JP4298072B2 - Cleaving method of hard brittle plate - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method of dividing a hard and brittle plate represented by a glass plate along a predetermined line and dividing it, for example, a glass on which display elements are formed at the time of manufacturing a flat panel display such as a liquid crystal or a plasma display. The present invention relates to a method used for cutting a substrate into a predetermined dimension.
[0002]
[Prior art]
In the manufacture of flat panel displays such as liquid crystal displays and plasma displays, display elements of the required dimensions are formed by forming multiple display elements on a large-area glass substrate and then cutting them into multiple pieces to increase productivity. Therefore, a process of cutting the glass substrate along a predetermined cutting line is indispensable at the time of manufacture. Hard brittle materials such as glass plates are also cut with diamond saws, etc., but since cutting takes a very long time, a method of cutting using cracks based on the brittleness of the material is widely adopted. ing.
[0003]
Currently, the most commonly used cutting method for glass plates, etc., is to push the sharp tip or sharp edge of a carbide tool such as a diamond tool against the glass surface and move it to the cutting surface. After forming a groove (scribe line) along the groove, a mechanical impact force such as bending or pulling is applied to the plate along this groove. This process consists of two steps, a scribing process and a breaking process. The apparatus which performs is installed adjacently, and a cleaving process is performed, transferring a workpiece | work from a scribing apparatus to a breaking apparatus.
[0004]
On the other hand, attempts have been made for a long time to cleave by generating local internal thermal stress on the glass plate. The basic principle is that the laser beam or other heating beam irradiated on the surface of the hard brittle plate is caused to travel along the cutting line, so that cracks due to local thermal stress generated in the part irradiated with the heating beam are used as the cutting line. It is something that goes along. In this method of cleaving a hard brittle plate using a local heating beam, various improved methods have been proposed for the purpose of improving the cleaving speed and the accuracy of the cleaved section.
[0005]
For example, Japanese Patent Application Laid-Open No. 59-97545 proposes a method in which a scribe line is put in advance on a glass plate with a cemented carbide chip or the like, a laser beam is irradiated on the line, and a thermal shock is applied. Japanese Patent Laid-Open No. 5-32428 discloses that the surface of a glass body to be processed is irradiated with laser light in an ultraviolet region having a high absorption rate with respect to the glass body, and the irradiation point is set as a target cutting line. Scanning along the surface of the glass body to be processed, and irradiating laser light in the infrared region along the scribed portion to give thermal distortion that leads to cleavage The glass processing method containing these is proposed.
[0006]
[Problems to be solved by the invention]
As for the cleaving method of a hard brittle plate using a laser beam, the greatest reason that has not been put into practical use although various methods have been proposed for a long time is low processing efficiency. For this reason, a breaking method based on mechanical impact force is used, which has a relatively high possibility of cracking deviating from a desired cutting line and requires a large installation space for the machine.
[0007]
However, flat panel displays are manufactured in a clean room because they have extremely fine light-emitting or light-shielding elements on the surface of the glass substrate, and are extremely disliked by dust. However, in the case of mechanical scribing and breaking, In addition, a considerable amount of glass fragments are sometimes generated, and when it is severe, the cut portion is chipped, thereby reducing the quality of the product or the yield of the product. In addition, when mechanical breaking occurs, it is necessary to insert deep scribe grooves so that cracks do not advance from the cutting line and chips are not generated in the cut portion, which reduces productivity and occurs. There is a problem that the dust must be increased and the scribing cutter (pointer needle or roller) is quickly worn, and the machine must be frequently stopped for the replacement.
[0008]
In addition, since two devices, a scribing device and a breaking device, are necessary for cleaving, there is an economic disadvantage that the installation area of the machine is increased and the floor area of the clean room must be increased.
[0009]
In order to solve the above-mentioned problems of the method of cleaving a hard brittle plate by mechanical scribing and breaking, which is generally performed at present, a highly brittle plate having high productivity by a laser beam or other heating beam is provided. The problem is to obtain a cleaving method.
[0010]
[Means for Solving the Problems]
In the method of the invention, by moving contact with sharp tip or peripheral high hardness of the tool from the hard and brittle plate to form a scribe line along the desired cutting line under surface of the hard and brittle plate is supported horizontally, By irradiating the upper surface, which is the surface opposite to the surface on which the scribe line is formed, with a laser beam or other heating beam that locally heats the hard brittle plate, the irradiation point is moved along the scribe line, thereby causing the hard brittleness. Cleave the board.
[0011]
In this case, a hard brittle plate to be cleaved is supported by a horizontal table having a groove in which the tool is arranged , a scribe line is formed on the lower surface of the hard brittle plate, and a heating beam is irradiated on the upper surface of the hard brittle plate. This is excellent in terms of treating dust generated during cleaving.
[0012]
When applying the method of the present invention to a hard brittle plate cleaving device, the tool for forming the scribe line and the irradiation device for the heating beam are opposed to each other with the hard brittle plate to be cut between them, and the irradiation point of the heating beam is set. A method of disposing a predetermined distance behind the traveling direction of the tool and causing the tool and the irradiation point of the heating beam to travel along the cutting line of the hard brittle plate while maintaining the predetermined distance or distance range. This is advantageous in terms of work efficiency and equipment space.
[0013]
The cutting line is not limited to a straight line, but can be cut along a circle or a free curve. The heating beam can be run while reciprocating back and forth along the breaking line, and it is usually preferable to apply such reciprocation.
[0014]
[Action]
The above-described method of the present invention is performed on the same surface of a hard brittle plate that is intended to cleave formation of a scribe line and irradiation of a heating beam, as compared to the conventional method described in Japanese Patent Laid-Open No. 59-97545. However, the difference is that the formation of the scribe line and the irradiation of the heating beam are performed on the opposite surfaces of the hard brittle plate, but this difference results in the cleaving efficiency, the accuracy of the cleaved surface, the amount of dust generated during cleaving, In terms of wear of hard tools, the following large differences occur.
[0015]
When one surface of the hard brittle plate is irradiated with a heating beam, a local heating region is generated at a position biased toward the irradiation side of the heating beam in the thickness direction of the condensing point. In the conventional method, as shown in FIG. 3, since the heating beam 3 is irradiated toward the surface on which the scribe line 4 is formed, the local heating region 5 is scribed in the thickness direction of the hard brittle plate 1. This heating region includes the scribe line 4. This is because the scribe line is irradiated with the heating beam with the maximum energy that is not attenuated.
[0016]
The vitreous material in the heating region 5 expands due to heat and tries to spread the surrounding unheated glass. Naturally, as this reaction, compressive stress acts on the glass in the heated region. That is, in the conventional method, the thermal stress acting on the groove bottom of the scribe line in the heating region is a compressive stress, and thus does not act effectively on the cleaving of the glass plate.
[0017]
Actually, the heating region 5 also extends in the surface direction of the hard brittle plate 1 as shown in FIG. 5, and a tensile stress in the circumferential direction is generated around the heating region 5. Therefore, the conventional method is cleaved by the tensile stress in the circumferential direction. However, the crushing efficiency is not increased because the thickness direction is the compression side, and a deep scribe line must be provided.
[0018]
On the other hand, in the method of the present invention shown in FIG. 2, since the surface on which the scribe line 4 is formed and the surface irradiated with the heating beam 3 are opposite surfaces, the heating region 5 generated by the irradiation of the heating beam 3 is hard and brittle. The position is biased to the opposite side of the scribe line 4 in the thickness direction of the plate 1. The vitreous material in the heating area 5 is thermally expanded and tends to spread the surrounding unheated glass. This force to spread out generates a tangential tensile force in the unheated part around the heating area 5. When the heating region 5 expands, the groove bottom portion of the scribe line 4 also becomes a compression region as shown in FIG. 4, but a tensile stress in the circumferential direction is generated around the planar heating region in FIG. The tensile stress in the state of FIG. 2 arises in an outer peripheral part. Since these tensile forces are stresses in the direction of locally separating the hard brittle plate 1 around the scribe line 4, the local crack generated at the groove bottom of the scribe line 4 proceeds linearly in the thickness direction. In addition, a cut surface with good squareness and surface accuracy can be obtained.
[0019]
If the planar heating region is an elliptical region that is long in the cutting direction as shown in FIG. 6, the tensile stress in the circumferential direction at the front end in the traveling direction of the heating region 5 where cutting starts can be increased, and the cutting efficiency can be increased. Further improvement can be achieved. The elliptical heating region can be realized by traveling while reciprocating the irradiation point of the heating beam in the direction along the cutting line as indicated by an arrow D in FIG. 5 and 6 is the contact position of the tool that forms the scribe line 4, and this position is outside the heating region 5.
[0020]
As understood from the above description, according to the invention of this application, the stress concentration due to the provision of the scribe line and the local thermal stress due to the irradiation of the heating beam act optimally for cleaving the hard brittle plate. Therefore, the cleaving speed is fast and the accuracy of the fractured surface can be increased. Also, the groove depth of the scribe line may be shallow (because it is localized stress concentration, depending on the shape of the deep end of the groove of the scribe line, the magnitude of the local stress does not change even if the groove depth is shallow. Therefore, the scribe line can be formed at a high speed and the wear amount of the tool is small.
[0021]
In addition, since the groove depth of the scribe line may be shallow, dust generated by forming the scribe line is greatly reduced. Also, if the hard brittle plate to be cut is supported on a horizontal plane and a scribe line is formed on the lower surface, dust generated when the scribe line is formed falls downward or is sucked from below. Immediately eliminated. When breaking with a heating beam, almost no dust is generated.
[0022]
According to the method of claim 2 , scribing and breaking can be performed in one process on the same machine, and the installation area of the machine required for the cleaving process of the glass substrate in the flat panel display manufacturing facility can be halved. The floor area of the clean room can be reduced.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a perspective view schematically showing the method of the present invention. In this embodiment, a method of cleaving the glass plate 1 which is a hard brittle plate along a straight cutting line is shown. A glass plate 1 to be cut is supported by a horizontal table having a groove, and a scribing roller 2 is disposed in the groove of the table. The scribing roller 2 is pressed upward and is pressed against the lower surface of the glass plate 1.
[0024]
Laser light projected from a carbon dioxide laser oscillator or the like is condensed on the upper surface of the glass plate 1 through an appropriate optical system including a condenser lens. The contact point A of the scribing roller 2 and the condensing point B of the laser beam 3 are separated by a predetermined distance in the tangential direction of the outer peripheral edge of the scribing roller 2.
[0025]
In this state, the scribing roller 2 and the laser beam 3 are caused to run synchronously in the direction indicated by the arrow C in the drawing, that is, in the tangential direction of the scribing roller 2, in the direction preceding the laser beam, or the position of the scribing roller 2. The scribing roller 2 is placed on the lower surface of the glass plate 1 by running a table supporting the glass plate 1 in a direction opposite to the arrow C in the figure while fixing the position of the laser beam condensing point B. As a result, a scribe line 4 is formed, and a laser beam condensing point B is scanned on the upper surface of the glass plate facing the scribe line with a predetermined distance behind the contact position of the scribing roller 2. The glass plate 1 is cleaved by local cracks growing from the bottom of the scribe line 4 at the condensing point B of the laser beam.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view showing an embodiment of the method of the present invention. FIG. 2 is an explanatory view showing the relationship between a scribe line and a heating region by a laser beam in the method of the present invention. FIG. 4 is an explanatory diagram showing the relationship between the line and the laser beam heating region. FIG. 4 is an explanatory diagram showing the relationship between the scribe line and the laser beam heating region in the method of the present invention when the heating region is widened. FIG. 6 is an explanatory diagram showing the planar expansion of the region and the stress around it. FIG. 6 is an explanatory diagram showing an example in which the planar expansion of the heating region is an ellipse.
1 glass plate 2 scribing roller 3 laser beam 4 scribe line

Claims (3)

A hard brittle plate is supported by a horizontal table on which a tool having a groove and having a sharp tip or a peripheral edge, which is a tool that is pressed upward in the groove and has a higher hardness than the hard brittle plate, under surface of the hard and brittle plate along its desired cutting line to form a scribe line by moving contacting a sharp tip or rim of the tool, to locally heat the hard and brittle plate on surface of the hard and brittle plate A method of cleaving a hard brittle plate, characterized by irradiating a heating beam and moving the irradiation point along the scribe line. The tool that forms the scribe line and the heating beam irradiation device are opposed to each other with a hard and brittle plate to be cut, and the irradiation point of the heating beam is set at a predetermined distance behind the tool in the running direction. The cutting method of a hard brittle board according to claim 1 , wherein the heating point and the irradiation point of the heating beam are run along a cutting line of the hard brittle board while maintaining the predetermined distance or distance range . 3. The heating region generated by the irradiation of the heating beam is made into an elliptical region that is long in the cutting direction by moving the heating beam while reciprocating in the direction along the cutting line. Cleaving method of hard brittle plate.

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