TWI385047B - Method for cutting brittle material substrates - Google Patents

Description

Cutting method of brittle material substrate

The present invention relates to a method of cutting a substrate of a brittle material such as a glass substrate or a ceramic substrate by laser irradiation.

Conventionally, as a method of cutting a brittle material substrate such as a glass substrate or a ceramic substrate, it is widely used such that a cutter wheel or the like is pressed against the surface of the brittle material substrate and simultaneously rotated to form a crack in a direction substantially perpendicular to the surface of the brittle material substrate (hereinafter It is called "vertical crack", and then a mechanical pressing force is applied to the substrate to advance the vertical crack toward the thickness of the substrate to cut the substrate.

However, in the case where a vertical crack of a brittle material substrate is formed using a cutter wheel, a small fragment called a cullet is generated, which may cause scratches on the surface of the brittle material substrate. In addition, micro cracks are likely to occur at the ends of the brittle material substrate after cutting, which may cause cracking of the brittle material substrate due to the micro cracks. Therefore, it is common to grind and clean the end portion of the brittle material substrate after cutting to remove microcracks or glass swarf.

On the other hand, in recent years, a carbon dioxide laser has been used to heat a brittle material substrate at a temperature at which the melting temperature is not full, whereby various methods of locally generating tensile stress to form a vertical crack due to thermal stress generated by a brittle material substrate have been used. Review and development. Since the cutting method using the laser beam is non-contact processing, it is possible to suppress the occurrence of potential defects such as the above-mentioned glass swarf or microcrack. However, since the vertical crack in the cutting method using the laser beam does not reach the entire thickness direction of the substrate and generally stops only at the surface portion, an external force must be applied to progress the vertical crack in the thickness direction of the substrate. Therefore, the end faces of the vertical cracks are pressed against each other, and there is still a flaw in the occurrence of microcracks or glass swarf.

In order to solve this problem, for example, in Patent Document 1, it is proposed that the initial crack is formed on the side surface of the glass substrate, and the predetermined line is first heated by a linear heater, and the peripheral portion of the crack before the progress is cooled by a cooling mechanism such as an air nozzle. A technique to make cracks more progressive.

Further, in Patent Document 2, it is proposed to cut a brittle material by causing at least two points to simultaneously irradiate a laser beam to form an initial crack, and then moving the laser beam along the planned cutting line to advance the initial crack in the direction of the cut line. Substrate method

Patent Document 1: Japanese Laid-Open Patent Publication No. 2000-281375

Patent Document 2: Japanese Patent Laid-Open No. Hei 7-328781

However, in the technique of the patent document 1, since the initial crack is formed on the side surface of the glass substrate, it is difficult to form the initial crack of a predetermined length (depth) in the direction in which the predetermined line is cut (the depth direction is viewed from the side surface of the substrate). . In addition, there is a need for a mechanism for fixing the support in a state in which the direction of the cut-off section is applied to the end portion of the cut-off line, or a mechanism for moving the sensor that detects the crack position of the progress, and the like. It is cumbersome and the device will be large. Further, since the heater line arranged along the cut line is heated to cut the entire line of the predetermined line, the amount of power consumption is larger than that in the case of partial heating.

Further, in the proposed technique of Patent Document 2, a plurality of laser oscillators are required, and it is necessary to use an optical axis changing means, and the apparatus is complicated and large. Further, when the initial crack is formed by irradiation with a plurality of laser beams, it is difficult to adjust the laser output or the irradiation position, and the accuracy of the initial crack formation position cannot be improved.

The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a method for cutting a brittle material substrate while minimizing the occurrence of micro-cracks or glass chips without causing an increase in size and complexity of the device.

Further, an object of the present invention is to provide a method of cutting a substrate on one side of a laminated substrate to be bonded and simply separating and removing the portion of the substrate to be cut.

The method for cutting a brittle material substrate according to the first aspect of the present invention is a method for cutting a brittle material substrate, wherein the brittle material substrate is cut by irradiating a laser beam, and the method further comprises: cutting a predetermined line on one side of the substrate a step of forming an initial crack by a cutter at a cutting start end; pressing a portion of the opposite side surface of the substrate on which the initial crack is formed to face the initial crack, and causing the initial crack to progress in a thickness direction of the substrate And forming an initial through crack to reach the opposite side surface; and the laser beam is relatively moved from the initial through crack along the predetermined cutting line, and the substrate is heated at a temperature at which the melting temperature is not full, thereby The thermal stress generated by the substrate causes the initial through crack to progress along the predetermined cut line.

A method for cutting a brittle material substrate according to a second aspect of the present invention is a method for cutting a brittle material substrate, wherein the brittle material substrate is cut by irradiating a laser beam, and the method further comprises: cutting a predetermined line on one side of the substrate a step of forming an initial crack by a cutter at a cutting start end; and the laser beam is relatively moved from the initial crack along the predetermined cutting line and simultaneously irradiated, and the substrate is heated at a temperature at which the melting temperature is not full, thereby being generated by the substrate The thermal stress causes the initial crack to progress along the predetermined cutting line to form an initial progress crack; and presses the portion of the opposite side surface of the substrate on which the initial progress crack is formed, and the portion of the initial progress crack opposite The initial progress of the crack progresses in the thickness direction of the substrate to form an initial through crack that reaches the opposite side surface; and the laser beam is relatively moved and simultaneously irradiated from the initial progress crack along the predetermined cutting line to melt the temperature Heating the substrate at a temperature that is less than full, whereby the initial stage is caused by thermal stress generated by the substrate The step of progressing the crack along the aforementioned cut-off line.

The method for cutting a brittle material substrate according to the third aspect of the present invention is a method for cutting a brittle material substrate, wherein one of the laminated substrates bonded to the two brittle material substrates is cut, and the method is characterized in that: (1) a step of forming an initial crack by a cutter at a cutting start end of the cutting line of the brittle material substrate; pressing the portion of the second brittle material substrate opposite to the initial crack, and causing the initial crack to the first brittle material substrate a step of forming an initial through crack in the thickness direction to form an opposite side surface of the first brittle material substrate; and the laser beam is relatively moved from the initial through crack along the predetermined cut line to a temperature at which the melting temperature is not full. The first brittle material substrate is heated, whereby the initial through crack is advanced along the predetermined cutting line by the thermal stress generated by the first brittle material substrate.

The method for cutting a brittle material substrate according to the fourth aspect of the present invention is a method for cutting a brittle material substrate, wherein one of the laminated substrates bonded to the two brittle material substrates is cut, and the method is characterized in that: (1) a step of forming an initial crack by a cutter at a cutting start end of the cutting line of the brittle material substrate; and the laser beam is relatively moved and simultaneously irradiated from the initial crack along the predetermined cutting line, and heated at a temperature at which the melting temperature is not full. a brittle material substrate, whereby the initial crack is advanced along the predetermined cutting line by the thermal stress generated by the first brittle material substrate to form an initial progress crack; and the second brittle material substrate is pressed against the initial crack pair In the part, the initial crack is advanced in the thickness direction of the first brittle material substrate to form an initial through crack in the opposite side surface of the first brittle material substrate, and the initial through crack is along the predetermined cut line. The laser beam is relatively moved and simultaneously irradiated, and the first brittle material substrate is heated at a temperature at which the melting temperature is not full. By thermal stress generated in the brittle material substrate so that a first initial step of the progression of the line through the cracks along the cleaving.

In the cutting method of the brittle material substrate of the present invention, since the initial crack is a crack that penetrates in the thickness direction of the substrate, the initial through crack is progressed along the planned cutting line by the irradiation of the laser beam, so The enlargement and complication of the device can minimize the occurrence of micro-cracks or glass swarf.

Further, in the method of the present invention in which one of the laminated substrates bonded to the two brittle material substrates is cut, in addition to the above effects, the second brittle material substrate is pressed while the crack is formed at the initial stage of formation. The first brittle material substrate and the second brittle material substrate are bent in part opposite to the initial crack, and the first end of the crack is bonded to the end surface of the crack, and the end portion of the first brittle material substrate is cut and removed. The bonding between the brittle material substrates is easily eliminated.

Further, by causing the initial crack formed by the cutter to be small, and irradiating the laser beam to advance the initial crack to a predetermined length, it is possible to further suppress the occurrence of microcracks or glass swarf.

Although the cutting method of the brittle material substrate of the present invention will be described in more detail below, the present invention is not limited to these embodiments.

Fig. 1 is a view showing the steps of an embodiment of the cutting method of the brittle material substrate of the present invention. Fig. 1 is a step diagram showing a case where the glass substrate 1 which is a brittle material substrate is cut by cutting the predetermined line 11. As shown in (a), the initial crack 31 is formed by the cutter wheel 2 before the cutting start end As of the surface 10a of the glass substrate 1. Although the length and depth of the initial crack 31 are not particularly limited, the length of the initial crack 31 is preferably in the range of 1 to 30 mm, more preferably in the range of several mm. Further, it is preferable that the depth of the initial crack 31 is 10% or more of the thickness of the substrate.

Next, as shown in Fig. (b), the portion of the back surface 10b of the glass substrate 1 facing the initial crack 31 is pressed by the breaking roller 4 in the direction of the surface 10a. As a result, the initial crack 31 progresses in the thickness direction of the glass substrate 1, and the crack 32 is formed at the initial stage of reaching the back surface 10b.

Next, as shown in (c), the elliptical-shaped laser beam 51 is irradiated from the initial stage of the glass substrate 1 through the crack 32 along the planned cutting line 11, and the laser beam 51 is irradiated from the vicinity of the end portion of the laser beam 51. Cooling water 61 as a cooling medium.

By irradiating the glass substrate 1 with the laser beam 51, the glass substrate 1 is heated at a temperature at which the melting temperature is not full in the thickness direction, and the glass substrate 1 tends to thermally expand, but cannot be inflated due to local heating, and the irradiation point is generated. The stress of the center compression. Thereafter, the surface of the glass substrate 1 is sprayed with cooling water 61 immediately after heating to be cooled, and tensile stress is generated at this time. By the action of the tensile stress, the initial penetration crack 32 is used as a starting point, and the crack progress of the entire thickness direction of the glass substrate 1 is covered. Thereafter, by moving the laser beam 51 along the planned cutting line 11, the crack 33 covering the entire thickness direction of the glass substrate 1 continuously progresses in the moving direction of the laser beam 51, and the glass substrate 1 is cut by the planned cutting line 11. Further, in this embodiment, although the glass substrate 1 is fixed and the laser beam 51 is moved, the glass substrate 1 may be moved to fix the laser beam 51 or both the glass substrate 1 and the laser beam 51 may be moved. In addition, even if the cooling water 61 is not sprayed, the crack 33 starting from the initial penetration crack 32 can be progressed by natural air cooling, but the spray cooling water 61 is forced to cool, and the crack 33 is rapidly and surely progressed, so it is preferable. .

The laser beam 51 used herein is not particularly limited, and is composed of a glass substrate 1 The material or thickness can be appropriately determined. When the brittle material substrate is a glass substrate, a laser beam having a wavelength of 9 to 11 μm is preferable because the absorption on the surface of the glass substrate is large. Such a laser beam can be a carbon dioxide laser. The illumination shape of the laser beam 51 to the glass substrate 1 is preferably an elliptical shape in which the relative movement direction of the laser beam is long, and the long diameter is in the range of 10 to 60 mm, and the short diameter is preferably in the range of 1 to 5 mm.

As the water sprayed from the cooling nozzle 60, distilled water is preferred. However, the glass substrate 1 after the cutting does not have an adverse effect, and an additive such as an surfactant may be added to the water. The amount of cooling water is usually in the range of 1 to 2 ml/min. The cooling of the glass substrate 1 by water is preferably a so-called water jet method in which water is sprayed together with a gas (usually air) from the viewpoint of quenching the glass substrate 1 heated by the laser beam 51. The area cooled by the cooling water is preferably a circular shape or an elliptical shape having a diameter of 1 to 5 mm. Further, the cooling area is rearward in the relative moving direction of the heating region of the laser beam 51, and is preferably formed in the vicinity of the rear end of the heating region.

The relative moving speed of the laser beam 51 may be appropriately determined depending on the laser beam output value, the irradiation area, the thickness of the brittle material substrate 50, and the like, but is preferably in the range of 1 to several hundreds of mm/sec.

The cutting method of the present invention can be used for cutting a conventionally known brittle material substrate such as a glass substrate, a ceramic substrate, a single crystal germanium substrate, or a sapphire substrate, and is suitably used in the field of panel manufacturing such as liquid crystal displays.

In the cutting method described above, since the cracks 33 are progressed by irradiating the laser beam with the initial through crack 32 formed at a small amount at the end portion of the glass substrate 1, the occurrence of glass swarf, microcracks, and the like can be effectively suppressed. . Further, in the case where the occurrence of glass swarf or microcracks or the like is further suppressed, it is recommended to shorten the crack formed by the cutter wheel 2 and irradiate the laser beam to form the remaining length necessary for the initial crack. A method of forming such an initial crack is shown in FIG.

In Fig. 2 (a-1), a crack 31a is formed by the cutter wheel 2 at the cutting start end As of the surface 10a of the glass substrate 1. The crack 31a may be a length that progresses by irradiation of a laser by a laser, and may be, for example, a point crack (tens of μm). Thereby, micro-cracks or glass swarf due to the use of the cutter wheel 2 can be suppressed to a minimum.

Next, as shown in Fig. (a-2), the laser beam 51 is irradiated from the crack 31a along the planned cutting line 11 and the cooling water 61 is sprayed as a cooling medium near the end portion of the laser beam 51 irradiated from the cooling nozzle 60. The crack 31a progresses along the planned cutting line 11 and becomes an initial crack 31 of a predetermined length. Since the progress of the crack 31a is performed so as not to be in contact with the glass substrate 1, microcracks, glass swarf, or the like does not occur. The step from the step of forming the crack 32 in the initial stage of the formation shown in the same figure (b) is the same as the cutting method shown in Fig. 1, and therefore the description thereof will be omitted. Further, the progress mechanism of the crack 31a caused by the irradiation of the laser beam is the same as the progress mechanism of the crack 33 starting from the crack 32 at the beginning.

Next, a method of cutting one of the brittle material substrates which laminates two sheets of the brittle material substrate will be described. FIG. 3 is a view showing a step of a method of dividing one portion of the glass substrate 7 of the laminated substrate P in which the glass substrate (the first brittle material substrate) 7 and the glass substrate (the second brittle material substrate) 8 are bonded together with the sealant S. As shown in the figure (a), the cutter wheel 2 is pressed and rotated simultaneously to form the initial crack 31 before the surface end portion of the glass substrate 7. The length and depth of the initial crack 31 are the same as those of the previous embodiment.

Next, as shown in (b), the portion of the back surface side of the glass substrate 8 facing the initial crack 31 is pressed by the breaking roller 4 in the direction of the glass substrate 7. As a result, the laminated substrate P is bent upward, and the initial crack 31 progresses toward the entire thickness direction of the glass substrate 7, and the initial penetration crack 32 is formed. At the same time, the bonding between the end faces of the cracks 32 at the initial stage, the peeling and removing portion 71 of the end portion of the glass substrate 7 and the glass substrate 8 are eliminated, and the separation of the cut portions 71 at the end portions of the glass substrate 7 can be eliminated. Easy to carry out.

Next, as shown in Fig. (c), the elliptical-shaped laser beam 51 is irradiated from the initial stage of the glass substrate 7 through the crack 32 along the planned cutting line 11, and the laser beam 51 is irradiated from the vicinity of the end portion of the laser beam 51. The cooling water 61 as the cooling medium starts from the initial penetration crack 32, and the crack 33 covering the entire thickness direction of the glass substrate 7 progresses. By moving the laser beam 51 along the cutting planned line 11, the crack 33 covering the entire thickness direction of the glass substrate 7 continuously progresses in the moving direction of the laser beam 51, and the glass substrate 7 is cut by the planned cutting line 11. Thereafter, as shown in (d), the cut-and-removed portion 71 is separated and removed from the build-up substrate P. Further, in this embodiment, the laminated substrate P is fixed and the laser beam 51 is moved. However, the laminated substrate P may be moved to fix the laser beam 51 or both the laminated substrate P and the laser beam 51 may be moved. In addition, even if the cooling water 61 is not sprayed, the crack 33 starting from the initial penetration crack 32 can be progressed by natural air cooling, but the spray cooling water 61 is forced to cool, and the crack 33 is rapidly and surely progressed, so it is preferable. .

Further, similarly to the above-described embodiment, from the viewpoint of further suppressing generation of glass swarf or microcracks caused by the cutter wheel 2, the crack formed by the cutter wheel 2 is shortened, and the laser beam is irradiated to form an initial turtle. It is no problem to split the remaining length.

For example, when the liquid crystal display panel is bonded to two glass substrates and the terminal electrodes are formed on the inner side surface of one of the glass substrates, the terminal covering the terminal electrode is cut and removed to make the terminal. Where the electrode is exposed.

[Industrial availability]

In the method for cutting a brittle material substrate according to the present invention, since the initial crack formed by the cutter is a crack that penetrates in the thickness direction of the substrate, the initial through crack is progressed along the planned cutting line by the irradiation of the laser beam, so that the crack does not occur. It is useful to increase the size and complexity of the device to minimize the occurrence of micro-cracks or glass swarf.

Further, in addition to the above effects, the method of the present invention in which one of the laminated substrates to which the two brittle material substrates are bonded is cut, and the second brittle material substrate is pressed while the crack is formed at the initial stage of formation. The bonding between the end faces of the cracks in the initial crack portion and the end portions of the cracks in the initial stage, the bonding between the cut portions of the end portions of the glass substrate and the glass substrate is eliminated, and the separation of the cut portions of the glass substrate is relatively easy. Useful.

1. . . Glass substrate (brittle material substrate)

2. . . Knife wheel (knife)

4. . . Broken roller

7. . . Glass substrate (first brittle material substrate)

8. . . Glass substrate (second brittle material substrate)

P. . . Laminated substrate

11. . . Cut the planned line

31. . . Initial crack

32. . . Initial through crack

33. . . Crack

51. . . Laser beam

61. . . Cooling water

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view showing the steps of an example of a method for cutting a brittle material substrate of the present invention.

Fig. 2 is a view showing the steps of another method of forming the initial crack.

Fig. 3 is a view showing a step of an example of a method of cutting a laminated substrate of the present invention.

1. . . Glass substrate (brittle material substrate)

2. . . Knife wheel (knife)

4. . . Broken roller

10a. . . surface

10b. . . back

11. . . Cut the planned line

31. . . Initial crack

32. . . Initial through crack

33. . . Crack

51. . . Laser beam

As. . . Cut start

Claims (4)

A method for cutting a brittle material substrate by cutting a laser beam by irradiating a laser beam, comprising: forming an initial crack by a cutter at a cutting start end of a cut line of one surface of the substrate; and pressing the foregoing Forming a portion of the substrate opposite to the initial crack on the opposite side surface of the surface of the initial crack, and stepping the initial crack toward the thickness direction of the substrate to form an initial through crack at the opposite side surface; And irradiating the laser beam relative to the predetermined breaking line along the predetermined cutting line, and simultaneously heating the substrate at a temperature at which the melting temperature is not full, whereby the initial through crack is cut along the aforementioned by the thermal stress generated by the substrate. The step of scheduling the progress of the line. A cutting method for a brittle material substrate, wherein a brittle material substrate is cut by irradiating a laser beam, characterized in that: a step of forming an initial crack by a cutter at a cutting start end of a cut line of one surface of the substrate; The initial crack moves the laser beam relative to each other along the predetermined cutting line, and simultaneously heats the substrate at a temperature at which the melting temperature is not full, thereby causing the initial crack to progress along the predetermined cutting line by the thermal stress generated by the substrate. a step of initializing the crack; pressing the portion of the opposite side surface of the substrate on which the initial progress crack is formed and the portion of the initial progress crack, and forming the initial progress crack in the thickness direction of the substrate to form a step of passing through the crack at the initial stage of the opposite side surface; and irradiating the laser beam relative to the predetermined cutting line along the predetermined cutting line and simultaneously irradiating the substrate, and heating the substrate at a temperature at which the melting temperature is not full, thereby relying on the substrate The resulting thermal stress causes the initial progress crack to progress along the aforementioned cut-off line. A method for cutting a brittle material substrate by cutting a brittle material substrate of one of the laminated substrates to which two brittle material substrates are bonded, and having a cutting tool at a cutting start end of a predetermined cutting line of the first brittle material substrate a step of forming an initial crack; pressing a portion of the second brittle material substrate opposite to the initial crack, and causing the initial crack to progress in a thickness direction of the first brittle material substrate to form an opposite side of the first brittle material substrate a step of penetrating the crack at the beginning of the first step; and irradiating the laser beam while moving along the predetermined cutting line along the predetermined cutting line, and simultaneously heating the first brittle material substrate at a temperature at which the melting temperature is not full, thereby The thermal stress generated by the brittle material substrate advances the initial through crack along the predetermined cut line. A method for cutting a brittle material substrate by cutting a brittle material substrate of one of the laminated substrates to which two brittle material substrates are bonded, and having a cutting tool at a cutting start end of a predetermined cutting line of the first brittle material substrate a step of forming an initial crack; the laser beam is relatively moved from the initial crack along the predetermined line to be cut, and the first brittle material substrate is heated at a temperature at which the melting temperature is not full, thereby utilizing the first brittle material substrate The generated thermal stress causes the initial crack to progress along the predetermined cutting line to form an initial progress crack; and presses the portion of the second brittle material substrate opposite to the initial crack to cause the initial crack to the first brittle material a step of forming a crack in the thickness direction of the substrate to form an initial through crack on the opposite side surface of the first brittle material substrate; and irradiating the laser beam while moving along the predetermined cut line from the initial through crack, so that the melting temperature is not Heating the first brittle material substrate at a full temperature, whereby the initial stress is caused by the thermal stress generated by the first brittle material substrate Progress through the cracking step along the line of cut.