JP2020083690A - Method of dividing laminated substrate - Google Patents

Abstract

To provide a method excellently dividing a laminated substrate.SOLUTION: The method includes: a first scribe step for introducing a first vertical crack with a depth of 30% or more and 50% or less, of a thickness of a first glass substrate from a first scribe line along an expected divide position on a surface of the first glass substrate; a second scribe step for introducing a second vertical crack with a depth of 5% or more and 10% or less, of a thickness of a second glass substrate from a second scribe line on a surface of a second glass substrate; a first braking step for extending the first vertical crack introduced in the first scribe step by contacting a braking bar to the laminated substrate after the first and second scribe steps; and a second braking step for extending the second vertical crack introduced in the second scribe step by contacting the braking bar to the laminated substrate after the first braking step.SELECTED DRAWING: Figure 4

Description

The present invention relates to a method for cutting a bonded substrate stack, and more particularly to a scribing process for cutting the bonded substrate stack.

As a method for dividing a glass substrate at a predetermined position to obtain a unit substrate, a scribing tool (such as a cutter wheel) is used to form a scribe line at a planned dividing position on one surface of the glass substrate and cracks are generated from the scribe line. A method of performing a scribe process for extending (penetrating) and then performing a break process for further extending a crack by pressing a break bar against the surface opposite to the glass substrate on which the scribe line is formed is already known. There is (for example, refer to Patent Document 1).

In addition, as a method of dividing a mother substrate (bonded substrate) formed by bonding two large-sized glass substrates at a predetermined position to obtain a unit substrate (cell substrate), the surface of each glass substrate (mother) Two scribing tools are brought into contact with each other at predetermined dividing positions (on the upper and lower sides of the substrate) in a (relative) movement direction so that a scribe line is formed by both of them at the same time, and a crack is extended from the scribe line. A method has also been known in which after performing (penetration), a break treatment is performed on a substrate having a smaller amount of crack permeation to simultaneously break the other glass substrate (for example, Patent Document 2). reference).

JP, 2016-108158, A JP, 2016-37413, A

In the case of dividing a single glass substrate, from the viewpoint of ensuring the maximum cross-sectional quality, the so-called low penetration, in which the amount of cracks penetrating from the scribe line is 15% or less of the thickness of the glass substrate, is used as scribing processing. It is preferable to scribe.

However, it is difficult to apply the same method to a bonded substrate. Specifically, although it is possible to perform low-penetration scribing treatment on each of the two bonded glass substrates, in order to extend the cracks generated in one of the glass substrates in the subsequent break treatment, It is necessary to make the pushing amount of the bar larger than in the case of a single plate, but in that case, the other glass substrate which is not the break target will break from the planned cutting position and break, so that the cutting cannot be performed well There's a problem.

Moreover, the method disclosed in Patent Document 2 performs so-called high-penetration scribing on two bonded glass substrates at the same time by performing so-called high-penetration scribing, in which the amount of crack penetration in scribing treatment is as large as 30% or more of the thickness of the glass substrate, The break is performed on the substrate having the smaller amount, but there is a problem in that the quality of the cross section of the substrate not directly subject to the break is not necessarily good. There is also a problem that the device configuration and control are complicated.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a method capable of suitably dividing a bonded substrate formed by bonding two glass substrates.

In order to solve the above problems, the invention of claim 1 is a method of cutting a bonded substrate obtained by bonding a first glass substrate and a second glass substrate at a predetermined planned cutting position, A first scribe line is formed along the planned dividing position on the surface of the first glass substrate, and the thickness of the first glass substrate is in the thickness direction of the first glass substrate from the first scribe line. First scribing step of introducing a first vertical crack having a depth of 30% or more and 50% or less, and forming a second scribe line along the planned dividing position on the surface of the second glass substrate. A second scribe that introduces a second vertical crack having a depth of 5% or more and 10% or less of the thickness of the second glass substrate from the second scribe line in the thickness direction of the second glass substrate. Step, and a first break step of bringing a break bar into contact with the bonded substrate having undergone the first and second scribing steps to extend the first vertical crack introduced in the first scribing step. And a second break step of bringing a break bar into contact with the bonded substrate having undergone the first break step and extending the second vertical crack introduced in the second scribing step. Is characterized by.

A second aspect of the present invention is the method for dividing a bonded substrate according to the first aspect, wherein in the first scribing step, grooves are provided at equal intervals on a blade edge and have a diameter of 1.0 mm to Using a first scribing wheel having a cutting edge angle of 2.0 mm and a cutting edge angle of 100° to 135°, a pushing load of the first scribing wheel with respect to the first glass substrate is 0.10 MPa to 0.20 MPa, In the second scribing step, a second scribing wheel is used, in which grooves are provided at equal intervals on the cutting edge, the diameter is 1.0 mm to 2.0 mm, and the cutting edge angle is 100° to 135°. The pushing load of the second scribing wheel with respect to the second glass substrate is set to 0.02 MPa to 0.16 MPa.

The invention of claim 3 is the method for cutting a bonded substrate according to claim 1 or 2, wherein the cutting edge angle is 50° to 90° in the first break step and the second break step. And the tip of the cutting edge is a curved bar having a cross-sectional curvature radius of 25 μm to 100 μm, and the pushing amount of the break bar into the first glass substrate in the first break step is 0.04 mm to 0. The pressing amount of the break bar with respect to the second glass substrate in the second break step is 0.10 mm to 0.14 mm.

According to the inventions of claims 1 to 3, it is possible to perform the cutting with the quality of the cross section suitably secured to the bonded substrate formed by bonding the two glass substrates.

It is a figure which shows typically the structure of the bonded board|substrate 10 used as the object of division|segmentation along a thickness direction in the division|segmentation method which concerns on this Embodiment, and the mode after division. 6 is a diagram for explaining formation of scribe lines on the bonded substrate stack 10. FIG. It is a figure which shows the mode of the bonded substrate stack 10 after a 1st scribing process and a 2nd scribing process are complete|finished. FIG. 6 is a diagram for explaining a break process for the bonded substrate stack 10. FIG. 6 is a diagram for explaining a break process for the bonded substrate stack 10. FIG. 6 is a diagram for explaining a break process for the bonded substrate stack 10. FIG. 6 is a diagram for explaining a break process for the bonded substrate stack 10. It is a figure which shows a mode after the bonded substrate stack 10 is cut along the planned cutting position P. FIG. It is a figure which shows the mode before a 1st break process at the time of performing a low penetration scribe in a 1st scribe process. It is a figure which shows the mode after a 1st break process at the time of performing a low penetration scribe in a 1st scribe process.

<Outline of substrate>
FIG. 1 is a diagram schematically showing a configuration of a bonded substrate 10 to be divided along the thickness direction in the dividing method according to the present embodiment, and a state after the division.

The bonded substrate 10 generally has a structure in which a first glass substrate 1 having a thickness t1 and a second glass substrate 2 having a thickness t2 are bonded to each other with an adhesive layer (adhesive material) not shown. The bonded substrate stack 10 is placed at a predetermined planned dividing position P from the non-bonding surface (lower surface in FIG. 1) of the first glass substrate 1 to the non-bonding surface (upper surface in FIG. 1) of the second glass substrate 2. By being divided along the thickness direction, it is divided into individual pieces 10a and 10b as indicated by an arrow AR1. The thickness t1 and the thickness t2 are both 0.05 mm to 0.2 mm and may be the same or different.

Further, the bonded substrate 10 may be a mother substrate for liquid crystal substrates. That is, the first glass substrate 1 is a TFT substrate, the second glass substrate 2 is a CF substrate, liquid crystal is sealed between the two, and a sealing member corresponding to an adhesive layer seals the liquid crystal. Alternatively, the two substrates may be bonded together. In this case, it is preferable that the planned dividing position is set at the position where the seal member exists.

<Details of division>
Next, a process of dividing the bonded substrate stack 10 to obtain the individual pieces 10a and 10b will be described. The dividing is roughly performed by forming a scribe line on the bonded substrate 10 by a scribe process, introducing a crack starting from the scribe line, and extending a crack by a break process.

The scribing process can be performed using a known scribing device. FIG. 2 is a diagram for explaining formation of scribe lines on the bonded substrate stack 10. More specifically, FIG. 2A shows a state of a scribing process (hereinafter referred to as a first scribing process) on the first glass substrate 1, and FIG. 2B shows a state of the second glass substrate 2. The state of the scribe process (hereinafter, second scribe process) is shown. Further, FIG. 3 is a diagram showing a state of the bonded substrate stack 10 after the first scribing process and the second scribing process are completed.

Both the first scribing process and the second scribing process can be performed using a known scribing device 100. The scribing apparatus 100 includes a stage 101 on which the bonded substrate stack 10 is mounted and fixed, and a scribing wheel (cutter wheel) 102 which is a disk-shaped member having a cutting edge having a triangular cross-section. The scribing wheel 102 is held by the scribing device 100 in a freely rotatable manner in a vertical plane.

However, the first scribing process and the second scribing process differ in the scribing conditions such as the type of scribing wheel 102 used and the scribing load. Therefore, in the present embodiment, as shown in FIG. 2A, the scribing device 100 and the scribing wheel 102 used in the first scribing process are specifically referred to as a scribing device 100A and a scribing wheel 102A, respectively, and as shown in FIG. As shown in b), the scribing device 100 and the scribing wheel 102 used in the second scribing process are particularly referred to as a scribing device 100B and a scribing wheel 102B, respectively.

In the actual use phase, the first scribing process and the second scribing process may be performed in one scribing device 100 by appropriately exchanging the scribing wheel 102A and the scribing wheel 102B.

Alternatively, the scribing wheel for high-penetration scribing and the scribing wheel for low-penetration scribing are pressed and rolled at the same time from both upper and lower sides of the bonded substrate stack 10, thereby forming scribe lines and extending vertical cracks. A mode in which both the glass substrate 1 and the second glass substrate 2 are simultaneously performed may be used.

As shown in FIG. 2A, in the first scribing process, the scribing wheel 102A is set while the bonded substrate 10 is placed and fixed on the stage 101 in a posture in which the first glass substrate 1 is on the upper side. The surface of the first glass substrate 1 is pressed and rolled along the planned dividing position P. On the other hand, as shown in FIG. 2B, in the second scribing process, the scribing wheel 102B with the bonded substrate 10 mounted and fixed on the stage 101 in a posture in which the second glass substrate 2 is on the upper side. On the surface of the second glass substrate 2 along the planned dividing position P by pressure contact rolling.

As a result, as shown in FIG. 3, scribe lines SL are formed along the planned dividing positions P on both the surfaces of the first glass substrate 1 and the second glass substrate 2, and cracks are generated from the respective scribe lines SL. CR1 and CR2 extend. The rolling of the scribing wheel 102A may be relative due to the movement of the stage 101 that fixes the bonded substrate stack 10.

More specifically, in the first scribing process, the depth (penetration depth) d1 of the vertical crack extending (penetrating) from the surface of the first glass substrate 1 is 0.3t1 to 0.5t1 (30 of the thickness t1). % To 50%), and the second scribing process is performed so that the depth (penetration depth) d2 of the vertical crack extending (penetrating) from the surface of the second glass substrate 2 is 0.05t2 to 0. It is performed so as to be 1t2 (5% to 10% of the thickness t2).

In other words, the first scribing process has a larger ratio of the penetration depth to the thickness of the glass substrate than the second scribing process. Therefore, the first scribing process is also called a high penetration scribe, and the second scribing is also called a low penetration scribe.

More specifically, in the first scribing process for performing high-penetration scribing, the scribing wheel 102A is provided with the groove portions G at equal intervals on the cutting edge, has a diameter of 1.0 mm to 2.0 mm, and has a cutting edge angle. Is preferably 100° to 135°, and the pressing load, which is the load applied by the scribing wheel 102A to the first glass substrate 1 during pressure contact, is preferably 0.10 MPa to 0.20 MPa. Further, in the second scribing process for performing low-penetration scribing, as the scribing wheel 102B, a large number of groove portions G are provided at equal intervals on the cutting edge, the diameter is 1.0 mm to 2.0 mm, and the cutting edge angle is It is preferable to use a material having an angle of 100° to 135° and a pushing load of 0.02 MPa to 0.16 MPa. Specific scribe conditions may be set according to the material and thickness of the bonded substrate stack 10.

When the scribe process is performed, the break process is subsequently performed. The break treatment includes a first break treatment for expanding the crack CR1 formed on the first glass substrate 1 in the first scribing treatment and a crack CR2 formed on the second glass substrate 2 for the second scribing treatment. Two-stage processing including the second break processing for extending In other words, after performing the first break process for the crack formed by the high penetration scribe, the second break process for the crack formed by the low penetration scribe process is performed.

The first break process and the second break process can be performed using a known (common) break device. 4 to 7 are diagrams for explaining the break process for the bonded substrate stack 10. The break processing can be performed using a known break device 200.

The break device 200 is a break bar which is a plate-like member having at least a surface portion made of an elastic body and capable of downwardly supporting a break target in a horizontal posture and a vertically downwardly-shaped triangular cutting edge 202e in cross section. And 202.

The break bar 202 is a plate-shaped metal (for example, cemented carbide) member in which a cutting edge 202e having an isosceles triangular shape in cross section is provided so as to extend in the blade crossing direction. 4 and 6, the break bar 202 is shown so that the blade crossing direction is perpendicular to the drawings. As the break bar 202, it is preferable to use one having an angle of the cutting edge 202e (blade angle) of 50° to 90° and a tip of the cutting edge 202e having a curved surface having a cross-sectional curvature radius of 25 μm to 100 μm. .. Specific break conditions may be determined according to the material and thickness of the bonded substrate stack 10.

During the break process, the bonded substrate 10 is placed and fixed on the support 201 with the surface of the first glass substrate 1 bonded to the dicing tape DT stretched on a dicing ring (not shown). More specifically, a protective film (not shown) is attached to the surface of the second glass substrate 2 when mounting and fixing.

FIG. 4 exemplifies a case where the first break process is performed in which the crack CR1 introduced along the planned dividing position P on the first glass substrate 1 is extended.

In such a case, in the bonded substrate 10, the first glass substrate 1 that is the target of extension of the crack CR1 is on the lower side, and the second glass substrate 2 side is on the upper side (in other words, the dicing tape DT is brought into contact with the support 201). )), and the position P and the cutting edge 202e of the break bar 202 are located in the same plane, and are fixedly mounted on the support 201.

In other words, the bonded substrate stack 10 and the break bar 202 are positioned so that the cutting edge 202e of the break bar 202 is positioned vertically above the crack CR2 formed in the second glass substrate 2.

Then, the break bar 202 positioned in this manner is lowered, and even after the cutting edge 202e thereof comes into contact with the second glass substrate 2 (to a protective film not shown in more detail), a predetermined distance (this Is referred to as the pushing amount). As a result, the crack CR1 extends along the planned dividing position P and extends to the opposite surface of the first glass substrate 1 as shown in FIG.

When the first break process is completed, subsequently, a second break process of extending the crack CR2 introduced along the planned dividing position P in the second glass substrate 1 is performed. FIG. 6 illustrates a case where the second break process is performed. The second break process is performed with the bonded substrate stack 10 turned upside down as compared with the case of the first break process. That is, in the second break process, in the bonded substrate 10, the second glass substrate 2 which is the target of extension of the crack CR2 is on the lower side, and the first glass substrate 1 side is on the upper side (in other words, a protective film (not shown)). The supporting member 201 is mounted and fixed on the supporting member 201 in such a manner that the planned dividing position P and the cutting edge 202e of the break bar 202 are located in the same plane.

In other words, the bonded substrate stack 10 and the break bar 202 are positioned so that the cutting edge 202e of the break bar 202 is located vertically above the crack CR1 formed in the first glass substrate 1.

Then, the break bar 202 positioned in this manner is lowered, and even after the cutting edge 202e thereof comes into contact with the first glass substrate 1 (more specifically, the dicing tape DT), the predetermined pushing amount is reached. Is pushed in. As a result, the crack CR2 extends along the planned dividing position P and reaches the opposite surface of the second glass substrate 2 as shown in FIG.

By performing the second break process, the bonded substrate stack 10 is divided along the planned division position P. In other words, it means that the cracks CR1 and CR2 formed at the planned dividing position P form a dividing plane.

FIG. 8 is a diagram showing a state after the bonded substrate stack 10 has been cut along the planned cutting position P. Specifically, the dicing tape DT attached to the surface of the first glass substrate 1 is stretched by an unillustrated expanding device by being pulled in opposite directions as indicated by arrows AR2a and AR2b in FIG. Be expanded (expanded). As a result, the two portions that were still in contact with each other at the dividing plane after the division are separated from each other to obtain the individual pieces 10a and 10b shown in FIG.

<Effects of proper use of scribe processing>
In the method for cutting a bonded substrate according to the present embodiment, as described above, high penetration scribing is performed on the first glass substrate 1 in the first scribing process and second glass substrate 2 in the second scribing process. After performing low-penetration scribing on the first glass substrate 1, a first break process for extending the crack CR1 formed on the first glass substrate 1 and a second break process for extending the crack CR2 formed on the second glass substrate 2 are performed. And, in that order. The effects obtained by this aspect will be described below.

FIG. 9 and FIG. 10 are diagrams showing the states before and after the first break process when the low penetration scribe is performed not only in the second scribe process but also in the first scribe process preceding this, which is shown as a comparative example. .. In addition, for simplification of discussion, it is assumed that the first glass substrate 1 and the second glass substrate 2 have the same thickness t.

For example, as shown in FIG. 9, both the first scribing process and the second scribing process are low-penetration scribing, so that d=0.05t to the first glass substrate 1 and the second glass substrate 2. It is assumed that 0.1 t of cracks CR3 and CR4 respectively extend along the planned dividing position P.

In contrast to the dividing method according to the present embodiment in which the first scribing process is a high-penetration scribing as shown in FIG. Since the ratio to the substrate thickness is smaller than in the case of the present embodiment, if the crack CR3 in the first glass substrate 1 is further expanded by the first break processing, the crack CR3 will be smaller than in the case of the present embodiment. It is necessary to increase the pushing amount. If the glass substrate is a single plate, no particular problem occurs. However, in the case of the bonded substrate, as shown in FIG. 10, not only the extension of the crack CR3 in the first glass substrate 1 but also the extension of the crack CR3 In some cases, so-called co-cracking may occur in which the crack 3α extends to the glass substrate 2. The crack 3α is not necessarily formed along the planned dividing position P.

Moreover, even if the second break treatment is further performed on the second glass substrate 2 in which co-cracking has occurred, the crack CR4 does not appropriately extend along the planned dividing position P, and co-cracking occurs. In some cases, the crack 3? In such a case, the cross section of the finally obtained piece may not meet the predetermined dimensional tolerance.

On the other hand, in the case of the present embodiment, since the ratio of the depth of cracks that have already spread to the thickness of the substrate is large, the first break treatment is performed even if the pressing amount is set smaller than in the case of the proportional case. Thus, the crack CR1 can be suitably extended to the opposite surface of the first glass substrate 1. Further, since the pushing amount is small, the occurrence of co-cracking as described above is avoided. Actually, the pushing amount in the first break process may be about 0.04 mm to 0.08 mm.

Note that, also in the present embodiment, since the second scribing process is a low-penetration scribing, the pushing amount when the crack CR2 formed by the second scribing process is extended in the second break process is the first break. Although it is necessary to make the amount larger than the indentation in the processing, since the crack CR1 has already spread from the surface to the adhesive surface in the first glass substrate 1, co-cracking such as proportionality does not occur. Actually, the pushing amount in the second break process may be about 0.10 mm to 0.14 mm.

For example, for the bonded substrate 10 having t1=t2=0.15 mm, the first scribing process, the second scribing process, the first break process, and the second break process are performed under the following conditions. Is exemplified. However, as the scribing wheel 102 (102A, 102B), one having groove portions G provided at the blade edge at equal intervals is used.

First scribe process:
Diameter of scribing wheel: 2mm;
Blade angle of scribing wheel: 100° to 110°;
Pushing load: 0.12 MPa to 0.18 MPa.

Second scribe process:
Diameter of scribing wheel: 2mm;
Blade angle of scribing wheel: 120° to 130°;
Pushing load: 0.1 MPa to 0.16 MPa.

First break process:
Break bar edge angle: 50° to 90°;
Radius of curvature of cross section of break bar tip: 25 μm to 100 μm;
Indentation amount: 0.06 mm to 0.08 mm.

Second break process:
Break bar edge angle: 50° to 90°;
Radius of curvature of cross section of break bar tip: 25 μm to 100 μm;
Indentation amount: 0.10 mm to 0.14 mm.

By the way, in the break process after performing the high penetration scribe on the first glass substrate 1 and the low penetration scribe on the second glass substrate 2, the second glass substrate 2 is targeted for the first break treatment. It is not preferable to do so. In such a case, in order to extend the crack in the second glass substrate 2, it is necessary to set the pushing amount to be the same as the above-described proportionality, and therefore co-cracking may occur.

In addition, from the viewpoint of the quality of the cross section of the glass substrate (for example, flatness, perpendicularity to the surface, etc.), when the crack formed by the low-penetration scribe is extended, the crack formed by the high-penetration scribe is extended. Although it is better than the case of co-cracking, the latter is superior in cutting quality to the quality of the cross section obtained by co-cracking, and the probability of deviation from the dimensional tolerance is sufficiently small in the case of co-cracking. Therefore, also from the viewpoint of yield, it can be said that the dividing method according to the present embodiment is superior in comparison.

However, although it is possible to provide a break treatment after performing high penetration scribing on both of the bonded glass substrates, the target of the second break treatment is to ensure the quality of the cut surface as much as possible. It is desirable to form such cracks by low-penetration scribe.

As described above, according to the present embodiment, when a bonded substrate formed by bonding two glass substrates together is cut, high penetration scribe is performed on one substrate and the other substrate is scribed. Perform low-penetration scribing to infiltrate the cracks in each, then spread the cracks formed by the high-penetration scribe by the break process first, and then spread the cracks formed by the low-penetration scribe by the break process. By doing so, it is possible to carry out the cutting in which the quality of the cross section is suitably ensured.

<Modification>
As long as the first break process for the first glass substrate 1 on which the high-permeation scribe is performed precedes the second break process for the second glass substrate 2 on which the low-permeation scribe is performed, the first scribe step and the second scribe process are performed. The order may be exchanged with the scribing process. In other words, a mode in which the low penetration scribe is performed on the second glass substrate 2 and then the high penetration scribe is performed on the first glass substrate 1 may be performed.
When the bonded substrate 10 is a mother substrate for a liquid crystal substrate, the first glass substrate 1 may be a CF substrate and the second glass substrate 2 may be a TFT substrate.

In the above-described embodiment, the case where the division is performed for one planned division position is taken as an example, but a plurality of planned division positions may be set for one bonded substrate. In such a case, the first scribing process, Each of the second scribing process, the first break process, and the second break process may be performed on all the planned dividing positions after the completion of the process for all the planned dividing positions.

1 First Glass Substrate 2 Second Glass Substrate 100 Scribing Device 101 Stage 102 (102A, 102B) Scribing Wheel 200 Break Device 201 Support 202 Break Bar 202e (Break Bar) Cutting Edge CR1, CR2, CR3, CR3α, CR4 Crack DT Dicing tape G Groove part (of scribing wheel) P Cutting position SL SL scribe line

Claims (3)

A method for cutting a bonded substrate obtained by bonding a first glass substrate and a second glass substrate at a predetermined planned cutting position,
A first scribe line is formed along the planned dividing position on the surface of the first glass substrate, and a first scribe line of the first glass substrate is formed from the first scribe line in the thickness direction of the first glass substrate. A first scribing step of introducing a first vertical crack having a depth of 30% or more and 50% or less of the thickness;
A second scribe line is formed on the surface of the second glass substrate along the planned dividing position, and a second scribe line of the second glass substrate is formed from the second scribe line in the thickness direction of the second glass substrate. A second scribing step of introducing a second vertical crack having a depth of 5% or more and 10% or less of the thickness;
A first break step of bringing a break bar into contact with the bonded substrate having undergone the first and second scribing steps to extend the first vertical crack introduced in the first scribing step;
A second break step of bringing a break bar into contact with the bonded substrate after the first break step to extend the second vertical crack introduced in the second scribing step;
A method for cutting a bonded substrate, comprising: The method for cutting a bonded substrate according to claim 1,
In the first scribing step, a first scribing wheel is used, in which grooves are provided at equal intervals on the cutting edge, the diameter is 1.0 mm to 2.0 mm, and the cutting edge angle is 100° to 135°. And a pressing load of the first scribing wheel with respect to the first glass substrate is 0.10 MPa to 0.20 MPa,
In the second scribing step, a second scribing wheel is used, in which grooves are provided at equal intervals on the cutting edge, the diameter is 1.0 mm to 2.0 mm, and the cutting edge angle is 100° to 135°. And a pushing load of the second scribing wheel with respect to the second glass substrate is 0.02 MPa to 0.16 MPa.
A method for cutting a bonded substrate, comprising: A method for cutting a bonded substrate according to claim 1 or 2, wherein
In the first break step and the second break step, a break bar having a cutting edge angle of 50° to 90° and a cutting edge having a curved surface having a radius of curvature of 25 μm to 100 μm is used.
In the first break step, the pressing amount of the break bar with respect to the first glass substrate is 0.04 mm to 0.08 mm,
In the second break step, the pressing amount of the break bar with respect to the second glass substrate is 0.10 mm to 0.14 mm.
A method for cutting a bonded substrate, comprising:

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