JP2007090762A - Method for splitting substrate and method for producing electro-optical device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique which can accurately perform splitting, for example, in the vicinity of the end part of a substrate made of a brittle material along a splitting schedule line. <P>SOLUTION: A method for splitting the substrate by using laser beams includes: a first process for setting an optical path to make the first laser beam (A) irradiate a splitting schedule line (K) formed on the substrate (102); a second process for setting the optical path so that the second laser beam (B) whose intensity is set to be relatively lower than that of the first laser beam irradiates a side nearer than the splitting schedule line to a seal member (103) set in the end part of the substrate or to be contacted with the substrate while being separated from the first laser beam; and a third process in which the irradiation with the first and second laser beams is carried out while the laser beams are advanced along the splitting schedule line. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a technique for cleaving a desired position of a substrate made of a brittle material (for example, a glass substrate), and more particularly, to a technical improvement for improving the accuracy of the cleaving position at a substrate edge or the like.

  In general, when a substrate made of a brittle material (for example, a glass substrate) is cleaved using a laser beam, a crack is generated in the substrate by a laser beam serving as a heat source and a cooling mechanism following a heating point by the laser beam. The substrate is cleaved by moving the laser beam or the substrate (for example, see Patent Document 1). At this time, a compressive stress is generated in the vicinity of the center of the point heated by the laser beam, and a tensile stress is generated evenly on the left and right in the periphery slightly away from the center.

  By the way, in the case of using the above technique, if the planned cutting line is sufficiently separated from the end of the substrate, the cutting can be performed as planned, but the planned cutting line is close to the end of the substrate. In such a case, there is an inconvenience that the actual cutting line (cut line) deviates from the planned cutting line. This is considered to be because the rigidity of the outer portion is small in the vicinity of the end of the substrate, and when the substrate is locally expanded by laser beam irradiation, the tensile stress toward the outside increases. Similar inconveniences may also occur when cutting a substrate bonded with a seal member interposed therebetween. That is, when the planned cutting line is set close to the position where the seal member is in contact, the laser beam that was originally uniform left and right due to the tensile stress generated on the substrate surface due to the hardening shrinkage phenomenon of the seal member. The tensile stress is non-uniform. For this reason, the cut line is drawn closer to the side closer to the seal member than the planned cutting line. In order to avoid such inconvenience, at present, it is necessary to set the planned cutting line at a position sufficiently separated from the position of the seal member. For this reason, for example, when manufacturing the electro-optical device such as a liquid crystal display device or an organic EL display device, if the above technique is used for cleaving the panel frame portion on which the seal member is disposed, it is difficult to narrow the panel frame. There is an inconvenience. Therefore, there has been a demand for a technique that can accurately perform cleaving in the vicinity of the end portion of the substrate along the planned cutting line.

US Pat. No. 5,609,284

  Therefore, an object of the present invention is to provide a technique that can perform cleaving in the vicinity of an end portion of a substrate made of a brittle material with high accuracy along a planned cutting line.

  The first aspect of the present invention is a method of cleaving a substrate made of a brittle material using a laser beam, and a first process of setting an optical path so that the first laser beam is irradiated onto a planned fracture line of the substrate. And a second laser beam whose intensity is set to be relatively lower than the intensity of the first laser beam is applied to a seal member provided in contact with the end of the substrate or the substrate from the planned cutting line. A second process of setting an optical path so that the first laser beam is irradiated at a distance closer to the first laser beam, and a first process of irradiating the first and second laser beams while proceeding along the planned cutting line. And cleaving the substrate including three processes.

  According to such a method, it is possible to balance each stress in the vicinity of the planned cutting line by irradiating the auxiliary second laser beam having a low intensity on the side close to the edge of the substrate. Thereby, it becomes possible to perform the cleaving in the vicinity of the end portion of the substrate made of a brittle material such as a glass substrate with high accuracy along the planned cutting line.

  Preferably, in the second process, the region of the second laser beam is brought into contact with the region where the tensile stress due to the first laser beam is generated in the substrate and the region where the tensile stress due to the second laser beam is generated. Determine the irradiation position.

  Thereby, the irradiation position of the second laser beam can be determined more accurately.

  A second aspect of the present invention is a method of cleaving a substrate made of a brittle material using a laser beam, and a first process of setting an optical path so that the first laser beam is irradiated on a planned fracture line of the substrate. And setting the optical path so that the second laser beam is irradiated away from the first laser beam closer to the end of the substrate or closer to the seal member provided in contact with the substrate than the planned cutting line. And the position of the sealing member provided in contact with the end of the substrate or the substrate and the position of the planned cutting line are close to each other, the intensity of the second laser beam is A third step of irradiating the first and second laser beams while traveling in a direction parallel to the planned cutting line, and an edge of the substrate; Or the above group A fourth process of irradiating only the first laser beam along the planned cutting line when the position of the sealing member provided in contact with the position of the planned cutting line is separated; A method for cleaving a substrate including

  Also by such a method, for the same reason as described above, it is possible to accurately perform cleaving in the vicinity of an end portion of a substrate made of a brittle material such as a glass substrate along the planned cutting line. In addition, it is possible to cut accurately in any situation by simply switching whether to irradiate the second laser beam depending on whether the planned cutting line is close to or away from the edge of the substrate. Can be performed.

  Preferably, in the third process, the region of the second laser beam is brought into contact with the region where the tensile stress due to the first laser beam is brought into contact with the region where the tensile stress due to the second laser beam is in contact with the substrate. Determine the irradiation position.

  Thereby, the irradiation position of the second laser beam can be determined more accurately.

  A third aspect of the present invention is a method for manufacturing an electro-optical device, which includes a step of forming an electro-optical panel and a step of cleaving the electro-optical panel using the substrate cleaving method. Here, as the “electro-optical device”, for example, a liquid crystal display device including a liquid crystal panel as an electro-optical panel, an inorganic EL display device including an electroluminescence (EL) panel as an electro-optical panel, or An organic EL display device, an electrophoretic display device including an electrophoretic panel as an electro-optical panel, and the like may be applicable.

  According to the present invention, the panel can be cleaved with high accuracy when the electro-optical device is manufactured.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a diagram for explaining an example of the configuration of an apparatus for carrying out a substrate cleaving method according to an embodiment. The cleaving apparatus shown in FIG. 1 is for cleaving a substrate made of a brittle material using a laser beam, and includes a laser light source 10, a beam splitter 12, a reflecting mirror 14, an attenuator 16, and a stage 18. ing.

The laser light source 10 generates a laser beam. The laser light source 10 may be appropriately selected depending on the conditions of the workpiece 100 to be cleaved. For example, a CO ₂ laser having a maximum output of about 50 W is used in this embodiment.

  The beam splitter 12 reflects some components of the laser beam emitted from the laser light source 10 and passes other components.

  The reflection mirror 14 reflects the laser beam that has passed through the beam splitter 12. The reflection mirror 14 is configured to be movable in the X direction shown in the figure. Thereby, the irradiation position on the workpiece 100 of the laser beam reflected by the reflection mirror 14 can be adjusted.

  When the laser beam separated by the beam splitter 12 is incident, the attenuator 16 reduces the intensity of the laser beam.

  The stage 18 has the workpiece 100 placed thereon, and freely moves the workpiece 100 in the X, Y, and Z directions. The stage 18 can relatively move the workpiece 100 and each laser beam. The stage 18 may be fixed and the irradiation position of the laser beam may be moved.

  FIG. 2 is a diagram for explaining the irradiation position of the laser beam. The laser beam irradiated to the workpiece 100 includes a laser beam A (first laser beam) reflected by the reflecting mirror 14 and a laser beam B (second laser beam) having passed through the attenuator 16 and having a reduced intensity. ). At this time, as shown in the figure, the region where the tensile stress caused by the laser beam A is brought into contact with the region where the tensile stress caused by the laser beam B is in contact with the inside of the substrate (described later) constituting the workpiece 100. The irradiation position of the laser beam B is determined.

  FIG. 3 is a diagram schematically showing a cross section of the workpiece 100 in order to explain the cleaving method. Here, in the present embodiment, it is assumed that the workpiece 100 is a panel in which two glass substrates 101 and 102 are bonded with a seal member 103 interposed therebetween. The panel having such a structure is used for forming a display unit in an electro-optical device such as a liquid crystal display device or an organic EL display device. In the manufacturing process of these electro-optical devices, after forming the panel as shown in FIG. 3, the desired position of the panel can be cleaved by the following method.

FIG. 3 schematically shows a state where the position of the seal member provided in contact with the substrate 102 of the workpiece 100 and the position of the planned cutting line are close to each other. As shown in the drawing, the optical path is set so that the laser beam A is irradiated on the planned cutting line K of the substrate 102, and the laser beam B is provided in contact with the substrate 102 rather than the planned cutting line K. The optical path is set so that the laser beam A is irradiated away from the laser beam A (see FIG. 1). Here, the cleaving line K extends in a direction perpendicular to the paper surface of FIG. The intensity of the laser beam B is set to be relatively lower than the intensity of the laser beam A. Such intensity adjustment is made by the attenuator 16. Then, the substrate 102 is cleaved by irradiating the laser beams A and B while proceeding in a direction parallel to the cleaving line K. The traveling speeds of the laser beams A and B are set to about 7 mm / second, for example. The energy densities of the laser beams A and B are appropriately set within a range of, for example, about 32 to 90 kJ / mm ² . Here, in the figure, stresses S1 and S2 indicate compressive stresses generated by the laser beam A, stresses S3 and S4 indicate tensile stresses generated by the laser beam A, and stresses S5 and S6 indicate compressive stresses generated by the laser beam B. , Stresses S7 and S8 indicate tensile stresses generated by the laser beam B. At this time, the intensity of the laser beam B is set so that the tensile stress S8 generated by the laser beam is equal to the tensile stress S0 by the seal member 103. Here, the tensile stress S0 due to the seal member 103 is, for example, about 0.035 MPa when the seal member 103 is an epoxy sealant. At this time, the intensity of the laser beam B is about 1/25 of the intensity of the laser beam A, which is the main cleaving laser. Further, the distance between the laser beam A and the laser beam B varies depending on various conditions, but is preferably about 4 mm or less.

  When the position of the seal member 103 provided in contact with the substrate 102 and the position of the planned cutting line K are sufficiently separated, only the laser beam A is advanced in a direction parallel to the planned cutting line K. Cleavage is performed by irradiation. In this case, for example, the intensity of the laser beam B may be made substantially zero by the attenuator 16, or the beam splitter 12 may be removed from the optical path.

  Even when the right seal member 103 in FIG. 3 does not exist and the position is the end of the substrate 102, the cleaving can be performed in the same manner as described above.

  FIG. 4 is a perspective view illustrating a specific example of an electronic apparatus including an electro-optical device manufactured by applying the above-described cleaving method as a display unit. FIG. 4A illustrates an application example to a mobile phone, and the mobile phone 1000 includes a display portion 1001 configured using the above-described electro-optical device. FIG. 4B illustrates an application example to a video camera, and the mobile phone 1100 includes a display portion 1101 configured using the above-described electro-optical device. FIG. 4C illustrates an application example to a television, and the television 1200 includes a display portion 1201 configured using the above-described electro-optical device. The electro-optical device according to the present invention can be similarly applied to a monitor device used for a personal computer or the like.

  As described above, according to the present embodiment, the stress near the cutting line is balanced by irradiating the auxiliary second laser beam having low intensity on the side close to the edge of the substrate. Can do. Thereby, it becomes possible to perform the cleaving in the vicinity of the end portion of the substrate made of a brittle material such as a glass substrate with high accuracy along the planned cutting line. In addition, it is possible to cut accurately in any situation by simply switching whether to irradiate the second laser beam depending on whether the planned cutting line is close to or away from the edge of the substrate. Can be performed.

  In addition, this invention is not limited to the content of embodiment mentioned above, A various deformation | transformation implementation is possible within the range of the summary of this invention. For example, in the above-described embodiment, the case of cleaving the glass substrate has been exemplified, but the substrate (substrate made of a brittle material) to which the present invention is applied is not limited to this, and is a ceramic, semiconductor substrate, amorphous carbon substrate. Various substrates may be applicable.

It is a figure explaining the apparatus structure for enforcing the cleaving method of the board | substrate of one Embodiment. It is a figure explaining the state of the laser beam irradiated to a to-be-processed body. It is the figure which showed typically the cross section of the to-be-processed body in order to demonstrate the cleaving method. It is a perspective view which shows the specific example of an electronic device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Laser light source, 12 ... Beam splitter, 14 ... Reflection mirror, 16 ... Attenuator, 18 ... Stage, 100 ... Workpiece, 101, 102 ... Glass substrate, 103 ... Sealing member

Claims (5)

A method of cleaving a substrate made of a brittle material using a laser beam,
A first step of setting an optical path so that the first laser beam is irradiated on the planned cutting line of the substrate;
The side closer to the seal member provided in contact with the end of the substrate or the substrate than the planned cutting line is the second laser beam set to be relatively lower in intensity than the first laser beam A second step of setting an optical path so that the light beam is irradiated separately from the first laser beam;
A third step of irradiating the first and second laser beams while proceeding along the planned cutting line;
A method for cleaving a substrate.   In the second step, the irradiation position of the second laser beam is set so that the region where the tensile stress due to the first laser beam is generated and the region where the tensile stress due to the second laser beam are in contact with each other in the substrate. The method for cleaving a substrate according to claim 1, which is determined. A method of cleaving a substrate made of a brittle material using a laser beam,
A first step of setting an optical path so that the first laser beam is irradiated on the planned cutting line of the substrate;
The optical path is set so that the second laser beam is irradiated away from the first laser beam toward the end of the substrate or closer to the seal member provided in contact with the substrate than the planned cutting line. The second process,
When the position of the sealing member provided in contact with the end of the substrate or the substrate and the position of the planned cutting line are close to each other, the intensity of the second laser beam is determined as the intensity of the second laser beam. And a third process of irradiating the first and second laser beams while traveling in a direction parallel to the planned cutting line,
When the position of the sealing member provided in contact with the end portion of the substrate or the substrate is separated from the position of the planned cutting line, only the first laser beam is allowed to travel along the planned cutting line. While irradiating the fourth process,
A method for cleaving a substrate.   In the third step, the irradiation position of the second laser beam is set so that the region where the tensile stress due to the first laser beam is generated and the region where the tensile stress due to the second laser beam are in contact with each other in the substrate. The method for cleaving a substrate according to claim 3, which is determined. Forming an electro-optic panel;
A step of cleaving the electro-optical panel using the substrate cleaving method according to claim 1;
A method for manufacturing an electro-optical device.

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