower surfaces of the glass plate 10. For all the test examples, as shown in FIG. 14, the laser beam was scanned in parallel with the short side of the glass plate 10 from one long side of the glass plate 10 to the other long side. The distance d from the short side of the glass plate 10 at the laser scanning position was set to d = 10 mm.

cooling regions

cooling nozzles

nozzles

29a and 29b to the

regions

cooling nozzles

29a and 29b and the main surface (upper surface 11 and lower surface 12) of the glass plate 10 was set to 45 °.
Regarding the distance Δy from the laser scanning path of the

cooling regions

40a and 40b, which are variables, Δy = 0 mm in Test Example 21, Δy = −2 mm in Test Example 22, and Δy = 2 mm in Test Example 23.
The initial crack was formed in the end surface 13 of the glass plate 10 so that it might reach the lower surface 12 from the upper surface 11 of the glass plate 10 using the wheel cutter.

As in Example 1, the test results are described below assuming that the main surface of the glass plate 10 is parallel to the xy plane, the laser beam is irradiated in the z-axis minus direction, and scanned in the x-axis plus direction. To do.

As in Example 1, in the test example 22 in which the region shifted from the laser scanning path (x-axis) to the y-axis direction minus side behind the laser beam 20 (x-axis direction minus side) was cooled, Among the glass plates, the chamfered portion 10c was formed on the glass plate on the negative side in the y-axis direction, and the protruding portion 10d was formed on the glass plate on the positive side in the y-axis direction. That is, it became the same as the cross-sectional shape shown in FIG.

On the other hand, in Test Example 23 in which the region shifted from the laser scanning path (x axis) to the y axis direction plus side is cooled behind the laser beam 20 (x axis direction minus side), of the two divided glass plates, A chamfered portion 10c was formed on the glass plate on the positive side in the y-axis direction, and a protrusion 10d was formed on the glass plate on the negative side in the y-axis direction. That is, it became the same as the cross-sectional shape shown in FIG.
In Test Example 21, it was not determined in which of the two divided glass plates the chamfered portion 10c was formed.

Also in Example 2, the laser beam 20 was scanned while cooling a region shifted in the y-axis direction from the laser scanning path (x-axis) behind the laser beam 20 (minus side in the x-axis direction). Thereby, the chamfered part 10c was able to be formed in the cut end surface of the glass plate 10 simultaneously with introducing the scribe lines 31 and 32 into the glass plate 10. Therefore, the glass plate cutting method according to Example 2 is also more productive than the conventional glass plate cutting method.

As mentioned above, although embodiment etc. of the cutting method of a glass plate were demonstrated, this invention is not limited to the said embodiment etc., A various deformation | transformation and improvement are possible in the range described in the claim. .
For example, a plurality of laser beams for forming the scribe lines 31 and 32 on both surfaces of the glass plate 10 may be irradiated onto the glass plate 10 simultaneously.
In the above-described embodiment and the like, the example in which the laser beam is scanned while cooling the region shifted from the laser beam scanning path in the period from the start of cutting to the end of cutting has been described. Just do it.
Further, the glass plate 10 may be either a flat plate or a curved plate, and may be any one of a template glass with a concavo-convex pattern on the surface, a meshed glass containing a metal net or wire inside, a laminated glass, and a tempered glass. May be.

This application is based on Japanese Patent Application No. 2013-094108 filed on Apr. 26, 2013, the contents of which are incorporated herein by reference.

DESCRIPTION OF SYMBOLS 10 Glass plate 10a Main part

10b Cutting part

10c Chamfering part

10d Projection part 11 Upper surface 12 Lower surface 13 End surface 20 Laser light 22 Light source 25

Lens

28, 29a,

29b Cooling nozzle

31, 32 Scribe line 33

Initial crack

40a, 40b area | region

Claims

Forming a scribe line on the first main surface and the second main surface by scanning the laser light while transmitting the laser light from the first main surface of the glass plate to the second main surface;
A method for cutting a glass plate, wherein the laser beam is scanned behind the laser beam to be scanned while cooling a region shifted from the scanning path of the laser beam.
In the right-handed xyz orthogonal coordinate space, the first principal surface forms an xy plane, the scanning direction of the laser light is the x-axis plus direction, and the first principal surface side in the normal direction of the first principal surface Is the z-axis direction plus side, and the second main surface side is the z-axis direction minus side,
The glass plate cut end surface on the y-axis direction plus side of the glass plate divided into the y-axis direction plus side and the y-axis direction minus side by shifting the region from the scanning path to the y-axis direction plus side. The method for cutting a glass plate according to claim 1, wherein a chamfered portion is formed on the glass plate.
Forming a protrusion on the cut end surface of the glass plate on the negative side in the y-axis direction;
The method for cutting a glass plate according to claim 2.
In the right-handed xyz orthogonal coordinate space, the first principal surface forms an xy plane, the scanning direction of the laser light is the x-axis plus direction, and the first principal surface side in the normal direction of the first principal surface Is the z-axis direction plus side, and the second main surface side is the z-axis direction minus side,
The glass plate cut end surface on the y-axis direction minus side of the glass plate divided into the y-axis direction plus side and the y-axis direction minus side by shifting the region from the scanning path to the y-axis direction minus side. The method for cutting a glass plate according to claim 1, wherein a chamfered portion is formed on the glass plate.
Forming a protrusion on the cut end surface of the glass plate on the positive side in the y-axis direction;
The method for cutting a glass plate according to claim 4.
The glass plate according to any one of claims 1 to 5, further comprising a step of dividing the glass plate along the scribe line by applying a bending force to the glass plate on which the scribe line is formed. Cutting method.
The optical axis of the laser beam is parallel to the normal direction of the first main surface,
The method for cutting a glass plate according to any one of claims 1 to 6.
The method for cutting a glass plate according to any one of claims 1 to 7, further comprising a step of forming an initial crack serving as a starting point of the scribe line on an end face of the glass plate.
The wavelength of the laser beam is 250 to 5000 nm.
The method for cutting a glass plate according to any one of claims 1 to 8.