JP6413694B2 - 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.

  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.

  As described above, the trench line is less likely to break along the scribe line than the normal scribe line. This prevents unintentional fragmentation of the brittle substrate, while increasing the difficulty of accurately performing the fragmentation of the brittle substrate along the trench line.

  The present invention has been made to solve the above-described problems, and its object is to provide a method for dividing a brittle substrate that can accurately perform division along a trench line that does not have a crack directly underneath it. It is to be.

  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.

  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 first and second portions are A trench line is formed. 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 a direction intersecting the trench line immediately below at least the first portion of the trench line.

  The brittle substrate is placed on the table such that the first surface of the brittle substrate faces the table.

  The second surface of the brittle substrate is in contact with the third portion of the second surface of the brittle substrate facing the first portion of the trench line and away from the fourth portion of the second surface facing the second portion. A stress applying member is brought into contact. The step of bringing the stress applying member into contact is performed so that the first portion is maintained in a crackless state.

  By keeping the stress applying member in contact with the third portion of the second surface of the brittle substrate while keeping the stress applying member in contact with the third portion of the second surface of the brittle substrate, the trench line By generating a crack extending from the second part toward the first part, the brittle substrate is divided along the trench line.

  According to the present invention, when the crack extends from the second portion of the trench line toward the first portion in order to divide the brittle substrate, the third portion that faces the first portion of the second surface is arranged. This part is in contact with the stress applying member in advance. As a result, the crack is prevented from extending out of the first portion of the trench line. Therefore, the division along the trench line can be performed accurately.

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 scribing instrument 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 scribing instrument 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 flowchart which shows schematically the division | segmentation method of a 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. FIG. 40 is schematic partial cross-sectional views (A) to (C) sequentially illustrating steps of a method for cutting a brittle substrate in the fifth embodiment of the present invention in a field of view along line XL-XL in FIG. 39. FIG. 40A is a schematic cross-sectional view taken along line XLIA-XLIA in FIG. 39, illustrating a configuration of a trench line in a crackless state (A), and a cross-sectional view illustrating a state in which a crack line is formed immediately below the trench line in a similar visual field (B). 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 sectional drawing which shows roughly 1 process of the cutting method of the brittle board | substrate in Embodiment 5 of this invention. It is sectional drawing which shows roughly 1 process of the cutting method of the brittle board | substrate in Embodiment 5 of this invention. It is a schematic side view by the visual field corresponding to the arrow XLV of FIG. It is sectional drawing which shows roughly 1 process of the cutting method of the brittle board | substrate in Embodiment 5 of this invention. It is sectional drawing 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 6 of this invention. It is a top view which shows roughly 1 process of the cutting method of the brittle board | substrate in Embodiment 7 of this invention. It is a top view which shows roughly 1 process of the cutting method of the brittle board | substrate in Embodiment 7 of this invention. It is a top view which shows roughly 1 process of the cutting method of the brittle board | substrate in Embodiment 7 of this invention. It is a flowchart which shows schematically the cutting method of the brittle board | substrate in Embodiment 8 of this invention. It is a top view which shows roughly 1 process of the cutting method of the brittle board | substrate in Embodiment 8 of this invention. It is a top view which shows roughly 1 process of the cutting method of the brittle board | substrate in Embodiment 8 of this invention. FIG. 55 is a schematic partial side view of an end face of a brittle substrate according to the field of view of arrow XLV in FIG. It is sectional drawing which shows roughly 1 process of the cutting method of the brittle board | substrate in Embodiment 8 of this invention. It is sectional drawing which shows roughly 1 process of the cutting method of the brittle board | substrate in Embodiment 8 of this invention. It is sectional drawing which shows roughly 1 process of the cutting method of the brittle board | substrate in Embodiment 8 of this invention. It is sectional drawing which shows roughly 1 process of the cutting method of the brittle board | substrate in Embodiment 8 of this invention. It is a top view which shows roughly 1 process of the cutting method of the brittle board | substrate in Embodiment 9 of this invention. It is a top view which shows roughly 1 process of the cutting method of the brittle board | substrate in Embodiment 9 of this invention.

  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 the flow FL1 (FIG. 1).

  With reference to FIGS. 2-4, the glass substrate 11 is prepared (FIG. 1: step S110). 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 midpoint N2 is formed on the upper surface SF1 (FIG. 1: step S120). 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 the process of forming the low load section LR (first portion) as a part of the trench line TL (FIG. 1: step S120L) and the high load section HR as a part of the trench line TL. Forming a (second portion) (FIG. 1: Step S120H). 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 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 °.

  The process of forming the trench line TL is continuous in the direction DC (FIGS. 4A and 4B) in which the glass substrate 11 intersects the trench line TL immediately below the high load section HR and the low load section LR of the trench line TL. It is performed so as to obtain a crackless state that is connected continuously. 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 S130) 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 is generated only along the high load section HR among the low load section LR and the high load section HR of the trench line TL. 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 S140). 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 (stress applying member) 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 portion SP4 facing the crack line CL in the thickness direction (vertical direction in FIG. 13) of the lower surface SF2. The portion SP4 is also a portion of the lower surface SF2 that faces the high load section HR in the thickness direction.

  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 portion SP4. The break bar 85 comes into contact with the portion SP3 (third portion) facing the low load section LR on the lower surface SF2 by the expansion of the contact portion following the first contact described above or the portion SP4 (described above). A state apart from the (fourth part) occurs. Such selective contact can be easily obtained, for example, by changing the posture of the break bar 85 having a certain degree of elasticity. At this time, the low load section LR is maintained in a crackless state.

  Referring to FIG. 15, the contact portion reaches portion SP4 by further expansion as shown by arrow CT2. In other words, the break bar 85 is brought into contact with the portion SP4 of the lower surface SF2 of the glass substrate 11 while maintaining the state where the break bar 85 is in contact with the portion SP3 of the lower surface SF2 of the glass substrate 11. As a result, the break bar 85 applies stress to the low load section LR in the crack line CL by the above-described process, and then applies stress to the crack line CL at the same time. 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). In other words, a crack that extends from the high load section HR to the low load section LR of the trench line TL is generated. As a result, the glass substrate 11 is divided along the trench line TL.

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

  With reference to FIGS. 17A and 17B, a scribing instrument 50 suitable for forming the above-described trench line TL will be described. The scribing instrument 50 is attached to a scribe head (not shown) and moves relative to the glass substrate 11 to scribe the glass substrate 11. The scribing instrument 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 scribing instrument 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 crack extends from the high load section HR to the low load section LR of the trench line TL in order to divide the glass substrate 11 (FIG. 16: arrow PR), it is shown in FIG. As described above, the portion of the lower surface SF2 that faces the low load section LR is in contact with the break bar 85 in advance. As a result, the crack is prevented from extending out of the low load section LR of the trench line TL. Therefore, the division along the trench line TL can be accurately performed.

  Further, before the step of dividing the glass substrate 11, the crack line CL is formed only along the high load section HR among the low load section LR and the high load section HR of the trench line TL (FIG. 9). That is, prior to the break process, a crack line CL is formed as a starting point for dividing the glass substrate 11. Thereby, the glass substrate 11 can be more reliably divided in the break process.

  Further, when forming the trench line TL (FIGS. 2 and 3) for defining the position at which the glass substrate 11 is divided, the cutting edge 51 (FIG. 17A) in the low load section LR as compared with the high load section HR. The load applied to)) 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, scribing instrument 50v may be used instead of scribing instrument 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, the movement of the cutting edge in the direction DB forms a trench line TL on the upper surface SF1 of the glass substrate 11 from the start point Q1 through the intermediate points Q2 and Q3 to the end point Q4. The trench line TL from the start point Q1 to the midpoint Q2 and from the midpoint Q3 to the end point Q4 is formed as a low load section LR. A trench line TL from the midpoint Q2 to the midpoint Q3 is formed as a high load section HR.

  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 Q3 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 Q3 to the end point Q4 along the trench line TL with the crack line CL as a 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 halfway point Q2 to Q3. However, the high load section HR may be formed at a portion intersecting the assist line AL, for example, from the start point Q1 to the halfway point Q3. May be formed.

  With reference to FIG. 29, a scribing instrument 50R suitable for forming the trench line TL in the present embodiment will be described next. The scribing instrument 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 scribing tool 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 direction DB. This is done by progressing. 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 direction DB is the same as the direction of the in-plane component Fi.

  The trench line TL is formed by using the scribing tool 50 (FIGS. 17A and 17B) or 50v (FIGS. 21A and 21B) moving in the direction DB instead of using the scribing tool 50R 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 scribing instrument having a cutting edge are prepared. By the movement of the blade edge, a trench line 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)
FIG. 38 is a flow FL2 schematically showing a method for dividing the glass substrate 11 (brittle substrate) in the present embodiment. FIG. 39 is a top view schematically showing a state immediately after step S220 (FIG. 38). 40 is a schematic partial cross-sectional view (A) to (C) showing the steps in order in the visual field along the line XL-XL in FIG. 39.

  First, the glass substrate 11 is prepared (FIG. 38: step S210). The glass substrate 11 has an upper surface SF1 having an edge EG and a lower surface SF2. Further, the glass substrate 11 has a thickness direction DT perpendicular to the upper surface SF1. Also, a scribing instrument 50R (FIG. 29) having a scribing wheel 51R (FIG. 30A) provided with a cutting edge is prepared.

  Next, the cutting edge comes into contact with the edge EG of the upper surface SF <b> 1 of the glass substrate 11 by the movement of the scribing wheel 51 </ b> R indicated by the arrow M <b> 1 (FIG. 40A). Next, the blade edge is moved on the glass substrate 11 while pressing the blade edge against the glass substrate 11 (FIG. 38: step S220). Hereinafter, the process will be described.

  First, the cutting edge rides on the edge EG of the glass substrate 11 by the movement of the scribing wheel 51R indicated by the arrow M2 (FIG. 40B). Thereby, a chip CP (FIG. 40C) is formed at the start point N1 (FIG. 39), which is one position on the edge EG (FIG. 38: step S220C).

  Next, as shown in the arrow M3 (FIG. 40C), while pressing the blade edge that has reached the starting point N1 in the step of forming the chip CP as described above onto the upper surface SF1 of the glass substrate 11, on the upper surface SF1. The scribing wheel 51R provided with the cutting edge is moved. As a result, plastic deformation occurs on the upper surface SF1 of the glass substrate 11. As a result, a trench line TL (first trench line) is formed from the start point N1 to the end point N3, which is another position on the upper surface SF1 (FIG. 38: step S220T). Therefore, the trench line TL has a first portion TP1 (see FIG. 43) that is away from the chip CP and a second portion TP2 (see FIG. 43) located on the chip CP. The trench line TL is formed so as to obtain the above-described crackless state immediately below a portion located away from the chip CP. The chip CP is preferably formed so that a crackless state is obtained immediately below the chip CP.

  Referring to FIG. 41A, the step of forming trench line TL is a crackless state in which glass substrate 11 is continuously connected in a direction DC intersecting trench line TL immediately below trench line TL. Is done to obtain. In the crackless state, the trench line TL is formed by plastic deformation, but no crack is formed along the trench line TL. Therefore, even if a bending moment is applied to the glass substrate 11, the division along the trench line TL does not easily occur. In order to obtain a crackless state, the load with which the blade edge is pressed against the glass substrate 11 should not be excessively increased. FIG. 41 (B) shows a comparative example of FIG. 41 (A), and shows a state in which a trench line TL and a crack line CL that is a crack extending immediately below the trench line TL are formed.

  A desired number of trench lines can be formed by repeating the process of forming the trench lines TL as necessary. FIG. 39 illustrates a case where three trench lines TL are formed.

  Referring to FIG. 42, a break process is next performed. Specifically, the glass substrate 11 is divided along the trench line TL by applying a stress to the glass substrate 11 to extend a crack starting from the chip CP from the start point N1 to the end point N3 (FIG. 38). : Step S230). The break process can be performed a plurality of times depending on the number of trench lines TL. A more detailed method of the break process will be described later.

  As described above, the glass substrate 11 is divided along the trench line TL.

  Next, the break process in this Embodiment is demonstrated below.

  Referring to FIG. 43, glass substrate 11 (FIG. 39) on which trench lines TL are 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.

  44 and 45, a break bar 85 is prepared. As shown in FIG. 45, the break bar 85 preferably has a protruding shape so that the surface of the glass substrate 11 can be pressed locally, and has a substantially V-shaped shape in FIG. As shown in FIG. 44, this projecting 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 portion SP4 facing the portion TP2 of the trench line TL in the thickness direction (vertical direction in FIG. 9) of the lower surface SF2.

  Next, as indicated by an arrow CT1, the contact portion is expanded along the trench line TL and approaches the portion SP4. The break bar 85 comes into contact with the portion SP3 (third portion) of the lower surface SF2 facing the portion TP1 of the trench line TL at the time of the first contact described above or by expansion of the subsequent contact portion, and the portion SP4 described above. A state apart from the (fourth portion) occurs. Such selective contact can be easily obtained, for example, by changing the posture of the break bar 85 having a certain degree of elasticity. At this point, the portion TP1 of the trench line TL is maintained in a crackless state.

  Referring to FIG. 46, as the expansion further proceeds as indicated by arrow CT2, the contact portion reaches portion SP4. In other words, the break bar 85 is brought into contact with the portion SP4 of the lower surface SF2 while maintaining the state where the break bar 85 is in contact with the portion SP3 of the lower surface SF2. As a result, the break bar 85 applies stress to the portion TP1 of the trench line TL in the above-described process, and then applies stress to the chip CP at the same time. Due to this stress, a crack extends from the chip CP along the trench line TL (see arrow PR in FIG. 47). In other words, a crack extending from the portion TP2 of the trench line TL toward the portion TP1 is generated. As a result, the glass substrate 11 is divided along the trench line TL.

  The glass substrate 11 is divided (FIG. 42) by the above break process.

  According to the present embodiment, when a crack extends from the portion TP2 of the trench line TL toward the portion TP1 in order to divide the glass substrate 11 (FIG. 47: arrow PR), as shown in FIG. A portion SP3 of the lower surface SF2 facing the portion TP1 is in contact with the break bar 85 in advance. As a result, the cracks are prevented from extending out of the trench line portion TP1. Therefore, the division along the trench line TL can be accurately performed.

  In addition, a chip CP formed on the edge EG of the glass substrate 11 is used as a trigger for extending the crack along the trench line TL. The chip CP is formed only when the cutting edge that moves at the start of formation of the trench line TL rides over the edge EG of the glass substrate 11. Therefore, the glass substrate 11 can be divided along the trench line TL in a simple process.

  For the formation of the chip CP, the cutting edge of the scribing wheel 51R, that is, the rotating cutting edge is used. Thereby, compared with the case where the fixed blade edge like a diamond point is used, the damage which a blade edge receives when a blade edge rides on the edge EG of the glass substrate 11 is suppressed.

(Embodiment 6)
Referring to FIG. 48, in the present embodiment, a process of forming high load section HR as a part of trench line TL and a process of forming low load section LR as a part of trench line TL are performed. . The high load section HR is formed from the start point N1 to an intermediate point N2 between the start point N1 and the end point N3. The low load section LR is formed from the midpoint N2 to the end point N3. The load applied to the cutting edge 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.

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

  According to the present embodiment, the high load section HR that is a portion extending from the chip CP in the trench line TL is formed by plastic deformation due to the high load. Thereby, compared with the case where the whole trench line TL is formed by the plastic deformation by the low load used in the low load section LR, the crack is likely to occur from the chip CP to the trench line TL. Therefore, in the break process (FIGS. 43 to 47), a crack triggered by the chip CP can be generated more reliably. Therefore, the glass substrate 11 can be more reliably divided along the trench line TL using the extension of the crack.

  39, the end point N3 is separated from the edge EG of the glass substrate 11, but the end point N3 is on the edge EG of the glass substrate 11 (on the right edge of the surface SF1 of the glass substrate 11 in the example of FIG. 39). May be located.

(Embodiment 7)
Referring to FIG. 49, first, a trench line TL having a chip CP at the start point and extending to the end point is formed in the direction DL by substantially the same method as in the fifth embodiment.

  Referring to FIG. 50, next, the blade edge is moved toward the direction DM on the upper surface SF <b> 1 while pressing the blade edge onto the upper surface SF <b> 1 of the glass substrate 11 by applying a load. As a result, plastic deformation is generated on the upper surface SF1 of the glass substrate 11, whereby an intersecting trench line TM (second trench line) is formed between the points T1 and T6. The formation of the intersecting trench line TM is performed so that a crackless state is obtained with respect to the intersecting trench line TM, as described in the fifth embodiment with respect to the trench line TL (FIG. 41A).

  A high load section HS is formed as a part of the intersecting trench line TM between the points T1 and T2, between the points T3 and T4, and between the points T5 and T6. Between the points T2 and T3 and between the points T4 and T5, a low load section LS is formed as a part of the intersecting trench line TM. The load applied to the cutting edge in the process of forming the high load section HS is higher than the load used in the process of forming the low load section LS. The high load section HS intersects with the trench line TL. The method for forming the intersecting trench line TM can be the same as the method for forming the trench line TL.

  Next, the crack is extended along the trench line TL starting from the chip CP by a break process similar to that of the fifth embodiment. Thereby, the glass substrate 11 is divided along the trench line TL (FIG. 51). As a result of this division, the crack extends only in the high load section HS of the intersecting trench line TM. As a result, a crack line CL is formed along a part of the intersecting trench line TM. Specifically, a crack line CL is formed in the high load section HS in a portion between a side newly generated by the division and one of a pair of intermediate points sandwiching the side.

  It should be noted that a crack line CL is hardly formed in a portion between a side newly generated by the division and the other of the pair of intermediate points sandwiching the side even in the high load section HS. This is because the ease of extension of cracks along the crack line CL is direction-dependent. This direction dependency is presumed to be caused by the distribution of internal stress generated when the glass substrate 11 is scribed.

  In the high load section HS, as shown in FIG. 41B, the glass substrate 11 is continuous in the direction DC intersecting the extending direction of the intersecting trench line TM by the crack line CL immediately below the intersecting trench line TM. The connection is broken. 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, by applying a stress to the glass substrate 11 by the same break process as in the fifth embodiment, the crack extends along the low load section LS starting from the crack line CL. Thereby, the glass substrate 11 is divided along the intersection trench line TM. That is, in addition to the division along the trench line TL described above, the division along the intersecting trench line TM is further performed.

  According to the present embodiment, substantially the same effect as in the fifth embodiment can be obtained. Further, the position where the glass substrate 11 is divided can be defined by the trench line TL and the intersecting trench line TM intersecting the trench line TL.

(Embodiment 8)
FIG. 52 is a flow FL3 schematically showing a method for dividing the glass substrate 11 (brittle substrate) in the present embodiment. FIG. 53 is a top view schematically showing a state immediately after step S320 (FIG. 52).

  First, the glass substrate 11 is prepared (FIG. 52: step S310). The glass substrate 11 has an upper surface SF1 and a lower surface that is the opposite surface. Moreover, the scribing instrument 50 (FIG. 17A) provided with the blade edge 51 is prepared.

  Next, the cutting edge is moved while being pressed onto the upper surface SF <b> 1 of the glass substrate 11. As a result, plastic deformation occurs on the upper surface SF1. As a result, a trench line TL extending from the point N1 to the point N3 via the point N2 (one point) is formed on the upper surface SF1 (FIG. 52: step S320). When the trench line TL is formed, the cutting edge moves on the point N2 in the scribe direction DL (one direction). Points N1 to N3 represent positions on the upper surface SF1.

  A desired number of trench lines TL can be formed by repeating the process of forming the trench lines TL as necessary. FIG. 53 illustrates a case where three trench lines TL are formed.

  The step of forming the trench line TL is performed so as to obtain the above-described crackless state (FIG. 41A). In a state where there is no crackless state (FIG. 41B), the glass substrate 11 is divided in a direction DC intersecting the trench line TL by a crack line CL extending along the trench line TL immediately below the trench line TL. Has been. The conventional typical scribe line formed for dividing the glass substrate is accompanied by the crack line CL, and is not formed in a crackless state.

  Next, the glass substrate 11 is separated along the break line BL intersecting the trench line TL at the point N2 on the upper surface SF1 of the glass substrate 11. This separation can be performed, for example, by forming a normal scribe line along the break line BL and then performing a normal break process.

  Referring to FIG. 54, the end surface SE where the trench line TL is exposed is formed by the separation (FIG. 52: step S330). The normal direction (normal vector) DN of the end surface SE at the location where the trench line TL is exposed has a component of the scribe direction DL (FIG. 53). The normal direction DN and the scribe direction DL are preferably substantially the same.

  Referring to FIG. 55, the step of separating glass substrate 11 is performed so that the crackless state is maintained. For this purpose, the load applied to the cutting edge when the above-described trench line TL is formed should be large enough to cause plastic deformation in the upper surface SF1, but not excessively large.

  Next, the surface roughness of the end surface SE is increased. This process can be performed by performing mechanical processing with minute crushing on at least the trench line TL of the end surface SE, and specifically, the trench line TL of the end surface SE is exposed. This can be done by grinding the spot. This grinding can be performed, for example, using a tool such as a file or a grindstone with a shaft.

  Next, the glass substrate 11 is divided along the trench line TL (FIG. 52: Step S340). For this purpose, the crack is extended along the trench line TL starting from this portion by a break process in which stress is applied to the portion where the trench line TL is exposed on the end surface SE. The break process can be performed a plurality of times depending on the number of trench lines TL. Hereinafter, the details of a preferable break process will be described.

  Referring to FIG. 56, glass substrate 11 (FIG. 53) on which trench lines TL are 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.

  Referring to FIG. 57, a break bar 85 is prepared. 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 end surface SE of the glass substrate 11.

  Next, as indicated by an arrow CT1, the contact portion is expanded along the trench line TL and approaches the end surface SE. The break bar 85 comes into contact with the portion SP3 of the lower surface SF2 facing the portion TP1 away from the end surface SE of the trench line TL at the time of the first contact described above or subsequent expansion of the contact portion, and the lower surface SF2 Of these, a state away from the portion TP2 connected to the end surface SE of the trench line TL occurs. Such selective contact can be easily obtained, for example, by changing the posture of the break bar 85 having a certain degree of elasticity. At this point, the portion TP1 of the trench line TL is maintained in a crackless state.

  Referring to FIG. 58, as the expansion further proceeds as indicated by arrow CT2, the contact portion reaches portion SP4. In other words, the break bar 85 is brought into contact with the portion SP4 of the lower surface SF2 while maintaining the state where the break bar 85 is in contact with the portion SP3 of the lower surface SF2. As a result, the break bar 85 applies a stress to the portion TP1 of the trench line TL by the above-described process, and then simultaneously applies a stress to the portion TP2 having an exposed portion on the end surface SE. Due to this stress, a crack extends from the exposed portion along the trench line TL (see arrow PR in FIG. 59). In other words, a crack extending from the portion TP2 of the trench line TL toward the portion TP1 is generated. As a result, the glass substrate 11 is divided along the trench line TL.

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

  When the scribing instrument 50 (FIG. 17A) is applied to the present embodiment, the pressed blade edge 51 is slid in the direction DA on the upper surface SF1. When the direction DB opposite to the direction DA is used, cracks along the trench line TL are less likely to occur in the present embodiment. Such direction dependency is presumed to be caused by the distribution of stress in the glass substrate 11 caused by the formation of the trench line TL. As a modification, a scribing device 50v (FIG. 21A) may be used.

  According to the present embodiment, when a crack extends from the portion TP2 of the trench line TL toward the portion TP1 in order to divide the glass substrate 11 (FIG. 59: arrow PR), as shown in FIG. A portion SP3 of the lower surface SF2 facing the portion TP1 is in contact with the break bar 85 in advance. As a result, the cracks are prevented from extending out of the trench line portion TP1. Therefore, the division along the trench line TL can be accurately performed.

  In addition, in order to form a portion that causes the crack to extend along the trench line TL, the surface roughness of the end surface SE (FIG. 55) where the trench line TL is exposed is increased. As a result, cracks starting from the locations where the trench lines TL are exposed on the end surface SE are likely to occur. Therefore, the division along the trench line TL (FIG. 3A) that does not have a crack directly below it can be performed even when the trench line TL is formed with a low load.

(Embodiment 9)
Referring to FIG. 60, a trench line TL is formed on upper surface SF1 of glass substrate 11 in substantially the same manner as in the eighth embodiment (FIG. 53). However, in the present embodiment, it is preferable to use a scribing instrument 50R (FIG. 29) having a scribing wheel 51R.

  Next, as in the eighth embodiment, the glass substrate 11 is separated along the break line BL.

  Referring to FIG. 61, the end surface SE where the trench line TL is exposed is formed by the above separation. In the present embodiment, the normal direction DN of the end face SE at the location where the trench line TL is exposed has a component in the direction opposite to the scribe direction DL (FIG. 60). It is preferable that the normal direction DN and the scribe direction DL are substantially opposite.

  Next, almost the same process as in the eighth embodiment is performed. That is, the surface roughness of the end surface SE is increased, and then the glass substrate 11 is divided along the trench line TL.

  According to the present embodiment, substantially the same effect as in the eighth embodiment can be obtained. Furthermore, according to the present embodiment, the scribing wheel 51R can be used for forming the trench line TL. When the scribing wheel 51R is applied to the eighth embodiment, cracks along the trench line TL are less likely to occur as compared with the present embodiment.

  The scribing device 50 (FIG. 17A) or 50v (FIG. 21A) may be used instead of the scribing device 50R. In this case, contrary to the eighth embodiment, it is preferable to use the direction DB which is not the direction DA but the opposite direction. As a result, cracks along the trench line TL are more likely to occur.

  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.

EG edge AL assist line CL, CM crack line CP chip SE end face SF1 upper face (first face)
HR, HS High load section (second part)
TP2 Second portion SF2 Lower surface (second surface)
LR, LS Low load section (first part)
TP1 First portion TL Trench line SP3 Third portion SP4 Fourth portion 11 Glass substrate (brittle substrate)
50, 50R, 50v Scribing device 51, 51v Cutting edge 51R Scribing wheel 80 Table 81 Rug 85 Break bar

Claims (5)

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;
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; Forming a trench line having a second portion, wherein the step of forming the trench line includes a step in which the brittle substrate intersects the trench line at least immediately below the first portion of the trench line. It is performed so as to obtain a crackless state that is continuously connected, and the step of placing the brittle substrate on the table so that the first surface of the brittle substrate faces the table;
The brittle substrate in contact with a third portion of the second surface of the brittle substrate that faces the first portion of the trench line and away from a fourth portion that faces the second portion. A step of bringing a stress applying member into contact with the second surface, wherein the step of bringing the stress applying member into contact is performed such that the first portion is held in a crackless state, and the stress applying member Maintaining the state in contact with the third portion of the second surface of the brittle substrate while bringing the stress applying member into contact with the fourth portion of the second surface of the brittle substrate. The step of dividing the brittle substrate, comprising the step of dividing the brittle substrate along the trench line by generating a crack extending from the second portion of the trench line toward the first portion. Method.   2. The brittleness according to claim 1, further comprising a step of generating a crack along only the second portion of the first and second portions of the trench line before the step of dividing the brittle substrate. 3. Substrate dividing method.   In the step of forming the trench line, a load applied to the cutting edge to form the second portion of the trench line is applied to the cutting edge to form the first portion of the trench line. The method for dividing a brittle substrate according to claim 2, which is higher than the load.   The method further comprises forming a chip in the edge by riding the cutting edge onto an edge of the first surface of the brittle substrate, wherein the second portion of the trench line is located on the chip. 2. The method for dividing a brittle substrate according to 1. Before the step of dividing the brittle substrate, forming an end surface in which the second portion of the trench line is exposed on the brittle substrate;
The method for dividing a brittle substrate according to claim 1, further comprising increasing a surface roughness of the end face.

Images