JP6379392B2 - Glass substrate cutting method and glass substrate manufacturing method - Google Patents

Description

  The present invention relates to a glass substrate cutting method and a glass substrate manufacturing method.

  A cutting method using a laser beam has been studied as a method for cutting a glass substrate.

  For example, Patent Document 1 discloses a method of cutting a glass substrate that is forcibly cooled by compressed gas or the like immediately after forming a notch recess having a predetermined depth by irradiating a laser beam.

  Patent Document 2 discloses a method for cutting a glass substrate in which a glass substrate is irradiated with laser light while being scanned, the glass is melted at an irradiated portion of the laser light, and the molten glass is blown off by an assist gas.

Japanese Unexamined Patent Publication No. 2004-059328 Japanese Unexamined Patent Publication No. 60-251138

  However, according to the method for cutting a glass substrate described in Patent Document 1, a portion corresponding to a notch recess formed by irradiating a laser beam on the cut surface, and then when the forced cooling is performed, the cut surface is cut. And a portion formed in the lower part of the notch recess, and the surface characteristics of both are different.

  As described above, when there are portions having different surface characteristics due to the cutting method in the cut surface, it is necessary to polish the cut surface to obtain a cut surface with uniform surface characteristics in order to obtain a product. For this reason, time was required for the grinding | polishing process about a cut surface.

  Moreover, since it is necessary to spray compressed gas (assist gas) with respect to a glass substrate immediately after irradiating a laser beam, the position of the glass substrate was easy to displace and the cutting precision might fall.

  According to the method for cutting a glass substrate described in Patent Document 2, there is a problem that the position of the glass substrate is displaced by the pressure of the assist gas, and the accuracy in cutting may be lowered. In addition, depending on the energy density of the laser beam, the amount of local thermal deformation of the glass increases, and a glass substrate may be cracked. Furthermore, since the molten glass removed by the assist gas adheres and solidifies on the cut surface and its periphery, it takes time for the polishing process to remove it.

  In view of the problems of the prior art described above, the present invention can cut a glass substrate with higher accuracy than the conventional glass substrate cutting method in which an assist gas is blown onto the glass substrate, and the occurrence of cracks in the glass substrate. It aims at providing the cutting method of the glass substrate which suppresses and can obtain a uniform cut surface.

In order to solve the above problems, the present invention is a method for cutting a glass substrate by irradiating a laser beam along a planned cutting line, wherein the thickness of the glass substrate is 3.0 mm or less. , A partial region in the width direction perpendicular to the cutting line of the glass substrate including a laser light irradiation region for irradiating the laser light on one surface of the glass substrate, the width direction of the glass substrate And heated to a temperature higher than the vaporization temperature of the laser light irradiation part from one surface of the glass substrate to the other surface in the laser light irradiation region, and cutting the laser light irradiation region of the glass substrate A method for cutting a glass substrate is provided, wherein the glass substrate is moved relative to the glass substrate along a predetermined line.

  According to the method for cutting a glass substrate of the present invention, it is possible to cut the glass substrate with higher accuracy than the method for cutting a glass substrate using a conventional assist gas. Moreover, generation | occurrence | production of the crack to a glass substrate at the time of a cutting | disconnection can be suppressed, and it can be set as a uniform cut surface.

Explanatory drawing of the cutting method of the glass substrate which concerns on embodiment of this invention Explanatory drawing of the distance between the laser oscillation apparatus and one surface of a glass substrate at the time of irradiating a laser beam with respect to the glass substrate which has an unevenness | corrugation on the surface Explanatory drawing of the distance between the laser oscillation apparatus and one surface of a glass substrate at the time of irradiating a laser beam with respect to the glass substrate which has an unevenness | corrugation on the surface Explanatory drawing of the structural example of the conveyance roller provided with the supporting member Explanatory drawing of the structural example which has arrange | positioned the conveyance roller provided with the supporting member on the conveyance path | route of a glass substrate. Explanatory drawing of the structural example which has arrange | positioned the conveyance roller provided with the supporting member on the conveyance path | route of a glass substrate. Explanatory drawing of the structural example of the conveyance roller which curves the one part area | region of the width direction of a glass substrate Explanatory drawing of the heating process in the cutting method of the glass substrate which concerns on embodiment of this invention. Explanatory drawing of the cooling process in the cutting method of the glass substrate which concerns on embodiment of this invention. Explanatory drawing about the precipitate in the cooling process in the cutting method of the glass substrate which concerns on embodiment of this invention Explanatory drawing of the relationship between the conveyance speed of the glass substrate of Experimental example 1 of this invention, the energy density of a laser beam, and evaluation of a cut surface. Explanatory drawing of the relationship between the conveyance speed of the glass substrate of Experimental example 2 of this invention, the energy density of a laser beam, and evaluation of a cut surface Explanatory drawing of the relationship between the conveyance speed of the glass substrate of Experimental example 3 of this invention, the energy density of a laser beam, and evaluation of a cut surface Explanatory drawing of the relationship between the conveyance speed of the glass substrate of Experimental example 4 of this invention, the energy density of a laser beam, and evaluation of a cut surface. Explanatory drawing of another method of curving a partial region in the width direction of the glass substrate

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiments, and the following embodiments are not departed from the scope of the present invention. Various modifications and substitutions can be made.

  In this embodiment, a configuration example of the method for cutting a glass substrate of the present invention will be described.

  The method for cutting a glass substrate according to the present embodiment is a method for cutting a glass substrate by irradiating a laser beam along a planned cutting line, and has the following configuration.

  A part of the width direction (hereinafter also referred to as “the width direction of the glass substrate”) orthogonal to the planned cutting line of the glass substrate including the laser light irradiation region that irradiates one surface of the glass substrate with the laser light The region is curved in the width direction of the glass substrate.

  Then, in the laser light irradiation region, heating is performed at a temperature higher than the temperature at which the laser light irradiation portion from one surface of the glass substrate to the other surface is vaporized.

  Furthermore, the laser beam irradiation region is moved relative to the glass substrate along a planned cutting line of the glass substrate.

  This will be specifically described with reference to FIGS.

  FIG. 1 schematically shows a configuration in which a glass substrate is cut by the glass substrate cutting method of the present invention, as viewed from the upper surface of the glass substrate on the side irradiated with laser light (one surface side).

  The glass substrate 11 is conveyed in the direction indicated by the arrow A in FIG. 1, and a portion (laser light irradiation region) irradiated with a laser beam 12 oscillated from a laser oscillation device (not shown) is cut on the glass substrate. It can move along the planned line 13.

  And in the cutting method of the glass substrate of this embodiment, the one part area | region of the width direction orthogonal to the cutting planned line of the glass substrate containing the irradiation area | region of a laser beam is curved to the width direction of a glass substrate. Yes. This will be described below.

  When the glass substrate is thin, particularly when the glass substrate is being transported, wrinkles may occur in the glass substrate. When wrinkles occur in the glass substrate, the surface of the glass substrate includes irregularities. And when irradiating a laser beam with respect to the glass substrate 11 which has an unevenness | corrugation on the surface, as shown to FIG. 2A, when irradiating a laser beam to the convex part 22 of the glass substrate 11 currently conveyed on the conveyance roller 21, laser The distance D1 is between the oscillation device 23 and one surface of the glass substrate 11. On the other hand, as shown in FIG. 2B, when the laser beam is irradiated onto the concave portion 24 of the glass substrate 11 being conveyed on the conveyance roller 21, the position of the laser oscillation device 23 does not change. And one surface of the glass substrate 11 are longer than the distance D1 and become the distance D2. Thus, due to the unevenness of the glass substrate surface, the distance between the laser oscillation device and one surface of the glass substrate changes, and the glass substrate may not be appropriately heated by the laser beam.

  In contrast, by curving a partial area in the width direction orthogonal to the planned cutting line of the glass substrate including the laser light irradiation area, wrinkles are generated in the glass substrate at least about the curved part of the glass substrate. Can be suppressed. For this reason, in the laser light irradiation region, the distance between one surface of the glass substrate 11 and the laser oscillation device that is the light source of the laser light is stabilized, and heating is appropriately performed along the planned cutting line of the glass substrate. Is possible. And a glass substrate can be cut with high precision and it can be set as a uniform cut surface.

  Method of curving a partial region in the width direction perpendicular to the planned cutting line of the glass substrate including the laser light irradiation region for irradiating the laser beam 12 on one surface of the glass substrate 11 in the width direction of the glass substrate Is not particularly limited. In addition, it can be said that curving in the width direction of a glass substrate curves the cross section of a glass substrate perpendicular | vertical to a conveyance direction upward or downward.

  Here, the structural example of the method of curving the one part area | region of the said glass substrate to the width direction of a glass substrate is demonstrated using FIGS. 3-6 and FIG. FIG. 3 shows a configuration example of the transport roller 32 provided with the support member 33. 4 and FIG. 5 show a glass substrate on the side (one surface side) irradiated with laser light in a configuration example in which the conveyance roller 32 having the support member 33 shown in FIG. 3 is arranged on the conveyance path of the glass substrate. The structure seen from the upper surface is shown typically.

  As a method of curving a partial region of the glass substrate in the width direction of the glass substrate, a partial region in the width direction of the glass substrate including a laser light irradiation region protrudes from a region of the other part of the glass substrate. The method of supporting a glass substrate from the other surface side of a glass substrate with a supporting member is mentioned.

  As shown in FIG. 3, when the support member 33 is arranged on a part of the width direction of the transport roller 32, the support member 33 causes the surface of a part of the region 31 of the glass substrate to be a region of another part of the glass substrate. It can be supported from the lower surface side (the other surface side) of the glass substrate so as to be higher than 34.

  As shown in FIG. 4, at least a part of the transport rollers 32 among the plurality of transport rollers 32 arranged on the transport path of the glass substrate transported in the direction indicated by the block arrow A in the figure is described above. Thus, the conveyance roller 32 including the support member 33 can be obtained. By configuring the transport roller in this way, a partial region in the width direction of the glass substrate can be curved in the range indicated by the region 41 in FIG. That is, the cross section of the glass substrate perpendicular to the transport direction can be curved upward. At this time, it is possible to select a place where the conveying roller including the support member 33 is disposed so that the irradiation region of the laser beam 12 is at least in the region 41.

  In FIG. 4, although the example which provided the supporting member 33 only in the one edge part side of the width direction of the conveyance roller 32 is shown, it is not limited to the form which concerns. Support members 33 can be provided at a plurality of locations in the width direction of the glass substrate according to the number of planned cutting lines 13 of the glass substrate. For example, when both ends in the width direction of the glass substrate are cut, the support member 33 can be provided also on the other end side in the width direction of the transport roller 32.

  The configuration of the support member 33 formed on the transport roller 32 is not particularly limited. As shown in FIG. 4, when the support member 33 is formed for each transport roller 32, for example, by arranging an O-ring on the transport roller 32 as the support member 33, a partial region in the width direction on the surface of the transport roller 32 is annular. Can be formed. Further, the support member 33 may be constituted by a tape-shaped guide member wound between a plurality of transport rollers, that is, a belt, instead of being provided for each transport roller 32 as shown in FIG. In this case as well, a partial region in the width direction orthogonal to the planned cutting line of the glass substrate 11 can be curved in the range indicated by the region 41 in FIG. That is, the cross section of the glass substrate perpendicular to the transport direction can be curved upward.

  Although the structure of the support member is not particularly limited as described above, it is preferable that the support member is constituted by a tape-shaped guide member wound between a plurality of transport rollers as shown in FIG. When the support member is constituted by a tape-shaped guide member wound between the conveyance rolls, the glass substrate can be supported by the support member from the other surface side even between the conveyance rolls, and the curved portion of the glass substrate can be supported. This is because the shape can be kept uniform and the generation of wrinkles can be further suppressed.

  The height H of the support member 33 shown in FIG. 3 is not particularly limited, and can be arbitrarily selected according to the thickness of the glass substrate to be cut.

  Further, the shape of the surface of the support member 33 that contacts the glass substrate is not particularly limited, and may be a flat shape as shown in FIG. 3 or a shape curved in the width direction of the transport roller. It may be.

  As another method of curving a partial region in the width direction orthogonal to the planned cutting line of the glass substrate, for example, as shown in FIG. There is a method in which the conveyance roller 32 having the portion 61 whose diameter is smaller than that of the portion is used.

  Thus, by providing the conveyance roller 32 with the portion 61 having a smaller diameter than other portions, a concavity is formed on the surface of the conveyance roller 32. For this reason, the glass substrate is bent by the concave portion, and the glass substrate 11 can be curved in the vicinity of the boundary between the portion 61 having a smaller diameter than the other portion and the other portion as shown in FIG. That is, the cross section of the glass substrate perpendicular to the transport direction can be curved downward.

  As a method of curving a partial region in the width direction orthogonal to the planned cutting line of the glass substrate without depending on the shape of the conveyance roller, for example, as shown in FIG. 14, a holding member such as a conveyance roller or a table For example, a method may be used in which the partial area of the glass substrate 11 held by 40 protrudes from the holding member 40 and is bent by its own weight. When the holding member 40 is a table, at least one of the glass substrate 11 and the laser oscillation device is moved to cut the glass substrate 11.

  As described above, when a partial region in the width direction of the glass substrate including the irradiation region of the laser beam 12 is curved, the irradiation region of the laser beam 12 is on the inclined portion of the curved portion of the glass substrate. It is preferable that they are arranged. This is because, as shown in FIGS. 3, 6, and 14, in the inclined portion of the curved glass substrate, the conveyance roller 32 or the support member 33 that supports the glass substrate from the other surface (lower surface) side, or the holding member. A gap will be generated between the member 40 and the glass substrate 11. For this reason, when irradiating a laser beam, it can suppress that the conveyance roller 32, the support member 33, etc. are heated, and damage to the conveyance roller 32 etc. can be suppressed.

  The incident angle of the laser beam 12 with respect to the glass substrate is not particularly limited. For example, as shown in FIGS. 3, 6, and 14, the laser light 12 is emitted from the glass substrate in an uncurved region of the glass substrate, that is, the region 34 of another part of the glass substrate in FIG. 3, for example. Irradiation can be performed so as to be substantially perpendicular to the surface. Further, the angle at which the laser beam 12 is irradiated may be adjusted according to the tilt angle of the glass substrate in the irradiation region of the laser beam 12. In other words, the glass substrate 11 may be irradiated with the laser beam 12 such that the surface of the glass substrate 11 and the laser beam 12 are substantially perpendicular to each other in the laser beam irradiation region.

  Moreover, in the case of FIG. 3, since the glass substrate is curved in a parabolic shape, a slope is formed on the right side and the left side in the figure among the curved parts. For this reason, as shown by the arrow 12 ′, the laser beam may be irradiated on the slope on the left side in the drawing.

  However, when the curved part of the glass substrate has a plurality of inclined surfaces, the support member 33 protrudes from the region of the other part of the glass substrate, and is part of the glass substrate in the width direction of the glass substrate. It is preferable to support the glass substrate so that the irradiation region of the laser beam is arranged on the slope on the end side in the width direction. That is, it is preferable that the irradiation region of the laser light is on the slope on the end side in the width direction of the glass substrate.

  As described above, at least a partial region in the width direction of the glass substrate including the laser light irradiation region may be curved in the width direction of the glass substrate, and the glass substrate is curved in the length direction of the glass substrate. The range is not particularly limited. That is, even in the range of the laser beam irradiation region in the length direction of the glass substrate, a partial region in the width direction orthogonal to the planned cutting line of the glass substrate may be curved in the width direction of the glass substrate. Good. In addition, the length direction of a glass substrate here means the direction parallel to the conveyance direction of a glass substrate.

  However, part of the glass substrate in the width direction including the planned cutting line of the glass substrate over a range from the laser beam irradiation region of the glass substrate to a portion separated by a predetermined distance along the planned cutting line of the glass substrate. It is preferable to curve the region in the width direction of the glass substrate.

  As described above, if the glass substrate is curved for a partial region in the width direction orthogonal to the planned cutting line of the glass substrate including at least the laser light irradiation region, it is compared with the case where the glass substrate is not curved. Thus, the generation of wrinkles can be suppressed in the laser light irradiation region. However, for example, when a glass substrate is being conveyed, if the glass substrate is bent as described above immediately before the laser light irradiation region, the degree of suppression of wrinkles may not be sufficient. For this reason, the glass substrate is cut with respect to a partial region in the width direction of the glass substrate including the planned cutting line of the glass substrate over a predetermined range upstream of the laser beam irradiation region in the conveyance direction of the glass substrate, for example. The glass substrate is preferably curved so that the planned line is arranged on the slope.

  For example, when the transport roller 32 including the support member 33 is disposed as illustrated in FIG. 4, the apex position of the transport roller 32 including the support member 33 disposed on the most upstream side in the transport direction of the glass substrate. In addition, it is preferable that the irradiation region of the laser beam 12 comes downstream. That is, in the case of FIG. 4, it is preferable that the laser light irradiation region is arranged on the downstream side in the transport direction of the glass substrate from the line XX ′. In particular, the irradiation region of the laser light 12 is preferably disposed between the transport rollers 32 in order to prevent the transport rollers 32 and the like from being damaged when the laser beams are irradiated.

  As described above, in the method for cutting a glass substrate of the present embodiment, a partial region in the width direction perpendicular to the planned cutting line of the glass substrate including the irradiation region of the laser light is arranged in the width direction of the glass substrate. It is curved. In the portion irradiated with the laser light 12 (laser light irradiation region), the laser light irradiation portion from the one surface to the other surface of the glass substrate is heated (heating step). Further, the region 14 which has already been irradiated with the laser light is separated from the laser light irradiation region by the conveyance of the glass substrate 11, and the laser light irradiation part (laser light is irradiated and the glass is vaporized after the laser light irradiation). The peripheral part of 15 is cooled (cooling step). This point will be described below with reference to FIGS. 1, 7, and 8. FIG. 1, 7, and 8, for convenience of description, the periphery of the laser light irradiation region is also illustrated as a flat shape. Moreover, although the cutting line 13 of a glass substrate is shown in the figure, the line which concerns on an actual glass substrate is not necessarily provided.

  The composition of the glass substrate to which the glass substrate cutting method of this embodiment can be applied is not particularly limited, and can be applied to various glass substrates. Examples thereof include non-alkali borosilicate glass, borosilicate glass, soda lime glass, high silica glass, and other oxide-based glasses mainly composed of silicon oxide.

  Further, the thickness of the glass substrate is not particularly limited, and can be arbitrarily selected according to, for example, the output of the laser oscillation device to be used.

  However, wrinkles are likely to occur on the glass substrate especially when the glass substrate is thin. Further, in the method for cutting a glass substrate of the present embodiment, in the laser light irradiation region, the glass light irradiation portion from one surface of the glass substrate to the other surface, that is, over the entire plate thickness direction, Heat above the temperature at which vaporizes. For the above two reasons, it is particularly effective when the glass substrate is thin. For this reason, for example, the thickness of the glass substrate is preferably 3.0 mm or less, more preferably 1.0 mm or less, further preferably 0.5 mm or less, and 0.2 mm or less. Particularly preferred. The lower limit is not particularly limited.

  Moreover, although the shape of the glass substrate shown in FIG. 1 is a rectangle, the shape of a glass substrate is not specifically limited, either. For example, a band-shaped glass substrate formed by a glass substrate forming apparatus such as a float method or a downdraw method may be used.

  Next, a heating process performed in a laser light irradiation region (a portion where the glass substrate is irradiated with laser light) will be described. FIG. 7 is an enlarged view of the vicinity of the irradiation region of the laser beam 12 in the cross section taken along line BB ′ in FIG.

  In the method for cutting a glass substrate of the present invention, the heating step is performed in the laser light irradiation region by irradiating the glass substrate with the laser light 12 as described above.

  In the laser light irradiation region of the glass substrate, the laser light irradiation portion 71 from one surface of the glass substrate to the other surface of the glass substrate is heated to a temperature higher than the temperature at which the glass vaporizes. Here, one surface of the glass substrate means a surface on which laser light is incident, and the other surface means an opposing surface. For this reason, about the laser beam irradiation part 71, glass is vaporized and a through-hole is formed in the laser beam irradiation direction (thickness direction of the glass substrate) in a short time.

  The peripheral portion 72 of the laser beam irradiation unit 71 is also heated by heat transfer from the laser beam irradiation unit.

  In this way, immediately after the heating step, that is, at the time of laser light irradiation (at the time of glass vaporization) or immediately after laser light irradiation, without blowing the assist gas to the laser light irradiation portion (without using the assist gas) ), The glass can be vaporized in the laser light irradiation portion in a short time. For this reason, the glass substrate can be processed with high accuracy without causing a positional shift and the like, and the occurrence of cracks in the glass substrate can be suppressed.

  The irradiation condition of the laser beam in the heating process is not limited. In the laser beam irradiation region of the glass substrate, from one surface (surface on which laser light is incident) side of the glass substrate to the other surface side. What is necessary is just to select so that a laser beam irradiation part can be heated more than the vaporization temperature of glass.

  Specifically, for example, from the thickness of the glass substrate that is the object to be cut, the glass composition, the conveyance speed of the glass substrate (the relative movement speed of the irradiation region of the laser light with respect to the glass substrate), etc. The energy density of the laser beam and the like may be selected so that heating can be performed. For example, it can be calculated by conducting a preliminary test in advance.

In particular, when the relative movement speed of the laser light irradiation region with respect to the glass substrate is v (m / hour), the energy density of the laser light is E (W / mm ² ), and the thickness of the glass substrate is t (mm). In addition,
E ≧ 50 × t × v
It is preferable to adjust the energy density of the laser beam to be irradiated so as to satisfy the above relationship.

  By cutting the glass substrate including the heating step in a state satisfying such regulations, the glass vaporizes the laser light irradiation part from one surface of the glass substrate to the other surface of the glass substrate in the laser light irradiation region. It can be surely heated above the temperature at which it is performed.

  The spot diameter of the laser beam irradiated onto the glass substrate (the beam diameter of the laser beam on one surface of the glass substrate) is not limited, and can be selected depending on the required processing accuracy.

Note that there is no particular limitation on the type of laser to be used, as long as the glass substrate can be heated at the irradiated portion by irradiating the glass substrate with oscillated laser light. Specifically, for example, a CO ₂ laser, an excimer laser, a copper vapor deposition laser, a YAG laser, or the like can be used.

  In the heating step, the glass is vaporized in the laser light irradiation section by irradiating the glass substrate with the laser light as described above. For this reason, the vaporized glass component (gas) will generate | occur | produce in a laser beam irradiation part and its periphery. When such components are deposited and adhered to the surface of an optical system such as a lens or mirror of a laser oscillation device arranged on the optical path of the laser light, it becomes impossible to irradiate the glass substrate with laser light with sufficient energy, In some cases, it may become impossible to irradiate a laser beam at a desired location, which may affect the processing accuracy of the glass substrate. For this reason, it is preferable to remove the vaporized glass component by irradiating the glass substrate with laser light. That is, it is preferable to remove the vaporized glass component of the laser light irradiation portion in the heating step. The means for removing the vaporized glass component is not particularly limited, and a mechanism for sucking the vaporized glass component, a mechanism for blowing off the glass component vaporized by gas, or the like can be used. The arrangement may be selected according to the means used, and the heating process is not hindered and the vaporized glass component can be removed before adhering to the lens, mirror, etc. arranged on the optical path of the laser beam. That's fine. For example, as shown by reference numeral 73 in FIG. 7, it may be arranged in the vicinity of a portion irradiated with laser light.

  In addition, when using the mechanism which blows off the glass component vaporized by gas, the kind of gas to be used is not particularly limited, but since it is used around the portion where the glass substrate is heated by laser light, it is a nonflammable gas. Is preferably used. Specifically, for example, an inert gas such as nitrogen or argon, air, or the like can be used. In this case, in order to prevent displacement of the position of the glass substrate, it is preferable to supply the glass substrate so that no gas is applied to it.

  Next, the cooling process will be described.

  In the cooling process, after the laser beam is irradiated, the glass substrate is conveyed, so that the laser beam irradiation part after laser beam irradiation (the portion that has already been irradiated with the laser beam) is moved away from the laser beam irradiation region, The peripheral part of the laser beam irradiation part is cooled.

  In the cooling step, as shown in FIG. 7, the peripheral portion 72 of the laser light irradiation portion 71 (the portion that is vaporized by the laser light irradiation in the heating step) 71 is cooled. When being cooled, at least a part of the peripheral portion 72 is deposited on the glass substrate surface (one surface of the glass substrate and / or the other surface) as substantially thread-like precipitates 81 and 82 as shown in FIG. There is a case. This is because, since glass has a low thermal conductivity, a temperature gradient is generated in the peripheral portion 72 in the cooling step after the heating step. Therefore, at least the peripheral portion 72 on the glass substrate is caused by the stress generated in the peripheral portion 72. It is inferred that a part is excluded and precipitates. In the drawing, the precipitates 81 and 82 are deposited on the upper surface (one surface) of the glass substrate, but may be deposited on the lower surface (the other surface) side. In addition, the place where the precipitate is deposited in the cooling process is not particularly limited because it varies depending on the cooling condition and the like. For example, the deposits 81 and 82 are located downstream of the irradiation region of the laser beam 12 in the conveyance direction of the glass substrate. Therefore, it is deposited from a position outside the irradiation region of the laser beam 12.

  As described above, since at least a part of the peripheral portion 72 of the laser light irradiation section is excluded from the cut surface irradiated with the laser light, it is possible to finally obtain a uniform cut surface.

  In order to produce the precipitate in the cooling step and obtain a uniform cut surface, it is preferable that the peripheral portion of the laser beam irradiation portion is cooled at an appropriate cooling rate. The cooling rate can be changed by the relative moving speed of the irradiation region of the laser beam with respect to the glass substrate. For this reason, it is preferable to select a relative moving speed of the irradiation region of the laser beam with respect to the glass substrate so that the precipitate is generated in the cooling process by performing a preliminary experiment or the like.

  The relative movement speed of the irradiation region of the laser beam with respect to the glass substrate can be selected by a preliminary experiment or the like as described above, and is not specified, but can be, for example, 144 (m / hour) or more.

  In the cooling step, when the precipitates 81 and 82 are generated, the precipitate 81 and the precipitate 82 may adhere to each other depending on the temperature of the precipitates 81 and 82, the distance between them, or the like. Further, in some cases, when the precipitate 81 and the precipitate 82 are bonded, it becomes difficult for a part of the peripheral portion 72 to be discharged from the peripheral portion 72 of the laser light irradiation unit 71, and the cut surface of the glass substrate is a uniform cut surface. It may not be possible. However, in the glass substrate cutting method of the present embodiment, a partial region in the width direction orthogonal to the planned cutting line of the glass substrate including the laser light irradiation region is curved in the width direction of the glass substrate. Yes. For this reason, for example, as shown in FIG. 9, one side that has been cut off in the vicinity of a laser beam irradiation section (a portion that is vaporized by irradiation with laser beam in the heating process) 71 in which the temperature of the precipitates 81 and 82 is particularly high. The glass substrate 91 and the glass substrate 92 on the other side are different in height. Therefore, the deposits 81 and 82 are prevented from adhering to each other in the vicinity of the laser beam irradiation unit 71, and as a result, the cut surface can be more reliably made a uniform cut surface.

  The precipitate 81 is deposited between the conveying rollers, and is deposited on the upper surface side or the lower surface side of the glass substrate 92 on the other side. In FIG. 9, for the convenience of description of the drawing, it appears that the precipitate 81 wraps around the lower end side of the conveying roller, but the precipitate 81 is deposited on the lower surface side of the glass substrate 92 on the other side. For example, it is located between the glass substrate 92 and the transport roller and does not hinder the behavior of the transport roller.

  Since the precipitates 81 and 82 generated in the cooling step may interfere with cooling, it is preferable to remove the precipitate generated in the peripheral portion of the laser beam irradiation section. The means for removing the precipitate is not particularly limited, and can be easily removed by a method such as blowing off with gas, removing by suction, or removing with a brush or baffle plate.

  Note that in the case where the deposit is blown off with a gas, it is preferable to use a low-pressure gas so as to give vibration or the like to the glass substrate and not affect the cutting accuracy of the glass substrate.

  A cooling process cools the peripheral part 72 of the laser beam irradiation part after laser beam irradiation as mentioned above, and the cooling temperature is not limited. For example, it is preferable that the peripheral part of the laser light irradiation part is cooled to a glass transition temperature or lower after the laser light irradiation part is heated.

  At this time, when the cooling is performed by the temperature of the ambient atmosphere after the heating step, the ambient temperature is preferably at least the glass transition temperature or less, preferably 100 ° C. or less, and particularly preferably 40 ° C. or less. . The ambient temperature referred to here is at least the temperature around the portion where the cooling process is performed, but is preferably the temperature around the entire glass substrate being cut.

  The glass substrate cutting method of the present embodiment described so far can be preferably used particularly when the glass substrate is cut along a cutting line along the conveyance direction of the glass substrate.

  And generally when manufacturing a glass substrate, in order to make a glass substrate into a desired size, both ends in the width direction of the glass substrate are cut along a cutting line along the conveyance direction of the glass substrate. The glass substrate cutting method in the form can be preferably used. In this case, after cutting both ends in the width direction of the glass substrate, only the center portion in the width direction is used as a product, so both ends in the width direction of the glass substrate, that is, the ears, are separated from the conveyance path of the glass substrate after cutting. It is preferred that

  Specifically, for example, an ear release means is provided on the downstream side of the heating step in the transport direction of the glass substrate, and the ear portion of the cut glass substrate is directed away from the transport direction of the glass substrate by the ear release means. Can be changed and separated.

  Although the specific configuration of the ear release means is not particularly limited, for example, a conveyance roller that serves as a fulcrum for changing the direction of the ear portion of the glass substrate, and a conveyance that contacts the ear portion of the glass substrate on the side opposite to the conveyance roller that serves as the fulcrum It can be comprised by the ear | edge part stable holding means which hold | suppresses an ear | edge part with a roller.

  The separated ears of the glass substrate can be introduced into a sub-transport path different from the transport path, and collected separately from the central portion of the glass substrate.

  In the above description of the glass substrate cutting method of the present embodiment, the glass substrate cutting method of the present embodiment has been described by taking the glass substrate being horizontally transported on the transport roller 32 as an example. However, the method for cutting a glass substrate of the present embodiment is not limited to the cutting of a glass substrate that is horizontally conveyed, and is also applicable to a glass substrate that is formed by, for example, a downdraw method and is vertically conveyed. can do. In this case, for example, a partial region in the width direction orthogonal to the planned cutting line of the glass substrate including the irradiation region of the laser beam that irradiates the laser beam is pressed from one surface of the glass substrate with the pressing member. It can be curved in the width direction. And it can cut | disconnect similarly about the glass substrate currently conveyed vertically by performing a heating process and a cooling process as mentioned above.

  Even when the glass substrate is vertically conveyed, the method for cutting the glass substrate of the present embodiment can be preferably used when cutting both ends in the width direction of the glass substrate. Also in this case, it is preferable that both ends in the width direction of the cut glass substrate are separated from the conveyance path of the glass substrate.

  Although the glass substrate cutting method of the present invention has been described above, in the glass substrate cutting method, since the assist gas is not sprayed on the glass substrate, the displacement of the position of the glass substrate is suppressed. Cutting can be performed with high accuracy. In addition, the generation of cracks in the glass substrate during cutting can be suppressed, and a cut surface with uniform surface characteristics can be obtained.

  The glass substrate cutting method of the present embodiment described above can be applied to a glass substrate manufacturing process to provide a glass substrate manufacturing method using the glass substrate cutting method.

  In such a method for producing a glass substrate, the glass substrate can be cut with high accuracy, generation of cracks in the glass substrate can be suppressed at the time of cutting, and a uniform cut surface can be obtained. The effect of shortening the polishing time of the cut surface in the polishing process or omitting the polishing process can be obtained.

Specific examples will be described below, but the present invention is not limited to these examples.
[Experimental Example 1]
In this experimental example, the glass substrate was cut by changing the energy density of the laser beam and the relative movement speed of the irradiation region of the laser beam with respect to the glass substrate, and the cut surface of the cut glass substrate was evaluated.

In cutting the glass substrate, a glass substrate (trade name: AN100, manufactured by Asahi Glass Co., Ltd.) made of non-alkali borosilicate glass having a length of 100 mm, a width of 100 mm, and a thickness of 0.1 mm according to the configuration shown in FIG. While carrying the glass substrate at the carrying speed, the laser beam using a CO ₂ laser was irradiated along the planned cutting line so that the spot diameter was about 0.3 mm and a predetermined energy density was obtained. When cutting, the ambient temperature (environmental temperature) of the glass substrate was room temperature (25 ° C.).

  At this time, as shown in FIGS. 3 and 4, a support member 33 is provided on the conveyance roller 32, and a partial region in the width direction of the glass substrate including the laser light irradiation region irradiated with the laser light is provided. Was irradiated with laser light while being bent in the width direction of the glass substrate. At this time, the laser beam 12 was applied to the slope on the end side in the width direction of the glass substrate as indicated by an arrow 12 in FIG. Further, as shown in FIG. 4, the support member 33 is provided on the two conveyance rollers 32, and an irradiation region of the laser beam 12 is disposed between the conveyance rollers 32 provided with the support member 33.

  Regarding the glass substrate after being cut, it was C when the glass substrate was not cut, but the precipitate was not observed in the portion irradiated with the laser, and the cut surface was visually confirmed to be uniform. Those that were not or were cracked in the glass substrate were evaluated as B. A glass substrate that could be cut and visually confirmed to be a uniform cut surface was evaluated as A. The results are shown in Table 1 and FIG. FIG. 10 is a graph showing a part of the results shown in Table 1.

図１０に示したグラフにおいて、直線Ｘは、レーザ光の照射領域のガラス基板に対する相対移動速度（ここではガラス基板の搬送速度）をｖ（ｍ／時間）、前記レーザ光のエネルギー密度をＥ（Ｗ／ｍｍ^２）、ガラス基板の板厚をｔ（ｍｍ）とした場合に、Ｅ＝５０×ｔ×ｖとなる直線である。

In the graph shown in FIG. 10, the straight line X represents the relative movement speed (here, the conveyance speed of the glass substrate) of the irradiation region of the laser light with respect to v (m / hour), and the energy density of the laser light with E ( W / mm ² ), and the thickness of the glass substrate is t (mm), and E = 50 × t × v.

  The straight line Y indicates the minimum value of the relative movement speed (here, the conveyance speed of the glass substrate) of the laser light irradiation region where the precipitate is generated in the cooling process. In this case, 144 (m / hour) )Met.

  According to FIG. 10, the A evaluation is distributed in a range surrounded by the straight line X and the straight line Y. When the energy density is smaller than the straight line X, the C evaluation is performed, and when the transport speed is slower than the straight line Y, the B evaluation is performed. It has become.

  First, in the case of irradiating laser light having an energy density equal to or higher than the straight line X at the relative movement speed (glass substrate transport speed) of each laser light irradiation area to the glass substrate, the glass substrate in the laser light irradiation area This is probably because the laser beam irradiation region from one surface to the other surface can be reliably heated to a temperature higher than the temperature at which the glass vaporizes.

  Furthermore, by setting the conveyance speed to be equal to or higher than the straight line Y, the peripheral portion of the laser light irradiation region after laser light irradiation can be sufficiently cooled and removed as a precipitate from the cut surface portion. It is thought that it can be.

  That is, in the glass substrate that has been evaluated as C, sufficient energy of the laser beam cannot be imparted with respect to the relative movement speed of the irradiation region of the laser beam with respect to the glass substrate (the conveyance speed of the glass substrate). Regarding the region, it is considered that the other surface of the glass substrate could not be heated to a temperature higher than the temperature at which the glass vaporizes (the temperature could not be sufficiently raised in the entire range in the thickness direction of the glass substrate). For this reason, it is estimated that the glass substrate could not be cut.

  Moreover, since the glass substrate which became B evaluation has irradiated the laser beam of sufficient energy density with respect to the relative moving speed (conveyance speed of a glass substrate) with respect to the glass substrate of the irradiation region of a laser beam, Cutting is done.

  However, the relative moving speed of the laser light irradiation area with respect to the glass substrate (glass substrate transport speed) is not sufficient, and the cooling speed of the peripheral area of the laser light irradiation area after laser light irradiation becomes slow, and the peripheral area is deposited. It is assumed that the cut surface did not become uniform because it was not excluded as a product. Or, when the temperature of the peripheral part of the laser light irradiation area after laser light irradiation is cooled by transporting the glass substrate, it is not the desired cooling rate, so that the cut surface and its periphery have cracked It is inferred.

On the other hand, it is considered that the energy density of the laser light can be appropriately selected for the A-evaluated glass substrate in accordance with the relative movement speed (glass substrate transport speed) of the laser light irradiation region with respect to the glass substrate. For this reason, it is considered that the laser beam irradiation region is heated from one surface of the glass substrate to the other surface at a temperature higher than the temperature at which the glass is vaporized. Furthermore, since the conveyance speed of the glass substrate is appropriate, the peripheral portion of the laser light irradiation region after laser light irradiation is cooled at an appropriate cooling rate, and the peripheral portion of the laser light irradiation region after laser light irradiation is a precipitate. It is considered that a uniform cut surface was obtained.
[Experiment 2]
In this experimental example, the energy density of the laser beam and the relative movement speed of the irradiation region of the laser beam with respect to the glass substrate are changed in the same manner as in Experimental Example 1 except that the thickness of the glass substrate to be cut is 0.2 mm. Then, the glass substrate was cut, and the cut surface of the glass substrate after cutting was evaluated.

  The results are shown in Table 2 and FIG. FIG. 11 is a graph of the results in Table 2.

図１１に示したグラフにおいても、直線Ｘは上述のＥ＝５０×ｔ×ｖ（ｔ＝０．２ｍｍ）となる直線である。

Also in the graph shown in FIG. 11, the straight line X is a straight line that satisfies the above-mentioned E = 50 × t × v (t = 0.2 mm).

  The straight line Y indicates the minimum value of the relative movement speed (here, the conveyance speed of the glass substrate) of the irradiation region of the laser beam, in which the precipitate is generated in the cooling process, and in this case, 144 (m / hour) )Met.

According to this, it has confirmed that A evaluation was distributed in the range enclosed by the straight line X and the straight line Y. FIG.
[Experiment 3]
In this experimental example, the energy density of the laser beam and the relative movement speed of the irradiation region of the laser beam with respect to the glass substrate are changed in the same manner as in Experimental Example 1 except that the thickness of the glass substrate to be cut is 0.3 mm. Then, the glass substrate was cut, and the cut surface of the glass substrate after cutting was evaluated.

  The results are shown in Table 3 and FIG. FIG. 12 is a graph of the results in Table 3.

図１２に示したグラフにおいても、直線Ｘは上述のＥ＝５０×ｔ×ｖ（ｔ＝０．３ｍｍ）となる直線である。

Also in the graph shown in FIG. 12, the straight line X is a straight line that satisfies the above-mentioned E = 50 × t × v (t = 0.3 mm).

  The straight line Y indicates the minimum value of the relative movement speed (here, the conveyance speed of the glass substrate) of the irradiation region of the laser beam, in which the precipitate is generated in the cooling process, and in this case, 144 (m / hour) )Met.

In this experimental example, the glass substrate is cut by changing the energy density of the laser beam to be irradiated without changing the conveyance speed of the glass substrate. According to this, when the energy density of the laser beam is increased to be higher than the straight line X, the glass is vaporized in the laser beam irradiation region from one surface of the glass substrate to the other surface in the laser beam irradiation region. It was possible to heat to a temperature higher than the temperature to be evaluated, and it was confirmed that the evaluation was A.
[Experimental Example 4]
In this experimental example, the energy density of the laser beam and the relative movement speed of the irradiation region of the laser beam with respect to the glass substrate are changed in the same manner as in Experimental Example 1 except that the thickness of the glass substrate to be cut is 0.6 mm. Then, the glass substrate was cut, and the cut surface of the glass substrate after cutting was evaluated.

  The results are shown in Table 4 and FIG. FIG. 13 is a graph of the results in Table 4.

図１３に示したグラフにおいても、直線Ｘは上述のＥ＝５０×ｔ×ｖ（ｔ＝０．６ｍｍ）となる直線である。

Also in the graph shown in FIG. 13, the straight line X is a straight line that satisfies the above-mentioned E = 50 × t × v (t = 0.6 mm).

  The straight line Y indicates the minimum value of the relative movement speed (here, the conveyance speed of the glass substrate) of the irradiation region of the laser beam, in which the precipitate is generated in the cooling process, and in this case, 144 (m / hour) )Met.

  In this experimental example, the energy density of the laser beam to be irradiated was lower than that of the straight line X. For this reason, sufficient energy of the laser beam cannot be imparted with respect to the relative movement speed of the laser beam irradiation region with respect to the glass substrate (the conveyance speed of the glass substrate), and the other surface of the glass substrate with respect to the laser beam irradiation portion It is considered that the glass substrate could not be heated to a temperature higher than the temperature at which it vaporizes. Therefore, it was considered that C evaluation was made because the glass substrate could not be cut.

  Although the cutting method of the glass substrate and the manufacturing method of the glass substrate have been described above in the embodiments and the like, the present invention is not limited to the above embodiments and the like. Various modifications and changes are possible within the scope of the gist of the present invention described in the claims.

  This application claims priority based on Japanese Patent Application No. 2013-112182 filed with the Japan Patent Office on May 28, 2013. The entire contents of Japanese Patent Application No. 2013-112182 are incorporated herein by reference. Incorporate.

DESCRIPTION OF SYMBOLS 11 Glass substrate 12 Laser beam 33 Support member 40 Holding member 71 Laser beam irradiation part 72 Peripheral part 81, 82 of laser beam irradiation part Precipitate

Claims (11)

A method for cutting a glass substrate by irradiating a laser beam along a planned cutting line by irradiating a laser beam,
The plate thickness of the glass substrate is 3.0 mm or less,
A partial region in the width direction orthogonal to the planned cutting line of the glass substrate including a laser light irradiation region for irradiating the laser light on one surface of the glass substrate is formed in the width direction of the glass substrate. Bend and
In the irradiation region of the laser beam, the laser beam irradiation part from one surface of the glass substrate to the other surface is heated to a temperature higher than vaporization,
A method for cutting a glass substrate, wherein the irradiation region of the laser beam is moved relative to the glass substrate along a planned cutting line of the glass substrate. Over the range from the laser light irradiation region to a portion separated by a predetermined distance along the planned cutting line of the glass substrate,
The method for cutting a glass substrate according to claim 1, wherein a partial region in the width direction of the glass substrate including a planned cutting line of the glass substrate is curved in the width direction of the glass substrate. The glass from the other surface side of the glass substrate is supported by a support member so that a partial region in the width direction of the glass substrate including the irradiation region of the laser light protrudes from a region of another part of the glass substrate. By supporting the substrate,
The method for cutting a glass substrate according to claim 1 or 2, wherein a partial region in the width direction of the glass substrate including the irradiation region of the laser light is curved in the width direction of the glass substrate. The support member is
Of the partial region in the width direction of the glass substrate that protrudes from the region of the other part of the glass substrate, the irradiation region of the laser light is disposed on the inclined surface on the end side in the width direction of the glass substrate. To be,
The method for cutting a glass substrate according to claim 3, wherein the glass substrate is supported. The glass from the other surface side of the glass substrate is held by the holding member so that a partial region in the width direction of the glass substrate including the irradiation region of the laser beam is bent from the other region of the glass substrate by its own weight. By holding the substrate,
The method for cutting a glass substrate according to claim 1 or 2, wherein a partial region in the width direction of the glass substrate including the irradiation region of the laser light is curved in the width direction of the glass substrate.   The peripheral part of the said laser beam irradiation part is a glass substrate cutting method as described in any one of Claims 1 thru | or 5 cooled to below glass transition temperature after the said laser beam irradiation part is heated. When the relative movement speed of the laser light irradiation region with respect to the glass substrate is v (m / hour), the energy density of the laser light is E (W / mm ² ), and the thickness of the glass substrate is t (mm). ,
E ≧ 50 × t × v
The method for cutting a glass substrate according to any one of claims 1 to 6, wherein the relationship is satisfied.   The method for cutting a glass substrate according to any one of claims 1 to 7, wherein a relative movement speed of the irradiation region of the laser beam with respect to the glass substrate is 144 (m / hour) or more.   The method for cutting a glass substrate according to any one of claims 1 to 8, wherein the vaporized glass component of the laser light irradiation part is removed.   The cutting method of the glass substrate as described in any one of Claims 1 thru | or 9 which removes the precipitate which generate | occur | produced in the peripheral part of the said laser beam irradiation part.   The manufacturing method of the glass substrate using the cutting method of the glass substrate as described in any one of Claims 1 thru | or 10.

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