JP6311798B2 - Method for dividing brittle substrate - Google Patents

Description

  The present invention relates to a method for dividing a brittle substrate.

  In the manufacture of electrical equipment such as flat display panels or solar cell panels, it is often necessary to break a brittle substrate such as a glass substrate. First, a scribe line is formed on the substrate, and then the substrate is divided along the scribe line. The scribe line can be formed by mechanically processing the substrate using the cutting edge. When the blade edge slides or rolls on the substrate, a trench due to plastic deformation is formed on the substrate, and at the same time, a vertical crack is formed immediately below the trench. Thereafter, stress is applied, which is called a break process. Thus, the substrate is divided by causing the vertical crack to advance completely in the thickness direction.

  The process of dividing the substrate is relatively often performed immediately after the process of forming a scribe line on the substrate. However, it has also been proposed to perform a process of processing the substrate between the process of forming the scribe line and the break process.

  For example, according to the technique of International Publication No. 2002/104078, in the method of manufacturing an organic EL display, a scribe line is formed on a glass substrate for each region to be each organic EL display before mounting a sealing cap. For this reason, the contact between the sealing cap and the glass cutter, which becomes a problem when the scribe line is formed on the glass substrate after the sealing cap is provided, can be avoided.

  Further, for example, according to the technique of International Publication No. 2003/006391, in a method for manufacturing a liquid crystal display panel, two glass substrates are bonded together after a scribe line is formed. As a result, two brittle substrates can be simultaneously broken in one break step.

International Publication No. 2002/104078 International Publication No. 2003/006391

  According to the above-described conventional technique, the brittle substrate is processed after the scribe line is formed, and then the break process is performed by applying stress. This means that vertical cracks already exist along the entire scribe line during processing into a brittle substrate. Therefore, the further extension in the thickness direction of the vertical crack occurs unintentionally during the processing, and the brittle substrate that should be integrated during the processing may be separated. Also, even when a substrate processing step is not performed between the scribe line formation step and the substrate break step, the substrate is usually transported or stored after the scribe line formation step and before the substrate break step. In this case, the substrate may be unintentionally divided.

  In order to solve the above-mentioned problems, the present inventor has developed a unique cutting technique. According to this technique, as a line that defines a position where a brittle substrate is divided, first, a trench line having no crack is formed immediately below the line. The formation of the trench line defines the position where the brittle substrate will be divided. Thereafter, if a state in which no crack is present immediately below the trench line is maintained, division along the trench line is not easily generated. By using this state, it is possible to prevent the brittle substrate from being unintentionally divided before the time point at which it should be divided, while predefining the position where the brittle substrate is to be divided.

  The trench line is formed by machining using a cutting edge. During this machining process, the cutting edge is damaged and eventually becomes unusable. Therefore, the cutting edge must be replaced at an appropriate timing, and this work burden is large in the dividing process. According to the study of the present inventor, the formation of the trench line is less likely to cause damage to the blade edge than the formation of the normal scribe line. However, in order to further reduce the above-described work burden, it is desired to develop a cutting method with less damage to the cutting edge.

  The present invention has been made in order to solve the above-described problems, and the purpose of the present invention is to reduce the damage to the cutting edge that performs processing for defining the position where the brittle substrate is divided. It is to provide a dividing method.

  The method for dividing a brittle substrate includes the following steps.

  A brittle substrate having a first surface and a second surface opposite to the first surface and having a thickness direction perpendicular to the first surface is prepared. Next, a trench line is formed by generating plastic deformation on the first surface of the brittle substrate by moving the blade edge on the first surface while pressing the blade edge onto the first surface of the brittle substrate. The The step of forming the trench line is performed so as to obtain a crackless state in which the brittle substrate is continuously connected in the direction intersecting the trench line immediately below the trench line. The step of forming the trench line includes a step of forming a low load section as a part of the trench line and a process of forming a high load section as a part of the trench line. The load applied to the cutting edge in the process of forming the high load section is higher than the load used in the process of forming the low load section. Next, the crack line is formed along a part of the trench line by extending the crack of the brittle substrate in the thickness direction along the trench line only in the high load section of the trench line. After the step of forming the crack line, the brittle substrate is divided along the trench line. The step of dividing the brittle substrate includes a step of extending the crack along the low load section starting from the crack line by applying stress to the brittle substrate.

  According to the present invention, when the trench line for defining the position where the brittle substrate is divided is formed, the load applied to the blade edge is reduced in the low load section as compared with the high load section. As a result, damage to the cutting edge can be reduced.

It is a flowchart which shows schematically the division | segmentation method of a brittle board | substrate in Embodiment 1 of this invention. It is a top view which shows roughly 1 process of the cutting method of the brittle board | substrate in Embodiment 1 of this invention. It is a schematic sectional drawing in alignment with line III-III of FIG. FIG. 4 is a schematic cross-sectional view (A) along line IVA-IVA in FIG. 2 and a schematic cross-sectional view (B) along line IVB-IVB in FIG. 2. It is a top view which shows roughly 1 process of the cutting method of the brittle board | substrate in Embodiment 1 of this invention. It is a schematic sectional drawing in alignment with line VI-VI of FIG. FIG. 6 is a schematic cross-sectional view taken along line VII-VII in FIG. 5. It is a top view which shows roughly 1 process of the cutting method of the brittle board | substrate in Embodiment 1 of this invention. It is a schematic sectional drawing in alignment with line IX-IX of FIG. It is a schematic sectional drawing in alignment with line XX of FIG. It is a top view which shows roughly 1 process of the cutting method of the brittle board | substrate in Embodiment 1 of this invention. It is sectional drawing which shows roughly 1 process of the cutting method of the brittle board | substrate in Embodiment 1 of this invention. It is sectional drawing which shows roughly 1 process of the cutting method of the brittle board | substrate in Embodiment 1 of this invention. It is a schematic side view by the visual field corresponding to the arrow XIV of FIG. It is sectional drawing which shows roughly 1 process of the cutting method of the brittle board | substrate in Embodiment 1 of this invention. It is sectional drawing which shows roughly 1 process of the cutting method of the brittle board | substrate in Embodiment 1 of this invention. The side view (A) which shows roughly the structure of the scribe tool used for the cutting method of a brittle board | substrate in Embodiment 1 of this invention, and the bottom view of the blade edge | tip by the visual field corresponding to arrow XVII of FIG. 17 (A) ( B). It is a top view which shows roughly 1 process of the cutting method of the brittle board | substrate in the 1st modification of Embodiment 1 of this invention. It is a top view which shows roughly 1 process of the cutting method of the brittle board | substrate in the 2nd modification of Embodiment 1 of this invention. It is a top view which shows roughly 1 process of the cutting method of the brittle board | substrate in the 3rd modification of Embodiment 1 of this invention. Side view (A) schematically showing the configuration of a scribing instrument used in the method for cutting a brittle substrate in the fourth modification of the first embodiment of the present invention, and a field of view corresponding to arrow XXI in FIG. 21 (A) It is a bottom view (B) of the blade edge by. It is a top view which shows roughly 1 process of the cutting method of the brittle board | substrate in Embodiment 2 of this invention. It is a top view which shows roughly 1 process of the cutting method of the brittle board | substrate in Embodiment 2 of this invention. It is a top view which shows roughly 1 process of the cutting method of the brittle board | substrate in Embodiment 2 of this invention. It is a top view which shows roughly 1 process of the cutting method of the brittle board | substrate in the 1st modification of Embodiment 2 of this invention. It is a top view which shows roughly 1 process of the cutting method of the brittle board | substrate in the 1st modification of Embodiment 2 of this invention. It is a top view which shows roughly 1 process of the cutting method of the brittle board | substrate in the 2nd modification of Embodiment 2 of this invention. It is a top view which shows roughly 1 process of the cutting method of the brittle board | substrate in the 3rd modification of Embodiment 2 of this invention. It is a side view which shows roughly the structure of the scribe tool used for the cutting method of the brittle board | substrate in Embodiment 2 of this invention. It is the front view (A) which shows schematically the structure of the scribing wheel and pin in FIG. 29, and the elements on larger scale (B) of FIG. 30 (A). It is a top view which shows roughly 1 process of the cutting method of the brittle board | substrate in Embodiment 3 of this invention. It is a top view which shows roughly 1 process of the cutting method of the brittle board | substrate in Embodiment 3 of this invention. It is a top view which shows roughly 1 process of the cutting method of the brittle board | substrate in Embodiment 4 of this invention. It is a top view which shows roughly 1 process of the cutting method of the brittle board | substrate in Embodiment 4 of this invention. It is a top view which shows roughly 1 process of the cutting method of the brittle board | substrate in Embodiment 4 of this invention. It is a top view which shows roughly 1 process of the cutting method of the brittle board | substrate in Embodiment 4 of this invention. It is a top view which shows roughly 1 process of the cutting method of the brittle board | substrate in Embodiment 4 of this invention. It is a top view which shows roughly 1 process of the cutting method of the brittle board | substrate in Embodiment 5 of this invention. It is a top view which shows roughly 1 process of the cutting method of the brittle board | substrate in Embodiment 5 of this invention. It is a top view which shows roughly 1 process of the cutting method of the brittle board | substrate in Embodiment 5 of this invention. It is a partial top view (A)-(D) which shows roughly 1 process of the cutting method of the brittle board | substrate in Embodiment 6 of this invention. 41A is a schematic partial cross-sectional view along line XLIIA-XLIIA (A), FIG. 41B is a schematic partial cross-sectional view along line XLIIB-XLIIB (B), and FIG. 41C is a line XLIIC-XLIIC. FIG. 42 is a schematic partial sectional view taken along line (C), and a schematic partial sectional view taken along line XLIID-XLIID in FIG. 41D.

  Hereinafter, a method for dividing a brittle substrate in each embodiment of the present invention will be described with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

(Embodiment 1)
A method for dividing the glass substrate 11 (brittle substrate) of the present embodiment will be described below with reference to a flow chart (FIG. 1).

  2 to 4, a glass substrate 11 is prepared (FIG. 1: step S10). The glass substrate 11 has an upper surface SF1 (first surface) and a lower surface SF2 (second surface opposite to the first surface). Further, the glass substrate 11 has a thickness direction DT perpendicular to the upper surface SF1.

  A scribing instrument having a cutting edge is also prepared. Details of the scribing device will be described later.

  Next, while the blade edge is pressed onto the upper surface SF1 of the glass substrate 11, the blade edge 51 is moved from the start point N1 to the end point N3 via the intermediate point N2 on the upper surface SF1. Thereby, plastic deformation is generated on the upper surface SF1 of the glass substrate 11. As a result, a trench line TL extending from the start point N1 to the end point N3 via the intermediate point N2 is formed on the upper surface SF1 (FIG. 1: step S20). In FIG. 2, three TLs are formed by the movement of the blade edge in the direction DA.

  The process of forming the trench line TL includes a process of forming the low load section LR as a part of the trench line TL (FIG. 1: Step S20L) and a process of forming the high load section HR as a part of the trench line TL (FIG. 1: Step S20H). In FIG. 2, a low load section is formed from the start point N1 to the midpoint N2, and a high load section is formed from the midpoint N2 to the end point N3. The load applied to the cutting edge 51 in the process of forming the high load section HR is higher than the load used in the process of forming the low load section LR. In other words, the load applied to the cutting edge 51 in the process of forming the low load section LR is lower than the load used in the process of forming the high load section HR, for example, 30 to 50 of the load in the high load section HR. %. Therefore, the width of the trench line in the high load section HR is larger than the width of the low load section LR. For example, the high load section HR has a width of 10 μm, and the low load section LR has a width of 5 μm. Further, the depth of the high load section HR is larger than the depth of the low load section LR. The cross section of the trench line TL has, for example, a V shape with an angle of about 150 °.

  In addition, since a high load is applied to the cutting edge 51 in the high load section HR, it is preferable that the distance of the high load section HR is small considering the life of the cutting edge 51. Furthermore, when the load is changed during the formation of the trench line TL, it is preferable that the scribe speed is reduced in the high load section HR in order to sufficiently increase the load in the high load section HR at a smaller distance. That is, since it is difficult to control to increase the load of the cutting edge 51 instantaneously, in practice, scribing is performed while increasing the load until a predetermined load is reached in a certain section starting from the position N2. . Therefore, by reducing the speed in the high load section HR, the load can be increased at a smaller distance, and the entire distance of the high load section HR can be reduced.

  The step of forming the trench line TL is a crackless state in which the glass substrate 11 is continuously connected in the direction DC (FIGS. 4A and 4B) intersecting the trench line TL immediately below the trench line TL. This is done so that a state is obtained. For this purpose, the load applied to the blade edge is made large enough to cause plastic deformation of the glass substrate 11 and small enough not to generate cracks starting from this plastic deformation part.

  Next, a crack line (FIG. 1: step S30) is formed as follows.

  With reference to FIGS. 5 to 7, first, an assist line AL that intersects the high load section HR is formed on the upper surface SF <b> 1 of the glass substrate 11. The assist line AL is accompanied by a crack that penetrates in the thickness direction of the glass substrate 11. The assist line AL can be formed by a normal scribing method.

  Next, the glass substrate 11 is separated along the assist line AL. This separation can be performed by a normal break process. As a result of this separation, the crack of the glass substrate 11 in the thickness direction is extended along the trench line TL only in the high load section HR of the trench line TL.

  With reference to FIGS. 8 and 9, the crack line CL is formed along a part of the trench line TL as described above. Specifically, the crack line CL is formed in a portion between the side newly generated by the separation and the midpoint N2 in the high load section HR. The direction in which the crack line CL is formed is opposite to the direction DA (FIG. 2) in which the trench line TL is formed. Note that a crack line CL is hardly formed in a portion between the side newly generated by the separation and the end point N3. This direction dependency is caused by the state of the cutting edge when the high load section HR is formed, and will be described in detail later.

  Referring to FIG. 10, the continuous connection is broken in the direction DC intersecting the extending direction of the trench line TL in the glass substrate 11 immediately below the high load section HR of the trench line TL by the crack line CL. Here, “continuous connection” means a connection that is not interrupted by a crack. In addition, in the state where the continuous connection is broken as described above, the portions of the glass substrate 11 may be in contact with each other through the cracks of the crack line CL.

  Next, a break process for dividing the glass substrate 11 along the trench line TL is performed (FIG. 1: step S40). At this time, by applying a stress to the glass substrate 11, the crack is extended along the low load section LR starting from the crack line CL. The direction in which the crack extends (arrow PR in FIG. 11) is opposite to the direction DA (FIG. 2) in which the trench line TL is formed.

  Next, details of the break process will be described below.

  Referring to FIG. 12, glass substrate 11 (FIG. 9) on which crack line CL is formed is placed on table 80 via rug 81 so that upper surface SF <b> 1 of glass substrate 11 faces table 80 via rug 81. Placed in. The rug 81 is made of a material that is more easily deformed than the materials of the glass substrate 11 and the table 80.

  With reference to FIGS. 13 and 14, a break bar 85 is prepared. As shown in FIG. 14, the break bar 85 preferably has a protruding shape so as to locally press the surface of the glass substrate 11, and has a substantially V-shaped shape in FIG. 14. As shown in FIG. 13, the protruding portion extends linearly.

  Next, the break bar 85 is brought into contact with a part of the lower surface SF2 of the glass substrate 11. This contact portion is separated from the facing portion SF2C facing the crack line CL in the thickness direction (vertical direction in FIG. 13) of the lower surface SF2.

  Next, as indicated by an arrow CT1, the contact portion is expanded along the low load section LR of the trench line TL and approaches the facing portion SF2C. The break bar 85 comes into contact with the portion facing the low load section LR and away from the portion facing the high load section HR on the lower surface SF2 due to the first contact described above or subsequent expansion of the contact section. A state arises.

  Referring to FIG. 15, as indicated by arrow CT2, the contact portion reaches opposing portion SF2C. In other words, the break bar 85 applies stress first to the low load section LR in the crack line CL by the above-described process, and then further applies stress to the crack line CL simultaneously. This stress causes the crack to extend along the low load section LR from the crack line CL (FIG. 15) (see arrow PR in FIG. 16).

  The glass substrate is divided (FIG. 11) by the above break process.

  With reference to FIGS. 17A and 17B, a scribe tool 50 suitable for forming the trench line TL described above will be described. The scribe device 50 is attached to a scribe head (not shown) and moves relative to the glass substrate 11 to scribe the glass substrate 11. The scribe device 50 has a cutting edge 51 and a shank 52. The blade edge 51 is held by the shank 52.

  The blade edge 51 is provided with a top surface SD1 (first surface) and a plurality of surfaces surrounding the top surface SD1. The plurality of surfaces include a side surface SD2 (second surface) and a side surface SD3 (third surface). The top surface SD1 and the side surfaces SD2 and SD3 face different directions and are adjacent to each other. The blade edge 51 has a vertex at which the top surface SD1, the side surfaces SD2 and SD3 merge, and the protrusion PP of the blade edge 51 is configured by this vertex. Further, the side surfaces SD2 and SD3 form ridge lines constituting the side portion PS of the blade edge 51. The side part PS extends linearly from the protrusion part PP. Moreover, since the side part PS is a ridgeline as mentioned above, it has the convex shape extended linearly.

  The cutting edge 51 is preferably a diamond point. That is, the cutting edge 51 is preferably made of diamond. In this case, the hardness can be easily increased and the surface roughness can be decreased. More preferably, the cutting edge 51 is made of single crystal diamond. More preferably, crystallographically, the top surface SD1 is a {001} plane, and each of the side surfaces SD2 and SD3 is a {111} plane. In this case, although the side surfaces SD2 and SD3 have different orientations, they are crystal surfaces that are equivalent to each other in terms of crystallography.

  Diamond that is not a single crystal may be used. For example, polycrystalline diamond synthesized by a CVD (Chemical Vapor Deposition) method may be used. Alternatively, polycrystalline diamond sintered from fine graphite or non-graphitic carbon without containing a binder such as an iron group element, or sintered diamond obtained by bonding diamond particles with a binder such as an iron group element May be used.

  The shank 52 extends along the axial direction AX. The blade edge 51 is preferably attached to the shank 52 so that the normal direction of the top surface SD1 is approximately along the axial direction AX.

  In forming the trench line TL using the scribe tool 50, first, the blade edge 51 is pressed against the upper surface SF1 of the glass substrate 11. Specifically, the protrusion part PP and the side part PS of the blade edge 51 are pressed in the thickness direction DT of the glass substrate 11.

  Next, the pressed blade edge 51 is slid in the direction DA on the upper surface SF1. The direction DA is obtained by projecting the direction extending from the protrusion PP along the side part PS onto the upper surface SF1, and roughly corresponds to the direction in which the axial direction AX is projected onto the upper surface SF1. When sliding, the blade edge 51 is dragged on the upper surface SF 1 by the shank 52. By this sliding, plastic deformation is generated on the upper surface SF <b> 1 of the glass substrate 11. The trench line TL is formed by this plastic deformation.

  In the formation of the trench line TL from the start point N1 to the end point N3 in the present embodiment, if the blade edge 51 is moved in the direction DB, in other words, the posture of the blade edge 51 is reverse with respect to the movement direction of the blade edge 51. 9, the formation of the crack line CL shown in FIG. 9 and the progress of the crack shown in FIG. 16 are less likely to occur than when the direction DA is used. More generally speaking, in the trench line TL formed by the movement of the blade edge 51 in the direction DA, cracks are likely to extend in the direction opposite to the direction DA. On the other hand, in the trench line TL formed by the movement of the blade edge 51 in the direction DB, cracks are likely to extend in the same direction as the direction DB. Such direction dependency is presumed to be related to the stress distribution generated in the glass substrate 11 due to the plastic deformation generated when the trench line TL is formed.

  According to the present embodiment, when the trench line TL (FIGS. 2 and 3) for defining the position where the glass substrate 11 is divided is formed, the cutting edge in the low load section LR as compared with the high load section HR. The load applied to 51 (FIG. 17A) is reduced. Thereby, damage to the blade edge 51 can be reduced.

  In addition, when the low load section LR is in a crackless state among the low load section LR and the high load section HR (FIGS. 8 and 9), there is no crack in the low load section LR as a starting point at which the glass substrate 11 is divided. . Therefore, when arbitrary processing is performed on the glass substrate 11 in this state, even if an unexpected stress is applied to the low load section LR, the glass substrate 11 is unlikely to be unintentionally divided. Therefore, the above process can be performed stably.

  Further, when both the low load section LR and the high load section HR are in a crackless state (FIGS. 2 and 3), there is no crack in the trench line TL as a starting point at which the glass substrate 11 is divided. Therefore, when arbitrary processing is performed on the glass substrate 11 in this state, even if an unexpected stress is applied to the trench line TL, unintentional division of the glass substrate 11 is unlikely to occur. Therefore, the above process can be performed more stably.

  The trench line TL is formed before the assist line AL is formed. Thereby, it is possible to avoid the influence of the assist line AL when the trench line TL is formed. In particular, the formation abnormality immediately after the cutting edge 51 passes over the assist line AL for forming the trench line TL can be avoided.

  Next, a modification of the first embodiment will be described below.

  Referring to FIG. 18, crack line CL may be formed in response to assist line AL intersecting trench line TL. Such a phenomenon may occur when the stress applied to the glass substrate 11 is large when the assist line AL is formed.

  Referring to FIG. 19, assist line AL may first be formed on upper surface SF <b> 1 of glass substrate 11, and then trench line TL (not shown in FIG. 19) may be formed.

  Referring to FIG. 20, assist line AL may be formed on lower surface SF2 of glass substrate 11 so as to intersect high load section HR in the planar layout. Thereby, both the assist line AL and the trench line TL can be formed without affecting each other.

  Referring to FIGS. 21A and 21B, a scribe device 50v may be used instead of the scribe device 50 (FIGS. 17A and 17B). The blade edge 51v has a conical shape having a vertex and a conical surface SC. The protruding part PPv of the blade edge 51v is constituted by a vertex. The side portion PSv of the blade edge is configured along a virtual line (broken line in FIG. 21B) extending from the apex to the conical surface SC. Thereby, the side part PSv has a convex shape extending linearly.

(Embodiment 2)
Referring to FIG. 22, first, glass substrate 11 is prepared. A scribing instrument having a cutting edge is also prepared. Details of the scribing device will be described later.

  Next, by moving the blade edge in the direction DB on the upper surface SF1 of the glass substrate 11, an assist line AL that intersects a later-described high load section HR (FIG. 23) is formed on the upper surface SF1.

  Referring to FIG. 23, by moving the blade edge in direction DB, trench line TL is formed on upper surface SF1 of glass substrate 11 from start point Q1 through intermediate point Q2 to end point Q3. The trench line TL from the start point Q1 to the midpoint Q2 is formed as a high load section HR. The trench line TL from the midpoint Q2 to the end point Q3 is formed as a low load section LR.

  Next, the glass substrate 11 is separated along the assist line AL. This separation can be performed by a normal break process. As a result of this separation, the crack of the glass substrate 11 in the thickness direction is extended along the trench line TL only in the high load section HR of the trench line TL.

  Referring to FIG. 24, the crack line CL is formed along a part of the trench line TL by the extension of the crack described above. Specifically, the crack line CL is formed in a portion between the side newly generated by the separation and the midpoint Q2 in the high load section HR. The direction in which the crack line CL is formed is the same as the direction DB (FIG. 23) in which the trench line TL is formed. Note that the crack line CL is not easily formed in a portion between the side newly generated by the separation and the midpoint Q2. This direction dependency is caused by the state of the cutting edge when the high load section HR is formed, and will be described in detail later.

  Next, a break process for extending the crack from the halfway point Q2 to the end point Q3 along the trench line TL with the crack line CL as the starting point is performed by the same break process (FIGS. 12 to 16) as in the first embodiment. Is called. Thereby, the brittle substrate 11 is divided.

  Referring to FIGS. 25 and 26, as a first modification, first, trench line TL may be formed, and then assist line AL may be formed. Referring to FIG. 27, as a second modification, crack line CL may be formed with the formation of assist line AL as a trigger. Referring to FIG. 28, assist line AL may be formed on lower surface SF2 of glass substrate 11 so as to intersect high load section HR in the planar layout. In the present embodiment, the high load section HR is formed from the start point Q1, but the high load section HR may be formed at a portion that intersects the assist line AL. For example, the low load section LR may be formed from the start point Q1 to a position just before the intersection with the assist line AL, and subsequently, the high load section HR may be formed so as to intersect with the assist line AL.

  With reference to FIG. 29, a scribe tool 50R suitable for forming the trench line TL in the present embodiment will be described. The scribe device 50R includes a scribing wheel 51R, a holder 52R, and a pin 53. The scribing wheel 51R has a substantially disk shape, and its diameter is typically about several millimeters. The scribing wheel 51R is held by a holder 52R via a pin 53 so as to be rotatable around a rotation axis RX.

  The scribing wheel 51R has an outer peripheral portion PF provided with a cutting edge. The outer peripheral portion PF extends in an annular shape around the rotation axis RX. As shown in FIG. 30A, the outer peripheral portion PF stands up like a ridge line at the visual level, thereby forming a cutting edge composed of a ridge line and an inclined surface. On the other hand, at the microscope level, as shown in FIG. 30 (B), the outer peripheral portion in the portion (below the two-dot chain line in FIG. 30 (B)) that actually acts when the scribing wheel 51R enters the upper surface SF1. The ridge line of the PF has a fine surface shape MS. Surface shape MS preferably has a curved shape having a finite radius of curvature in a front view (FIG. 30B). The scribing wheel 51R is formed using a hard material such as cemented carbide, sintered diamond, polycrystalline diamond, or single crystal diamond. The entire scribing wheel 51R may be made of single crystal diamond from the viewpoint of reducing the surface roughness of the ridgeline and the inclined surface.

  The formation of the trench line TL using the scribe device 50R is performed by rolling the scribing wheel 51R on the upper surface SF1 of the glass substrate 11 (FIG. 29: arrow RT), so that the scribing wheel 51R moves on the upper surface SF1 in the traveling direction DB. And is done by proceeding. Progression by this rolling is performed while pressing the outer peripheral portion PF of the scribing wheel 51R onto the upper surface SF1 of the glass substrate 11 by applying a load F to the scribing wheel 51R. As a result, by causing plastic deformation on the upper surface SF1 of the glass substrate 11, a trench line TL having a groove shape is formed. The load F has a vertical component Fp parallel to the thickness direction DT of the glass substrate 11 and an in-plane component Fi parallel to the upper surface SF1. The traveling direction DB is the same as the direction of the in-plane component Fi.

  In addition, the formation of the trench line TL is not performed by the scribe tool 50R moving in the direction DB, but the scribe tool 50 (FIGS. 17A and 17B) or 50v (FIGS. 21A and 21B) moving in the direction DB. B)) may be used.

  Since the configuration other than the above is substantially the same as the configuration of the first embodiment described above, the same or corresponding elements are denoted by the same reference numerals, and description thereof is not repeated.

  Also according to the present embodiment, substantially the same effect as in the first embodiment can be obtained. In the present embodiment, since the trench line TL can be formed using a rotating blade edge instead of a fixed blade edge, the life of the blade edge can be extended.

(Embodiment 3)
With reference to FIG. 31, first, a glass substrate 11 and a scribe tool having a blade edge are prepared. Due to the movement of the blade edge, a trench line TL is formed between the points R1 and R6 on the upper surface SF1 of the glass substrate 11. A trench line TL between the points R1 and R2, between the points R3 and R4, and between the points R5 and R6 is formed as a high load section HR. A trench line TL between the points R2 and R3 and between the points R4 and R5 is formed as a low load section LR. As a method for forming trench line TL, any of those described in the first or second embodiment (including modifications thereof) can be used.

  Next, the glass substrate 11 is separated along a plurality of break lines BL each intersecting the high load section HR. The break line BL may be formed by any method such as a normal scribe process or a process of generating a vertical crack from the trench line TL, and the break line BL can be separated by a normal break process.

  Referring to FIG. 32, with the separation of glass substrate 11 described above as a trigger, a crack line CL is formed in a portion between a side newly generated by the separation and one of a pair of intermediate points sandwiching the side. Is formed. The direction in which the crack line CL is formed is opposite to the direction DA when the trench line TL is formed in the direction DA (FIG. 17A or 21A), and the trench line TL is in the direction DB (FIG. 17 (A), FIG. 21 (A) or FIG. 29) is the same as the direction DB.

  Next, a break process for extending cracks along the trench line TL starting from the crack line CL is performed by the same break process (FIGS. 12 to 16) as in the first embodiment. Thereby, the brittle substrate 11 is divided.

  According to the present embodiment, the position where the glass substrate 11 is divided can be defined by the plurality of trench lines TL and the plurality of break lines BL intersecting therewith.

(Embodiment 4)
Referring to FIG. 33, by moving blade edge 51 in direction DA (see FIG. 17A), a trench line is formed between end points S1 and S3 on upper surface SF1 of glass substrate 11 in direction DL. A trench line TL between the end point S1 and the midpoint S2 is formed as a low load section LR. The trench line TL between the midpoint S2 and the end point S3 is formed as a high load section HR.

  Referring to FIG. 34, the glass substrate is then moved by moving the blade edge 51 in the direction DA (FIG. 17A) on the upper surface SF1 of the glass substrate 11 while pressing the blade edge 51 onto the upper surface SF1 of the glass substrate 11. By causing plastic deformation on the upper surface SF1 of 11, the intersecting trench line TM intersecting the low load section LR of the trench line TL on the upper surface SF1 is formed in the direction DM. The step of forming the intersecting trench line TM is performed so that a crackless state can be obtained in the same manner as the trench line TL. That is, the step of forming the intersecting trench line TM is performed so as to obtain a crackless state in which the glass substrate 11 is continuously connected in the direction intersecting the intersecting trench line TM immediately below the intersecting trench line TM. Is called.

  Next, the glass substrate 11 is separated along the break line BM that intersects the intersecting trench line TM. This separation can be performed by a normal scribe process and a break process. The break line BM intersects the intersecting trench line TM at a point shifted in the direction DM from the intersection between the intersecting trench line TM and the trench line TL. As a result of this separation, a crack line CM (FIG. 35) accompanied by cracks penetrating in the thickness direction of the glass substrate 11 is formed along the intersecting trench line TM.

  Next, the glass substrate 11 is separated along the break line BL intersecting the high load section HR of the trench line TL. This separation can be performed by a normal scribe process and a break process. As a result of this separation, a crack line CL (FIG. 36) with cracks penetrating in the thickness direction of the glass substrate 11 is formed along the high load section HR.

  Next, a break process for extending cracks along the trench line TL starting from the crack line CL is performed by the same break process (FIGS. 12 to 16) as in the first embodiment. Thereby, the brittle substrate 11 is divided along the trench line TL (FIG. 37). Thereafter, a break process is performed along the crack line CM, and the brittle substrate 11 is further divided.

  According to the present embodiment, the position where the glass substrate 11 is divided can be defined by the trench line TL and the intersecting trench line TM intersecting with the trench line TL.

  Note that the blade edge 51v (FIG. 21A) may be used instead of the blade edge 51 (FIG. 17A). Further, the formation of the trench line TL may be performed in the direction opposite to the direction DL (FIG. 33), and in this case, the blade edge 51 (FIG. 17A) is moved in the direction DB. Similarly, the formation of the intersecting trench line TM may be performed in the direction opposite to the direction DM (FIG. 34), and in this case, the blade edge 51 (FIG. 17A) is moved in the direction DB. When the cutting edge is moved in the direction DB, the cutting edge of the scribing wheel 51R (FIG. 29) may be used instead of the cutting edge 51.

(Embodiment 5)
Referring to FIG. 38, by applying a load, the cutting edge of scribing wheel 51R (FIG. 29) is moved on top surface SF1 of glass substrate 11 while the cutting edge is moved in direction DB (FIG. 29). As a result, plastic deformation occurs on the upper surface SF1 of the glass substrate 11. As a result, the intersecting trench line TM is formed in the direction DM (FIG. 38) on the upper surface SF1. When the formation of the intersecting trench line TM is started, the cutting edge of the scribing wheel 51R (FIG. 29) performs an operation of riding on the edge of the glass substrate 11. At this time, a minute chip CP is generated at the edge of the glass substrate 11. As a result, a chip CP located on the edge of the glass substrate 11 is provided at one end of the intersecting trench line TM.

  Referring to FIG. 39, next, by moving the cutting edge on upper surface SF1, trench line TL is formed between points T1 and T6 on upper surface SF1. A trench line TL between the points T1 and T2, between the points T3 and T4, and between the points T5 and T6 is formed as a high load section HR. A trench line TL between the points T2 and T3 and between the points T4 and T5 is formed as a low load section LR. The intersecting trench line TM intersects the high load section HR on the upper surface SF1. The method for forming trench line TL may be any of those described in the above-described first or second embodiment (including modifications thereof).

  Next, cracks are extended along the intersecting trench line TM from the chip CP. Thereby, the glass substrate 11 is separated along the intersecting trench line TM (FIG. 40). As a result of this separation, a crack line CL is formed in the high load section HR at a portion between a side newly generated by the separation and one of a pair of intermediate points sandwiching the side.

  Next, a break process for extending cracks along the trench line TL starting from the crack line CL is performed by the same break process (FIGS. 12 to 16) as in the first embodiment. Thereby, the brittle substrate 11 is divided.

  Also according to the present embodiment, substantially the same effect as in the fourth embodiment can be obtained. Further, according to the present embodiment, the chip CP is used as a starting point for generating a crack along the intersecting trench line TM. Therefore, the break process along the break line BM (FIG. 34) intersecting the intersecting trench line TM can be omitted. Further, since the cutting edge that rides on the edge of the glass substrate 11 is that of the scribing wheel 51R (FIG. 29), the cutting edge 51 (FIG. 17A) or 51v (FIG. 21A) that is a fixed cutting edge is used. As compared with the case where it is done, the damage applied to the blade edge by the ride is suppressed. If this damage is not particularly problematic, it is possible to use the cutting edge 51 or the cutting edge 51v instead of the cutting edge of the scribing wheel 51R (FIG. 29).

(Embodiment 6)
With reference to FIG. 41 (A) and FIG. 42 (A), the cutting apparatus of the glass substrate 11 in this Embodiment is demonstrated first. The cutting device includes a scribe device 50 (see also FIG. 17A), a conveyor 70, a break roller 61, and an auxiliary roller 62. The conveyor 70 conveys the glass substrate 11 in the direction CV while exposing the upper surface SF1 of the glass substrate 11. The scribe device 50 is fixed to a scribe head (not shown), and scribes the upper surface SF <b> 1 of the glass substrate 11 by contacting the glass substrate 11 moved by the conveyor 70. The break roller 61 is a member that locally presses the lower surface SF2 of the glass substrate 11 in order to perform a break process. The auxiliary roller 62 is a roller that comes into contact with the glass substrate 11 on the upper surface SF1 that is the opposite surface so that the break roller 61 can be pressed onto the lower surface SF2. The auxiliary roller 62 is disposed at a position different from the break roller 61 in the planar layout (FIG. 41A) so that the glass substrate 11 can be stably bent by being pressed by the break roller 61. Preferably, The break rollers are disposed so as to sandwich the rotation axis direction (vertical direction in FIG. 41A).

  In addition, in order to make a figure legible in FIG. 41 (A) and FIG. 42 (A), the conveyor 70 is typically shown with the dashed-two dotted line. The same applies to the other drawings.

  Next, the cutting method by the above-described cutting apparatus will be described below.

  As the conveyor 70 moves in the conveyance direction CV, the glass substrate 11 is conveyed in the conveyance direction CV. As a result, the cutting edge 51 (see also FIG. 17) of the scribe instrument 50 runs from the right edge of the glass substrate 11 onto the upper surface SF1. Due to this riding, a chip CP is formed on the right edge of the glass substrate 11.

  The cutting edge 51 riding on the upper surface SF1 moves in the direction opposite to the transport direction CV relative to the upper surface SF1 of the glass substrate 11 by moving the glass substrate 11 in the transport direction CV. The relative moving direction of the blade edge 51 with respect to the upper surface SF1 corresponds to the direction DB (FIG. 17A). During this movement, a load is applied to the cutting edge 51, whereby a high load section HR of the trench line TL is formed on the upper surface SF1.

  41 (B) and 42 (B), after the glass substrate 11 is further transported, the load applied to the blade edge 51 is made smaller than that in the high load section HR, so that the trench line TL Formation of the low load section LR is started.

  41 (C) and 42 (C), when glass substrate 11 is further conveyed, stress is applied to high load section HR provided with chip CP by break roller 61 and auxiliary roller 62. Is done. Thereby, a crack extends from the chip CP, and as a result, a crack line CL is formed in the high load section HR. In FIG. 42C, the crack line CL penetrates the glass substrate 11 in the thickness direction and reaches the lower surface SF2.

  Referring to FIGS. 41 (D) and 42 (D), when glass substrate 11 is further conveyed, application of stress to low load section LR by break roller 61 and auxiliary roller 62 is started. The crack extends from the crack line CL described above to the portion of the low load section LR that has been subjected to stress application. Thereafter, as the glass substrate 11 is conveyed, cracks extend in the low load section LR. When the crack is extended, the low load section LR is extended by forming the low load section LR by the scribe device 50. Thereby, the glass substrate 11 is divided according to the extended length while extending the low load section LR of the trench line TL. That is, the continuous division of the glass substrate 11 proceeds.

  According to this Embodiment, the glass substrate 11 can be divided | segmented continuously. Thereby, the glass substrate 11 can be divided without being restricted by the length of the glass substrate 11.

  In addition, unlike the high load section HR, in the low load section LR, the crack is difficult to extend to a portion where the stress application by the break roller 61 has not yet been received. Therefore, it is possible to prevent the crack from reaching the blade edge 51 and further extending beyond the position of the blade edge 51 in the continuous dividing step shown in FIG. Thereby, the continuous division | segmentation of the glass substrate 11 can be performed stably.

  In the present embodiment, the chip CP at the edge of the glass substrate 11 is used to generate the crack line CL. However, the crack line CL may be formed using other triggers. Further, instead of the scribe device 50, a scribe device 50v (FIG. 21) or 50R (FIG. 29) may be used.

  Although the method for dividing a brittle substrate according to each of the above embodiments is particularly preferably applied to a glass substrate, the brittle substrate may be made of a material other than glass. For example, ceramics, silicon, a compound semiconductor, sapphire, or quartz may be used as a material other than glass.

AL Assist line BL, BM Break line CL, CM Crack line CP Chipped HR High load section SC Conical surface PF Outer periphery SD1 Top surface SD2, SD3 Side surface AX Axial direction SF1 Upper surface SF2 Lower surface LR Low load region TL Trench lines PP, PPv Projection Part MS Surface shape TM Cross trench line PS, PSv Side part SF2C Opposing part RX Rotating shaft 11 Glass substrate (brittle substrate)
50, 50R, 50v Scribe tool 51, 51v Cutting edge 51R Scribing wheel 52 Shank 52R Holder 53 Pin 61 Break roller 62 Auxiliary roller 70 Conveyor 80 Table 81 Rug 85 Break bar

Claims (7)

Providing a brittle substrate having a first surface and a second surface opposite to the first surface and having a thickness direction perpendicular to the first surface;
A trench line is formed by generating plastic deformation on the first surface of the brittle substrate by moving the blade edge on the first surface while pressing the blade edge onto the first surface of the brittle substrate. A step of forming the trench line so as to obtain a crackless state in which the brittle substrate is continuously connected in the direction intersecting the trench line immediately below the trench line. And forming the trench line includes:
Forming a low load section as part of the trench line;
Forming a high load section as a part of the trench line, the load applied to the cutting edge in the step of forming the high load section is higher than the load used in the step of forming the low load section, Furthermore, a step of forming a crack line along a part of the trench line by extending a crack of the brittle substrate in the thickness direction along the trench line and only in the high load section of the trench line. When,
A step of dividing the brittle substrate along the trench line after the step of forming the crack line, and the step of dividing the brittle substrate starts from the crack line by applying stress to the brittle substrate. Including a step of extending cracks along the low load section,
Method for cutting a brittle substrate.   The step of forming the crack line includes a step of forming an assist line intersecting the high load section on the first surface of the brittle substrate with a crack penetrating in the thickness direction of the brittle substrate. The method for dividing a brittle substrate according to claim 1.   The method for cutting a brittle substrate according to claim 2, wherein the step of forming the crack line includes a step of separating the brittle substrate along the assist line. Further comprising forming an assist line on the second surface of the brittle substrate, the assist line intersecting the high load section in a planar layout;
The method for cutting a brittle substrate according to claim 1, wherein the step of forming the crack line includes a step of separating the brittle substrate along the assist line. After the step of forming the trench line, the cutting edge is moved on the first surface of the brittle substrate while pressing the cutting edge onto the first surface of the brittle substrate, thereby moving the first edge of the brittle substrate. Forming a cross trench line intersecting the low load section of the trench line on the first surface by generating plastic deformation on the surface, and forming the cross trench line, It is performed so as to obtain a crackless state in which the brittle substrate is continuously connected in a direction intersecting the intersecting trench line immediately below the intersecting trench line, and further along the intersecting trench line, Further comprising the step of forming a crack line with cracks penetrating in the thickness direction of the brittle substrate,
The method for dividing a brittle substrate according to any one of claims 1 to 4. Prior to the step of forming the trench line, the blade edge is moved on the first surface while applying a load to the blade edge against the first surface of the brittle substrate to move the blade edge of the brittle substrate. Forming a cross trench line that crosses the high load section of the trench line on the first surface by generating plastic deformation on the first surface, the cross trench line comprising: The forming step is performed so as to obtain a crackless state in which the brittle substrate is continuously connected in a direction intersecting the intersecting trench line immediately below the intersecting trench line, and the crack line is further formed. The forming step separates the brittle substrate by extending cracks along the intersecting trench line. Done by
The method for dividing a brittle substrate according to claim 1.   The method for dividing a brittle substrate according to claim 1, wherein the low load section is extended by the step of forming the low load section when the process of extending the crack is performed.

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