TWI678343B - Breaking method of brittle substrate - Google Patents

Abstract

The cutting method of the brittle substrate of the present invention can accurately perform cutting along a trench line without cracks directly below it.

A trench line TL having a first portion LR and a second portion HR is formed on the first surface SF1 of the glass substrate 11 so as to obtain a crack-free state. The glass substrate 11 is placed on the stage so that the first surface SF1 faces the stage. The stress applying member is brought into contact with the third portion facing the first portion LR of the trench line TL in the second surface SF2 of the glass substrate 11 and away from the fourth portion facing the second portion HR. On the second side SF2. The step of bringing the stress applying member into contact is performed so that the first portion LR is kept in a crack-free state. By keeping the stress applying member in contact with the third part while keeping the stress applying member in contact with the fourth part, a crack extending from the second part HR of the groove line TL to the first part LR is generated.

Description

Breaking method of brittle substrate

The invention relates to a method for breaking a brittle substrate.

In the manufacture of electrical equipment such as flat panel display panels or solar cell panels, it is often necessary to break fragile substrates such as glass substrates. 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 a substrate using a blade edge. A groove caused by plastic deformation is formed on the substrate by sliding or rolling the blade tip on the substrate, and at the same time, a vertical crack is formed directly below the groove. Thereafter, a stress application called a breaking step is performed. Thereby, the substrate is divided by allowing the vertical cracks to run completely in the thickness direction.

The relatively large number of steps for breaking the substrate is performed immediately after the step of forming a scribe on the substrate. However, a step of processing a substrate between the step of forming a scribe line and the step of breaking is also proposed.

For example, according to the technology of International Publication No. 2002/104078, in a method for manufacturing an organic EL (electroluminescence) display, before installing a sealed top cover, a glass substrate is provided for each area that becomes an organic EL display Form a scribe. Therefore, it is possible to avoid contact between the sealing top cover and the glass cutter, which becomes a problem when a scribe is formed on the glass substrate after the sealing top cover is provided.

In addition, 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 after forming a scribe line. Thereby, two fragile substrates can be cut simultaneously in one cutting step.

[Prior Art Literature] [Patent Literature]

[Patent Document 1] International Publication No. 2002/104078

[Patent Document 2] International Publication No. 2003/006391

According to the conventional technique described above, the processing of the fragile substrate is performed after the scribe line is formed, and the breaking step is performed by applying a subsequent stress. This means that there are already vertical cracks along the entire scribe line when processing a fragile substrate. As a result, during the processing, the vertical crack is further extended in the thickness direction, and the brittle substrate that is supposed to be integrated during processing may be separated. In addition, even when the processing step of the substrate is not performed between the step of forming the scribe line and the step of cutting the substrate, it is usually necessary to transport or store the substrate after the step of forming the scribe line and before the step of cutting the substrate. Sometimes the substrate is accidentally broken.

In order to solve the above problems, the present inventors have developed a unique breaking technique. According to this technique, first, a groove line having no crack directly below is formed as a line defining a position where the fragile substrate is to be broken. The position where the fragile substrate is divided is defined by the formation of the trench lines. Thereafter, as long as a state where no crack exists directly under the trench line is maintained, it is not easy to generate a break along the trench line. By using this state, the position at which the fragile substrate is broken can be specified in advance, and the fragile substrate can be prevented from being accidentally broken before the time at which the fragile substrate should be broken.

As described above, it is more difficult for the trench line to generate a break along it as compared with a general scribe line. This can prevent accidental breaking of the fragile substrate, but on the other hand, there is a problem that it is difficult to accurately break the fragile substrate along the groove line.

The present invention has been made in order to solve the above problems, and an object thereof is to provide a method for cutting a brittle substrate that can accurately perform cutting along a trench line without a crack directly below it.

The method for breaking a fragile substrate has 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.

The blade tip is pressed against the first surface of the fragile substrate while the blade tip is moved on the first surface to cause plastic deformation on the first surface of the fragile substrate, thereby forming the first and second portions. Grooved line. The step of forming the trench line is performed in such a manner as to obtain a state in which the fragile substrate directly below at least the first part of the trench line is continuously connected in a direction crossing the trench line, that is, a crack-free state.

The fragile substrate is placed on the stage so that the first surface of the fragile substrate faces the stage.

The stress-applying member is brought into contact with the third part of the fragile substrate that is opposed to the first part of the trench line and the third part facing away from the fourth part opposite to the second part of the fragile substrate. 2 sides. The step of bringing the stress applying member into contact is performed so that the first part is kept in a crack-free state.

By maintaining the state where the stress applying member is in contact with the third part of the second face of the fragile substrate, and by bringing the stress applying member into contact with the fourth part of the second face of the fragile substrate, the second part of the groove line is generated. The crack extending toward the first part thereby cuts off the fragile substrate along the groove line.

According to the present invention, when a crack is extended from the second portion of the groove line to the first portion in order to break the brittle substrate, the third portion of the second surface opposing the first portion comes into contact with the stress applying member in advance. As a result, the crack is prevented from extending away from the first portion of the groove line. This allows accurate division along the trench line.

11‧‧‧ glass substrate (brittle substrate)

50, 50R, 50v

51, 51v‧‧‧‧tip

51R‧‧‧ crossed wheel

52‧‧‧ handle

52R‧‧‧Retainer

80‧‧‧ carrier

81‧‧‧ cushion

85‧‧‧ Breaking lever

AL‧‧‧Auxiliary line

AX, IVA, IVB, III, VI, VII, IX, X, XIV, XVII, XXI, XL, XLIA ‧‧‧ lines

BL, BM‧‧‧ branch break

CL, CM‧‧‧ Rift Line

CP‧‧‧ gap

CT1, PR, RT‧‧‧arrow

DA, DB, DC, DM‧‧‧

DT‧‧‧thickness direction

EG‧‧‧Edge

F‧‧‧Load

Fi‧‧‧ in-plane ingredients

Fp‧‧‧ vertical composition

FL1, FL2, FL3 ‧‧‧ flow

HR, HS‧‧‧‧High Load Section (Part 2)

LR, LS‧‧‧‧Low load interval (Part 1)

M1, M2, M3‧‧‧ arrows

MS‧‧‧ Surface shape

N1, Q1‧‧‧ starting point

N2, Q2, Q3

N3, Q4‧‧‧

PF‧‧‧ Peripheral Department

PP, PPv ‧‧‧ protrusion

PS, PSv‧‧‧ side

R1, R2, R3, R4, R5, R6, T1, T2, T3, T4, T5, T6‧‧‧points

RX‧‧‧Rotary shaft

S1, S2, S3‧‧‧ endpoints

SC‧‧‧ cone

SD1‧‧‧Top

SD2, SD3‧‧‧ side

SE‧‧‧face

SF1‧‧‧upper surface (first side)

SF2‧‧‧ lower surface (second side)

SP3‧‧‧Part 3

SP4‧‧‧Part 4

TP1‧‧‧Part 1

TP2‧‧‧Part 2

TM, TL‧‧‧Trench line

FIG. 1 is a schematic view showing a method for cutting a brittle substrate according to Embodiment 1 of the present invention. The flowchart.

FIG. 2 is a plan view schematically showing one step of a method for cutting a brittle substrate according to Embodiment 1 of the present invention.

FIG. 3 is a schematic cross-sectional view taken along the line III-III of FIG. 2.

FIG. 4 (A) is a schematic cross-sectional view along the line IVA-IVA in FIG. 2, and (B) is a schematic cross-sectional view along the line IVB-IVB in FIG. 2.

FIG. 5 is a plan view schematically showing one step of a method for cutting a brittle substrate according to Embodiment 1 of the present invention.

FIG. 6 is a schematic cross-sectional view taken along the line VI-VI of FIG. 5.

FIG. 7 is a schematic cross-sectional view taken along the line VII-VII in FIG. 5.

FIG. 8 is a plan view schematically showing one step of a method for cutting a brittle substrate according to the first embodiment of the present invention.

FIG. 9 is a schematic cross-sectional view taken along the line IX-IX of FIG. 8.

Fig. 10 is a schematic cross-sectional view taken along the line X-X in Fig. 8.

FIG. 11 is a plan view schematically showing one step of a method for cutting a brittle substrate according to Embodiment 1 of the present invention.

FIG. 12 is a cross-sectional view schematically showing one step of a method for cutting a brittle substrate according to the first embodiment of the present invention.

FIG. 13 is a cross-sectional view schematically showing one step of a method for cutting a brittle substrate according to Embodiment 1 of the present invention.

FIG. 14 is a schematic side view in a field of view corresponding to the arrow XIV in FIG. 13.

FIG. 15 is a cross-sectional view schematically showing a step of a method for cutting a brittle substrate according to Embodiment 1 of the present invention.

FIG. 16 is a cross-sectional view schematically showing a step of a method for cutting a brittle substrate according to the first embodiment of the present invention.

FIG. 17 (A) is a schematic view showing a breaking direction of a brittle substrate according to Embodiment 1 of the present invention. The side view of the constitution of the scoring device used in the method, and (B) are bottom views of the blade tip in the field of vision corresponding to the arrow XVII in FIG. 17 (A).

FIG. 18 is a plan view schematically showing a step of a method for breaking a brittle substrate according to a first modification of the first embodiment of the present invention.

FIG. 19 is a plan view schematically showing a step of a method for breaking a brittle substrate according to a second modification of the first embodiment of the present invention.

FIG. 20 is a plan view schematically showing one step of a method for breaking a brittle substrate according to a third modification of the first embodiment of the present invention.

FIG. 21 (A) is a side view schematically showing a configuration of a scribing device used in a method for cutting a brittle substrate according to a fourth modified example of Embodiment 1 of the present invention, and (B) is a view showing the same structure as FIG. 21 Bottom view of the blade tip in the field of view corresponding to arrow XXI of (A).

FIG. 22 is a plan view schematically showing one step of a method for cutting a brittle substrate according to Embodiment 2 of the present invention.

FIG. 23 is a plan view schematically showing one step of a method for cutting a brittle substrate according to Embodiment 2 of the present invention.

FIG. 24 is a plan view schematically showing one step of a method for cutting a brittle substrate according to Embodiment 2 of the present invention.

FIG. 25 is a plan view schematically showing one step of a method for breaking a brittle substrate according to a first modification of the second embodiment of the present invention.

FIG. 26 is a plan view schematically showing one step of a method for breaking a brittle substrate according to a first modification of the second embodiment of the present invention.

FIG. 27 is a plan view schematically showing a step of a method for breaking a brittle substrate according to a second modification of the second embodiment of the present invention.

FIG. 28 is a plan view schematically showing one step of a method for breaking a brittle substrate according to a third modification of the second embodiment of the present invention.

FIG. 29 is a schematic view showing a method for cutting a brittle substrate according to Embodiment 2 of the present invention; Side view of the composition of the marking device used in

Fig. 30 (A) is a front view schematically showing the configuration of the scribing wheel and pin of Fig. 29, and (B) is an enlarged view of a part of Fig. 30 (A).

FIG. 31 is a plan view schematically showing one step of a method for cutting a brittle substrate according to Embodiment 3 of the present invention.

FIG. 32 is a plan view schematically showing one step of a method for breaking a brittle substrate according to Embodiment 3 of the present invention.

FIG. 33 is a plan view schematically showing one step of a method for cutting a brittle substrate according to Embodiment 4 of the present invention.

FIG. 34 is a plan view schematically showing one step of a method for breaking a brittle substrate according to Embodiment 4 of the present invention.

FIG. 35 is a plan view schematically showing one step of a method for cutting a brittle substrate according to Embodiment 4 of the present invention.

FIG. 36 is a plan view schematically showing one step of a method for cutting a brittle substrate according to Embodiment 4 of the present invention.

FIG. 37 is a plan view schematically showing a step of a method for cutting a brittle substrate according to Embodiment 4 of the present invention.

Fig. 38 is a flowchart schematically showing a method for cutting a brittle substrate according to a fifth embodiment of the present invention.

FIG. 39 is a plan view schematically showing one step of a method for cutting a brittle substrate according to Embodiment 5 of the present invention.

40 (A)-(C) are schematic partial cross-sectional views showing steps of a method for breaking a fragile substrate according to a fifth embodiment of the present invention in the field of view along the line XL-XL in FIG. 39.

Fig. 41 is a schematic cross-sectional view of XLIA-XLIA along the line of Fig. 39, (A) is a diagram showing the structure of a groove line in a state without cracks, and (B) is shown directly below the groove line in the same field A sectional view of a state where a crack line is formed.

FIG. 42 is a plan view schematically showing a step of a method for breaking a brittle substrate according to Embodiment 5 of the present invention.

FIG. 43 is a cross-sectional view schematically showing a step of a method for cutting a brittle substrate according to Embodiment 5 of the present invention.

FIG. 44 is a cross-sectional view schematically showing a step of a method for cutting a brittle substrate according to Embodiment 5 of the present invention.

FIG. 45 is a schematic side view in a field of view corresponding to the arrow XLV of FIG. 44.

FIG. 46 is a cross-sectional view schematically showing one step of a method for cutting a brittle substrate according to Embodiment 5 of the present invention.

FIG. 47 is a cross-sectional view schematically showing a step of a method for cutting a brittle substrate according to Embodiment 5 of the present invention.

FIG. 48 is a plan view schematically showing one step of a method for cutting a brittle substrate according to Embodiment 6 of the present invention.

FIG. 49 is a plan view schematically showing one step of a method for cutting a brittle substrate according to Embodiment 7 of the present invention.

FIG. 50 is a plan view schematically showing one step of a method for cutting a brittle substrate according to Embodiment 7 of the present invention.

FIG. 51 is a plan view schematically showing one step of a method for cutting a brittle substrate according to Embodiment 7 of the present invention.

Fig. 52 is a flowchart schematically showing a method for cutting a brittle substrate according to Embodiment 8 of the present invention.

FIG. 53 is a plan view schematically showing one step of a method for breaking a brittle substrate according to Embodiment 8 of the present invention.

Fig. 54 is a plan view schematically showing one step of a method for breaking a brittle substrate according to Embodiment 8 of the present invention.

Fig. 55 is a schematic partial side of the end face of the brittle substrate in the field of view of the arrow XLV of Fig. 54 view.

FIG. 56 is a cross-sectional view schematically showing a step of a method for cutting a brittle substrate according to Embodiment 8 of the present invention.

FIG. 57 is a cross-sectional view schematically showing one step of a method for cutting a brittle substrate according to Embodiment 8 of the present invention.

FIG. 58 is a cross-sectional view schematically showing a step of a method for cutting a brittle substrate according to Embodiment 8 of the present invention.

FIG. 59 is a cross-sectional view schematically showing one step of a method for cutting a brittle substrate according to Embodiment 8 of the present invention.

FIG. 60 is a plan view schematically showing one step of a method for cutting a brittle substrate according to Embodiment 9 of the present invention.

FIG. 61 is a plan view schematically showing a step of a method for cutting a brittle substrate according to Embodiment 9 of the present invention.

Hereinafter, a method for dividing a brittle substrate according to each embodiment of the present invention will be described based on the drawings. Moreover, the same or equivalent parts are given the same reference numerals in the drawings below, and descriptions thereof are not repeated.

(Embodiment 1)

Hereinafter, a method for cutting the glass substrate 11 (brittle substrate) according to this embodiment will be described with reference to the flow FL1 (FIG. 1).

The glass substrate 11 is prepared with reference to FIGS. 2 to 4 (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). The glass substrate 11 has a thickness direction DT perpendicular to the upper surface SF1.

In addition, a scribing tool having a blade tip is prepared. The details of the scribing device are described below.

Next, while pressing the blade tip against the upper surface SF1 of the glass substrate 11, The blade point 51 moves on the upper surface SF1 from the start point N1 to the end point N3 via the halfway point N2. As a result, plastic deformation occurs on the upper surface SF1 of the glass substrate 11. As a result, a groove line TL extending from the starting point N1 to the ending point N3 via the halfway point N2 is formed on the upper surface SF1 (FIG. 1: Step S120). In FIG. 2, three TLs are formed by the blade tip moving in the direction DA.

The step of forming the trench line TL includes: forming a low load section LR (part 1) as a part of the trench line TL (FIG. 1: step S120L); and forming a high load section HR (part 2) as a trench Step of a part of the line TL (FIG. 1: Step S120H). In FIG. 2, a low-load interval is formed from the start point N1 to the halfway point N2, and a high-load interval is formed from the halfway point N2 to the end point N3. The load applied to the cutting edge 51 in the step of forming the high load section HR is higher than the load used in the step of forming the low load section LR. In other words, the load applied to the cutting edge 51 in the step of forming the low load section LR is lower than the load used in the step of forming the high load section HR, for example, about 30 to 50% of the load in the high load section HR. . Therefore, the width of the high load interval HR is larger than the width of the low load interval LR. For example, the high-load interval HR has a width of 10 μm, and the low-load interval LR has a width of 5 μm. The depth of the high load interval HR is greater than the depth of the low load interval LR. The cross section of the trench line TL has, for example, a V shape with an angle of about 150 °.

The step of forming the trench line TL is to obtain the glass substrate 11 directly below the high-load interval HR and the low-load interval LR of the trench line TL in a direction crossing the trench line TL (FIG. 4 (A) and (B )) Is performed in a state of being continuously connected, that is, a state without cracks. Therefore, the load applied to the blade edge is large enough to cause plastic deformation of the glass substrate 11 and small enough not to generate cracks starting from the plastic deformed portion.

Next, a crack line is formed as follows (FIG. 1: Step S130).

Referring to FIGS. 5 to 7, an auxiliary line AL that intersects the high-load section HR is first formed on the upper surface SF1 of the glass substrate 11. The auxiliary line AL is accompanied by a crack that penetrates in the thickness direction of the glass substrate 11. The auxiliary line AL can be formed by a general scribing method.

Next, the glass substrate 11 is separated along the auxiliary line AL. This separation can use the usual points The breaking step is performed. Taking this separation as an opportunity, the crack of the glass substrate 11 in the thickness direction extends along the groove line TL only in the high-load interval HR in the groove line TL.

Referring to FIGS. 8 and 9, by the above steps, cracks are generated only along the low-load interval LR and the high-load interval HR of the high-load interval HR along the groove line TL. Specifically, a crack line CL is formed in a portion between the edge newly generated by separation and the halfway point N2 in the high-load interval 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. Furthermore, it is difficult to form a crack line CL in a part between the newly generated edge and the end point N3 by separation. This direction dependency is due to the state of the blade tip when the high-load section HR is formed, which will be described in detail below.

Referring to FIG. 10, by the crack line CL directly below the high load interval HR of the trench line TL, the continuous connection of the glass substrate 11 in the direction DC crossing the extending direction of the trench line TL is disconnected. Here, "continuous connection", in other words, refers to the connection that has not been cut off by the fissure. In addition, in a state where the continuous connection is disconnected as described above, portions of the glass substrates 11 may be in contact with each other via the crack of the crack line CL.

Next, a cutting step of cutting the glass substrate 11 along the trench line TL is performed (FIG. 1: step S140). At this time, the stress is applied to the glass substrate 11 so that the cracks extend 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, the details of the above-mentioned breaking step will be described below.

Referring to FIG. 12, a glass substrate 11 (FIG. 9) having a crack line CL formed thereon is placed on the top surface SF1 of the glass substrate 11 and faces the stage 80 with a spacer 81 interposed therebetween. It is placed on the stage 80. The spacer 81 includes a material that is easier to deform than the materials of the glass substrate 11 and the stage 80.

13 and 14, a breaking lever 85 (a stress applying member) is prepared. The breaking lever 85 preferably has a shape protruding as shown in FIG. 14 so as to be able to locally press the surface of the glass substrate 11, and has a substantially V-shape in FIG. 14. As shown in Figure 13, the break The protruding portion of the rod 85 extends linearly.

Next, the breaking lever 85 is brought into contact with a part of the lower surface SF2 of the glass substrate 11. The contact portion of the breaking lever 85 is separated from the portion SP4 of the lower surface SF2 that faces the crack line CL in the thickness direction (longitudinal direction in FIG. 13). Part SP4 is also the part of the lower surface SF2 that faces the high load section HR in the thickness direction.

Next, as indicated by arrow CT1, the above-mentioned contact portion extends along the low-load interval LR of the trench line TL and approaches the side of the portion SP4. At the initial contact mentioned above, or by the subsequent extension of the contact part, the breaking lever 85 is brought into contact with the part SP3 (part 3) opposite to the low load section LR on the lower surface SF2, and since The above part SP4 (Part 4) is left. Such selective contact can be easily obtained, for example, by changing the posture of the breaking lever 85 having a certain degree of elasticity. Moreover, at this point in time, the low load section LR is maintained in a crack-free state.

Referring to FIG. 15, as shown by an arrow CT2, the expansion is further advanced so that the above-mentioned contact portion reaches the portion SP4. In other words, while maintaining the state of the part SP3 of the breaking lever 85 in contact with the lower surface SF2 of the glass substrate 11, the state of the breaking lever 85 in contact with the part SP4 of the lower surface SF2 of the glass substrate 11. As a result, the breaking lever 85 first applies stress to the low-load interval LR in the crack line CL by the above steps, and thereafter, also simultaneously applies stress to the crack line CL. Due to the stress, the crack is extended from the crack line CL (FIG. 15) along the low load section LR (see arrow PR in FIG. 16). In other words, a crack is generated that extends from the high load section HR to the low load section LR of the groove line TL. As a result, the glass substrate 11 is cut along the trench line TL.

The glass substrate is divided by the above-mentioned division steps (FIG. 11).

17 (A) and (B), the scribe tool 50 suitable for forming the above-mentioned groove line TL is demonstrated. The scribing tool 50 scribes the glass substrate 11 by being relatively moved with respect to the glass substrate 11 by being mounted on a scribing head (not shown). The scribing tool 50 includes a blade point 51 and a handle 52. The blade tip 51 is held by the shank 52.

The cutting edge 51 is provided with a top surface SD1 (first surface) and a plurality of surfaces surrounding the top surface SD1. This These multiple surfaces include a side surface SD2 (second surface) and a side surface SD3 (third surface). The top faces SD1, the side faces SD2, and SD3 face different directions and are adjacent to each other. The cutting edge 51 has a vertex at which the top surface SD1, the lateral surfaces SD2, and SD3 merge, and the apex constitutes a protrusion PP of the cutting edge 51. In addition, the side surfaces SD2 and SD3 form a ridge line forming the side portion PS of the blade edge 51. The side portion PS extends linearly from the protrusion portion PP. Since the side portion PS is a ridge line as described above, it has a convex shape extending linearly.

The blade 51 is preferably a diamond pen. That is, it is preferable that the cutting edge 51 is made of diamond. In this case, the hardness can be easily made high and the surface roughness can be made small. More preferably, the cutting edge 51 is made of single crystal diamond. In terms of crystallography, it is further preferred that the top surface SD1 is a {001} surface, and each of the side surfaces SD2 and SD3 is a {111} surface. In this case, although the side faces SD2 and SD3 have different directions, they are crystallographically equivalent crystalline faces.

Furthermore, diamonds other than single crystals can also be used. For example, polycrystalline diamonds synthesized by a CVD (Chemical Vapor Deposition) method can also be used. Alternatively, polycrystalline diamond sintered from particulate graphite or non-graphite carbon without a binding material such as iron group elements, or sintered diamond in which diamond particles are bonded by a binding material such as iron group elements .

The shank 52 extends in the axial direction AX. The blade point 51 is preferably mounted on the shank 52 such that the normal direction of the top surface SD1 is substantially along the axial direction AX.

In the formation of the trench line TL using the scribing device 50, the blade tip 51 is first pressed against the upper surface SF1 of the glass substrate 11. Specifically, the protruding portion PP and the side portion PS of the blade point 51 are pressed in the thickness direction DT of the glass substrate 11.

Next, the pressed blade point 51 is slid in the direction DA on the upper surface SF1. The direction DA is a direction obtained by projecting a direction extending from the protruding portion PP along the side portion PS onto the upper surface SF1, and substantially corresponds to a direction obtained by projecting the axial direction AX onto the upper surface SF1. When sliding, the blade 51 is pulled and slid on the upper surface SF1 by the handle 52. With this sliding Plastic deformation occurs on the upper surface SF1 of the glass substrate 11. The groove lines TL are formed by the plastic deformation.

Furthermore, in the formation of the groove line TL from the start point N1 to the end point N3 in this embodiment, when the tool tip 51 is moved toward the direction DB, in other words, when the tool tip 51 is moved based on the moving direction of the tool tip 51 as a reference, the tool tip When the posture of 51 is tilted in the opposite direction, it is more difficult to generate the crack line CL shown in FIG. 9 and the progress of the crack shown in FIG. 16 than in the case of using the direction DA. More generally, in the groove line TL formed by the movement of the blade point 51 in the direction DA, a crack is easily extended in a direction opposite to the direction DA. On the other hand, in the groove line TL formed by the movement of the blade point 51 in the direction DB, a crack is easily extended in the same direction as the direction DB. It is speculated that the direction dependency may be related to the stress distribution in the glass substrate 11 caused by the plastic deformation generated when the trench line TL is formed.

According to this embodiment, when the crack is extended from the high load section HR to the low load section LR of the groove line TL to break the glass substrate 11 (FIG. 16: arrow PR), as shown in FIG. 15, the lower surface SF2 The portion facing the middle and low load section LR is in contact with the breaking lever 85 in advance. As a result, the crack is prevented from extending away from the low load interval LR of the trench line TL. This makes it possible to accurately cut off along the trench line TL.

In addition, before the step of breaking the glass substrate 11, a crack line CL is formed only along the low load section LR and the high load section HR of the groove line TL (FIG. 9). That is, before the breaking step, a crack line CL is formed as a breaking point of the glass substrate 11. This makes it possible to more reliably perform the division of the glass substrate 11 in the division step.

In addition, when the groove line TL (FIG. 2 and FIG. 3) for defining the position where the glass substrate 11 is divided is formed, the tool tip 51 (FIG. 17 (A)) The load applied is reduced. This can reduce damage to the blade tip 51.

Further, when the low-load interval LR in the low-load interval LR and the low-load interval LR in the high-load interval HR is in a crack-free state (FIGS. 8 and 9), there is no crack in the low-load interval LR that becomes the starting point for breaking the glass substrate 11. . Therefore, in this state, the glass substrate 11 is arbitrarily processed. In the shape, even if an unexpected stress is applied to the low load section LR, it is difficult for the glass substrate 11 to be accidentally broken. Thereby, the above-mentioned processing can be performed stably.

In addition, when both the low load section LR and the high load section HR are in a crack-free state (FIGS. 2 and 3), there is no crack on the groove line TL that becomes the starting point for breaking the glass substrate 11. Therefore, when the glass substrate 11 is arbitrarily processed in this state, even if an unexpected stress is applied to the trench line TL, it is difficult for the glass substrate 11 to be accidentally broken. Thereby, the above-mentioned processing can be performed stably.

The trench line TL is formed before the auxiliary line AL is formed. Accordingly, it is possible to avoid affecting the auxiliary line AL when the trench line TL is formed. In particular, it is possible to avoid formation abnormality immediately after the blade tip 51 passes over the auxiliary line AL to form the groove line TL.

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

Referring to FIG. 18, the crack line CL can also be formed by taking the opportunity of the auxiliary line AL and the groove line TL crossing. This phenomenon occurs when the stress applied to the glass substrate 11 when forming the auxiliary line AL is large.

Referring to FIG. 19, an auxiliary line AL may be formed on the upper surface SF1 of the glass substrate 11 first, and then a trench line TL is formed (not shown in FIG. 19).

Referring to FIG. 20, the auxiliary line AL can also be formed on the lower surface SF2 of the glass substrate 11 in such a manner as to intersect the high load section HR in a planar layout. This makes it possible to form both the auxiliary line AL and the trench line TL when they do not affect each other.

Referring to Figs. 21 (A) and (B), a scribing device 50v may be used instead of the scribing device 50 (Figs. 17 (A) and (B)). The cutting edge 51v has a conical shape having a vertex and a conical surface SC. The protruding portion PPv of the blade point 51v is constituted by a vertex. The side portion PSv of the cutting edge is constituted from an apex along an imaginary line (dashed line in FIG. 21 (B)) extending on the conical surface SC. Thereby, the side portion PSv has a convex shape extending linearly.

(Embodiment 2)

22, first, a glass substrate 11 is prepared. A scoring device with a blade tip is also prepared. The details of the scribing device are described below.

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

Referring to FIG. 23, a groove line TL is formed on the upper surface SF1 of the glass substrate 11 from the starting point Q1 through the midpoints Q2 and Q3 and to the ending point Q4 by moving the blade tip in the direction DB. A groove line TL is formed from the start point Q1 to the halfway point Q2 and from the halfway point Q3 to the end point Q4 as the low-load interval LR. A groove line TL from the halfway point Q2 to the halfway point Q3 is formed as the high load section HR.

Next, the glass substrate 11 is separated along the auxiliary line AL. This separation can be carried out by a usual breaking step. Taking this separation as an opportunity, the crack of the glass substrate 11 in the thickness direction extends along the groove line TL only in the high-load interval HR in the groove line TL.

Referring to FIG. 24, a crack line CL is formed along a portion of the groove line TL by the extension of the crack. Specifically, a crack line CL is formed in a portion between the edge newly generated by separation and the halfway point 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. Furthermore, a crack line CL is formed in a portion between the edge newly generated by the separation and the halfway point Q2. This direction dependency is due to the state of the blade tip when the high-load section HR is formed, which will be described in detail below.

Next, with the same breaking step (FIG. 12 to FIG. 16) as in the first embodiment, a breaking step of extending the crack along the groove line TL starting from the crack line CL and extending from the halfway point Q3 to the end point Q4 is performed. Thereby, the fragile substrate 11 is cut.

25 and 26, as a first modification, the trench line TL may be formed first, and the auxiliary line AL may be formed after that. Referring to FIG. 27, as a second modification example, a crack line CL can also be formed with the formation of the auxiliary line AL as an opportunity. Referring to FIG. 28, the auxiliary line AL can also be formed on the lower surface SF2 of the glass substrate 11 in such a manner as to intersect with the high-load section HR in a planar layout. In addition, in the present embodiment, the high-load interval HR is formed from the halfway point Q2 to Q3. The charge interval HR may be formed at a portion crossing the auxiliary line AL, and may be formed from the starting point Q1 to the halfway point Q3, for example.

Next, a scribing tool 50R suitable for forming the trench line TL in this embodiment will be described with reference to FIG. 29. The scribing device 50R includes a scribing wheel 51R, a holder 52R, and a pin 53. The scribing wheel 51R has a substantially disc-like shape, and its diameter is typically about several mm. The scribing wheel 51R is held by a holder 52R via a pin 53 so as to be rotatable about a rotation axis RX.

The scribing wheel 51R has an outer peripheral portion PF provided with a knife edge. The outer peripheral portion PF extends in a ring shape around the rotation axis RX. As shown in FIG. 30 (A), the outer peripheral portion PF is ridged at a visual level, thereby forming a cutting edge including a ridge and an inclined surface. On the other hand, at the microscope level, as shown in FIG. 30 (B), the portion where the scribing wheel 51R actually invades by invading the upper surface SF1 (FIG. 30 (B) is closer to the two-point chain line Bottom), the ridge line of the outer peripheral portion PF has a fine surface shape MS. The surface shape MS in a front view (FIG. 30 (B)) is preferably a curved shape having a limited radius of curvature. The scribing wheel 51R is formed using a hard material such as cemented carbide, sintered diamond, polycrystalline diamond, or single crystal diamond. From the viewpoint of reducing the surface roughness of the ridgeline and the inclined surface, the entire scribing wheel 51R may be made of single crystal diamond.

The formation of the groove line TL using the scribing device 50R is performed by rolling the scribing wheel 51R on the upper surface SF1 of the glass substrate 11 (FIG. 29: arrow RT) to make the scribing wheel 51R travels in the direction DB on the upper surface SF1. This rolling travel is performed while applying a load F to the scribing wheel 51R to press the outer peripheral portion PF of the scribing wheel 51R against the upper surface SF1 of the glass substrate 11. Accordingly, the groove line TL having a groove shape is formed by plastic deformation on the upper surface SF1 of the glass substrate 11. 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.

In addition, the formation of the trench line TL can also be performed using a scribing device 50 (FIG. 17 (A) and (B)) or 50v (Figs. 21 (A) and (B)) instead of using the scribing device 50R moving in the direction DB.

In addition, the configuration other than the above is substantially the same as the configuration of the first embodiment, and therefore the same or corresponding elements are assigned the same reference numerals, and descriptions thereof will not be repeated.

According to this embodiment, it is also possible to obtain substantially the same effects as in the first embodiment. Moreover, in this embodiment, since the groove line TL can be formed using a rotating blade tip without being fixed, it is possible to extend the life of the blade tip.

(Embodiment 3)

Referring to FIG. 31, first, a glass substrate 11 and a scribe tool having a blade tip are prepared. A groove line is formed between the points R1 and R6 on the upper surface SF1 of the glass substrate 11 by the movement of the blade point. The groove lines TL between the points R1 and R2, between the points R3 and R4, and between the points R5 and R6 are formed as the high load section HR. The trench line TL between the points R2 and R3 and between the points R4 and R5 is formed as a low load interval LR. As the method for forming the trench line TL, any method described in the above-mentioned Embodiment 1 or 2 (including variations thereof) can be used.

Next, the glass substrate 11 is separated along a plurality of breaking lines BL that intersect the high load section HR. The formation of the break line BL can also be performed by any method such as a normal scribing step or a step of generating a vertical crack from the trench line TL, and the break line BL can be separated by a normal break step.

Referring to FIG. 32, taking the above-mentioned separation of the glass substrate 11 as an opportunity, a crack line CL is formed at a portion between an edge newly generated by the separation and one of a pair of halfway points across the edge. 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. 17 (A) or FIG. 21 (A)), and is opposite to the direction DB (FIG. 17 (A), FIG. 21). (A) or FIG. 29) The direction DB when the trench line TL is formed is the same.

Next, with the same breaking step (FIG. 12 to FIG. 16) as in the first embodiment, a breaking step of extending the crack along the groove line TL with the crack line CL as a starting point is performed. Thereby, the fragile substrate 11 is cut.

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

(Embodiment 4)

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

Referring to FIG. 34, next, while pressing the knife edge 51 on the upper surface SF1 of the glass substrate 11, the knife edge 51 is moved in the direction DA (FIG. 17 (A)) on the upper surface SF1 of the glass substrate 11, This causes plastic deformation on the upper surface SF1 of the glass substrate 11, so that on the upper surface SF1, an intersecting trench line TM that intersects the low load interval LR of the trench line TL is formed in the direction DM. The step of forming the cross trench line TM is performed in the same manner as the trench line TL to obtain a crack-free state. That is, the step of forming the cross trench line TM is performed so as to obtain a state in which the glass substrate 11 immediately below the cross trench line TM is continuously connected in a direction crossing the cross trench line TM, that is, a state without cracks.

Next, the glass substrate 11 is separated along a break line BM crossing the cross groove line TM. This separation can be performed by a usual scribing step and a breaking step. The break line BM crosses the cross trench line TM at a point shifted from the intersection of the cross trench line TM and the trench line TL in the direction DM. Taking this separation as an opportunity, a crack line CM (FIG. 35) is formed along the cross groove line TM along with a crack that penetrates in the thickness direction of the glass substrate 11.

Next, the glass substrate 11 is separated along a break line BL that intersects the high load section HR of the trench line TL. This separation can be performed by a usual scribing step and a breaking step. Taking this separation as an opportunity, a crack line CL (FIG. 36) is formed along the high load section HR along with a crack that penetrates in the thickness direction of the glass substrate 11.

Next, with the same breaking step (FIG. 12 to FIG. 16) as in the first embodiment, a breaking step of extending the crack along the groove line TL with the crack line CL as a starting point is performed. Thus along the trench The line TL breaks the fragile substrate 11 (FIG. 37). Thereafter, a breaking step is performed along the crack line CM to further break the brittle substrate 11.

According to this embodiment, the position where the glass substrate 11 is divided can be specified by the trench line TL and the cross trench line TM crossing it.

It is also possible to use a cutting edge 51v (FIG. 21 (A)) instead of the cutting edge 51 (FIG. 17 (A)). The formation of the trench line TL may be performed in a direction opposite to the direction DL (FIG. 33). In this case, the blade point 51 (FIG. 17 (A)) moves in the direction DB. Similarly, the formation of the cross trench line TM can also be performed in a direction opposite to the direction DM (FIG. 34). In this case, the blade point 51 (FIG. 17 (A)) moves in the direction DB. When the blade tip moves in the direction DB, the blade tip of the scribing wheel 51R (FIG. 29) may be used instead of the blade tip 51.

(Embodiment 5)

FIG. 38 is a flowchart FL2 schematically showing a method for cutting the glass substrate 11 (brittle substrate) according to this embodiment. FIG. 39 is a plan view schematically showing a state immediately after step S220 (FIG. 38) is completed. FIG. 40 is a schematic partial cross-sectional view (A) to (C) showing steps sequentially in the field of view along the line XL-XL in FIG. 39.

First, the glass substrate 11 is prepared (FIG. 38: Step S210). The glass substrate 11 includes an upper surface SF1 and a lower surface SF2 having edges EG. The glass substrate 11 has a thickness direction DT perpendicular to the upper surface SF1. Further, a scribing tool 50R (FIG. 29) having a scribing wheel 51R (FIG. 30 (A)) provided with a blade tip is prepared.

Next, the blade of the scribing wheel 51R is brought into contact with the edge EG of the upper surface SF1 of the glass substrate 11 by the movement of the scribing wheel 51R shown by the arrow M1 (FIG. 40 (A)). Next, the blade tip is moved on the glass substrate 11 while pressing the blade tip against the glass substrate 11 (FIG. 38: Step S220). This step is described below.

First, by moving the scribing wheel 51R shown by an arrow M2 (FIG. 40 (B)), the blade edge is made to cross the edge EG of the glass substrate 11. Accordingly, a notch CP is formed at a position on the edge EG, that is, the starting point N1 (FIG. 39) (FIG. 40 (C)) (FIG. 38: step S220C).

Next, the blade tip of the upper starting point N1 is pressed against the upper surface SF1 of the glass substrate 11 by the step of forming the notch CP as described above, and the setting is as shown by the arrow M3 (FIG. 40 (C)). The knife-pointed scribing wheel 51R moves on the upper surface SF1. 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 starting point N1 to another end point N3 on the upper surface SF1 (FIG. 38: Step S220T). Accordingly, the trench line TL includes a first portion TP1 (refer to FIG. 43) separated from the notch CP and a second portion TP2 (refer to FIG. 43) located on the notch CP. The trench line TL is formed in such a manner as to obtain the above-mentioned crack-free state immediately below the portion located away from the notch CP. Furthermore, it is preferable that the notch CP is also formed in such a manner that a crack-free state is obtained just below it.

Referring to FIG. 41 (A), the step of forming the trench line TL is performed to obtain a state where the glass substrate 11 directly below the trench line TL is continuously connected in a direction DC crossing the trench line TL, that is, a state without cracks . In the crack-free state, although the groove line TL is formed by plastic deformation, no crack is formed along the groove line TL. Therefore, even if a bending moment is applied to the glass substrate 11, it is difficult to generate a break along the groove line TL. In order to obtain a crack-free state, it is sufficient if the load of the blade tip against the glass substrate 11 is not excessively increased. 41 (B) shows a comparative example of FIG. 41 (A), and shows a state where a trench line TL is formed and a crack extending along the trench line TL, that is, a crack line CL, is formed.

By repeating the formation steps of the trench lines TL as needed, a desired number of trench lines can be obtained. FIG. 39 illustrates a case where three trench lines TL are formed.

Referring to FIG. 42, the breaking step is performed next. Specifically, by applying stress to the glass substrate 11, a crack starting from the notch CP is extended from the start point N1 to the end point N3, and the glass substrate 11 is divided along the groove line TL (FIG. 38: Step S230). The breaking step may be performed multiple times according to the number of the trench lines TL. Furthermore, a more detailed method of the breaking step is described below.

Through the above steps, the glass substrate 11 is cut along the trench line TL.

Next, the division procedure of this embodiment will be described below.

Referring to FIG. 43, the glass substrate 11 (FIG. 39) in which the groove line TL is formed is placed across the spacer 81 so that the upper surface SF1 of the glass substrate 11 faces the stage 80 through the spacer 81. Placed on the stage 80.

A breaking lever 85 is prepared with reference to FIGS. 44 and 45. As shown in FIG. 45, the breaking lever 85 preferably has a shape protruding so as to be able to locally press the surface of the glass substrate 11, and has a substantially V-shape in FIG. 45. As shown in FIG. 44, the protruding portion extends linearly.

Next, the breaking lever 85 is brought into contact with a part of the lower surface SF2 of the glass substrate 11. The contact portion is separated from the portion SP4 facing the portion TP2 of the trench line TL in the thickness direction (longitudinal direction in FIG. 9) in the lower surface SF2.

Next, as indicated by arrow CT1, the above-mentioned contact portion extends along the trench line TL and approaches the side of the portion SP4. At the time of the above-mentioned initial contact, or by the subsequent expansion of the contact portion, the breaking rod 85 comes into contact with the portion SP3 (part 3) of the lower surface SF2 opposite to the portion TP1 of the groove line TL, And from the state of the above-mentioned part SP4 (part 4). This selective contact can be easily obtained, for example, by changing the posture of the breaking lever 85 having a certain degree of elasticity. Furthermore, at this point in time, a portion TP1 of the trench line TL is maintained in a crack-free state.

Referring to FIG. 46, as shown by arrow CT2, the expansion is further advanced so that the above-mentioned contact portion reaches the portion SP4. In other words, while maintaining the state where the breaking lever 85 is in contact with the portion SP3 of the lower surface SF2, the breaking lever 85 is in contact with the portion SP4 of the lower surface SF2. As a result, the breaking lever 85 first applies stress to the portion TP1 of the trench line TL through the above steps, and thereafter, simultaneously applies stress to the notch CP. Due to this stress, the crack extends from the notch CP along the groove line TL (see arrow PR in FIG. 47). In other words, a crack is generated that extends from a portion TP2 to a portion TP1 of the trench line TL. As a result, the glass substrate 11 is cut along the trench line TL.

The glass substrate 11 is divided by the above-mentioned division steps (FIG. 42).

According to this embodiment, when the crack is extended from the portion TP2 to the portion TP1 of the trench line TL to break off the glass substrate 11 (FIG. 47: arrow PR), as shown in FIG. 46, the lower surface SF2 and the portion TP1 The opposing portion SP3 contacts the breaking lever 85 in advance. This suppresses the crack from extending away from the portion TP1 of the trench line. This makes it possible to accurately cut off along the trench line TL.

In addition, the notch CP formed on the edge EG of the glass substrate 11 is used as an opportunity to extend the crack along the groove line TL. This notch CP is formed only by the edge of the upper glass substrate 11 that is moved by the blade tip that is moved when the trench line TL is started to be formed. Thus, the glass substrate 11 can be divided along the trench line TL in a simple procedure.

In the formation of the notch CP, a cutting edge of the scribing wheel 51R, that is, a rotating cutting edge is used. Therefore, compared with a case where a fixed blade tip such as a diamond pen is used, damage to the blade tip when the blade tip crosses the edge EG of the glass substrate 11 can be suppressed.

(Embodiment 6)

Referring to FIG. 48, in this embodiment, a step of forming a high load interval HR as a part of the trench line TL and a step of forming a low load interval LR as a part of the trench line TL are performed. The high-load interval HR is formed from the starting point N1 to a midpoint N2 between the starting point N1 and the ending point N3. The low load interval LR is formed from the halfway point N2 to the end point N3. The load applied to the tool tip in the step of forming the low load section LR is lower than the load used in the step of forming the high load section HR.

In addition, as for the structure other than the above, since the structure is substantially the same as that of the fifth embodiment, the same or corresponding elements are given the same reference numerals, and descriptions thereof will not be repeated.

According to this embodiment, the portion of the groove line TL extending from the notch CP, that is, the high-load section HR is formed by plastic deformation under a high load. As a result, compared with a case where the entire groove line TL is formed by plastic deformation under a low load used in the low load section LR, A crack is easily generated from the notch CP to the trench line TL. Accordingly, in the breaking step (FIG. 43 to FIG. 47), a crack with the gap CP as an opportunity can be more reliably generated. Thereby, the glass substrate 11 can be divided more reliably along the groove line TL using the extension of the crack.

Furthermore, the end point N3 leaves the edge EG of the glass substrate 11 in FIG. 39, but the end point N3 may also be located on the edge EG of the glass substrate 11 (in the example of FIG. 39, it is on the right edge of the surface SF1 of the glass substrate 11). ).

(Embodiment 7)

Referring to FIG. 49, first, a trench line TL is formed in the direction DL along with a notch CP at the starting point and extending to the end point by a method substantially the same as that in the fifth embodiment.

Referring to FIG. 50, the blade tip is pressed against the upper surface SF1 of the glass substrate 11 by applying a load, and the blade tip is moved toward the direction DM on the upper surface SF1. As a result, plastic deformation occurs on the upper surface SF1 of the glass substrate 11, and a cross trench line TM (second trench line) is formed between the points T1 and T6. The formation of the cross trench line TM is the same as the method described for the trench line TL (FIG. 41 (A)) in the fifth embodiment, and the cross trench line TM is obtained in a crack-free state.

Between the points T1 and T2, between the points T3 and T4, and between the points T5 and T6, high load sections HS are formed as part of the cross-groove line TM. A low load interval LS is formed between the points T2 and T3 and between the points T4 and T5 as a part of the cross trench line TM. The load applied to the tool tip in the step of forming the high load section HS is higher than the load used in the step of forming the low load section LS. The high load section HS crosses the trench line TL. The method of forming the cross trench line TM can be the same as the method of forming the trench line TL.

Next, the crack is extended along the trench line TL starting from the notch CP by the same breaking step as in the fifth embodiment. As a result, the glass substrate 11 is cut along the trench line TL (FIG. 51). Taking this break as an opportunity, the crack extends only in the high-load section HS in the cross-groove line TM. As a result, a crack line CL is formed along a part of the intersecting trench line TM. Specifically, in borrowing A crack line CL is formed in the high-load section HS on a portion between the edge newly generated by the division and one of a pair of halfway points across the edge.

Furthermore, it is difficult to form a crack line CL even in a high-load section HS on a portion between the edge newly generated by the division and the other of a pair of halfway points across the edge. The reason for this is that there is a direction dependency on the ease of extension of the crack along the crack line CL. It is presumed that this direction dependency is due to the distribution of internal stress generated when the glass substrate 11 is scribed.

In the high-load section HS, as shown in FIG. 41 (B), the glass substrate 11 is continuously connected in the direction DC that intersects with the extending direction of the crossing groove line TM directly below the crossing groove line TM due to cracks The line CL is disconnected. Here "continuous connection" in other words means a connection that has not been interrupted by a fissure. Furthermore, in a state where the continuous connection is disconnected as described above, portions of the glass substrates 11 may be in contact with each other via the crack of the crack line CL.

Next, stress is applied to the glass substrate 11 in the same breaking step as in the fifth embodiment, whereby the cracks extend along the low load section LS starting from the crack line CL. Thereby, the glass substrate 11 is divided along the cross groove line TM. That is, in addition to the division along the trench line TL, the division along the crossing trench line TM is also performed.

According to this embodiment, it is possible to obtain substantially the same effects as those of the fifth embodiment. In addition, the position where the glass substrate 11 is broken can be specified by the trench line TL and the crossing trench line TM crossing it.

(Embodiment 8)

FIG. 52 is a flowchart FL3 schematically showing a method for cutting the glass substrate 11 (brittle substrate) according to this embodiment. Fig. 53 is a plan view schematically showing a state immediately after step S320 (Fig. 52) is completed.

First, the glass substrate 11 is prepared (FIG. 52: Step S310). The glass substrate 11 has an upper surface SF1 and a lower surface which is the opposite surface. Further, a scribing tool 50 provided with a blade point 51 is prepared (FIG. 17 (A)).

Next, the blade tip is moved while pressing on the upper surface SF1 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 through the point N2 (one point) is formed on the upper surface SF1 (FIG. 52: Step S320). When the groove line TL is formed, the blade tip moves at the point N2 in the scribe direction DL (one direction). The points N1 to N3 indicate positions on the upper surface SF1.

By repeating the formation steps of the trench lines TL as needed, a desired number of trench lines TL can be formed. FIG. 53 illustrates a case where three trench lines TL are formed.

The step of forming the trench line TL is performed in such a manner as to obtain the above-mentioned crack-free state (FIG. 41 (A)). Furthermore, in a state where there is no crack (FIG. 41 (B)), the glass substrate 11 crosses the trench line TL due to the crack line CL extending along the trench line TL directly below the trench line TL. It breaks in the direction of DC. The conventional typical scribe line formed for breaking a glass substrate is accompanied by a crack line CL, and is not formed in a crack-free state.

Next, the glass substrate 11 is separated along a break line BL at which the point N2 on the upper surface SF1 of the glass substrate 11 intersects the trench line TL. This separation can be performed, for example, by the formation of a usual scribe line along the break line BL, and the usual break step thereafter.

Referring to FIG. 54, the end surface SE exposing the trench line TL is formed by the above separation (FIG. 52: step S330). The normal direction (normal vector) DN of the end surface SE on the portion where the trench line TL is exposed has a component in 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 the glass substrate 11 is performed in a manner to maintain a crack-free state. Therefore, the load applied to the cutting edge when the groove line TL is formed may be a size sufficient to cause plastic deformation on the upper surface SF1 but not excessively large.

Second, the surface roughness of the end surface SE is increased. This step can be performed by machining at least the portion of the end surface SE where the groove line TL is exposed, and, specifically, by grinding the portion of the end surface SE where the groove line TL is exposed. get on. This grinding can be performed using a tool such as a file or a grindstone with a shaft.

Next, the glass substrate 11 is cut along the trench line TL (FIG. 52: Step S340). For that purpose Next, a cracking step of applying stress to a portion of the groove line TL exposed on the end surface SE is performed, so that the crack extends along the groove line TL with the portion as a starting point. The breaking step may be performed multiple times according to the number of the trench lines TL. In the following, the details of the cutting step which is preferably performed will be described.

Referring to FIG. 56, the glass substrate 11 (FIG. 53) in which the trench line TL is formed is opposed to the stage 80 with the spacer 81 interposed therebetween via the spacer 81. Placed on the stage 80.

A breaking lever 85 is prepared with reference to FIG. 57. Next, the breaking lever 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 arrow CT1, the above-mentioned contact portion extends along the groove line TL and approaches the side of the end surface SE. At the time of the above-mentioned initial contact, or by the subsequent expansion of the contact portion, the breaking rod 85 comes into contact with the portion SP3 of the lower surface SF2 that is opposite to the portion TP1 of the groove line TL that leaves from the end surface SE, And it is in a state of leaving from a portion TP2 of the lower surface SF2 that is connected to the end surface SE of the trench line TL. This selective contact can be easily obtained, for example, by changing the posture of the breaking lever 85 having a certain degree of elasticity. Furthermore, at this point in time, a portion TP1 of the trench line TL is maintained in a crack-free state.

Referring to FIG. 58, as shown by the arrow CT2, the expansion is further advanced so that the above-mentioned contact portion reaches the portion SP4. In other words, while maintaining the state where the breaking lever 85 is in contact with the portion SP3 of the lower surface SF2, the breaking lever 85 is in contact with the portion SP4 of the lower surface SF2. As a result, the breaking lever 85 first applies stress to the portion TP1 of the trench line TL through the above steps, and thereafter, simultaneously applies stress to the portion TP2 having the exposed portion on the end surface SE. Due to the stress, a crack is extended from the exposed portion along the groove line TL (see arrow PR in FIG. 59). In other words, a crack is generated that extends from a portion TP2 to a portion TP1 of the trench line TL. As a result, the glass substrate 11 is cut along the trench line TL.

The glass substrate 11 is divided by the above-mentioned division steps.

When the scribing device 50 (FIG. 17 (A)) is applied to this embodiment, it is pressed The blade point 51 slides in the direction DA on the upper surface SF1. When the direction DB opposite to the direction DA is used, it is difficult to generate cracks along the trench line TL in this embodiment. It is presumed that this direction dependency is caused by the distribution of the stress in the glass substrate 11 caused by the formation of the trench line TL. Furthermore, as a modification, a scribing device 50v may be used (FIG. 21 (A)).

According to this embodiment, when the crack is extended from the portion TP2 to the portion TP1 of the trench line TL to break the glass substrate 11 (FIG. 59: arrow PR), as shown in FIG. 58, the lower surface SF2 and the portion TP1 The opposing portion SP3 contacts the breaking lever 85 in advance. This suppresses the crack from extending away from the portion TP1 of the trench line. This makes it possible to accurately cut off along the trench line TL.

In addition, in order to form a portion that is an opportunity for the crack to extend along the trench line TL, the surface roughness of the end surface SE (FIG. 55) exposing the trench line TL is increased. This makes it easy to generate a crack starting from the portion of the trench line TL exposed on the end surface SE. Therefore, even when the trench line TL is formed with a low load, it can be divided along the trench line TL (FIG. 3 (A)) without a crack directly below it.

(Embodiment 9)

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

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

Referring to FIG. 61, the end surface SE exposing the trench line TL is formed by the above separation. The normal direction DN of the end surface SE on the portion where the trench line TL is exposed has a component in the present embodiment which is opposite to the scribe direction DL (FIG. 60). The normal direction DN and the scribe direction DL are preferably substantially opposite.

Next, steps substantially the same as those in the eighth embodiment are performed. That is, the surface roughness of the end surface SE is increased, and then the glass substrate 11 is cut along the groove line TL.

According to the present embodiment, it is also possible to obtain substantially the same effects as in the eighth embodiment. and then According to this embodiment, the scribing wheel 51R can be used when forming the groove line TL. Furthermore, when the scribing wheel 51R is applied to the eighth embodiment, cracks are less likely to occur along the groove line TL than in the present embodiment.

The scribing device 50 (FIG. 17 (A)) or 50v (FIG. 21 (A)) may be used instead of the scribing device 50R. In this case, it is preferable to use the direction DB, which is the opposite direction to the direction DA, instead of the direction DA, as in the eighth embodiment. This makes it easier to generate cracks along the trench line TL.

The method for cutting a brittle substrate in each of the above embodiments can be particularly preferably applied to a glass substrate, but the brittle substrate can also be made of a material other than glass. For example, as materials other than glass, ceramics, silicon, compound semiconductors, sapphire, or quartz can also be used.

Claims (5)

A method for breaking a fragile substrate includes the step of preparing a fragile substrate, the fragile substrate having a first surface and a second surface opposite to the first surface, and having a thickness direction perpendicular to the first surface; The blade tip is pressed against the first surface of the fragile substrate, and the blade tip is moved on the first surface while plastic deformation occurs on the first surface of the fragile substrate. 2 steps of the trench line; and the step of forming the trench line is to obtain the brittle substrate continuously connected at least directly above the first part of the trench line in a direction crossing the trench line The state is performed in a crack-free state; and the method for breaking the brittle substrate further includes the step of placing the brittle substrate on the carrier such that the first surface of the brittle substrate is opposite to the stage. ; And a third portion of the stress-applying member that is in contact with the first portion of the groove line on the second surface of the fragile substrate, and separates from the fourth portion that is opposite to the second portion square A step of contacting the second surface of the fragile substrate by the method; and a step of contacting the stress applying member is performed in a manner that the first part is maintained in a crack-free state; and the method for breaking the fragile substrate further includes the following steps. : Maintaining the state where the stress applying member is in contact with the third portion of the second face of the brittle substrate while keeping the stress applying member in contact with the fourth portion of the second face of the brittle substrate, while A crack is generated extending from the second portion to the first portion of the groove line, and the fragile substrate is cut along the groove line. For example, the method for breaking a brittle substrate according to claim 1, before the step of breaking the brittle substrate, further comprising the step of generating a crack only along the second part of the first and second parts of the groove line. . For example, the method for breaking a brittle substrate according to claim 2, wherein in the step of forming the groove line, a load applied to the blade edge to form the second part of the groove line is higher than that for forming the groove. The first part of the thread and the load applied to the blade tip. For example, the method for breaking a fragile substrate according to claim 1, further comprising a step of forming a notch on the edge by causing the blade edge to cross the edge of the first surface of the fragile substrate, and the first Part 2 is located on the above-mentioned notch. The method for breaking a fragile substrate according to claim 1, before the step of breaking the fragile substrate, further comprising: forming the end surface of the second part exposing the groove line on the fragile substrate; and making the end surface Step of increasing the surface roughness.