TWI647081B - Breaking method of brittle substrate - Google Patents

Abstract

An object of the present invention is to provide a fragile substrate provided with a film stably.

In the present invention, the knife edge 51 is caused to slide plastically on the surface SF1 of the brittle substrate 4 to cause plastic deformation, thereby forming the groove line TL. The process of forming the trench line TL is performed as follows: a crack-free state is obtained in which the brittle substrate 4 is continuously connected in a direction crossing the trench line TL directly below the trench line TL. A film 21 is formed on the surface SF1 of the fragile substrate 4 so as to at least partially cover the trench line TL. Then, the crack is extended along the trench line TL to form a crack line CL.

Description

Breaking method of brittle substrate

The present invention relates to a method for breaking a brittle substrate, and more particularly to a method for breaking a brittle substrate provided with a film.

In the manufacture of electrical devices such as flat display panels or solar cell flat panels, it is often necessary to break brittle 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 milling cutter. By sliding or rolling the milling cutter on the substrate, a groove is formed on the substrate by plastic deformation, and at the same time, a vertical crack is formed directly below the groove. Thereafter, stress is applied in a so-called breaking step. The crack is completely advanced in the thickness direction by the breaking step, thereby breaking the substrate.

A film may be provided on the broken brittle substrate. In this case, the surface of the fragile substrate is scribed with the film. For example, Japanese Patent Application Laid-Open No. 2000-280234 discloses a method for cutting a color filter substrate for a flat display panel. The color filter substrate is manufactured by an inkjet method and has an ink containing layer and a protective layer provided on a glass substrate. When a film is provided on the substrate in this manner, the scribing is liable to become unstable. In order to cope with the problem, according to the technique of the above-mentioned publication, the scribing conditions are changed during the formation of the scribing.

[Prior technical literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2000-280234

Although attempts have been made to improve the technique described in the aforementioned publication, it is still difficult to form a scribe line stably on a brittle substrate provided with a film. It is considered that it is difficult to optimize the scribing conditions for both the material of the film and the material of the fragile substrate. If the formation of the scribe line is unstable, the breaking of the substrate using it is also unstable.

The present invention has been made in order to solve the above-mentioned problems, and an object thereof is to provide a method for breaking a brittle substrate that can stably break a brittle substrate provided with a film.

The cutting method of the brittle substrate of the present invention includes the following steps: preparing a brittle substrate having a surface and having a thickness direction perpendicular to the surface; pressing a blade tip on the surface of the brittle substrate; and pressing the blade through the pressing step The blade tip slides on the surface of the fragile substrate, thereby plastically deforming on the surface of the fragile substrate to form a groove line having a groove shape. The step of forming the groove line may be performed as follows: a state in which the brittle substrate is continuously connected in a direction crossing the groove line, that is, a crack-free state, is provided directly below the groove line. In addition, the method for breaking a brittle substrate of the present invention further includes the following steps: after the step of forming the groove line, forming a film that at least partially covers the groove line on the surface of the brittle substrate; and After the step, a crack line is formed by extending a crack in the brittle substrate along the groove line in the thickness direction. Through the crack line, the fragile substrate is continuously connected and disconnected immediately below the groove line in a direction crossing the groove line. The method for cutting a brittle substrate of the present invention further includes a step of cutting the brittle substrate along the crack line.

In addition, the above-mentioned "pressing the blade tip against the surface" means pressing the blade tip at any position on the "surface", so it can also mean pressing the blade tip on the edge of the "surface".

According to the present invention, as a line defining a position for breaking a brittle substrate, a groove line having no cracks is formed directly below it. The crack line used as a direct opportunity for breaking is It is formed after the trench line is formed. Thus, the brittle substrate after the formation of the trench line and before the formation of the crack line not only specifies the position to be broken by the trench line, but also because the crack line has not yet been formed, it is in a state where no break is easily generated. In this state, a film is formed on the trench line, that is, a line at which the position where the brittle substrate is to be broken is defined. Thereafter, the crack line used as a direct opportunity for breaking is formed by extending the crack to align itself along the groove line. Thereby, a crack line can be formed stably without being affected by the presence of a film. Therefore, the brittle substrate can be stably separated.

4‧‧‧ glass substrate (brittle substrate)

4a‧‧‧ substrate

4b‧‧‧ substrate

11‧‧‧ Components

21‧‧‧ film

21a‧‧‧Part

21b‧‧‧part

22‧‧‧ film

22a‧‧‧part

22b‧‧‧part

50‧‧‧ cutting appliances

50p‧‧‧ cutting device

51‧‧‧Blade

51P‧‧‧Blade

51v‧‧‧ blade

52‧‧‧Handle

52p‧‧‧knife holder

AL‧‧‧Auxiliary line

AX‧‧‧axis direction

CL‧‧‧ crack line

DA‧‧‧ Direction

DB‧‧‧ Direction

DC‧‧‧ direction

DT‧‧‧thickness direction

ED1‧‧‧ side (first side)

ED2‧‧‧ side (second side)

ED3‧‧‧side

ED4‧‧‧Edge

FB‧‧‧External Force

HL‧‧‧Incision

IB-IB‧‧‧line

IIB-IIB‧‧‧line

IIIB-IIIB‧‧‧line

IVB-IVB‧‧‧line

IXB-IXB‧‧‧line

N1‧‧‧ position (1st position)

N2‧‧‧ position (2nd position)

N3‧‧‧Location

N4‧‧‧Location

PP‧‧‧ protrusion

PPv‧‧‧ protrusion

PS‧‧‧Side

PSv‧‧‧ Side

SC‧‧‧ cone

SD1‧‧‧Top (first side)

SD2‧‧‧ side (second side)

SD3‧‧‧side (3rd side)

SF1‧‧‧upper surface (surface)

SF2‧‧‧ lower surface

SL‧‧‧ crossed

S10 ~ S60‧‧‧‧step

TL‧‧‧Trench line

UL‧‧‧ incision

VB-VB‧‧‧line

VIB-VIB‧‧‧line

XEt‧‧‧End

XES‧‧‧End

XB-XB‧‧‧line

XIB-XIB‧‧‧line

XIIB-XIIB‧‧‧line

XIIIB-XIIIB‧‧‧line

XIVB-XIVB‧‧‧line

XIXB-XIXB‧‧‧line

XVB-XVB‧‧‧line

XVIB-XVIB‧‧‧line

XVIIB-XVIIB‧‧‧line

XVIIIB-XVIIIB‧‧‧line

XXB‧‧‧arrow

XXXIIIB‧‧‧Arrow

FIG. 1 is a schematic plan view (A) showing a method for cutting a brittle substrate according to Embodiment 1 of the present invention, and a schematic cross-sectional view (B) along the line IB-IB.

FIG. 2 is a schematic plan view (A) showing a method for cutting a brittle substrate according to Embodiment 1 of the present invention, and a schematic cross-sectional view (B) along the line IIB-IIB.

FIG. 3 is a schematic plan view (A) showing a method for cutting a brittle substrate according to Embodiment 1 of the present invention, and a schematic cross-sectional view (B) along a line IIIB-IIIB thereof.

FIG. 4 is a schematic plan view (A) showing a method for cutting a brittle substrate according to Embodiment 1 of the present invention, and a schematic cross-sectional view (B) along the line IVB-IVB.

FIG. 5 is a schematic plan view (A) showing a method for cutting a brittle substrate according to Embodiment 1 of the present invention, and a schematic cross-sectional view (B) along the line VB-VB.

FIG. 6 is a schematic plan view (A) showing a method for cutting a brittle substrate according to Embodiment 1 of the present invention, and a schematic cross-sectional view (B) along the line VIB-VIB.

FIG. 7 is a cross-sectional view (A) schematically showing the structure of a trench line formed in a method for breaking a brittle substrate according to Embodiment 1 of the present invention, and a cross-sectional view (B) schematically showing the structure of a crack line.

FIG. 8 is a flowchart schematically showing the structure of a method for cutting a brittle substrate according to Embodiment 1 of the present invention.

FIG. 9 is a plan view (A) showing a method of breaking a brittle substrate in a comparative example, and a cross-sectional view (B) along the line IXB-IXB.

FIG. 10 is a plan view (A) and a cross-sectional view (B) along a line XB-XB of a brittle substrate cutting method of a comparative example.

FIG. 11 is a schematic plan view (A) showing a method for cutting a brittle substrate according to Embodiment 2 of the present invention, and a schematic cross-sectional view (B) along the line XIB-XIB.

FIG. 12 is a schematic plan view (A) showing a method for cutting a brittle substrate according to Embodiment 2 of the present invention, and a schematic cross-sectional view (B) along the line XIIB-XIIB.

FIG. 13 is a schematic plan view (A) showing a method for cutting a brittle substrate according to Embodiment 2 of the present invention, and a schematic cross-sectional view (B) along the line XIIIB-XIIIB.

FIG. 14 is a schematic plan view (A) showing a method for cutting a brittle substrate according to Embodiment 2 of the present invention, and a schematic cross-sectional view (B) along the line XIVB-XIVB.

15 is a schematic plan view (A) showing a method for cutting a brittle substrate according to Embodiment 2 of the present invention, and a schematic cross-sectional view (B) along a line XVB-XVB.

FIG. 16 is a plan view (A) showing a method for breaking a brittle substrate of a comparative example, and a cross-sectional view (B) along a line XVIB-XVIB thereof.

FIG. 17 is a plan view (A) and a cross-sectional view (B) along a line XVIIB-XVIIB of a brittle substrate cutting method of a comparative example.

FIG. 18 is a schematic plan view (A) showing a method for breaking a brittle substrate according to a modified example of Embodiment 2 of the present invention, and a schematic cross-sectional view (B) along the line XVIIIB-XVIIIB.

FIG. 19 is a schematic plan view (A) showing a method for breaking a brittle substrate according to a modified example of Embodiment 2 of the present invention, and a schematic cross-sectional view (B) along the line XIXB-XIXB.

Fig. 20 is a side view (A) schematically showing the configuration of an apparatus used in a method for breaking a fragile substrate according to Embodiment 3 of the present invention, and an outline view of the apparatus possessed by the above-mentioned apparatus is shown from an arrow XXB point of Fig. 20 (A). Top view of the structure of the blade (B).

21 (A) and 21 (B) are plan views schematically showing a method for cutting a brittle substrate according to Embodiment 3 of the present invention.

22 (A) and (B) are schematic views showing the brittleness of the first modification of the third embodiment of the present invention. Top view of the method of breaking the substrate.

Fig. 23 is a plan view schematically showing a method for breaking a brittle substrate according to a second modification of the third embodiment of the present invention.

FIG. 24 is a plan view schematically showing a method for breaking a brittle substrate according to a third modification of the third embodiment of the present invention.

FIG. 25 is a plan view schematically showing a first step of a method for cutting a brittle substrate according to Embodiment 4 of the present invention.

Fig. 26 is a plan view schematically showing a second step of the method for cutting a brittle substrate according to the fourth embodiment of the present invention.

Fig. 27 is a plan view schematically showing a third step of the method for cutting a brittle substrate according to the fourth embodiment of the present invention.

FIGS. 28 (A) and 28 (B) are plan views schematically showing a method for cutting a brittle substrate according to a first modification of the fourth embodiment of the present invention.

Fig. 29 is a plan view schematically showing a method for cutting a brittle substrate according to a second modification of the fourth embodiment of the present invention.

30 (A) and (B) are plan views schematically showing a method for cutting a brittle substrate according to Embodiment 5 of the present invention.

31 (A) and (B) are plan views schematically showing a method for cutting a brittle substrate according to Embodiment 6 of the present invention.

Fig. 32 is a plan view schematically showing a method for cutting a brittle substrate according to a modification of the sixth embodiment of the present invention.

Fig. 33 is a side view (A) schematically showing the configuration of an appliance used in a method for breaking a fragile substrate according to Embodiment 7 of the present invention, and an outline view of the appliance possessed by the appliance at the point of view of arrow XXXIIIB in Fig. 33 (A). Top view of the structure of the blade (B).

Hereinafter, embodiments of the present invention will be described based on the drawings. In addition, for the following figure The same or equivalent parts in the formula are marked with the same reference numbers without repeating their descriptions.

(Embodiment 1)

A method of dividing the brittle substrate according to this embodiment will be described below.

1 (A) and (B), first, a glass substrate 4 (brittle substrate) is prepared (FIG. 4: Step S10). The glass substrate 4 has an upper surface SF1 (front surface) and a lower surface SF2 opposite thereto. The glass substrate 4 has a thickness direction DT perpendicular to the upper surface SF1. In addition, a cutting tool 50 having a blade tip 51 and a handle 52 is prepared. The tool tip 51 is held by being fixed to a tool holder 52 serving as a holder thereof.

Next, the blade tip 51 is pressed against the upper surface SF1 of the glass substrate 4 (FIG. 8: Step S20). Next, the pressed blade point 51 is slid on the upper surface SF1 of the glass substrate 4 (see the arrow in FIG. 1 (A)).

2 (A) and (B), plastic deformation occurs on the upper surface SF1 of the glass substrate 4 by the above-mentioned sliding of the blade tip 51. Thereby, a trench line TL having a trench shape is formed on the upper surface SF1 (FIG. 8: Step S30). Referring to FIG. 7 (A), the process of forming the trench line TL can be performed as follows: obtained directly below the trench line TL, the extending direction of the glass substrate 4 and the trench line TL (the lateral direction of FIG. 2 (A)) The state of continuous connection in the direction of crossing DC is a state without cracks. In the crack-free state, although the trench line TL is formed by plastic deformation, no crack is formed along it. Therefore, even if an external force such as a bending moment is simply applied to the glass substrate 4 as in the previous breaking process, a break along the groove line TL is not easily generated. Therefore, the breaking process along the trench line TL is not performed in a state without a crack line. In order to obtain a crack-free state, the load applied to the blade tip 51 is set to a level where cracks do not occur and a level where plastic deformation occurs.

The crack-free state must be maintained for a necessary period of time. To maintain a crack-free state, it is only necessary to avoid operations such as applying excessive stress on the glass substrate 4 in the trench line TL, such as applying a large external stress that may cause damage to the substrate or heating accompanied by a large temperature change. .

3 (A) and (B), a film 21 is formed on the surface SF1 of the glass substrate 4 while maintaining a crack-free state (FIG. 8: Step S40). The film 21 is formed so as to at least partially cover the trench line TL. The film 21 may be made of an inorganic material, and may particularly be made of a metal.

4 (A) and 4 (B), the glass substrate 4 is processed while maintaining a crack-free state. For example, the member 11 is provided on the film 21. The member 11 may also be separated from the trench line TL. The member 11 has a portion across the trench line TL. A member (not shown) may be provided on the lower surface SF2. The step of providing a member can be performed, for example, by joining a previously prepared member or depositing a raw material.

5A and 5B, after the film 21 is formed as described above, the crack of the glass substrate 4 is extended along the groove line TL in the thickness direction DT. Thereby, the crack line CL is formed in alignment with the trench line TL by itself (FIG. 8: Step S50). Referring to FIG. 7 (B), through the crack line CL, directly below the trench line TL, the glass substrate 4 is continuous in the direction DC crossing the extending direction of the trench line TL (lateral direction of FIG. 5 (A)). Disconnected. Here, the so-called "continuous connection", in other words, the connection without being cut by a crack. In addition, in a state of being continuously connected and disconnected as described above, parts of the glass substrates 4 may be in contact with each other through the cracks of the crack line CL.

The formation of the crack line CL is started, for example, by applying a stress such as releasing the internal stress and strain near the trench line TL to the glass substrate 4 due to the end portion XEx or XEt of the trench line TL. The stress is applied by, for example, pressing the blade edge again on the formed trench line TL to generate external stress, or by applying heat such as laser light irradiation.

6 (A) and (B), the glass substrate 4 is divided into substrate pieces 4a and 4b along the crack line CL (FIG. 8: Step S60). That is, a so-called breaking process is performed. The breaking step can be performed, for example, by applying an external force FB to the glass substrate 4 (FIG. 5 (B)). By the tension applied to the film 21 when the glass substrate 4 is cut, the film 21 is cut into portions 21 a and 21 b together with the glass substrate 4. Thereby, the substrate sheet 4a provided with the portion 21a provided with the film 21 and the substrate sheet 4b provided with the portion 21b provided with the film 21 were obtained.

Next, a method for cutting the glass substrate 4 of the comparative example will be described below. In this comparative example, a general scribing step and a breaking step were performed.

9 (A) and (B), in this comparative example, the trench line TL is not formed, and the film 21 and the member 11 are provided on the glass substrate 4. Next, the blade tip 51 is pressed against the upper surface SF1 of the glass substrate 4. Next, the pressed blade point 51 is slid on the upper surface SF1 on which the film 21 is provided (see the arrow in FIG. 9 (A)).

Referring to FIGS. 10 (A) and (B), the film 21 is divided into portions 21a and 21b by the above-mentioned sliding of the blade tip 51. At the same time, a crack line SL is formed on the upper surface SF1 of the glass substrate 4. Next, the glass substrate 4 is cut along the scribe line SL in a breaking step.

In the comparative example, the upper surface SF1 of the glass substrate 4 is scribed together with the film 21. In this case, the formation of the scribe line SL used as a direct opportunity for breaking the glass substrate 4 is likely to become unstable. As a result, the breaking of the glass substrate 4 is liable to become unstable. In addition, the quality of the cut surface of the film 21 is liable to decrease.

On the other hand, according to this embodiment, as a line defining the position where the glass substrate 4 is to be broken, a trench line TL having no cracks immediately below it is formed. The crack line CL used as a direct opportunity for breaking is formed after the trench line TL is formed. With this, the glass substrate 4 after forming the trench line TL and before forming the crack line CL not only specifies the position where the glass substrate 4 is to be cut off by the trench line TL, but because the crack line CL has not yet been formed, it is in a position where it is not easy to generate a break. Off state. In this state, the film 21 is formed on the trench line TL, that is, a line at which the position where the glass substrate 4 is to be broken is defined. Thereafter, the crack line CL used as a direct opportunity for breaking is formed by extending the crack by self-alignment along the trench line TL. Thereby, the crack line CL can be formed stably without being affected by the presence of the film 21. Therefore, the glass substrate 4 can be stably cut.

The formation process of the crack line CL in this embodiment is fundamentally different from a so-called breaking process. The breaking step is a method in which the formed crack is further extended in the thickness direction to completely separate the substrate. On the other hand, the formation process of the crack line CL is a change from a crack-free state obtained by forming the trench line TL to a cracked state. The change is considered by opening It is caused by the internal stress of the crack-free state. The state of the plastic deformation when the groove line TL is formed, and the magnitude or direction of internal stress generated by the formation of the groove line TL, are both rolling using a rotary blade and sliding with a blade as in this embodiment. The situation is different. When the blade tip is used for sliding, cracks are likely to occur under a wider scribe line. Moreover, opening the internal stress requires several opportunities, and it is considered to act as such an opportunity to generate a crack on the trench line TL by using the external stress application as described above. Details of a preferred method for forming the trench line TL and the crack line CL are described in the following third to seventh embodiments.

Moreover, according to this embodiment, when the glass substrate 4 is cut, the film 21 is cut together with the glass substrate 4. Thereby, the film 21 can be cut | disconnected with the cutting | disconnection of the glass substrate 4. Therefore, it is not necessary to cut the film 21 using a cutting tool. Therefore, it is possible to avoid chipping due to cutting of the film 21. In addition, as compared with the case where the film 21 and the glass are simultaneously scribed by the knife edge 51, the wear of the knife edge 51 can be suppressed.

In the case where the film 21 is made of an inorganic material, a material that is difficult to break like a synthetic resin is not used for the film 21. Thereby, the breaking of the breaking film 21 provided with the glass substrate 4 can be surely generated. Moreover, it is possible to avoid generation of chips of the inorganic material. In addition, abrasion generated when the blade 51 scribes an inorganic material can be avoided. In particular, when the film 21 is made of a metal, a material that is difficult to break like a synthetic resin is not used for the film 21. Thereby, the breaking of the breaking film 21 provided with the glass substrate 4 can be surely generated. In addition, it is possible to avoid generation of metal chips. In addition, abrasion generated when the blade 51 scribes metal can be avoided.

(Embodiment 2)

In the method for cutting a brittle substrate according to this embodiment, first, the same steps as those in the first embodiment are performed up to the steps of FIGS. 2 (A) and (B).

11 (A) and (B), the above-mentioned crack-free state is maintained, and a film 22 is formed on the surface SF1 of the glass substrate 4 (FIG. 8: Step S40). The film 22 is formed so as to at least partially cover the trench line TL. The film 22 may be made of a synthetic resin.

12 (A) and (B), a cutting tool 50p having a blade tip 51p and a handle 52p is prepared. The blade tip 51p is held by being fixed to a handle 52p serving as its holder. The cutting tool 50 p is a person who is more suitable for processing the film 22 than the cutting tool 50.

13 (A) and (B), the cutting edge HL is cut into the film 22 along the groove line TL (refer to the arrow of FIG. 12 (A)) using the blade point 51p. The cut HL is formed by completely cutting the film 22 in the thickness direction DT of the film 22. In other words, the cut HL penetrates the film 22 in the thickness direction DT. The HL film 22 is divided into portions 22a and 22b by making an incision.

14 (A) and (B), the crack line CL is formed by the same method as that of the first embodiment (FIG. 5 (A) and (B)).

15 (A) and (B), the glass substrate 4 is divided into substrate pieces 4a and 4b along the crack line CL (FIG. 8: Step S60). That is, a so-called breaking step is performed. The breaking step is the same as in the first embodiment (FIG. 5 (B)), and can be performed by applying an external force FB to the glass substrate 4. By cutting the glass substrate 4, a substrate sheet 4a provided with a portion 22a of the film 22 and a substrate sheet 4b provided with a portion 22b of the film 22 are obtained.

Next, a method for cutting the glass substrate 4 of the comparative example will be described below. In this comparative example, a general scribing step and a breaking step were performed.

16 (A) and (B), in this comparative example, the trench line TL is not formed, and a film 22 is provided on the glass substrate 4. Next, the blade tip 51 is pressed against the upper surface SF1 of the glass substrate 4. Next, the pressed blade tip 51 is slid on the upper surface SF1 on which the film 22 is provided (see the arrow in FIG. 16 (A)).

Referring to FIGS. 17 (A) and (B), the film 22 is divided into portions 22a and 22b by the above-mentioned sliding of the blade tip 51. At the same time, a crack line SL is formed on the upper surface SF1 of the glass substrate 4. Next, the substrate 4 is cut along the scribe line SL in a breaking step.

In this comparative example, the upper surface SF1 of the glass substrate 4 is scribed together with the film 22. In this case, the formation of the scribe line SL used as a direct opportunity for breaking the glass substrate 4 is likely to become unstable. As a result, the breaking of the glass substrate 4 is liable to become unstable.

In particular, when the film 22 is made of synthetic resin, it is necessary to cut the film 22 and form the scribe line SL on the glass substrate 4 at the same time. However, in the cutting of the film 22 and the formation of the scribe line SL, in general, there is a considerable difference between the optimal blade point 51 and its use conditions. Therefore, it is difficult to optimize the cutting edge 51 and its use conditions, and as a result, the formation of the scribe line SL is particularly liable to become unstable.

On the other hand, according to this embodiment, as in the first embodiment, the crack line CL can be formed stably without being affected by the presence of the film 22. Therefore, the glass substrate 4 can be stably cut.

Before forming the crack line CL, a cut is made in the film 22 along the trench line TL. Thereby, the film 22 is reliably cut off. The step of cutting into the film 22 is performed by completely cutting the film 22 in the thickness direction DT of the film 22. Thereby, the film 22 is cut more reliably.

In particular, when the film 22 is made of a synthetic resin, since the toughness of the film 22 is high, it is difficult to obtain a break that depends only on the application of tension as in the first embodiment. Even in this case, the film 22 can be divided by using a slit. In addition, the synthetic resin film 22 is less likely to generate chips. In addition, the synthetic resin film 22 makes the blade point 51p hard to wear.

In addition, instead of the cutting device 50p (FIG. 12 (B)) particularly suitable for the film 22, the cutting device 50 (FIG. 1 (B)) may be used. In this case, a common cutting device may be used in two steps.

Next, a first modified example of this embodiment will be described. The film 22 is completely cut in the thickness direction DT in the above-mentioned FIGS. 13 (A) and (B), but in this modification, as shown in FIGS. The film 22 is partially cut in the direction DT. In other words, incomplete cutting is performed in the thickness direction DT. Thereby, a cut UL that does not penetrate the film 22 is cut into the film 22.

19 (A) and (B), a crack line CL is formed next. The film 22 was not completely cut at this point. By the tension applied to the film 22 when the glass substrate 4 is broken, the above-mentioned incomplete cut is changed to a complete cut in the thickness direction DT, so that the film 22 is completely broken. According to this modification, the glass substrate 4 is prevented from being damaged when the film 22 is cut.

Next, a second modification of this embodiment will be described. In this modification, the film 22 is partially cut along the trench line TL. In other words, along the trench line TL, a portion where a notch is not formed is formed in a portion of the film 22. The notch may be formed intermittently along the groove line TL in the entirety or in one place. The incision may be complete in the thickness direction or incomplete. Thereby, a cut HL (see FIG. 13) or a cut UL (see FIG. 18) is cut into a part along the groove line TL of the film 22.

Next, a crack line CL is formed. The film 22 was not completely cut at this point. The complete breaking of the film 22 is generated by the tension applied to the film 22 when the glass substrate 4 is broken, and the above-mentioned incomplete cut is changed to a continuous expansion along the groove line TL. Depending on the type of film, there are those that are easily cracked in a specific direction. According to this modification, the film 22 can be easily cut by breaking the film 22 with a slit as a starting point, and damage to the glass substrate 4 can be reduced. Yu.

(Embodiment 3)

First, the cutting edge of the method for cutting a fragile substrate used in this embodiment will be described below.

20 (A) and (B), the cutting edge 51 is provided with a top surface SD1 (first surface) and a plurality of surfaces surrounding the top surface SD1. The plurality of surfaces include a side surface SD2 (a second surface) and a side surface SD3 (a third surface). The top faces SD1, the side faces SD2, and SD3 (the first to third faces) face different directions and are adjacent to each other. The cutting edge 51 has a vertex where the top surface SD1, the lateral surfaces SD2, and SD3 meet, and the apex of the cutting edge 51 constitutes the protrusion PP of the cutting edge 51. In addition, the side surfaces SD2 and SD3 have ridgelines constituting the side portion PS of the blade point 51. The side portion PS extends linearly from the protrusion portion PP. Since the side PS is a ridge line as described above, it has a convex shape extending linearly.

The cutting edge 51 is preferably a diamond cutting head. That is, from the point that hardness and surface roughness can be reduced, the cutting edge 51 is preferably made of diamond. More preferably, the blade tip 51 is made of single crystal diamond. Further more preferably, in terms of crystallography, the top surface SD1 is a {001} surface, and the side surfaces SD2 and SD3 are each a {111} surface. In this case, although the side faces SD2 and the side faces SD3 have different orientations, they are crystallographically equivalent crystal planes.

In addition, non-single crystal diamond can be used, for example, polycrystalline diamond synthesized by a CVD (Chemical Vapor Deposition) method. Alternatively, polycrystalline diamond particles sintered from particulate graphite or non-graphite-like carbon and sintering a bonding material not containing an iron group element or the like can be bonded and sintered by a bonding material such as an iron group element.

The tool holder 52 extends in the axial direction AX. The tool tip 51 is preferably attached to the tool holder 52 such that the normal direction of the top surface SD1 is substantially along the axial direction AX.

In order to form the groove line TL using the cutting tool 50 (FIG. 7 (A)), on the upper surface SF1 of the glass substrate 4, the protruding portion PP and the side portion PS of the blade 51 are pressed against the thickness direction DT of the glass substrate 4 . Next, the blade point 51 is slid on the upper surface SF1 substantially along the direction in which the side portion PS is projected on the upper surface SF1. As a result, a groove-shaped trench line TL without vertical cracks is formed on the upper surface SF1. The groove line TL is generated by plastic deformation of the glass substrate 4, but the glass substrate 4 may be slightly cut at this time. However, since such cutting may generate fine fragments, it is preferable to keep it as small as possible.

The groove line TL and the crack line CL (FIG. 7 (B)) may be formed simultaneously by the sliding of the blade tip 51, and only the groove line TL may be formed. The crack line CL is a crack extending from the depression of the trench line TL to the thickness direction DT, and extends linearly on the upper surface SF1. According to the method described later, after forming only the trench line TL, a crack line CL can be formed along the trench line TL.

Next, a method for cutting the glass substrate 4 will be described below.

Referring to FIG. 21 (A), in step S10 (FIG. 8), a glass substrate 4 is first prepared. The glass substrate 4 has a flat upper surface SF1. The edge surrounding the upper surface SF1 includes an edge ED1 (first edge) and an edge ED2 (second edge) facing each other. In the example shown in FIG. 21 (A), the edges are rectangular. Therefore, the edges ED1 and ED2 are parallel to each other. In the example shown in FIG. 21 (A), the sides ED1 and ED2 are short sides of a rectangle. The glass substrate 4 has a thickness direction DT perpendicular to the upper surface SF1 (FIG. 20 (A)).

Next, in step S20 (FIG. 8), the blade 51 is pressed to the position N1 on the upper surface SF1. The details of the position N1 will be described later. The pressing of the blade 51 is referred to FIG. 20 (A), so that the glass substrate 4 On the upper surface SF1, the protruding portion PP of the blade point 51 is arranged between the side ED1 and the side portion PS, and the side portion PS of the blade point 51 is arranged between the protruding portion PP and the side ED2.

Next, in step S30 (FIG. 8), a plurality of trench lines TL (five lines in the figure) are formed on the upper surface SF1. The formation of the trench line TL is performed between the position N1 (the first position) and the position N3. Position N2 (second position) is located between positions N1 and N3. Therefore, a trench line TL is formed between the positions N1 and N2 and between the positions N2 and N3.

The positions N1 and N3 may be located at a distance from the edge of the upper surface SF1 of the glass substrate 4 as shown in FIG. 21 (A), or one or both of them may be located at the edge of the upper surface SF1. The trench line TL to be formed has a distance from the edge of the glass substrate 4 in the former case, and is in contact with the edge of the glass substrate 4 in the latter case.

Among the positions N1 and N2, the position N1 is closer to the edge ED1; and among the positions N1 and N2, the position N2 is closer to the edge ED2. In the example shown in FIG. 21 (A), the position N1 is closer to the side ED1 among the edges ED1 and ED2, and the position N2 is closer to the side ED2 among the edges ED1 and ED2. Both are located close to either of the edges ED1 or ED2.

When the trench line TL is formed, in this embodiment, the cutting edge 51 is displaced from the position N1 to the position N2, and further from the position N2 to the position N3. That is, referring to FIG. 20 (A), the cutting edge 51 is displaced in a direction from the side ED1 to the side ED2, that is, the direction DA. The direction DA corresponds to a direction in which an axis AX extending from the tool tip 51 is projected on the upper surface SF1. In this case, the tool tip 51 is dragged on the upper surface SF1 by the tool holder 52.

Next, the crack-free state (FIG. 7 (A)) described in the first embodiment is maintained for a desired time. During this period, as step S40 (FIG. 8), a film 21 (FIG. 3 (A) and (B)) is formed in the same manner as in Embodiment 1, or a film 22 is formed in the same manner as in Embodiment 2 (FIG. 11 (A) and FIG. 11). (B)). In the latter case, as described in Embodiment 2 or its modification, as described in the second embodiment or its modification, a slit is cut into the film 22 along the groove line TL (see the arrow in FIG. 12 (A)) (for example, see FIG. B) incision HL).

Referring to FIG. 21 (B), in step S50 (FIG. 8), after forming the trench line TL, the glass is made by The crack on the substrate 4 extends from the position N2 to the position N1 (see the dotted arrow in the figure) along the trench line TL in the thickness direction DT (FIG. 7 (B)) to form a crack line CL. The formation of the crack line CL is started by crossing the auxiliary line AL and the groove line TL at the position N2. For this purpose, the auxiliary line AL is formed after the trench line TL is formed. The auxiliary line AL is a general scribe line accompanied by a crack in the thickness direction DT, and is a strain that releases the internal stress near the trench line TL. The method for forming the auxiliary line AL is not particularly limited, but may be formed using the edge of the upper surface SF1 as a base point as shown in FIG. 21 (B).

In addition, it is more difficult to form the crack line CL in the direction from the position N2 to the position N3 than in the direction from the position N2 to the position N1. That is, the easiness of extension of the crack line CL has a direction dependency. Therefore, a crack line CL may be formed between the positions N1 and N2 but may not be formed between the positions N2 and N3. This embodiment is for the purpose of breaking the glass substrate 4 along the positions N1 and N2, and not for the purpose of breaking the glass substrate 4 along the positions N2 and N3. Therefore, it is necessary to form the crack line CL between the positions N1 and N2. On the other hand, the difficulty of forming the crack line CL between the positions N2 and N3 is not a problem.

Next, in step S60 (FIG. 8), the glass substrate 4 is cut along the crack line CL. Specifically, a breaking step is performed. In addition, if the crack line CL is completely advanced in the thickness direction DT when it is formed, the formation of the crack line CL and the disconnection of the glass substrate 4 may occur at the same time. In this case, the breaking step may be omitted.

The glass substrate 4 is divided as described above.

Next, the first to third modification examples of the above-mentioned breaking method will be described below.

Referring to FIG. 22 (A), the first modification relates to a case where the intersection of the auxiliary line AL and the groove line TL as a crack line CL (FIG. 21 (B)) is insufficient. Referring to FIG. 22 (B), the glass substrate 4 is separated along the auxiliary line AL by applying an external force such as a bending moment to the glass substrate 4. This starts the formation of the crack line CL.

In addition, in FIG. 22 (A), the auxiliary line AL is formed on the upper surface SF1 of the glass substrate 4, but the auxiliary line AL to separate the glass substrate 4 may also be formed on the lower surface SF2 of the glass substrate 4. on. In this case, the auxiliary line AL and the trench line TL are in a plan layout and cross each other at the position N2, but are not in direct contact with each other.

Moreover, in the first modification, the strain of the internal stress in the vicinity of the trench line TL is released by separating the glass substrate 4, thereby starting to form the crack line CL. Therefore, the auxiliary line AL itself may be a crack line CL formed by applying a stress to the trench line TL.

Referring to FIG. 23, in a second modification, in step S20 (FIG. 8), the blade tip 51 is pressed to the position N3 on the upper surface SF1 of the glass substrate 4. In step S30 (FIG. 8), when the groove line TL is formed, in this modification, the cutting edge 51 is shifted from the position N3 to the position N2, and then is shifted from the position N2 to the position N1. That is, referring to FIG. 20, the cutting edge 51 is displaced from the side ED2 toward the side ED1, that is, toward the direction DB. The direction DB corresponds to a direction opposite to the direction in which the axis AX extending from the tool tip 51 is projected on the upper surface SF1. In this case, the tool tip 51 is pushed on the upper surface SF1 by the tool holder 52.

Referring to FIG. 24, in the third modification, in step S30 (FIG. 8), when the trench line TL is formed, it is pressed at a position N2 with a larger force than the position N1 of the upper surface SF1 of the glass substrate 4.刀尖 51。 Blade 51. Specifically, the position N4 is taken as the position between the positions N1 and N2, and when the groove line TL is formed to reach the position N4, the load of the blade 51 is increased. In other words, compared with the position N1, the load of the trench line TL is increased between the end portions of the trench line TL, that is, between the positions N4 and N3. Thereby, the load other than the terminal portion is reduced, and the crack line CL can be more easily caused to form from the position N2.

According to this embodiment, the crack line CL can be more reliably formed from the trench line TL.

In this embodiment, which is different from Embodiment 4 described later, the auxiliary line AL has not been formed at the time of forming the trench line TL (FIG. 21 (A)). Therefore, the crack-free state can be maintained more stably without being affected by the auxiliary line AL. In addition, when the stability of the crack-free state is not a problem, the state in which the auxiliary line AL (FIG. 21 (A)) is not formed may be replaced, and the state in FIG. 22 (A) where the auxiliary line AL is formed may be maintained without crack status.

(Embodiment 4)

A method for cutting a brittle substrate according to this embodiment will be described below with reference to FIGS. 25 to 27.

Referring to FIG. 25, in this embodiment, the auxiliary line AL is formed before the trench line TL is formed. The method of forming the auxiliary line AL itself is the same as that shown in FIG. 21 (B) (Embodiment 3).

Referring to FIG. 26, next, in step S20 (FIG. 8), the blade tip 51 is pressed against the upper surface SF1, and then, in step S30 (FIG. 8), a trench line TL is formed. The method of forming the trench line TL itself is the same as that shown in FIG. 6 (A) (Embodiment 3). The auxiliary line AL and the groove line TL cross each other at a position N2. Next, as in the third embodiment, as step S40 (FIG. 8), a film 21 is formed in the same manner as in the first embodiment (FIGS. 3 (A) and (B)), or a film 22 is formed in the same manner as in the second embodiment (FIG. 11). (A) and (B)). In the latter case, as described in Embodiment 2 or its modification, as described in the second embodiment or its modification, a slit is cut into the film 22 along the groove line TL (see the arrow in FIG. 12 (A)) (for example, referring to FIG. 13 ( B) incision HL).

Referring to FIG. 27, the glass substrate 4 is then separated along the auxiliary line AL by a general breaking process in which an external force such as a bending moment is applied to the glass substrate 4. Thereby, as step S50 (FIG. 20), the formation of the crack line CL (FIG. 7 (B)) is started (refer to a dotted arrow in the figure). In addition, in FIG. 25, the auxiliary line AL is formed on the upper surface SF1 of the glass substrate 4, but the auxiliary line AL to separate the glass substrate 4 may be formed on the lower surface SF2 of the glass substrate 4. In this case, the auxiliary line AL and the trench line TL cross each other at the position N2 in a plan view, but do not directly contact each other.

The configuration other than the above is substantially the same as the configuration of the third embodiment.

Referring to FIG. 28 (A), in the first modification, the auxiliary line AL is formed on the lower surface SF2 of the glass substrate 4. Next, as in FIG. 23 (Embodiment 3), the trench line TL is formed from the position N3 to the position N1. Referring to FIG. 28 (B), the glass substrate 4 is separated along the auxiliary line AL by applying an external force such as a bending moment to the glass substrate 4. Thereby, the formation of the crack line CL is started (refer to a dotted arrow in the figure).

Referring to FIG. 29, in a second modification, in step S30 (FIG. 8), a trench line TL is formed. At this time, as compared with the position N1 of the upper surface SF1 of the glass substrate 4, the blade point 51 is pressed with a greater force at the position N2. Specifically, the position N4 is taken as the position between the positions N1 and N2, and when the groove line TL is formed to reach the position N4, the load of the blade 51 is increased. In other words, compared with the position N1, the load of the trench line TL is increased between the end portions of the trench line TL, that is, between the positions N4 and N3. Thereby, the load other than the terminal portion is reduced, and the crack line CL can be more easily caused to form from the position N2.

(Embodiment 5)

Referring to FIG. 30 (A), in the method for breaking a fragile substrate in this embodiment, in step S30 (FIG. 8), a trench line TL is formed from a position N1 to a side ED2 through a position N2. Next, the crack-free state (FIG. 7 (A)) described in the first embodiment is maintained for a desired time. During this period, as step S40 (FIG. 8), a film 21 (FIG. 3 (A) and (B)) is formed in the same manner as in Embodiment 1, or a film 22 is formed in the same manner as in Embodiment 2 (FIG. 11 (A) and FIG. 11). (B)). In the latter case, as described in Embodiment 2 or its modification, as described in the second embodiment or its modification, a slit is cut into the film 22 along the groove line TL (see the arrow in FIG. 12 (A)) (for example, referring to FIG. 13 ( B) incision HL).

Referring to FIG. 30 (B), between the position N2 and the edge ED2, a stress is applied to release the strain in the vicinity of the trench line TL. As a result, a crack line is caused to form along the trench line TL (FIG. 8: Step S50).

To apply the stress, specifically, on the upper surface SF1, between the position N2 and the side ED2 (the area between the dotted line and the side ED2 in the figure), the pressed blade point 51 slides. This sliding is performed until the edge ED2 is reached. The blade point 51 is preferably slid in a manner crossing the track of the groove line TL originally formed, and more preferably slid in such a manner as to overlap the track of the groove line TL originally formed. The length of this re-sliding is, for example, about 0.5 mm. In addition, the sliding again may be performed on each of the groove lines TL after forming a plurality of groove lines TL (FIG. 30 (A)), or one groove line may be sequentially performed on each of the groove lines TL. The process of TL formation and sliding again.

As a variation, in order to apply a stress between the position N2 and the edge ED2, the above may be replaced. The blade tip 51 slides again, and laser light is irradiated between the position N2 on the upper surface SF1 and the edge ED2. With the thermal stress thus generated, the strain of the internal stress near the trench line TL can also be released, thereby causing the formation of crack lines to begin.

The configuration other than the above is substantially the same as the configuration of the third embodiment.

(Embodiment 6)

Referring to FIG. 31 (A), in the method for cutting a fragile substrate in this embodiment, in step S30 (FIG. 8), the blade point 51 is shifted from position N1 to position N2, and then to position N3 to form A trench line TL separated from an edge of the upper surface SF1. The method of forming the trench line TL itself is substantially the same as that of FIG. 21 (A) (Embodiment 3).

Next, the crack-free state (FIG. 7 (A)) described in the first embodiment is maintained for a desired time. During this period, as step S40 (FIG. 8), a film 21 (FIG. 3 (A) and (B)) is formed in the same manner as in Embodiment 1, or a film 22 is formed in the same manner as in Embodiment 2 (FIG. 11 (A) and FIG. 11). (B)). In the latter case, as described in Embodiment 2 or its modification, as described in the second embodiment or its modification, a slit is cut into the film 22 along the groove line TL (see the arrow in FIG. 12 (A)) (for example, see FIG. 13 ( B) incision HL).

Referring to FIG. 31 (B), the same stress is applied as in FIG. 30 (B) (Embodiment 5 or a modification thereof). This causes the formation of crack lines along the trench line TL (FIG. 8: Step S50).

Referring to FIG. 32, as a modification example of the step of FIG. 31 (A), in the formation of the groove line TL, the cutting edge 51 may be displaced from the position N3 to the position N2, and then from the position N2 to the position N1.

The configuration other than the above is substantially the same as the configuration of the third embodiment.

(Embodiment 7)

Referring to Figs. 33 (A) and (B), in each of the above-mentioned embodiments, the knife point 51 (Figs. 20 (A) and (B)) may be used instead of the knife point 51v. The cutting edge 51v has a conical shape including a vertex and a conical surface SC. The protrusion PPv of the blade point 51v is constituted by a vertex. The side PSv of the cutting edge is constituted along a virtual line (dashed line in FIG. 33 (B)) extending from the vertex to the conical surface SC. Thereby, the side portion PSv has a convex shape extending linearly.

In each of the above embodiments, the first and second sides of the edge of the glass substrate are rectangular short sides, but the first and second sides may be rectangular long sides. The shape of the edges is not limited to a rectangular shape, and may be, for example, a square shape. The first and second sides are not limited to those having a straight shape, and may be curved. In each of the above embodiments, the surface of the glass substrate is a flat surface, but the surface of the glass substrate may be curved.

Although a glass substrate is used as a brittle substrate particularly suitable for the above-mentioned breaking method, the brittle substrate is not limited to a glass substrate. The fragile substrate may also be made of glass, such as ceramic, silicon, compound semiconductor, sapphire, or quartz.

The present invention is within the scope of the invention, and various embodiments can be freely combined, and various embodiments can be appropriately changed and omitted.

Claims (10)

A method for breaking a fragile substrate includes the following steps: preparing a fragile substrate having a surface and having a thickness direction perpendicular to the surface; pressing a blade tip on the surface of the fragile substrate; and pressing the blade through the pressing process. The blade tip slides on the surface of the fragile substrate, thereby plastically deforming on the surface of the fragile substrate to form a groove line having a groove shape; wherein the process of forming the groove line is to obtain Directly below the trench line, the fragile substrate is continuously connected in a direction intersecting the trench line, that is, a state without cracks; and the method for breaking the fragile substrate further includes the following steps: After the process of the groove line, a film covering the groove line is formed on the surface of the brittle substrate at least partially; after the process of forming the film, the crack of the brittle substrate is formed along the groove line on the surface of the brittle substrate. Stretching in the thickness direction to form a crack line; wherein, the crack line is directly below the groove line, Said substrate of a brittle continuously connected in the disconnect direction intersecting the line of the trench; and the above-described method of breaking a brittle substrate, comprising the further step of: breaking the substrate along the fracture of said frangible line. The brittle substrate cutting method according to claim 1, wherein the step of cutting the brittle substrate includes a step of cutting the film together with the brittle substrate. The breaking method of the brittle substrate according to claim 2, wherein the film is made of an inorganic material. The breaking method of the brittle substrate according to claim 2, wherein the film is made of metal. For example, the method for breaking a fragile substrate according to claim 1 further includes a step of cutting into the film along the groove line before forming the crack line. The method for cutting a brittle substrate according to claim 5, wherein the step of cutting into the cut is performed by completely cutting the film in the thickness direction of the film. The cutting method for a brittle substrate according to claim 5, wherein the step of cutting into the cut is performed by partially cutting the film in a thickness direction of the film. The method for breaking a fragile substrate according to any one of claims 5 to 7, wherein the film is made of a synthetic resin. The breaking method of a brittle substrate according to any one of claims 1 to 7, wherein the brittle substrate is made of glass. The cutting method of the brittle substrate according to any one of claims 1 to 7, wherein in the step of preparing the brittle substrate, the surface is surrounded by edges including first and second sides facing each other; In the step of sharpening, the blade tip includes a protruding portion and a side portion extending from the protruding portion and having a convex shape, and the step of pressing the blade tip is to place the side portion of the blade edge on the surface of the fragile substrate. It is carried out so as to be arranged between the protrusion and the second side. In the step of forming the groove line, it is formed between the first position and a second position closer to the second side than the first position. The groove line; and the step of forming the crack line is performed by extending a crack of the fragile substrate along the groove line from the second position to the first position in the thickness direction.